POSTER SESSION ABSTRACTS Academic research paper on "Psychology"

Poster Session Abstracts

POSTER SESSION I

Poster 1

RESPONSES TO SEARCH-AND-RESCUE ROBOTS IN A SIMULATED DISASTER ENVIRONMENT: THE INFLUENCE OF ROBOT BEHAVIOR

Cindy L. Bethel1, Kristen Salomon1, & Robin R. Murphy2 University of South Florida, 2Texas A&M University

Descriptors: stress, robotics

Robots are commonly used for victim location and management in urban search and rescue (US&R). It can take 4-10 hours to extricate trapped victims. Robots may serve as surrogates for rescue staff, staying with victims until human help arrives. Research shows that US&R robots are operated to maximize assessment, using fast, erratic, and potentially stress-inducing robot movement. We hypothesized that robot behavior influences victims' responses; slow/fluid robot movement may be perceived as more calming than fast/erratic movement, and participants' physiological responses should correspond. Participants were recruited from a university area (N 5 128, aged 1862 years, 62% female). Participants interacted with two US&R robots in counterbalanced order and were randomly assigned to a robot movement condition: fast/erratic or slow/fluid. Supine participants engaged in resting baselines and two robot interactions in a simulated disaster environment. We measured participant's heart rate (HR), respiration, skin conductance level (SCL), and self-reported valence and arousal. Fluid robots elicited more positive and calm self-reports, F(1, 121) 5 5.02, p < .05, than erratic robots, F(1, 121) 5 5.98, p < .05. Participant's HR decreased in response to the slow robot but increased in response to the erratic robot, F(1, 111) 5 5.02, p < .05. A robot type by operating mode interaction emerged for SCL, F(1, 122) 5 5.02, p < .05. Respiratory sinus arrhythmia (RSA) processing is ongoing. Findings illustrate the importance of movement in determining responses to non-anthropomorphic robots.

Poster 2

THE FEEDBACK-RELATED NEGATIVITY AND FRONTAL MIDLINE THETA DURING GAMBLING IN EXTREME BIS/BAS GROUPS

Koen B.E. Bocker, Ivo Heitland, Edmund R. Volkerts, & J. Leon Kenemans Utrecht University

Descriptors: BIS/BAS, theta power, feedback related negativity

The present study tested whether subjects showing high vs. low punishment sensitivity (behavioral inhibition system, BIS), or high vs. low trait-anxiety would show increased processing of negative feedback. In contrast, high vs. low reward sensitivity (behavioral activation system, BAS) would correlate with increased processing of positive feedback. Processing of negative feedback during gambling evokes frontal midline theta activity (Fm theta) and the feedback-related negativity (FRN). Sixty female undergraduate students, preselected on the basis of extreme BIS and BAS scores, were separated into four different groups (low BIS/low BAS; high BIS/low BAS; low BIS/high BAS and high BIS/high BAS; n 5 15 each) and participated in a gambling task during which Fm theta activity and FRN were recorded. A highly sensitive BIS, high trait-anxiety and high inattention were associated with decreased Fm theta activity during the processing of losses in the gambling task. A highly sensitive BIS and high inattention were both further associated with a larger difference between evoked Fm theta activity following losses compared to gains. Finally, there was a significant BIS X BAS interaction effect. FRN was small for subjects with high BIS/low BAS, compared to the other three BIS/BAS groups. Thus, anxious, inattentive and punishment-sensitive (especially when also reward-insensitive) individuals all showed indications of a lack of adequate and effortful processing of negative feedback.

Poster 3

PSYCHOPHYSIOLOGY OF FEAR OFFSET

Floris Klumpers, Amber N.V. Ruigrok, J. Leon Kenemans, & Johanna M.P. Baas Utrecht University

Descriptors: startle, fear

The psychophysiology of fear is relatively well studied. However, few studies have explored reductions in fear that occur when a threatening period ends. In this study, we aimed to investigate the psychophysiological correlates of threat offset. An instructed threat paradigm was used to induce fear in 25 participants. The auditory startle response was probed during and following alternating periods of shock threat and safety. Results show a fear induced potentiation of the startle response during the threat cue. This response was positively correlated to trait anxiety (r 5 .50, p < .05). Startle potentiation disappeared within 1 - 3 s after threat offset, and showed no further decline. Potentiation of the startle response after threat offset and the decline in startle potentiation were not related to trait anxiety. These results indicate that, regardless of individual differences in fear, subjects were able to fully down-regulate their fear almost immediately after threat cues disappeared.

Poster 4

THE DOPAMINE TRANSPORTER GENOTYPE AND PUNISHMENT/ REWARD SENSITIVITY PREDICT ANXIETY IN A SAMPLE OF HEALTHY FEMALE STUDENTS

Ivo Heitland, Koen B.E. Bocker, Ed R. Volkerts, J. Leon Kenemans, & Ronald S. Oosting Utrecht University

Descriptors: dopamine transporter, anxiety, punishment sensitivity This study aimed to investigate the role of the dopamine transporter 3'SLTR VNTR genotype (DAT) in anxiety, punishment/reward sensitivity and neurophysiology. Healthy female students (N 5 58) provided DNA by buccal swabs, filled in an anxiety (STAI) and feedback sensitivity (BIS/BAS) questionnaires and completed EEG-measurements that included a gambling task measuring a feedback related negativity (FRN). Carriers ofthe 10/ 10 DAT genotype, which indicates a relatively active DAT resulting in low brain dopamine (DA) levels, showed more anxiety, made less risky choices during gambling and showed a smaller FRN than carriers of the 9/10 genotype (a relatively inactive DAT resulting in high brain DA levels). High DATactivity and/or low DA levels hence were related to anxiety and risk avoidance, suggesting the 10/10 DAT genotype as risk factor for anxiety. High punishment sensitivity and low reward sensitivity, which both were linked to higher anxiety levels, showed further significant interactions with the DAT. Even though high punishment sensitivity was related to anxiety (r 5 .60, p < .01), this link couldnot be observed in the 9/ 10 DAT group. This suggests that the 9/10 genotype of the DAT might be a resilience factor for anxiety, even in individuals who are at risk for anxiety due to high punishment sensitivity. In conclusion, the 10/10 and 9/10 genotypes of the DAT were introduced as risk and resilience factors in anxiety, especially when interacting with punishment sensitivity.

Poster 5

ELECTROPHYSIOLOGICAL EVIDENCE FOR RAPID PREFERENTIAL PROCESSING OF ELECTROSHOCK CONDITIONED FACES

Markus Junghofer1, Maria C. Pastor2, Rosario Poy2, Raul Lopez2, Pilar Segarra2, Angels Esteller2, & Javier Molto2 1University of Münster, 2Jaume I University

Descriptors: affective processing, aversive face conditioning, EEG Prior electrophysiological research revealed preferential neural processing of aversively conditioned faces in the EPN (120-300 ms) and LPP (> 300 ms) time range. In a recent MEG study, we found amplified processing of 104 olfactory conditioned faces in prefrontal and secondary visual cortex regions starting already around 50 ms, indicating affective evaluation via fast thalamo-amygdala connections ('low road'). Using shock-conditioning of 8 neutral faces (4 CS+), we explored rapid affective evaluation.

Poster 6

FREE WILL: A QUESTION OF PERSONALITY? AN INVESTIGATION OF LATERALIZED READINESS POTENTIALS IN EEG

Eva-Maria Leicht, Markus Quirin, Julius Kuhl, & Thomas Gruber University of Osnabruck

Descriptors: LRP, free will, personality

Previous research initiated by Benjamin Libet suggests that human volition and decision are determined. However, the studies conducted have been questioned for several reasons such as strong interindividual differences in the onset of preparatory neural motor activity or the personal relevance of the decisions to be made. The present study investigates the chronology of neural motor activity as indicated by lateralized readiness potentials (LRPs) and subjective moment of decision making as a function of (a) personal relevance of the decision and (b) personality differences. Specifically, we used a modification of Libet's paradigm that includes the presentation of a rotating clock hand. Twenty participants were asked to decide by key press whether attributes presented in the center of the clock described themselves or not. Afterwards, they reported the position of the clock hand. In general, data from previous studies could be replicated. In addition, however, we found substantial moderating effects of personal relevance of the decisions and personality differences. The findings are discussed with respect to an integrative model of physical determinism and the psychological impression of freedom and self-determination (Kuhl, 2008).

Poster 7

POST-EVENT PROCESSING IN MUSICAL PERFORMANCE ANXIETY

Susanne Gorges, & Georg W. Alpers University of Wiirzburg

Descriptors: musical performance anxiety, heart rate, post-event processing Negative rumination contributes to the maintenance of social anxiety. Although musical performance anxiety (MPA) and social anxiety are closely related, little

is known about negative rumination in MPA. The aim of the current study was to explore subjective and physiological responses of post-event processing in 29 music students after they performed in a public concert and gave a public speech. The videotapes of the participants' own performances were presented, and their feelings, self-perceived performance quality, and heart rate (HR) were assessed. In addition, the participants filled out questionnaires on social anxiety, rumination, perfectionism, and MPA. Participants' anxiety ratings before watching the videotape of the concert were significantly correlated with the MPA trait questionnaire, the social phobia scale, and performance anxiety in the public concert. Rumination over the concert was marginally correlated with cognitive symptoms of MPA, and was significantly higher than rumination over the speech, despite higher performance quality ratings of the concert. The high MPA group reported higher anxiety and had a marginally higher HR in the concert than in the speech videotape condition. We found significant correlations among HR and perfectionism as well as physiological symptoms of MPA, but only in the concert videotape condition. We conclude that negative rumination seems to be an important aspect of MPA. Perfectionism, which is linked with physiological activation, seems to play a particularly critical role in post-event processing in MPA.

EMOTION MODULATES OUTPUT SYSTEMS

Fatima S. Erthal1, Mirtes G. Pereira1, Leticia Oliveira1, Izabel F. Mocaiber2, Mateus Joffily2, Eliane Volchan2, & Luiz Pessoa3 1Fluminense Federal University, 2Federal University of Rio de Janeiro, 3Indiana University

Descriptors: emotion, fmri, behavior

Affective pictures drive the activity of brain networks and impact behavior. We showed previously that viewing unpleasant pictures interfered in the performance of a basic nonemotional visual detection task. In the present study, we employed functional magnetic resonance imaging to test the hypothesis that behavioral interference may result from the interaction between affective and motor-related signals in the brain. As in our previous study, subjects performed a simple target-detection task that followed the presentation of unpleasant or neutral pictures. Our results revealed enhanced activation in the occipital cortex and the middle insula across the unpleasant vs. neutral picture viewing conditions.

Poster 8

SENSATION SEEKING, RISK ANTICIPATION, AND FEEDBACK PROCESSING IN A GAMBLING TASK

Marta Bianchin1, & Alessandro Angrilli2 1University of Padova, 2University of Padova, CNR Institute of Neuroscience

Descriptors: decision making, sensation seeking, erps

Risk anticipation is an important cognitive/emotional component of decision making. The concept of a sensation seeking personality trait was developed by Zuckerman (1994) to account for differences in people's willingness to participate in risky activities across a wide range of behaviors. The aim of this study was to investigate the influence of sensation seeking in decision making. For this purpose we compared behavioral and EEG data from a group of 14 high sensation seekers, with those collected from a group of 12 low sensation seekers. The task was a modified version of the IGT (Bechara et al., 1994), adapted for ERP analysis and PC presentation. During the gambling task EEG was measured by means of 38 tin electrodes. Results indicated three main findings. First, high sensation seekers did not learn to avoid risky decks. Second, low sensation seekers, compared to high sensation seekers, showed greater anticipatory negativity before risky than before safe choices. Instead, high sensation seekers showed a reversed pattern. Third, in feedback related potentials, high sensation seekers, compared to low sensation seekers, showed larger positive wave (P300) in response to wins than losses, and this was particularly evident in prefrontal recording sites. Our results suggest that decision-making behavior of high sensation seekers reflects increased reward seeking and immediate gratification behavior, and high sensation seekers' inability to evaluate correctly future outcomes. Thus, results point to the central role of the orbitofrontal cortex in anticipatory processes of risk taking behavior.

Poster 9

EFFECTS OF SIMULATED MICROGRAVITY ON HUMAN EMOTION PROCESSING AND STARTLE REFLEX MODULATION

Simone Messerotti Benvenuti1, Marta Bianchin1, & Alessandro Angrilli2 1University of Padova, 2University of Padova, CNR Institute of Neuroscience

Descriptors: emotion, simulated microgravity, startle reflex

The aim of the present study was to investigate the influences of simulated micro-gravity on psychophysiological responses to emotional pictures. For this purpose, we selected a sample of 22 male subjects with characteristics similar to those of an astronaut. A group of 11 males submitted to simulated microgravity (BR; 4-hours head-down bed rest) were compared with a matched group of 11 sitting controls. The experimental session consisted of passive viewing of 75 affective pictures, divided in three emotional categories: pleasant, neutral and unpleasant. Slides were randomly presented for 6 seconds. During picture viewing, startle reflex, pre-pulse inhibition (PPI), and evoked potentials from three scalp sites (Pz, F7, and F8) were recorded. Results showed an impaired startle reflex habituation in BR subjects compared to controls. The PPI task, which reflects orienting of attention towards primary stimulus, showed in BR a reduced elaboration ofunpleasant stimuli compared to pleasant stimuli. Furthermore, evoked potentials showed specific cortical inhibition to arousing emotional pictures in BR subjects compared to controls, this occurred at both, intermediate component (P300) and late positive complex (SPW). Results point to an impairment of emotional processing in humans under microgravity condition. This altered perception could threaten the success of spatial missions, for instance in case of impaired capability of astronauts to adequately perceive an emergency situation.

Poster 11

RESPONSE SELECTION, RESPONSE THRESHOLD AND STIMULUS-RESPONSE CONFLICT: LAPLACIAN ERP STUDIES

Clemence Roger, Franck Vidal, Thierry Hasbroucq, & Boris Burle Laboratory of Neurobiology of Cognition, Aix-Marseille University, CNRS

Descriptors: motor areas, stimulus-response conflict, laplacian

Thanks to Laplacian transformation of monopolar data, Vidal et al. (2003) revealed three noticeable features of the motor command in choice reaction time tasks. First, just before the response, a negativity develops over the contralateral Primary Motor Cortex (M1), revealing an increase in the correct response activation. Second, a pos-itivity over the incorrect M1 develops symmetrically, which reveals an active inhibition of the incorrect response. Finally, a fronto-central negativity, likely generated within the Supplementary Motor Area (SMA), precedes the activation/inhibition pattern by about 50 ms. This fronto-central activity was proposed to reflect the response selection stage. Here, we investigated the impact of stimulus-response conflict on those three components, in two different compatibility tasks: A Simon and an Eriksen task. The results are similar for the two tasks. We show that the activity recorded over SMA is largely reduced in the compatible condition. Over the M1s, the activation is larger in the incompatible condition whereas no compatibility effect shows up on inhibition. The sensitivity of SMA to compatibility suggests that this structure is involved in stimulus-response translation. In relation to a formal model of decision making, the increased activity over the contralateral M1 suggests that the response threshold is enhanced under incompatible situations, likely to reduce the risk of an error.

Poster 12

CHARACTERIZATION OF ELECTROENCEPHALOGRAPHIC (EEG) COMPONENTS ELICITED BY OVERT SPEECH PRODUCTION IN THE PICTURE NAMING TASK: A LAPLACIAN ERP STUDY

Stephanie Ries, Niels Janssen, Stephane Dufau, F. Xavier Alario, & Boris Burle Aix-Marseille University, CNRS

Descriptors: speech monitoring, ERP

We characterized a sequence of electroencephalographic (EEG) events elicited by the picture naming task. EEG has scarcely been used to investigate the neural processes of speech production, presumably because of feared contamination of the EEG signal by the artifacts generated by articulation. We addressed this challenge using a blind source separation algorithm based on the canonical correlation analysis. Clean EEG data were successfully obtained. A surface Laplacian transformation of the signal was also computed. As a result, a clear succession of activities was revealed. A spatio-temporal sequence of visual evoked potentials were observed between 95 and 160 ms post-stimulus. This was followed by the emergence of more sustained fronto-central activities, best seen time-locked to the response. Peaking 250 ms before vocal onset, we observed activity over the supplementary motor area which resembles activity previously associated with decision-making processes. Shortly after vocal onset, there was a clear negativity (peak 45 ms) similar to the one reported previously in segmental responses, and that likely reflected performance monitoring. This negativity was followed by activity over the left temporal cortex (peak 178 ms). These activities were affected differentially by visual complexity, picture name, lexical frequency, and length. A tentative interpretation of these observations provides a window on the temporal sequence of mental operations underlying picture naming.

FACE NAMING AND TIP-OF-THE-TONGUE STATE: AN EVENT-RELATED POTENTIALS STUDY PROVIDING FURTHER FINDINGS

Monica Lindin, & Fernando Diaz University of Santiago de Compostela

Descriptors: tip-of-the-tongue state, face naming

In a previous study (Diaz, Lindin, Galdo-Alvarez, Facal, & Juncos-Rabadain, 2007), the event-related potentials associated with correct naming (KNOW) and failure to name (tip-of-the-tongue, TOT) the faces of famous people were determined. The aims of the present study were 1) to establish, with greater temporal precision, the ERP correlates of the genesis of the TOT state, as well as the time interval in which the TOT phenomena takes place, and 2) to determine the influence of the delay of the verbal response on the LNW. A task involving identification and naming of the 800 faces of famous people with three response categories: KNOW (correct naming), DONt KNOW (name not known), and TOT, was employed. The results indicated that the latencies of Early P3 and N450 components were significantly longer in the TOT than in the KNOW response category, which may reflect slower access, to information about the famous people in TOT than in KNOW from the 300 ms post-stimulus. No LNW was detected, which was attributed to the delay of the verbal response, and shows that the brain activity associated with the verbal response modulates the amplitude of LNW.

Poster 14

A MAGNETOENCEPHALOGRAPHIC STUDY FOR THE CHARACTERIZATION OF THE TIMING AND THE CORTICAL AREAS ASSOCIATED WITH FACE NAMING AND THE TIP-OF-THE-TONGUE STATE

Monica Lindin, & Fernando Diaz University of Santiago de Compostela

Descriptors: tip-of-the-tongue, face naming

The aims of the present magnetoencephalographic study were 1) to identify the brain areas showing differential activation for correct naming (KNOW) versus failure to name (tip-of-the-tongue, TOT) faces, and 2) to characterize the onset and time course of the TOT state. We employed a task involving identification and naming of the faces of famous people with three response categories: KNOW (correct naming), DONt KNOW (name not known), and TOT. The results revealed that in the TOT state, relative to successful naming, a hypoactivation ofthe brain areas belonging to the neural network of name access (left temporal and frontal areas, bilateral parahippocampal gyrus, and the fusiform gyrus) was observed in the 310-520 ms interval, and this may reflect the genesis of the TOT state. On the contrary, in the 740-820 ms interval, a higher activation in TOT than in KNOW response category was obtained in the bilateral occipital, left temporal, and right frontal and parietal areas, which may be related to the failed attempt to retrieve the name.

Poster 15

COVERT AND OVERT PROCESSING OF SAD AND HAPPY FACES: EARLY ERP EFFECTS

Jennifer N. Barrie, Fern E. Jaspers-Fayer, & Mario Liotti Simon Fraser University

Descriptors: emotion, EEG/ERP

Recent studies exploring early effects of emotion on face-sensitive event-related potentials have produced inconsistent findings. Neuroimaging shows different neural systems involved in covert vs. overt processing of emotion, with activations in limbic and paralimbic areas recruited for covert processing of facial expressions. We hypothesized that only emotional faces presented covertly would yield significant modulations of the N170, vertex positive potential (VPP) and early anterior positivity (EAP) whereas overt presentations would not. We expected covert sad faces to elicit enhanced effects compared to neutral and happy faces, which were expected to elicit equal electrophysiological responses. High-density-electroencephalography was recorded while subjects viewed photographs of emotional faces with a colored square positioned over the nose. In the overt task, subjects identified the emotion of the face. In the covert task, they identified the color of the square. Results revealed that covertly presented sad faces elicited a greater N170 response over right temporal-parietal sites (N 5 170; t 5 2.4, p 5 .03) and a greater positivity over frontal sites (VPP; t 5 3.6, p < .05). Findings suggest that covert emotion recruits different neural regions at early stages of face processing, supporting separable systems of emotion processing.

THE INFLUENCE OF PREFERENCE ON THE NEURAL CORRELATES OF MEMORY

Isabel Taake1, Fern Jaspers-Fayer1, Gord Hotchkiss2, & Mario Liotti1 1Simon Fraser University, 2Enquiro Search Solutions Descriptors: differential memory effect

The Event Related Potential (ERP) literature shows enhanced activity in the 400 - 700 ms time window during encoding for stimuli that will later be remembered (the DM effect). Our study investigated whether or not emotional preference for a product modulated the DM effect. ERPs were used to describe differences in neural activity during encoding and recognition of preferred vs. unpreferred vs. unknown brands. First, participants (N 5 17) provided subjective ratings of preference and familiarity for 300 different products found in grocery stores. During the encoding part of the experiment, two-thirds of the rated stimuli were presented, and participants classified them as liquid or solid. Five minutes after the encoding session, participants were asked to freely recall as many items as they remembered. Finally, in the recognition phase, all of the stimuli were presented randomly and participants classified them as old or new. Participants freely recalled significantly more preferred than unpreferred items (p < .05) overall for recognized items compared to forgotten items. This DM effect was more enhanced for preferred items (p < .05) and unknown items (p < .05). People seem to form stronger memory traces for preferred compared to disliked/unknown items.

Poster 17

ELECTRODERMAL ACTIVITY RELATED TO ANTICIPATION OF PAIN INCREASES DURING OPERANT CONDITIONING OF ALTERED PAIN SENSITIVITY

Susanne Becker, Anne-Kathrin Brascher, Dieter Kleinbohl, Jasmin-Fleur Ahlheim, & Rupert Holzl University of Mannheim

Descriptors: skin conductance responses (scr), pain perception, fear Enhanced perceptual short-term sensitization to tonic heat-pain stimulation (25 s duration) was operantly conditioned by intrinsic reinforcement (contingent decreases/increases in pain intensity) within an implicit operant learning paradigm in healthy participants, aiming at heightened pain sensitivity. According to the fear-avoidance theory of exaggerated pain perception, the development of fear of pain parallel to the operant conditioning was assumed. Such fear of pain or enhanced salience should be represented in increased physiological responses during the anticipation of painful stimuli. Therefore, electrodermal activity (skin conductance responses, SCRs) was assessed and compared between a control condition (without operant conditioning) and a learning condition with operant conditioning of enhanced perceptual sensitization. In order to enable anticipation of painful stimuli, each stimulus onset was announced (6 s previously) by a signal. SCRs during anticipation were analyzed by a decomposition analysis. In the learning condition, SCRs were increased during anticipation ofpainful stimuli compared to the control condition. This result suggests that, as hypothesized, operant learning of altered pain sensitivity is accompanied by a development or augmentation of fear of pain. Since fear can worsen pain, this result is important in the context of pain that is becoming chronic, as emphasized by the fear-avoidance theory (but not demonstrated in physiological responses before).

Poster 18

DYNAMICS OF SEXUAL STEROIDS' LEVEL IN RATS' MALES BRAIN DURING FORMING OF THE CONDITIONED REFLEX

Vladimir Sashkov Institute of Developmental Physiology Russian Academy of Education

Descriptors: steroid hormones, brain, conditioned reflex

The cognitive functions of realization in an ontogenesis in many ways is deter-mined by the influence of sexual steroids both gonadal, and a cerebral parentage. We investigated the dynamics of sexual hormones' levels in the brain of male rats of different ages during the formation of a conditioned reflex. Studies were conducted on 180 male rats, of the Vistar's line, at the ages of 1,2, 6 and 18 months. A conditioned reflex was formed in a Morris' water labyrinth. The amount of testosterone and estradiol in blood plasma, hypothalamus, hippocampus, amygdale, cingular and frontal cortex were found by method of the radioimmune analysis. Data were statistically analyzed with the help of «SPSS-13.0». Data revealed that the forming of conditioned reflex increased when 1- and 6-months old rats were kept out of water. Otherwise this process was decreased with 18-months old rats. In all male age groups, the dynamic testosterone and estradiol level is revealed not only in blood plasma, but also in all investigated structures of brain during the formation of a conditioned reflex. Change of number and character of correlations of learning' level with the amount of sexual steroids in a brain can confirm the existence of age features and mechanisms of testosterone and estradiol that the organization of learning and memory. The data specify the important role of testosterone and estradiol in brain in conditioned-reflex and memory mechanisms.

LACK OF EARLY SEARCH FOR TRUTH IN HIGH SCHIZOTYPAL PEOPLE: ERP EVIDENCE

Isabel Orenes, David Beltran, Gorka Navarrete, Axit Fumero, & Carlos Santamaria University of La Laguna

Descriptors: schizotypy, verification, P1

Most people tend to verify their thoughts against reality. This tendency might ensure our understanding of the real world, but there might be individual differences in this. In particular, schizophrenic patients, and non-clinical populations predisposed to schizophrenia (schizotypy) could be an exception, showing a tendency not to verify information. To test this hypothesis, we selected the 10% highest- and lowest-scoring individuals on the SPQ (Raine, 1991) from a sample of 371 healthy people, and recorded event-related potentials (ERP) while they performed a sentence-picture verification task. Trials consisted of affirmative or negative sentences such as The circle is/is not red, followed by colored circles that either corresponded or not with the sentences. The P1 visual component in response to the picture onset was analyzed in order to test whether color expectancy had different effects in high and low schizotypal participants. As expected, in the low-schizotypal group P1 amplitude was higher for true than for false items, showing an early tendency toward verification. In contrast, in the high schizotypy group, P1 amplitude was higher for circles that made sentences false than for those that made them true. Thus, it seems that people showing schizotypal traits do not follow a verification strategy when solving this task (behavioral results are congruent with this point). Further research is needed to ascertain the extent to which this tendency could be related to the formation and maintenance of delusion in schizophrenia.

Poster 20

KEEPING IN MIND WHAT IS NOT TRUE: N200 EFFECTS OF EXCLUSIVE DISJUNCTIONS

David Beltran, & Carlos Santamaria University of La Laguna

Descriptors: disjunction, conjunction, N200

The present study concerns how people represent conjunctive vs. disjunctive assertions, such as: "The figure is a circle and is red,'' vs. "The figure either is a circle or is red.'' In both cases the same possibility is represented in that it is explicitly mentioned in the assertion (a red circle). However, given that the semantic status of this possibility differs in each sentence (true in conjunctions, false in disjunctions), some record of being a false possibility (or NOT true) should be tagged to the representation of the disjunction. To test this hypothesis, we conducted a verification study in which sentences of these sorts were contrasted against figures that made them true or false. The ERP response to the processing of figures was registered and analyzed in the time window of the visual N200 component. Consistent with literature (e.g. Folstein & Van Petten, 2008), we predicted that mismatching between the figure that was explicitly mentioned in the assertion and the depicted figure should yield larger N200s than matching between them, and that this effect should be modulated by the type of assertion. Results confirmed this prediction. N200 amplitudes were significantly larger for mismatching (false conjunctions and true disjunctions) than for matching conditions (true conjunctions and false disjunctions), and also for disjunctive than for conjunctive assertions. Hence, it seems that participants kept in mind the same possibility for conjunctions and disjunctions, but tagged a NOT true (or false) status in the case of disjunctions.

Poster 21

EEG CORRELATES OF THE SEMANTIC VISUAL PROCESSING IN HUMANS

Andrij O. Cherninskyi, Sergij O. Sobishchanskyi, Igor G. Zyma, & Sergij A. Kryzhanovskyi Taras Shevchenko National University of Kyiv

Descriptors: ERP, ICA, semantic analysis

In order to find the correlates of the semantic processing of visual stimuli in humans, we recorded event-related potentials (ERPs) for emotionally neutral normal and distorted (nonsense) images from the International Affective Picture System. It was found that ERPs from both types of stimuli had the same form that consists of three waves: P1 (latency 110 -125 ms), N1 (145 -160 ms), P2 (230-240 ms). Positive fluctuations of the ERPs from normal (semantic) versus distorted images had bigger amplitudes. Additionally, the amplitude of P2 from semantic stimuli quickly (80 ms) reached maximum and slowly (350 ms) turned to baseline. In contrast, the amplitude of P2 from distorted images quickly (50 ms) reached maximum (approx. 100 ms) and after that began to decrease to baseline (260 ms). We assume that successful semantic processing is related to increasing neuronal synchrony. At the next stage of our investigation the independent component analysis (ICA) was applied to distinguish the components ofEEG related to semantic analysis. It was found that three-component waveforms (P1-N1-P2) were extracted from only the one of the ICA components. The dipole model was used to localize the source of this activity. It was revealed that this source was localized in the inferior temporal cortex. It is important that left hemisphere location of that dipole was registered in about 50% of participants and another 50% demonstrated right hemi-

sphere location of this one. Thus, ICA with the EEG source localization technique may provide useful data on the cognitive processes in humans.

Poster 22

CENTRAL AND PERIPHERAL HEMODYNAMICS DURING EMOTIONAL ACTIVATION IN ESSENTIAL HYPOTENSION

Michela Sarlo, Andrea Devigili, Massimiliano de Zambotti, & Luciano Stegagno University of Padova

Descriptors: hypotension, transcranial doppler sonography, impedance cardiography Essential hypotension has been associated with reduced cognitive performance and altered regulation of cerebral blood flow. On the other hand, the presence of possible impairments in emotional reactivity remains largely unexplored, despite some evidence of lower positive affect in hypotension. This study was aimed at investigating systemic and cerebral hemodynamic changes in chronic hypotensives during emotional activation. Impedance cardiography and blood pressure (BP) measures were recorded from 15 hypotensives and 15 normotensives during the viewing of 3-min blocks of pleasant, unpleasant and neutral pictures. Doppler sonography blood flow velocities in both middle cerebral arteries (MCA) were also measured continuously. Valence and arousal ratings were collected after each block. Significantly higher increases in systolic BP were observed in normotensives than hypotensives during picture viewing, independent of content. However, no evidence of lower sympathetic control was found for the latter group, as assessed by pre-ejection period. MCA flow velocity showed a significantly lower increase in hypotensives, specifically during the viewing of pleasant pictures. Interestingly, highly significant negative correlations between changes in MCA flow velocity and subjective arousal were found only in hypotensives, and specifically for the pleasant condition, indicating a dissociation between self-report of emotional activation and cerebral perfusion. This effect might suggest a failure to integrate peripheral and central arousal responses under positive stimulation.

Poster 23

THE NEURAL CORRELATES OF ATTENTIONAL BIAS IN BLOOD PHOBIA AS REVEALED BY THE N2PC

Giulia Buodo, Michela Sarlo, Marianna Munafo, & Daniela Palomba University of Padova

Descriptors: blood phobia, n2pc, emotion

A large body of experimental investigations has consistently demonstrated that anxiety and pathological fears are associated with an attentional bias, i.e., a systematic tendency to selectively attend to stimuli that are relevant to the individual's concerns. Conversely, a lack of attentional bias in blood phobia has been reported, using both behavioral and event-related potential (ERP) measures. However, in the tasks employed so far, at-tentional resources to single stimuli, rather than attentional selection, were evaluated. The present study investigated whether disorder-relevant pictures can capture visuo-spatial attention when paired with neutral or non-specific unpleasant pictures for blood-phobic individuals while they had to focus on a visual detection task. The N2pc component of the ERPs was measured as an index of spatial attentional selection. Results showed that in blood phobics, but not in controls, pictures of injuries elicited a reliable early N2pc not only when paired with neutral, but also with unpleasant pictures, suggesting that phobic contents did bias visuospatial attention. A late N2pc reversal to injury pictures suggests that early orienting to phobic cues was followed by cognitive avoidance.

Poster 24

MULTIMODAL ASSESSMENT OF EMOTIONAL DISTRESS AFTER WORK-RELATED ACCIDENTS

Marta Ghisi, Simona Scozzari, Giulia Buodo, Arianna Di Natale, Caterina Novara, & Daniela Palomba University of Padova

Descriptors: work accidents, emotional distress, post-traumatic stress disorder Work accidents can be traumatic events that give rise to a variety of symptoms of emotional distress. Overall, these symptoms have been described as a dysfunctional stress response, sometimes meeting the diagnostic criteria for acute stress disorder, or post-traumatic stress disorder (PTSD). The present study was aimed at investigating the severity of emotional distress symptoms in individuals who experienced workplace accidents. A multimodal assessment was adopted, including subjective and psychophysiological indices of affective and cognitive responding. Thirty-eight subjects who had experienced work-related accidents were recruited from the Italian National Association for Victims of Occupational Injuries (Associazione Nazionale Mutilati e Invalidi del Lavoro, ANMIL) and compared with 38 control subjects. In a sub-group of subjects, skin conductance and the startle reflex were recorded during the viewing of standardized trauma-related and trauma-unrelated pictures. Participants who experienced a work accident reported more severe post-traumatic symptoms than controls, as indicated by

higher PTSD Symptom Scale (PSS) scores. They also showed more attentional and memory deficits than controls. Moreover, participants with higher PSS scores showed more severe depressive symptomatology and lower psychophysiological reactivity than participants with lower PSS scores, indicating a lack of concordance between self-reported symptoms and physiological activation.

Poster 25

DELTA EEG BAND AS A MARKER OF LINGUISTIC LEFT HYPOFRONTALITY IN SCHIZOPHRENIA PATIENTS

Chiara Spironelli, Luciano Stegagno, & Alessandro Angrilli University of Padova

Descriptors: psychosis, language, lateralization

Delta activity is a demonstrated index of cortical inhibition, which reflects the amount of neurons not engaged in specific cognitive processes. To study the brain dysfunction/ inhibition and the degree of linguistic dominance across different linguistic tasks, delta activity was measured in 17 schizophrenia patients and 17 matched controls. Most of patients suffered from paranoid schizophrenia, and obtained relatively high rating in Delusions (P1) and Conceptual disorganization (P2) subscales of the PANSS. Delta amplitude was measured while participants performed three (visuo-perceptual, rhyming and semantic judgment) linguistic tasks. Compared with healthy controls, patients showed no overall delta difference, revealing neither detrimental effects of pharmacological treatment nor brain structural alteration. The analysis of four quadrants/regions of interest revealed, in controls, higher delta amplitude in right vs. left anterior sites.

Poster 26

EEG DELTA BAND AS A MARKER OF BRAIN DAMAGE IN RECOVERED NON-FLUENT APHASIC PATIENTS

Chiara Spironelli, & Alessandro Angrilli University of Padova

Descriptors: neurological disorders, language, lateralization

In the present study, EEG delta band was used to investigate, in recovered aphasic patients, both brain dysfunction/inhibition, and functional linguistic recovery. Delta amplitude was measured in 17 chronic non-fluent aphasic patients while engaged in three linguistic tasks: Orthographic, Phonological and Semantic. The average mapping of aphasics' structural lesion located core damage in left cortical-subcortical perisylvian areas. Compared with matched controls, patients showed higher delta levels (p < .05), a result which suggests that diaschisis/cortical inhibition persists, to some extent, also in the chronic phase. The analysis of four specific regions of interest revealed a peak of delta amplitude in left perilesional EEG sites (p < .01), posterior to the core damage where residual suffering tissue probably projects its dysfunctional activity. Significant task modulation was found in patients, who showed greater left posterior delta amplitude (inhibition) in all tasks (p's < .001) and smaller left vs. right delta amplitude (left anterior disinhibition, p < .05) only during the Phonological one. Instead, controls showed greater left vs. right delta disinhibition at anterior sites in all tasks (p's < .01). Delta band, besides its ability to reflect a structural damage, was effective in the assessment of both patients' functional impairment, and their linguistic reorganization at hemispheric level, with a spatial scalp distribution consistent with lesion map.

Poster 27

VERBAL INSTRUCTION ABOLISHES FEAR CONDITIONED TO RACIAL OUT-GROUP FACES

Kimberley M. Mallan, James Sax, & Ottmar V. Lipp University of Queensland

Descriptors: race bias, fear conditioning, prepared learning

Previous research has demonstrated that fear conditioning to racial out-group faces is more resistant to extinction than is fear conditioning to racial in-group faces, suggesting that out-group stimuli may be subject to prepared fear learning (Olsson et al., 2005). The current study demonstrates that fear conditioning to racial out-group faces is reduced by verbal instruction. This does not conform with a second criterion of prepared fear learning, encapsulation from cognitive interventions. Four groups of Caucasian participants were trained with male in-group (Caucasian) or out-group (Chinese) faces as conditional stimuli in a differential human fear conditioning paradigm. In each group, presentation of one face (CS+) was paired with an aversive electrotactile shock, whereas a second face was presented alone (CS —). Before extinction, half of the participants in each group were instructed that no more shocks would be presented. Fear conditioning, larger electrodermal responses to CS + than to CS — and larger fear-potentiated startle during CS+ than during CS — , were evident in all groups during acquisition. Resistance to extinction was found in the racial out-group and the no-instruction condition, but was not present in the racial out-group, instructed-extinction condition. Thus, resistance to extinction of fear learning to racial out-group faces does not appear to reflect evolu-

tionarily prepared learning. It may be better explained by differential exposure to in- and out-group race faces (latent inhibition).

Poster 28

MY PARIETAL CORTEX 'KNOWS' WHAT YOU ARE DOING: THE HUMAN MIRROR NEURON SYSTEM MEASURED BY FNIRS

Saskia Koehler1, Johanna Egetemeir2, Prisca Stenneken2, Paul Pauli1, Andreas Fallgatter1, & Martin J. Herrmann1 1University of Wurzburg, 2Bielefeld University

Descriptors: fnirs, mirror neuron system, parietal cortex

We used functional near-infrared spectroscopy (fNIRS) to investigate brain activity during the execution and observation of actions in 20 healthy participants. Furthermore, we examined the role of the observer's orientation. Participants were asked to perform object-related grasping movements and to observe them from two different perspectives (egocentric and allocentric perspective) in a video clip. Brain activation was measured by changes in oxy- and deoxyhaemoglobin concentrations with a 52-channel NIRS system (Hitachi ETG-4000). We found stronger activation (increase in oxy- with a corresponding decrease in deoxyhaemoglobin concentration) during the execution and observation compared to a control condition in the inferior parietal cortex, but not in the frontal or motor cortex. Interestingly, the activation in the parietal cortex was stronger for the egocentric, compared to the allocentric, perspective. Our results provide further evidence for an observation-execution matching system in the human brain and its dependence on the observer's orientation. To our knowledge, this is the first NIRS study involving an action execution and action observation condition at the same time.

Poster 29

BRAIN ACTIVATION DURING JOINT ACTION MEASURED WITH FUNCTIONAL NEAR-INFRARED SPECTROSCOPY

Johanna Egetemeir1, Prisca Stenneken1, Saskia Koehler2, Andreas J. Fallgatter2, & Martin J. Herrmann2 1Bielefeld University, 2University of Wurzburg

Descriptors: joint action, human mirror system, fnirs

Many everyday situations require humans to execute actions together with a partner. Which brain mechanisms underlie the engagement in such joint actions? To investigate this question we used functional near-infrared spectroscopy (fNIRS) to discover differences of brain activity during the execution of solitary actions in comparison to the execution of nearly-natural joint actions. fNIRS allows the measurement of brain activity in nearly-natural situations and has not yet been applied in such joint action settings. Subjects were 17 healthy participants which completed an object-related grasping task and also displacing movements, namely, setting a table. They either executed the task alone (solitary action), together with a partner (joint action), or observed the partner executing the action (action observation). Brain activation was measured by changes in oxy- and deoxyhaemoglobin concentrations with a 52-channel NIRS system (Hitachi ETG-4000). Compared to the solitary action, the joint action task elicited a stronger activation in regions of the inferior parietal cortex and frontal cortex. Interestingly, these regions, which are outside the visual processing stream, are also involved in our action observation task. Results suggest the notion of an involvement of the human mirror system in joint action. This study shows that fNIRS is a suitable tool for investigating joint action in nearly natural situations.

Poster 30

AUDITORY ATTENTION TO TARGETS IN THE CONGENITALLY BLIND ENHANCES OCCIPITAL GAMMA-BAND OSCILLATORY ACTIVITY

Mario Liotti1, Jessica J. Green1, Fern Jaspers-Fayer1, & Marty G. Woldorff2 1Simon Fraser University, 2Duke University

Descriptors: auditory attention, congenital blindness, reorganization In an earlier ERP study, we reported that in the congenitally blind brain, electrical activity associated with auditory attention to targets in a dichotic task shows marked plasticity changes with a prolonged negativity (200 - 450 ms) over occipital areas (Liotti, Ryder & Woldorff, 1998). In the present study, auditory target-related EEG time-frequency activity was analyzed in 11 congenitally blind and 10 sighted participants. Theta (4-7 Hz) and gamma (30-40 Hz) activity was extracted in each of seven consecutive 50-ms intervals following auditory targets (200 -550 ms). In the theta-band range, target-related activity was observed in both groups over centro-parietal scalp, reflecting prominent P3b waves that did not appear to be reorganized in the blind. More importantly, in the gamma-band range, differential target-related activity in the congenitally blind was observed over occipital scalp. Beamformer spatial filtering (BESA 5.1) was used to image the sources of gamma-band activity for each time interval, which were then subjected to nonparametric statistical analysis using random permutation tests to determine significance increases (blind > control, p < .005). Group images were displayed on a surface rendered brain

using AFNI software. Gamma-band activity was centered in L lateral occipital cortex and bilateral medial occipital cortex (peak: 300 - 350 ms). Boosting of gamma-band activity in specific regions of visual extrastriate cortex appears to selectively account for cortical reorganization in auditory attention in the congenitally blind.

Poster 31

TACTILE FREQUENCY DISCRIMINATION WITH CONSECUTIVE AND SIMULTANEOUS STIMULUS PRESENTATION

Tobias Katus, Julia Adler, & Matthias M. Muller University Leipzig

Descriptors: tactile, frequency discrimination

Several recent studies examined frequency discrimination with vibrotactile stimuli in the flutter range (5-50 Hz). Typically, these studies presented consecutive stimuli separated by a temporal gap. We compared performance under consecutive and simultaneous presentation conditions in a within-subject design. In our experiment, mechanical stimuli in the flutter range were delivered to both index fingers. Subjects were instructed to determine the location (finger) where the stimulus with higher frequency was presented. Responses were given by foot button press. Results show an interference effect when stimuli were presented simultaneously. Performance was significantly reduced compared to consecutive presentation. Therefore, comparing two ongoing tactile streams is assumed to be more demanding than comparing a stream against a memory trace. We consider this effect to be related to contralateral SI suppression in the presence of additional ipsilateral input, as reported by a number of recent neurophysiological studies.

Poster 32

AN ERP SOURCE LOCALIZATION STUDY OF PERFORMANCE MONITORING IN AUTISM SPECTRUM DISORDER

Diane L. Santesso1, Irene E. Drmic2, Michelle K. Jetha3, Karen J. Mathewson3, Susan E. Bryson4, Joel O. Goldberg2, Geoffrey B. Hall3, Sidney J. Segalowitz1, & Louis A. Schmidt3

1Brock University, 2York University, 3McMaster University, 4Dalhousie University

Descriptors: error-relatednegativity, autism spectrum disorder, anterior cingulate cortex Electrophysiological and fMRI studies have linked autism spectrum disorders (ASD) with dysfunction of frontal cortical networks, including the anterior cingulate cortex (ACC), which are critical for performance monitoring. A recent study examined performance monitoring in ASD using the error-related negativity (ERN) and correct-related negativity (CRN) as indices of ACC activity in children. Smaller ERNs were reported in ASD than controls, with no difference in the CRN, suggesting insensitivity to performance outcomes which may lead to poor behavioral adaptation and social impairment. We examined response monitoring using a modified flanker task in 14 adults with ASD and 16 age- and IQ-matched controls. Compared to controls, ASD individuals had smaller ERNs at FCz. Despite no group differences in the CRN, individuals with ASD showed less differentiation between error and correct trials than controls, suggesting general dysfunction in the performance monitoring system. These differences, however, could be accounted for by social skills: Poor social skills were related to the smaller ERNs explaining the group difference. LORETA source localization of the ERN revealed ACC activation in both groups, with controls showing slightly greater activity. Significant differences, however, were apparent when localizing the correct-error difference wave: ASD individuals exhibited less ACC (BA 32, 24) and prefrontal (BA 11) activity than controls. These findings provide support for ACC and prefrontal dysfunction in ASD relating to underlying poor social skills and social deficits.

Poster 33

CARDIAC RESPONSES TO AFFECTIVE AUDITORY AND VISUAL STIMULI IN ADULTS WITH AUTISM SPECTRUM DISORDER (ASD)

Karen J. Mathewson1, Irene E. Drmic2, Michelle K. Jetha1, Diane L. Santesso3,

Susan E. Bryson4, Joel O. Goldberg2, Geoffrey B. Hall1, Sidney J. Segalowitz3, & Louis A. Schmidt1

1McMaster University, 2York University, 3Brock University, 4Dalhousie University Descriptors: autism spectrum disorder, RSA, emotions

Few studies have examined parasympathetic functioning in autism, especially during affective challenges. Heart period and respiratory sinus arrhythmia (RSA) were derived from ECG recordings in 15 high-functioning adults with autism and 16 age, sex, and IQ-matched controls. ECG was collected during rest and two tasks designed to elicit affective processing: listening passively to affective music selections that varied in valence and intensity; and viewing Ekman faces that varied in expression (happy, fearful, or neutral) in an emotional Stroop task. We found that during rest, heart period was shorter and RSA lower in the autism spectrum disorder (ASD) group, suggesting a baseline state of higher arousal as compared to matched controls. Cardiac responses to affective music interacted with group. Whereas heart period in control participants decreased with increased music intensity, autonomic measures in the ASD group did not change. For Stroop performance, heart period decreased and RSA declined significantly from baseline across groups. Faster

color-naming was associated with greater parasympathetic reactivity in control participants, but response times in the ASD group were unrelated to RSA. Autonomic measures did not relate to trait anxiety in the ASD group, suggesting that higher autonomic arousal in this group may not be anxiety-driven. We speculate that deficits in psychophysiological reactivity among adults with ASD may affect the processing of emotional information, thereby contributing to the maintenance of social deficits in this population.

Poster 35

TIDAL VOLUME MEASUREMENT DURING SLOW PACED BREATHING IS RELATED TO SEVERAL CARDIAC INDICES

Ben Allen, Thomas J Pardikes, & Bruce H Friedman Virginia Polytechnic Institute and State University

Descriptors: slow breathing, tidal volume, heart rate variability

Tidal volume(Vt) measurement is essential to the study of slow breathing. Novice slow breathers may breathe too deeply, which can lead to an excessive decrease in carbon dioxide and a decrease in cardiac vagal tone. Although calibration of strain gauges with a fixed volume bag is necessary to render Vt measurements in milliliters, this metric may not be necessary. The present study (N 5 70) examined the utility of a strain gauge as a proxy Vt measurement during slow paced breathing (.075 — .108 Hz). Vt was quantified as the difference between the average maximum strain gauge amplitude during inspiration and the average minimum strain gauge amplitude during expiration. Vt was negatively correlated with mean heart rate (r 5 .48, p < .001), pre-ejection period (r 5

— .20, p 5 .08), and several measures of heart rate variability (peak-to-valley RSA: r 5

— .30, RMSSD: r 5 — .24, pNN50: r 5 — .37, all p < .05). Multiple regression analyses were conducted to determine the unique relationship between these cardiac measures and Vt during slow breathing. The final regression model (R square 5 .51) indicated respiration rate and peak-to-valley RSA were negatively related to Vt, while low frequency power (LF: .05 - .15 Hz) and RMSSD were positively related to Vt. Heart rate displayed a strong positive relation with Vt and absorbed any shared variance between PEP and Vt. Strain gauge amplitude, used as a proxy tidal volume (Vt) measurement, displayed important relationships to several cardiac indices during slow breathing (.075-.108 Hz) and should be validated in future research.

Poster 36

EFFECTS OF RESPIRATION RATE ON FOUR METRICS OF RSA DURING A QUIET REST AND DUAL STRESSOR TASK

Thomas J. Pardikes, Ben Allen, & Bruce H. Friedman Virginia Polytechnic Institute and State University

Descriptors: respiratory sinus arrhythmia

Much debate exists over the relationship between respiratory sinus arrhythmia (RSA), an index of heart rate variability (HRV), and respiratory parameters. To examine this issue, the relationship between respiration rate (RR) and four metrics of RSA was investigated in this study. The electrocardiogram (ECG) and RR were recorded in 107 college students under two three-minute conditions: (1) sitting quiet rest; (2) A dual stressor task consisting of hand cold pressor combined with mental arithmetic. Pearson's correlation and single linear regression models were used to explore the relationship between respiration rate (RR) and (1) root mean square of successive differences of heart period (RMSSD), (2) peak-to-trough RSA, (3) the natural log of ECG spectral power (Fast Fourier Transform) in the high frequency band (HF; .015-.4 Hz), and (4) the peak frequency of the HF band (HF-peak). Results showed that HF peak had a strong relationship with RR only during rest (r square 5 .40). RR and HF peak were not significantly related during stress (r square 5 .014). RSA and HF power weakly correlated with RR during rest (R square 5 .091, R square 5 .072), but RMSSD did not significantly relate to RR (R square 5 .002) during rest. During stress, RMSSD, RSA and HF power all displayed a weak albeit significant negative relationship to RR (R square 5 .064, R square 5 .098, R square 5 .042) respectively. These findings suggest that (a) the relationship between RR and RSA varies across HRV metrics and experimental contexts and (b) in general, this relationship is significant but quite modest.

Poster 37

MEAN DAILY TEMPERATURE MODERATES THE SHARED ENVIRONMENTALITY OF THE SKIN CONDUCTANCE RESPONSE

Greg Perlman1, Wendy Johnson2, William G. Iacono1, & Matt McGue1 University of Minnesota, 2University of Edinburgh

Descriptors: skin conductance response, heritability, adolescents

Skin conductance response (SCR) magnitude has been found heritable and to correlate with indices of fearfulness, suggesting that the SCR may provide a marker of genetic risk for fear-related psychiatric conditions. Interestingly, the SCR has been shown to increase during warmer months (i.e. summer) relative to colder months (i.e. winter and fall) even when laboratory conditions are held constant. If the heritability of the SCR is sensitive to seasonal temperature variation, then the SCR may have less utility as a genetic marker

during conditions when heritability is lowest. To our knowledge, the question of whether SCR heritability changes as a function of seasonal temperature has not been examined. This study employs biometric moderation modeling to examine the genetic and environmental variance underlying the SCR as a function of daily temperature. We recorded the SCR to an intense, sudden blast of noise from approximately 3500 adolescent twins from the Minnesota Twin and Family Study year round from 1990 to 2005. Mean daily temperature was extracted from a national weather database. Our results indicated that the shared environmental variance underlying the SCR increased as daily temperature increased, while the genetic and non-shared environmental variances remained relatively constant. In addition, this effect was present in the raw SCR peak but not in the raw SCR baseline. This indicates that the heritability of the SCR decreases during warmer months due to an increase in shared environment and that this is a property of the peak response.

Poster 38

PERSONALITY DIMENSIONS ARE ASSOCIATED WITH ERP TIMEDOMAIN AND TIME-FREQUENCY FEATURES IN ADULT MALES

Scott J. Burwell, Steve M. Malone, Micah A. Hammer, Daniel Bedford, Ian McLaughlin, D. Vidovic, & William G. Iacono University of Minnesota

Descriptors: personality, event-related potentials, time-frequency Broad personality dimensions are sometimes thought to be associated with various forms of psychopathology. For instance, high levels of negative emotionality (NEM) and low levels of dispositional constraint (CON) characterize externalizing disorders, such as antisocial behavior and substance abuse. A robust body of research has found that P300 amplitude is reduced in individuals with externalizing psychopathology or at risk for such problems. However, associations between ERP and personality measures have not been as well documented. The present investigation used high-density ERP data from approximately 400 adult males from the Minnesota Twin Family Study (mean age 5 29.6; range 28.5 to 31.9) to examine associations between ERP features and the personality factors of positive emotionality (PEM), NEM, and CON from the Multidimensional Personality Questionnaire. Subjects were divided into groups representing the extremes of the distribution on each personality dimension, and these groups were compared with respect to time-domain amplitude and latency measures as well as time-frequency features. Principal components analysis (PCA) was used to reduce the time-frequency surfaces into meaningful components. Results indicate a time-frequency component related to NEM and CON corresponding to the P300 peak. Amplitude was reduced in individuals high in NEM and low in CON. In addition, a component spanning earlier peaks was associated with CON; subjects low in CON displayed reduced amplitude.

Poster 39

CROSS-TASK AND CO-TWIN SIMILARITY IN ERP COMPONENTS DURING ADOLESCENCE: A TEMPORAL-SPATIAL PRINCIPAL COMPONENTS ANALYSIS

Greg Perlman, Steve M. Malone, Edward M. Bernat, & William G. Iacono University of Minnesota

Descriptors: event-related potential, adolescence

ERP components with similar spatial and temporal characteristics are assumed to measure similar psychological processes across different experimental tasks and stimuli conditions (i.e. P300b amplitudes share much in common). However, it is unclear whether similar ERP components demonstrate a sufficiently high correlation to support this assumption. In this study, we examined the correlations among prominent ERP components in a sample comprised of 48 pairs of monozygotic (MZ) twins between the ages of 14 and 16 years old. We recorded EEG data using a 64-sensor dense-array net during a three-stimulus oddball paradigm and a Go/No-Go paradigm. Temporal-spatial principal components analysis was used to identify P3B amplitude, P3A amplitude, and N2 amplitude components from each task and stimuli-type. We observed robust correlations among P3B amplitudes across tasks and conditions, while the inter-correlations among N2 and P3A amplitudes were moderate. The correlations between identical twins, a lower-bound estimate of reliability, were moderate for P3B and P3A amplitudes and modest for N2 amplitudes and components elicited by frequent, non-target stimuli. This pattern of results indicates that similar ERP components share much variance and have modest reliability across tasks and conditions, consistent with the notion that they tap similar psychological processes.

Poster 40

ERP FEATURES IN ADULT FEMALES WITH TRAITS INDICATIVE OF BORDERLINE PERSONALITY DISORDER

Micah A. Hammer, Steve M. Malone, Scott J. Burwell, Daniel W. Bedford, Ian B. McLaughlin, Dragana Vidovic, Casey S. Gilmore, & William G. Iacono University of Minnesota

Descriptors: borderline personality, ERP, time-frequency

Among the fundamental characteristics of Borderline Personality Disorder (BPD) are underlying behavioral disinhibition and emotional dysregulation. Behavioral

disinhibition, as evidenced in antisocial behavior and substance use disorders, has been associated with reductions in visually elicited P300 amplitude. More recently, time-frequency analysis has been used to further elucidate the relationships between event-related potentials and behavioral disinhibition. Although research is meager, reductions in P300 amplitude have been found in patients with the disorder. Using a visual oddball paradigm, the present study seeks to explore the underlying dynamics of the ERP in a group of adult females with dispositional characteristics that typify BPD using time-frequency analysis in addition to timedomain measures. Subjects (N 5 413) were drawn from the Minnesota Twin Family Study (MTFS), and included all female subjects (mean age 5 29.5; range, 28.5 to 31.4) with usable ERP data from the third follow-up assessment of the older cohort. Borderline characteristics were assessed using a previously validated scale derived from the Multidimensional Personality Questionnaire (MPQ-BPD scale). Subjects were grouped based on extremes of this distribution. Time-domain and time-frequency measures yielded parallel results. Subjects scoring high on the MPQ-BPD showed reduced amplitude responses in general. The strongest effect was found for a time-frequency component that approximately corresponds to the P300 peak.

Poster 41

THE LONGITUDINAL STABILITY OF P3 BRAIN AMPLITUDE REDUCTION IN SUBJECTS DIAGNOSED WITH LIFETIME EXTERNALIZING DISORDERS

Henry H. Yoon, William G. Iacono, & Stephen M. Malone University of Minnesota

Descriptors: p3 event-related potential, longitudinal, externalizing disorders Cross-sectional findings from the Minnesota Twin Family Study (MTFS) consistently demonstrate significant reductions in the visual P300 (P3b) wave of the brain event-related potential in adolescent and young adult subjects diagnosed with substance use disorders (SUDs) and antisocial behaviors (ASBs). In the current study, we examined 337 twenty-nine year-old male subjects to determine whether such reductions are apparent in adulthood and whether these reductions display longitudinal stability as a marker for externalizing psychopathology. Subjects were identified for lifetime DSM-III-R criteria for SUDs (alcohol, nicotine, illicit drug dependence), ASBs (adult antisocial behaviors, antisocial personality disorder) as well as a combination of these disorders by age 29. Comparisons at age 29 were made against controls free of externalizing disorders on P3 amplitude derived from a visual oddball task. These same groups were also compared on P3 using their age 17 data. Results revealed significant P3 reductions in all subjects with a lifetime externalizing diagnosis at age 29. Furthermore, these significant reductions were already present over a decade earlier at age 17. Overall, these findings suggest that reduced P3 amplitude is an effective brain index of externalizing disorders in adulthood that taps a developmentally stable brain feature underlying behavioral disinhibition.

Poster 42

AGE-DEPENDENT CHANGES OF EEG FREQUENCY CHARACTERISTICS AND ECG-CHANGES RELATED TO WORKING MEMORY PROCESSES IN ARITHMETIC TASK

Roland Boha, Mate Benyovszky, Zsofia Anna Gaal, Brigitta Toth, & Mark Molrnr Institute of Psychology, Hungarian Academy of Sciences

Descriptors: mental arithmetics, eeg spectra, aging

The aim of the present study was to compare the the freqency-, and area-specific characteristics of the EEG recorded in a group (N 5 51) of young and elderly subjects to define age-related differences related to performance in arithmetic task. Methods: A group of old (n 5 19, aged 66.7 yrs) and young (n 5 32, aged 22 yrs) subjects were studied. During the task a simple adding arithmetic operation was required. The EEG was recorded by 33 channels 2048 ms long, and epochs were analyzed by calculating relative and absolute spectra. The ECG and behavioral measures (RT, number of errors) were also recorded. Repeated measures ANOVA was used for statistical data analysis. Results: As a result of task performance, delta and beta1 power increased in the elderly, while in the young the increase of theta was observed. The relative alpha2 band decreased in both groups in both sides but was more robust in the right in the elderly. Theta power increases during the task were more conspicuous in the young in the frontal area. The number of correct responses was significantly lower, and RT was higher in the elderly, but task-related ECG-changes were more robust in the young. Conclusions: Except for the theta band, the changes observed as a result of task performance were more robust in the elderly, which probably indicates an increased task demand in this group. The more conspicuous frontal theta increase in the young may correspond to their better performance, which is possibly due to more efficient working memory processes. ECG findings indicate a more active involvement of the young subjects in the task.

AGE-RELATED ELECTROPHYSIOLOGICAL ASPECTS OF PROBABILITY LEARNING

Zsofia Anna Gaail, Roland Boha, & Mark Molrnr Institute of Psychology, Hungarian Academy of Sciences

Descriptors: aging, eeg complexity, probability learning

The effects of aging were investigated on the resting EEG (eyes closed, eyes open conditions) and on that recorded during probability learning in the young and elderly (N 5 64). Absolute spectra, Omega complexity (OM) and synchronization likelihood (SL) were calculated in the conventional EEG frequency bands in young (n 5 31, MA 5 22.71 + 3.58 yrs) and elderly (n 5 33, MA 5 66.09 + 3.88 yrs) adults. No differences were found between the groups regarding the frequency spectra. The total power was higher in the young in the eyes-closed condition, but activation (opening eyes) eliminated group differences. OM and SL showed group differences at anterior sites during eyes open condition: OM was higher and SL was lower in the elderly. In a probability learning task, the performances of young (n 5 14,MA 5 21.93 + 1.73 yrs) and old (n 5 15,MA 5 66.47 + 4.61 yrs) adults were compared. After presenting an emotional picture (selected from IAPS), participants predicted whether the figure in the following picture would point to the left or to the right. Feedback adequacy was 90%. Behavioral data showed that young adults learned the task after the 23rd probe, while old participants did not learn at all. ERPs to the feedback during hits were subtracted from ERPs during misses: A positive potential was found between 330-430 ms at frontal sites for young but not for the elderly subjects. Our results indicate that the frontal areas are the most sensitive to aging effects, which can be shown best with complexity measures in the resting EEG. This functional background may be responsible for poor learning efficiency in the elderly.

Poster 44

STARTLE MODULATION AND AUTONOMIC REACTIVITY IN PSYCHOPATHY: THE ROLE OF THE AFFECTIVE AND THE ANTISOCIAL FACETS

Rosario Poy, Pilar Segarra, M. Carmen Pastor, Ratil Lopez, Angels Esteller, Alicia Fonfria, Carla Colomer, M. Pilar Tormo, & Javier Molto Jaume I University

Descriptors: startle reflex, skin conductance, hare psychopathy checklist-revised (pcl-r) This study examined the role of the lower order facets underlying the two broad components of psychopathy (interpersonal/affective and social deviance) in explaining psychophysiological reactivity to affective pictures. Participants were 69 male inmates assessed using the Hare's PCL-R. Eyeblink responses to noise probes, skin conductance changes and subjective ratings of valence, arousal and dominance were obtained during a passive viewing task (erotic couples, female nudes, thrill, babies, objects, suffering, threat to self, aggression, and mutilation IAPS pictures, 6 s presented). Preliminary hierarchical regression analyses showed that facet 2 (Affective)—independently of facet 1 (Interpersonal)—scores were inversely related to the magnitude of startle potentiation during mutilation scenes (and directly to dominance ratings). Moreover, facet 4 (Antisocial)— independently of facet 3 (Lifestyle)—scores were related to smaller electrodermal changes during pleasant and unpleasant contents. Our results suggest that psychopaths' blunted defensive reaction seems to be specifically related to the affective traits of psychopathy, whereas their classically reported autonomic hyporreactivity seems to be specifically related to the antisocial (not the lifestyle) features of the disorder. These data add to the increasing evidence for the differential association between psychopathy facets and physiological and cognitive dysfunctions, and provide support to the validity of the four-facet model of psychopathy in disentangling the etiology of this personality disorder.

Poster 45

AVERSIVE CONDITIONING DEFICITS IN NON-CRIMINAL PSYCHOPATHS

Raul Lopez, Rosario Poy, M. Carmen Pastor, Pilar Segarra, Angels Esteller, Carla Colomer, Alicia Fonfria, & Javier Molto Jaume I University

Descriptors: aversive learning, peripheral measures, psychopathic personality inventory-revised

The present study explored differences in aversive learning as a function of PPI-R scales in a sample of 74 undergraduate students (42 females). Skin conductance changes and startle responses were obtained during a differential aversive conditioning task. Two NimStim neutral faces served as CSs (8 s presentation); a 500 ms train of electric pulses was used as the US, delivered immediately after each CS+ offset during the acquisition phase. The task consisted of 4 blocks (1 habituation, 2 acquisition, and 1 extinction) of 12 trials each (6 CS+, 6 CS —), with 8 probes presented at 5.5 or 6.5 s after picture onset; ITIs varied randomly between 15 and 25 s. ANOVA with group (high vs. low PPI-R total scorers) as a between-subjects factor showed enhanced skin conductance changes and greater blinks to CS+ than to CS — during acquisition in both groups. CS+/CS — differentiation persisted throughout extinction in the low but not in high psychopathy group. Subsequent

multiple regression analyses conducted with extinction data showed that the Self-Centered Impulsivity factor scores (especially the Machiavellian Egocentricity scale) were related to smaller CS+/CS — electrodermal differentiation, whereas Fearlessness scale scores (a Fearless Dominance factor) were inversely related to the magnitude of the CS+/CS — startle differentiation. The lack of persistence of aversive conditioning in non-criminal psychopaths —as assessed by PPI-R - is consistent with prior findings from our lab demonstrating aversive conditioning deficits in incarcerated psychopaths as assessed by Hare's PCL-R.

Poster 46

ERROR PROCESSING AND CONFLICT MONITORING SHOW EVIDENCE OF HERITABILITY IN ADHD

Grainne McLoughlin, Fruhling Rijsdijk, Charlotte Tye, Philip Asherson, Jonna Kuntsi, & Robert Plomin Institute of Psychiatry, King's College London

Descriptors: error monitoring, heritability, genetics

The error negativity (Ne), an ERP correlate of error monitoring, has been shown to be affected by dopaminergic manipulations (de Bruijn, 2004; de Bruijn, 2006, Zirnheld, 2004). This process has been localized to medial frontal brain regions, in particular the anterior cingulate cortex (ACC). Additionally, conflict monitoring (N2), which is correlated with the Ne, has been localized to this brain region. Studies in children and adults with attention deficit hyperactivity disorder (ADHD) have found that alterations in these electrophysiological parameters are mediated by familial factors (and may be genetically mediated) (Albrecht, 2008; McLoughlin et al., in press), and are therefore potential endophenotypes of the disorder. However, it is not known to what extent these processes are genetically and environmentally mediated. Using an arrow flanker task, we collected EEG data on 44 twin pairs who were concordant and discordant for ADHD and 22 matched controls. If these parameters are true endophenotypes of ADHD, it is expected that unaffected co-twins of ADHD probands will be less similar to controls than they are to their siblings. There were significant differences in N2 and Ne amplitude between siblings of ADHD probands and controls (p < .05). These results indicate that there are heritable effects on these parameters in ADHD and this may be related to dopaminergic dysfunction. Further investigations will examine the relationship of these parameters to risk alleles related to dopaminergic pathways.

Poster 47

STRIATAL ACTIVATION TO NEGATIVE FEEDBACK DIFFERS BETWEEN BEHAVIORALLY INHIBITED AND NON-INHIBITED ADOLESCENTS

SarahM. Helfinstein1, Brenda Benson2, Yair Bar-Haim3, Koraly Perez-Edgar4, Allison Detloff2, Daniel S. Pine2, Nathan A. Fox1, & Monique Ernst2 1University of Maryland, College Park, 2National Institute of Mental Health, 3Tel Aviv University, 4George Mason University

Descriptors: striatum, motivation, temperament

The temperamental style of behavioral inhibition (BI) is characterized by heightened sensitivity to novelty and enhanced responsivity to threat. In addition, in two recent studies we have shown enhanced striatal response in BI adolescents to cues signaling the potential to earn reward or punishment. These findings suggest that unique functional patterns in the mesencephalic dopaminergic system may contribute to the expression of BI. We thus expected that BI individuals would show enhanced striatal response to valenced feedback as well. However, this has not been tested, nor is it known whether temperamental differences in striatal activation are seen in response to receipt of reward, punishment, or both. To examine these questions, BI and behaviorally non-inhibited (BN) adolescents performed a response selection task where they believed their choice of a button press determined monetary outcomes and a control motor task where their button press was always rewarded. Striatal responses to positive and negative feedback were examined. Group differences emerged only in response to punishment, with stronger caudo-dorsal striatal activation to punishment in the BI than the BN group. In addition, rostro-ventral striatum was activated in response to reward in both groups. These results suggest that BI and BN individuals may differ in their dopaminergic response to negative feedback. Previous findings of enhanced striatal response to anticipation of reward among BI subjects may reflect enhanced sensitivity to potentially missing a reward, rather than potentially winning a reward.

Poster 48

NEUROMAGNETIC AND AUDIOMETRIC INVESTIGATION OF TRANSIENT TINNITUS

Magdalene Ortmann1, Winfried Schlee2, Nadia Müller2, & Nathan Weisz2 1University of Münster, 2University of Konstanz

Descriptors: tinnitus, MEG, audiometry

Tinnitus is defined as an auditory perception in absence of any external source of sound. Thus far, most research in humans has been done on patients with chronic tinnitus. In this study focus was laid on transient tinnitus and gamma band activity as its neural

correlate. To measure transient tinnitus, we invited 14 members of rock bands (m:f 5 13:1), who reported having transient tinnitus after band practice on a regular basis, both directly after band practice and in a control condition. Additionally, we conducted a wide range of measurements including audiometry, a five minute resting MEG and questionnaires. Data were analyzed in R and Matlab. To localize sources of oscillatory brain changes we used a frequency-domain adaptive spatial filtering algorithm, called Dynamic Imagine of Coherent Sources (D.I.C.S.). Our analyses showed that transient tinnitus was accompanied by temporary hearing loss in both ears and by an increase in gamma band activity in the right auditory cortex. Also, tinnitus frequency was strongly correlated to hearing loss (r 5 — .84), with tinnitus frequencies being most likely located in higher frequencies. Confirming previous results, we conclude that deafferentation, caused by e.g. hearing loss, triggers an increase in gamma band synchrony in the auditory cortex. We hypothesize that this synchronized signal is misinterpreted on higher levels of information processing as a real tone, and develop a model for the conscious perception of tinnitus.

Poster 49

AEROBIC FITNESS EFFECTS ON COGNITIVE TASK PREPARATION

Keita Kamijo1, Kevin C. O'Leary2, Matthew B. Pontifex2, Jason R. Themanson3, & Charles H. Hillman2 Japan Society for the Promotion of Science, 2University of Illinois, Urbana-Champaign, 3Illinois Wesleyan University

Descriptors: aerobic fitness, task preparation, CNV

Aerobic fitness effects on task preparation were examined in 65 young adults (43 females) separated into higher-fit and lower-fit groups according to their maximal oxygen consumption. Participants performed a modified Sternberg working memory task, which required participants to encode a memory set containing an array of 3, 5, or 7 letters (S1) and decide whether a single probe letter (S2) was present in the encoded array. The task was performed under Accuracy instructions and Speed instructions while measures oftask performance (i.e., response speed, accuracy) and contingent negative variation (CNV) were collected. Analyses revealed that participants responded more slowly and accurately during Accuracy instructions relative to Speed instructions. No significant fitness differences were evident between groups on task performance measures. However, CNV amplitude was significantly larger in the frontal region for lower-fit participants compared to higher-fit participants during Speed instructions; an effect not found for the Accuracy instructions. These results suggest that lower-fit individuals may recruit increased resources to respond as quickly as possible, whereas higher-fit individuals might require fewer resources irrespective of task instructions. These alterations in CNV amplitudes suggest that aerobic fitness may selectively benefit cognitive preparation rather than motor preparation. The present study supports previous findings showing fitness-related differences in cognitive function even during early adulthood.

Poster 50

STABILIZATION OF ERROR-RELATED BRAIN ACTIVITY ACROSS THE LIFESPAN

Matthew B. Pontifex1, Mark R. Scudder1, Mike L. Brown1, Kevin C. O'Leary1, Chien-Ting Wu1, Jason R. Themanson2, & Charles H. Hillman1 1University of Illinois, Urbana-Champaign 2Illinois Wesleyan University

Descriptors: ERN, children, older adults

The stability of the error-related negativity (ERN) and the error positivity (Pe) across the lifespan was investigated in 56 preadolescent children (24 female), 57 college-age young adults (34 female), and 26 older adults (12 female). Participants completed a modified flanker task during which event-related potentials and task performance were measured. Response locked averages were created using sequentially increasing subsets of2, 4, 6, 8, 10, and 12 errors of commission from each participant and a within participant grand average of all error of commission trials (mean 5 31.2 + 1.7,range 5 14-156; Olvet & Hajcak, in press). Findings indicated that across age cohorts ERN and Pe exhibited nonsignificant differences relative to the within-participants grand average after six trials. Further, results indicated that the ERN and Pe exhibited excellent internal reliability in preadolescent children and young adults after six trials, but older adults required eight trials to reach similar reliability. These data replicate and extend previous findings in preadolescent children, young adults and older adults, indicating that the ERN and Pe may be accurately quantified with as few as six to eight commission error trials.

Poster 51

FITNESS AND THE MODULATION OF COGNITIVE CONTROL IN PREADOLESCENT CHILDREN

Matthew B. Pontifex, Lauren B. Raine, Laura Chaddock, Matt VanPatter, Michelle W. Voss, Jennifer S. Kim, Neal J. Cohen, Arthur F. Kramer, & Charles H. Hillman University of Illinois, Urbana-Champaign

Descriptors: cognitive control, children, ERN

Fitness effects on the cognitive control of action monitoring were assessed in 9 -10 year old children separated into higher- and lower-fit groups according to their maximal

oxygen consumption. ERPs and task performance were measured during compatible and incompatible stimulus-response conditions of a subsequently administered modified flanker task. Higher-fit participants exhibited higher performance accuracy, overall, than lower-fit participants, particularly in the more challenging incompatible condition, where higher-fit participants were able to maintain their performance levels but lower-fit participants were not. Neuroelectric indices of action monitoring suggest a possible mechanism for the behavioral findings. That is, higher-fit participants exhibited smaller ERN amplitudes in the compatible condition, and greater modulation of the ERN potential between the compatible and incompatible conditions, relative to lower-fit participants who exhibited large ERN amplitudes in both conditions. These findings suggest that lower-fit participants may exert increased activation of their action monitoring system to meet the demands of more simplistic tasks, and thus are unable to up-regulate their cognitive control processes to meet increased task demands, resulting in decrements in response accuracy. In contrast, higher-fit participants appear better able to maintain high levels of task performance despite increases in task difficulty by selectively modulating cognitive control processes to meet task demands.

Poster 52

HOW DO SUBJECTS EXPERIENCE AN FMRI SESSION? CONCORDANCE BETWEEN SUBJECTIVE AND NEUROENDOCRINE STRESS INDICATORS

Ulrike Lueken1, Markus Muehlhan1, Hans-Ulrich Wittchen2, & Clemens Kirschbaum3 1Neuroimaging Center, Technische Universitat, 2Insitute of Clinical Psychology and Psychotherapy, Technische Universitat, 3Technische Universitat

Descriptors: stress, cortisol, fmri

Background. In routine care patients, magnetic resonance imaging (MRI) examinations may produce adverse anxiety-related reactions, followed by impaired data quality and premature terminations of scans. The aim of the present study was to translate these findings into a research setting where subjects undergo a series of functional MRI scans. Methods. Scanner-naive subjects (N 5 34) participated in an fMRI task containing a training phase, two experimental runs (attentional task), and a structural scan. In order to control for differences in cognitive load, we used the same task for both runs. We assessed subjective state affectivity using a multidimensional approach and neuroendocrine stress indicators. Assessments were carried out before and after each experimental phase. Results. All indicators changed significantly during the entire assessment. Negative mood, vigilance, restlessness and alpha-amylase peaked immediately before the fMRI session. Negative mood was selectively correlated with cortisol, while vigilance was associated with alpha-amylase. Subjective state measures showed dissociable trends, pointing towards the incremental value of multidimensional mood assessments. Conclusions. Results extend previous reports of routine care patients in a typical research setting. Subjects participating in fMRI experiments are likely to show pronounced changes in state affectivity and neuroendocrine stress markers in the course of the assessment. The impact of these changes on functional activation patterns induced by the MRI environment remains to be evaluated.

Poster 53

ARE YOUR RUNS COMPARABLE? DIFFERENCES IN SUBJECTIVE AND NEUROENDOCRINE STRESS INDICATORS IN THE COURSE OF AN FMRI SESSION

Markus Muehlhan1, Ulrike Lueken1, Michael N. Smolka2, & Clemens Kirschbaum3 1Neuroimaging Center, Technische Universitat, 2Section of Systems Neuroscience, Faculty of Medicine Carl Gustav Carus, Technische Universitat, 3Technische Universitat

Descriptors: fmri, stress, alpha-amylase

Background. Participating in a functional magnetic resonance (fMRI) experiment can alter subjective and neuroendocrine stress markers. However, data from several runs are usually pooled. In the present study we aimed to compare stress responses and neural activation patterns during the first and second run to see whether subjective, physiological, and neural responses are comparable. Methods. Scanner-na'ive subjects (N 5 34) participated in an fMRI session encompassing two experimental runs. Identical tasks were employed for both runs (attentional task). We assessed subjective state affectivity and neuroendocrine stress indicators. Assessments were carried out before and after each experimental phase. Results. Negative mood, restlessness and alpha-amylase were significantly higher during the first run, as well as intra-subject variability in stress indicators. Fifteen percent of our subjects responded with elevated cortisol levels towards the fMRI session exceeding 2.5 nmol/l. Preliminary analysis of fMRI data yielded pronounced differences in neural activation patterns between the first and second run. Conclusions. Although identical paradigms were used, results indicate that psychological processes may differ significantly between two runs. Pooling data from several runs may thus yield increased error variance. In a subgroup of subjects, pronounced cortisol responses may occur in response to the scanner. Further studies are needed to evaluate the impact of elevated cortisol levels and autonomic response systems on functional activation patterns.

FUNCTIONAL HEMISPHERIC LATERALIZATION OF EXECUTIVE FUNCTION BY TRANSCRANIAL DIRECT CURRENT STIMULATION

Colleen A. Dockery1, Tilman Gaber2, Niels Birbaumer1, & Christian Plewnia3 1Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, 2Max Planck Institute of Biological Cybernetics, 3University Hospital Tübingen

Descriptors: executive function, dorsolateral prefrontal cortex, transcranial direct current stimulation

The executive functions underlying Tower of London (TOL) planning performance depend on the integrity of the dorsolateral prefrontal cortex (DLPFC) and can be modified by acute transcranial direct current stimulation (tDCS) with lasting benefits to performance. Both anodal and cathodal tDCS of the left DLPFC result in phase-dependent, polarity-specific benefits on TOL performance (Dockery et al., 2009). This experiment evaluated differential effects of DLPFC hemisphere stimulated by comparing TOL performance in a between-subject design with 46 randomly assigned healthy participants (left n 5 24, right n 5 22). tDCS (real or sham) was applied over three sessions. Subjects were then grouped according to tDCS sequence, defined as either anodal tDCS before cathodal (tDCS_AC), or the contrary (tDCS_CA). For reaction time, a significant interaction of STIMULATION CONDITION X tDCS SEQUENCE, F(2,82) 5 18.063, p 5 .000, showed that only the real tDCS groups but not sham tDCS were sensitive to phase of application. A significant interaction of HEMISPHERE X tDCS SEQUENCE, F(1,41) 5 5.144, p 5 .029 showed that left DLPFC benefited more from the tDCS_CA sequence (tDCS_AC: 8.208 + 0.538, tDCS_CA: 6.561+0.515) while right DLPFC benefited from tDCS_AC (tDCS_AC: 7.489 + 0.538, tDCS_CA: 8.257 + 0.538). This study elucidates how tDCS can be used to study differences in the functional anatomy ofdorsolateral prefrontal cortical circuits and their role in planning. The results suggest optimal stimulation parameters to achieve the most beneficial effects of tDCS on these executive functions.

Poster 55

EMOTIONAL IMAGERY ACTIVATES REWARD CIRCUITS

Vincent D. Costa, Peter J. Lang, & Margaret M. Bradley University of Florida

Descriptors: imagery, reward, fmri

Research on emotional perception and learning indicates that appetitive cues engage nucleus accumbens (NAc) and medial prefrontal cortex (mPFC), whereas amygdala activity is modulated by the emotional intensity of both appetitive and aversive cues. Using event-related fMRI, we examined activation of mesocorticolimbic regions when 32 healthy male and female participants vividly imagined pleasant, neutral, and unpleasant scenes. Each trial began with visual presentation of a text for 12 s and the visual offset of the text signaled a subsequent 12 s period during which participants continued to vividly imagine themselves actively involved in the described event. Results indicate that pleasant imagery selectively activates NAc and mPFC, whereas amygdala activation was enhanced during both pleasant and unpleasant imagery. NAc and mPFC activity were each correlated with the rated pleasure of the imagined scenes, while amygdala activity was correlated with rated emotional arousal. Functional connectivity of NAc and mPFC was evident throughout imagery, regardless of hedonic content, while temporally correlated activation of the amygdala with NAc and mPFC was specific to imagining pleasant scenes. Together these findings provide strong evidence that text-driven imagery engages appetitive and aversive motivational circuits, and implies that NAc, mPFC, and the amygdala form an integrative circuit whose activity reflects appetitive motivation.

Poster 56

FEAR LESS! NEURAL CORRELATES OF FEAR REVERSAL

Vincent D. Costa, Margaret M. Bradley, & Peter J. Lang University of Florida

Descriptors: fear, pain, emotion regulation

Threat of shock prompts fear related changes in the brain and body, while instructions that reverse a prior threat eliminate anticipatory fear. The present study used fMRI to examine the neural bases for plasticity of instructed fear. Color and shape were covaried to form four sets of perceptual cues. In an initial learning phase, one dimension (color or shape) cued threat of shock and safety. In a second phase the shock contingency was shifted to a different perceptual dimension so that half of the cues retained their affective meaning, while the remaining half reversed their prior association with threat or safety. During the initial learning phase, threat compared to safety cues elicited increased activation in the pain matrix, including anterior insula, ventrolateral prefrontal cortex (vPFC), caudate, inferior parietal lobule, rostral anterior cingulate, and dorsomedial prefrontal cortex (dmPFC). Comparing activity before and after the instructed reversal, viewing a previously threatening cue that now signaled safety reduced activity in anterior insula, vPFC, and dmPFC. Increased activation occurred in the same regions for cues whose meaning shifted from safe to threat, and also in the orbitofrontal cortex and ventral striatum, representing a

reward prediction error. Electrodermal responses confirmed fear learning in each phase. These data indicate that simple instructions are sufficient for the brain to flexibly encode and learn changes in the aversive associations that mediate fear.

Poster 57

FAST AND EASY: REFLEX MODULATION FOR SIMPLE PICTURES

Bethany C. Wangelin, Margaret M. Bradley, & Peter J. Lang University of Florida

Descriptors: emotion, startle, P300

Attention and emotion differentially modulate the blink component of the startle reflex and the P3 component of the event-related potential to the startle probe. The present study investigated the modulation of blinks and ERPs when subjects viewed pictures that depicted only a few, easily distinguishable emotional categories. When emotional cues readily match existing memory representations and have also been primed by the presentation of similar exemplars, affective modulation is hypothesized to be facilitated. To further assist in rapid recognition, pictures were selected to comprise simple, figure-ground compositions. Sixteen subjects viewed simple pictures depicting erotic love, violence, or neutral people. Pictures were presented for 3 sec with a variable intertrial interval. Acoustic startle probes were presented at 250,750, or 2500 ms after picture onset in a counterbalanced order. Startle blink magnitude was recorded, and the P300 component of the ERP to each probe was measured using dense array EEG. Results indicated significant startle reflex potentiation when viewing pictures of violence, compared to neutral or erotic content, at all three probe delays, which was independent of early prepulse inhibition. P300 amplitude at centro-parietal sites was reduced for probes presented during erotic or violent scenes, compared to neutral pictures. Together, these findings suggest that affective reactions are facilitated when processing easily recognized stimuli that are primed by repeated presentation of category exemplars.

Poster 58

EMOTIONAL PERCEPTION IN DEPRESSIVES AND CONTROLS: RAPID FUNCTIONAL IMAGING

Dean Sabatinelli1, Andreas Keil2, Margaret M. Bradley2, & Peter J. Lang2 'University of Georgia, 2University of Florida

Descriptors: emotion, fmri, depression

Depression has been associated with dysfunctional corticolimbic networks, particularly with respect to the processing of pleasant stimuli. Here we rapidly collected blood oxygen level dependent (BOLD) signals in midline structures as control (n 5 12) and undergraduates reporting depressive symptoms (n 5 8) viewed a mixed series of affective and neutral pictures. We expected depressive symptoms to be associated with differential BOLD signal in subcortical and frontal cortical structures, relative to controls, and explored whether group differences might differ across specific picture contents. Fifty grayscale pictures consisting of 10 categories of pleasant, neutral, and unpleasant contents were presented in an event-related series (3 seconds on, 12 seconds dark screen) while 8 sagittal slices covering midline structures and extending laterally to sample both amygdalae were collected every 500 ms on a 3T GE Signa MR scanner. Relative to controls, depressive subjects showed less amygdala and more medial prefrontal activity during pleasant picture perception. BOLD signal in depressives also suggested relatively greater BOLD signal in inferotemporal, intraparietal, and middle occipital cortex during pleasant picture perception relative to controls. These data support the perspective that depression may be associated with distinct patterns of corticolimbic activity during emotional perception. Further analyses will examine temporal interactions across regions of interest, as well as the role of specific categories of pleasant and unpleasant picture stimuli.

Poster 59

HYPER- AND HYPO-REACTIVITY IN PTSD: TRAUMA RECURRENCE AND NEGATIVE AFFECTIVITY

Lisa M. McTeague1, Peter J. Lang1, Joshua R. Shumen1, Marie-Claude Laplante1, & Bruce N. Cuthbert2 1University of Florida, 2University of Minnesota

Descriptors: PTSD, startle, trauma

Within PTSD, a potential dose-response relationship was investigated between past trauma recurrence and current comorbidity and intensity of physiological reactions to aversive imagery. Principal PTSD (n 5 49; 22 single trauma exposure, 27 multiple trauma exposure) and control (n 5 76; 46 never trauma-exposed, 30 trauma-exposed) participants imagined scenarios while startle probes were presented and eye-blink responses recorded. Autonomic and facial expressivity changes were also assessed. Overall, PTSD patients exceeded controls in defensive reactivity during idiographic trauma imagery and, though less pronounced, showed heightened reactivity to standard anger, panic, and physical danger imagery. In subgroup analyses, controls with and without trauma exposure showed isomorphic patterns. However, within PTSD only the singleexposed patients evinced robust startle and autonomic responses, exceeding both controls and multiple-exposed PTSD. Despite greater reported arousal, the multiple- relative to single-exposed PTSD group showed blunted defensive reactivity associated with

more chronic and severe PTSD, greater comorbidity, and more pervasive dimensional dysphoria (e.g., depression, trait anxiety). Whereas PTSD patients generally show physiological hyper-arousal during aversive imagery, concordant with self-reported distress, the most symptomatic patients with histories of recurrent traumatization show discordant physiological hypo-reactivity, perhaps attributable to sustained high stress and persistent negative affectivity that ultimately compromises defensive responding.

Poster 60

ATTENTION CAPTURE IN BLOOD-INJURY FEAR: PARAFOVEAL & FOVEAL PROCESSING

Lisa M. McTeague1, Andreas Low2, Shumen R. Joshua1, Andreas Keil1, & Peter J. Lang1 1University of Florida, 2University of Greifswald

Descriptors: emotion, fear, attention

The aim of the current investigation was to explore whether individuals reporting significant blood-injury fear would demonstrate hyper-sensitivity to mutilation pictures presented briefly and parafoveally. Whether such pronounced reactivity would be similarly revealed during more sustained foveal processing was also explored. Forty undergraduates were selected based on responses to the Mutilation Questionnaire. Participants initially viewed a series of parafoveal presentations (150 ms) of pleasant and unpleasant (threat, mutilation) pictures each paired to the left or right of a neutral picture. Next, a series of individual, foveal (3 s) pictures depicting the same contents were viewed. Overall, during parafoveal presentation more arousing pictures prompted greater lateral-occipital P2 responses in the contralateral hemisphere. High- relative to low-fearful participants demonstrated more positivity to mutilation pictures, with the strongest effect in the right hemisphere when these fear-relevant pictures were presented to the left visual hemifield. Interestingly, during foveal presentation the same pattern of increased late positive potential (LPP) and decreased startle probe P3 responses to more arousing contents was observed in both groups. Taken together, these data suggest that fearful individuals are hyper-sensitive to relatively degraded fear cues, even amidst competition by concurrent stimuli, whereas more thorough processing in central fixation results in similar levels of motivational engagement irrespective of fearfulness.

Poster 61

THE TIME COURSE OF ATTENTION TO FACIAL EXPRESSIONS DISTINGUISHES HEALTHY CONTROLS, SOCIALLY ANXIOUS INDIVIDUALS, AND SOCIAL PHOBIA PATIENTS

Andreas Keil, Lisa M. McTeague, Joshua R. Shumen, Marie-Claude Laplante, & Peter J. Lang University of Florida

Descriptors: steady-state potential, attention dynamics

This study examined whether emotional expressions modulate the time-varying amplitude of the steady-state Visual Evoked Potential (ssVEP), a continuous measure of attentive electrocortical facilitation. Pictures with facial expressions (happy, neutral, fearful, angry) were flickered at a rate of 17.5 Hz for a duration of 3428 ms. Participants varied in social anxiety severity and included controls, a group high on self-reported social anxiety, and patients diagnosed with social phobia. Although main effects of facial expression were small, strong interaction effects emerged between group and expression: Social phobia patients showed earlier and stronger initial (within 300 ms of flicker onset) increase of the ssVEP amplitude for angry and fearful faces, compared to the low- and high anxious controls. Neutral and happy faces did not show such early differences in temporal dynamics. However, stronger disengagement as indicated by ssVEP amplitude reduction over time was observed for the patients and socially anxious students across all facial expressions. These data suggest that both socially anxious students and social phobia patients evidence attention disengagement over time. They also suggest that early differences indicative of early hypervigilance for faces with threat features may not be seen in an analogue sample, but may require greater severity as reflected in patient status. The observed pattern of initial attention hypervigilance and subsequent perceptual avoidance may represent a marker of the psychopathology of social anxiety.

Poster 62

LOUDNESS DEPENDENCY OF MISMATCH NEGATIVITY (MMN): EVIDENCE FROM CSD-PCA

Nathan A. Gates1,2, Craig E. Tenke1,3, Daniel M. Alschuler4, Christopher J. Kroppmann4, Gerard E. Bruder1,3, & Jürgen Kayser1,3 1Division of Cognitive Neuroscience, New York State Psychiatric Institute, 2Queens College and the Graduate Center of the City University of New York, 3College of Physicians and Surgeons, Columbia University, 4Division of Cognitive Neuroscience, New York State Psychiatric Institute

Descriptors: mismatch negativity, current source density, laplacian, loudness dependency

Auditory N1/P2 covaries with stimulus intensity (loudness dependency; LDAEP). Intensity deviants also produce MMN but it is unclear to what extent this effect is affected

by loudness. These relations were explored in a modified MMN task in which binaural tones were presented at four intensities, using one intensity in a block as standard (70%) and the remaining three as deviants (10% each). An additional block used equiprobable (25%) intensities to validate LDAEP effects. Dense ERPs (72-channel) were recorded from 13 healthy adults who watched a silent film and reported its content after each block. Neuronal generator patterns underlying LDAEP and MMN, obtained by temporal PCA of reference-free CSD waveforms, included: 1) N1 sink (113 ms peak); 2) temporal N1 sink (159 ms); 3) P2 source (218 ms). These three factors revealed robust, monotonic relationships with intensity for standards and equiprobable stimuli. In contrast, tangential N1 was augmented with increases but not decreases in intensity. Whereas temporal N1 sink and temporal P2 source for deviants showed a similar association with intensity, these CSD-PCA factors had secondary midline maxima (N1: frontocentral; P2: midcentral) that were responsive to large intensity increases but not decreases. Likewise, these effects were present for factor score differences (deviant minus standard) revealing characteristic MMN and P3a topographies. The findings suggest that MMN of tone intensity is elicited primarily by louder rather than softer deviants, and that LDAEP effects may be affected by a selective MMN for loud tones.

Poster S3

REFERENCE-FREE ERP OLD/NEW EFFECTS OF VISUAL RECOGNITION MEMORY FOR WORDS AND FACES IN SCHIZOPHRENIC AND HEALTHY ADULTS

Jurgen Kayser, Craig E. Tenke, Christopher J. Kroppmann, Shiva Fekri, Daniel M. Alschuler, Nathan A. Gates, Roberto B. Gil, & Gerard E. Bruder New York State Psychiatric Institute

Descriptors: schizophrenia, recognition memory, current source density (csd) For words, we previously reported a preserved ERP 'old-new effect' (enhanced parietal positivity 300-800 ms to correctly recognized repeated items) in schizophrenia over mid-parietal sites using 31-channel nose-referenced surface potentials (ERP) and reference-free current source densities (CSD). However, patients showed poorer word recognition memory and reduced lateral-parietal P3 sources. The present study investigated whether these abnormalities are specific to words. Stimulus-locked high-density ERPs (67-channel) were recorded from 53 schizophrenic (27 male) and 42 healthy (18 male) right-handed adults during parallel visual continuous recognition memory tasks using words or unknown faces. To identify and measure neuronal generator patterns underlying ERPs, unrestricted Varimax-PCA was performed using CSD estimates (spherical spline surface Laplacian). Two late source factors peaking at 407 ms (lateral parietal maximum) and 805 ms (centroparietal maximum) accounted for most of the variance between 250 and 950 ms. Poorer (74.9 + 22.0% vs. 85.4 + 12.5% correct) and slower (818+ 174 vs. 755 + 147 ms) performance in patients was accompanied by reduced stimulus-locked left parietal sources (both overall and old/new effects). However, patients showed parietal old/new effects in both tasks, but words revealed a medialrather than lateral-parietal topography seen for faces and controls for either task. In agreement with prior results, ERP correlates of recognition memory deficits in schizophrenia suggest functional impairments of lateral posterior cortex (stimulus representation).

Poster S4

CHARACTERIZATION OF N1/P2 LOUDNESS DEPENDENCY BY TEMPORAL PRINCIPAL COMPONENTS ANALYSIS OF CURRENT SOURCE DENSITY (CSD-PCA): PREDICTION OF TREATMENT RESPONSE IN DEPRESSED PATIENTS

Craig E. Tenke, Jurgen Kayser, Nathan A. Gates, Daniel M. Alschuler, Christopher J. Kroppman, Shiva Fekri, Jonathan W. Stewart, Patrick J. McGrath, & Gerard E. Bruder New York State Psychiatric Institute

Descriptors: surface laplacian, loudness dependency, depression

Auditory EP loudness dependency (LDAEP) shows promise as a predictor of clinical response in depressed patients treated with serotonin agonists. Quantification of LDAEP used N1/P2 peak-to-peak differences and inverse models of N1 corresponding to primary auditory cortex generators (e.g., BESA, LORETA). Reference-free unrestricted Varimax CSD-PCA (covariance matrix) offers a conservative, model-independent alternative. Auditory 72-channel ERPs (BioSemi) were recorded from 23 healthy adults and 15 depressed patients listening to 40 ms, 1000-Hz pure binaural tones (1600 -2100 ms ISI) at five, equiprobable intensities (60-100 dB SPL). Subsequently, patients began treatment with an SSRI, NDRI, or both antidepressants, and were assessed for treatment response after 4 - 12 weeks (7 remitters; 8 nonremitters). An N1 factor (116 ms peak latency) with a tangentially-oriented sink/source topography consistent with activation of auditory cortex showed a robust, monotonic association with intensity. As predicted, the loudness dependency of this sink was greater for remitters than for non-remitters, who did not differ from controls. Also, N1 was greater for remitters (p 5 .006). The P2 factor (226 ms; midline source topography) showed intensity effects that were less robust, while a radial temporal lobe N1 sink (167 ms) and a temporal lobe P3 source (351 ms) failed to show consistent effects. Thus, CSD-PCA offers a concise, but

conservative, characterization of LDAEP generators, and may be of clinical value for predicting response to antidepressants.

Poster 65

FINDING MCGURK: LOCALIZATION OF THE SOURCE OF THE MCGURK-EFFECT AND RELATED OSCILLATORY ACTIVITY

Julian Keil1, Nathan Weisz1, & Niklas Ihssen2 'University of Konstanz, 2Bangor University

Descriptors: mcgurk-effect, gamma oscillation, MEG

The McGurk-effect is an illusion demonstrating an interaction between auditory and visual systems in speech perception. If a mismatch between the sound and the accompanying visual input occurs, the fusion of both modalities to a novel percept can be observed. The present study was designed to clarify the conditions under which this effect occurs and the identification of cerebral sources associated with it. We are interested in the potential influence of ongoing brain oscillations associated with varying perceptions. In the present study, videos of an actor articulating syllables were dubbed with audio tracks of different syllables. The subjects were presented with 390 videos, part of which contained the original audio tracks, part of which contained mismatching tracks. As an indicator of the perception, the subjects reported via button press what they had perceived. MEG was used to record oscillatory brain activity. Previous studies have shown increased gamma band activity related to incongruent stimuli. FMRI-studies have shown an involvement of superior temporal gyrus in speech perception. We propose that the source of the McGurk-effect lies in the supratemporal auditory cortex and could be reflected by increased gamma oscillations. We hypothesize an increased long-range synchronization between these areas to reflect the crossmodal interaction. Promising preliminary results in the trials with a perceived illusion point to an increase in temporal low-gamma oscillations as well as to a decrease of prefrontal alpha activity prior to the sound onset.

Poster 66

HEARING MUSIC WITHIN NOISE: AN ECOG STUDY

Nadia Muller, Julian Keil, & Nathan Weisz University of Konstanz

Descriptors: phantom perception, auditory, intracranial

Perception is a process that structures the sensory information our neuronal system is exposed to so that we get a consistent experience of the environment. When we lack information our brain compensates for missing input in order to create a meaningful percept. We investigated if our brain can make sense out of pure noise when presented with noise in a meaningful context. Therefore, we compared periods ofpink noise in the context of famous versus unknown songs. Based on the fact that perception of continuity is aided by experience, we hypothesize that these identical noise periods are processed differently such that noise within famous songs is more likely to elicit a real percept. Accordingly, ECoG is recorded from epilepsy patients. Time-frequency analyses of the induced responses are calculated for each electrode, and conditions were statistically compared using a within-subject nonparametric permutation test. Preliminary data indicate a relatively stronger alpha power reduction in the superior temporal cortex for noise periods within famous songs compared to unknown songs. However, data have yet to substantiate if, and how, the brain responses elicited by the same noise periods differ depending on the information content of the context.

Poster 67

MODIFICATION OF SYNCHRONOUS BRAIN ACTIVITY IN CHRONIC TINNITUS - A NEUROFEEDBACK THERAPY

Isabel Lorenz, Thomas Hartmann, Winfried Schlee, Nadia Muller, Julian Keil, & Nathan Weisz University of Konstanz

Descriptors: eeg-neurofeedback, tinnitus, oscillatory brain activity Tinnitus is the perception of a sound (e.g., a ringing or hissing noise) without any external source. Tinnitus patients display an abnormal pattern of oscillatory brain activity as revealed by Magnetoencephalography (MEG), mainly reflected in the alpha (8-13 Hz) and delta (.5-4 Hz) frequency range in perisylvian regions: alpha power is reduced whereas delta power is enhanced compared to a healthy control group. Based on theses findings, an EEG-neurofeedback training was conducted aiming at a normalization of temporal alpha and delta power. Ten participants suffering from chronic tinnitus completed ten training sessions distributed across four weeks. Measurements of tinnitus loudness and tinnitus-related distress were taken. Tinnitus patients were able to normalize their EEG activity by means of neurofeedback demonstrating significantly higher alpha power and significantly lower delta power after the training, compared to before training. Furthermore, tinnitus loudness and tinnitus-related distress were significantly reduced after the training. Aside from being a promising avenue as a treatment for tinnitus, the neurofeedback work confirms that alpha and delta oscillations might play a functionally important role for the emergence and/or maintenance of the phantom sound.

EFFECTS OF REFRESHING MEMORY ON P300-BASED GKT ADMINISTERED ONE MONTH AFTER A MOCK-CRIME FOR REPEATED OFFENDERS

Yuki Hamamoto1, Shinji Hira2, & Isato Furumitsu3 1Nagoya University, 2Fukuyama University, 3University of East Asia

Descriptors: guilty knowledge test, P300, refreshing memory

The present study examined whether procedure of refreshing memory (RM) of a mock-crime scene prior to administration ofa standard P300-based guilty knowledge test (GKT) would enhance the test accuracy for repeated offenders whose memory of each specific crime might be vague. Participants were required to enact both of two mock-crimes. At the first mock-crime, the participants entered a room and stole a ring from one of five desk drawers. At the second mock-crime, they entered another room and stole a wallet from a bag. The ring was used as the critical item in the GKT that was administered approximately one month after the first mock-crime. Prior to the GKT, a RM group viewed a videotape that depicted the room in which they had committed the first mock crime, while the participants in a no-RM (NRM) group viewed a videotape of the same length that depicted scenes from other parts of the college. P300 amplitude was measured as an index of the GKT. The critical item elicited significantly larger P300 amplitudes than non-critical items only in the RM group but not in the NRM group. In addition, the correct detection rate of the P300 amplitude was higher in the RM group (94.4%) than in the NRM group (70.5 %). These results suggest that P300-based GKT became effective even in those who repeated crimes by procedure of RM. The RM procedure should be innovated in the P300-based GKT in the real forensic field. Applications of the GKT using P300 as an index into the real forensic field may then become more feasible.

Poster 69

TOP-DOWN EFFECTS ON THE REGULARITY REPRESENTATION REVEALED BY VISUAL MISMATCH NEGATIVITY

Motohiro Kimura1, Andreas Widmann2, & Erich Schroger2 1Nagoya University, 2University of Leipzig

Descriptors: regularity representation, top-down attention, visual mismatch negativity Regular patterns embedded in discrete visual events can be automatically represented in the memory at the level of the visual system. However, regular patterns that can be automatically represented are known to be considerably limited (e.g., "repetition of standard'' in the oddball sequence). In the present study, we tested top-down effects on regular patterns represented in the memory. We presented deviant (low-luminance) and standard (high-luminance) stimuli in a fixed manner at a 600-ms stimulus onset asynchrony (i.e., SSSSDSSSSD ... ) and tested the elicitation of visual mismatch negativity (vMMN) by deviant stimuli under three attention conditions: (1) ''Unattend condition'' where participants were instructed to ignore the luminance, (2) "Attend condition'' where instructed to detect luminance changes, and (3) ''Attend-Pattern condition'' where instructed to detect violations of the large-scale regular luminance pattern (SSSSD). Because vMMN is known to be elicited when the current input mismatches the memory representation, it was hypothesized that vMMN would not be elicited by deviant stimuli if the large-scale regular pattern (SSSSD) was represented in the memory. Results showed that vMMN was elicited in the Attend condition, but not in the Unattend and Attend-Pattern conditions. These results imply that the large-scale regular pattern was represented in the memory representation only in the Attend-Pattern condition. These results demonstrate top-down effects on the regular patterns represented in the memory at the level of the visual system.

Poster 70

AFFECTIVE PRIMING IN ERP: UNCONSCIOUS AND CONSCIOUS PROCESSING OF FACIAL EXPRESSIONS AND CULTURAL EFFECTS

Haruka Kondo1, Tsunetaka Okita2, & Hideki Ohira1 1Nagoya University, 2Aichi Shukutoku University

Descriptors: affective priming, face perception, cultural effect

Recent theories of emotion suggest that threat-related stimuli are quickly processed via automatically operating neural mechanisms, which work outside conscious awareness. These mechanisms allow fast evaluation of potentially harmful stimuli. Furthermore, recent studies showed that functions of such threat-related neural mechanisms are dependent on cultural factors. We examined such automatic neural processing of threat-related stimuli and its modulation by a cultural factor using ERPs in a backward masking paradigm. A facial expression of fear or happy (prime) was followed immediately by a neutral face mask (target). The prime was presented either subliminally or supraliminally for conscious detection. Additionally, the pair of faces (prime and target) was either in cultural in-group (Japanese) or in cultural out-group (Caucasian) for Japanese participants. ERP data revealed a double dissociation for the subliminal versus supraliminal perception of cultural in-group and out-group fearful faces. In the supraliminal condition, an N320 component that was elicited at midline sites showed a cultural effect. A P500 component in the parietal region was sensitive to affective valence of a prime. These effects were not observed in the subliminal condition. In conclusion,

these findings suggest that processing related to cultural groups offaces and processing related to facial expressions are distinctly conducted in a serial fashion.

Poster 71

NEURAL BASES OF BEHAVIOR SELECTION WITHOUT AN OBJECTIVE CORRECT ANSWER

Takashi Nakao1, Takahiro Osumi1, Hideki Ohira2, Yukinori Kasuya3, Jun Shinoda3, & Jitsuhiro Yamada3

1Japan Society for the Promotion of Science, Nagoya University, 2Nagoya University, 3Kizawa Memorial Hospital, Chubu Medical Center for Prolonged Traumatic Brain Dysfunction

Descriptors: anterior cingulate cortex, medial prefrontal cortex, behavior regulation Life choices (e.g. occupation choice) often include situations with two or more possible answers. How does the brain respond to such conflict-ridden situations? We investigated whether the dorsal anterior cingulate cortex (dACC) evaluates the degree of conflict between possible answers. Additionally, we investigated whether the medial prefrontal cortex (MPFC) or the medial temporal lobe (MTL) has a function in behavior selection with plural possible answers. We used an occupational choice task (e.g. Which occupation do you think you could do better? — dancer or chemist) with two possible answers and a word-length task (e.g. Which word is longer? — dentist or comedian) that has a correct answer. The conflicts in each task were manipulated. Results showed that the dACC and the MTL were activated when the conflict during occupational choice was large, and that the MPFC and posterior cingulate cortex were activated more in the occupational choice task than in the word-length task. Our results show that dACC evaluates the degree conflict between possible answers, and that the MTL, MPFC, and posterior cingulate cortex have a function in behavior selection without an objective correct answer. It is thought that the MTL has a function to reduce conflict when a large conflict is detected in dACC. Furthermore, the MPFC and posterior cingulate are thought to have a function of biasing any of plural answers in behavior selection without an objective answer.

Poster 72

PREFRONTAL CORTEX MODULATES PERIPHERAL IMMUNE FUNCTION ACCORDING TO CONTROLLABILITY OF ACUTE STRESS

Hideki Ohira1, Kenta Kimura2, Michio Nomura3, Tokiko Isowa4, Naho Ichikawa1, Masahiro Matsunaga5, Seisuke Fukuyama6, Jun Shinoda6, & Jitsuhiro Yamada6 1Nagoya University, 2The University of Tokyo, 3Hiroshima University, 4Mie University, 5Fujita Health University, 6Kizawa Memorial Hospital

Descriptors: prefrontal cortex, immunity, stress

The most rapid immune responses to acute stress are the redistribution of lymphocytes, an increase of natural killer (NK) cells, and a decrease of helper Tcells. Also, the redistribution of lymphocytes is attenuated when a stressor is uncontrollable. To explore neural bases of such phenomenon, we conducted simultaneous recording of brain activity using 15O-positron emission tomography (PET), as well as measurement of cardiovascular parameters and the numbers of subsets of lymphocytes during performance of a stochastic learning task during which controllability was manipulated. Specifically, we set a controllable condition where participants could obtain monetary rewards with a probability of 70% and an uncontrollable condition where participants could obtain rewards in a completely random way. Consistent with our previous studies, physiological responses, including redistribution of lymphocytes, were enhanced in the controllable condition and attenuated in the uncontrollable condition. The orbitofrontal and dorsolateral prefrontal cortices were more activated in the uncontrollable condition, probably reflecting more necessity for monitoring and evaluation of contingency between stimuli, actions, and outcomes. More importantly, correlation analyses indicated that in the situation of uncontrollable acute stress, activation in those prefrontal regions was correlated with redistribution of NK cells. This result represents evidence that the prefrontal cortex can modulate peripheral immune function on the basis of evaluation of controllability of acute stress.

Poster 73

THE STRUCTURE OF THE MINDFUL BRAIN

Hiroki Murakami1, Takashi Nakao1, Masahiro Matsunaga2, Yukinori Kasuya3, Jun Shinoda3, Jitsuhiro Yamada3, & Hideki Ohira1 1Nagoya University, 2Fujita Health University, 3Kizawa Memorial Hospital

Descriptors: voxel based morphology, mindfulness, insula

Mindfulness, which is the practice of bringing one's complete attention to the experiences occurring in the present moment in a nonjudgmental or accepting way, is called the third wave of behavioral cognitive therapy and has been confirmed to be effective in improving emotion regulation. In this study, we investigated the association of mindfulness tendency and regional gray matter volume in the human brain by optimized voxel-based morphometry. Describing/labeling with words, one of the five factors in the mindfulness questionnaire, is positively associated with the right insula and right parahippocampal gyrus. Nonjudging of experience is positively associated with the right parahippocampal gyrus. The insula, which is included in Damasio's somatic marker circuit, represents subjective

feelings from the body and feelings of emotion. The parahippocampal gyrus is known as negatively associated with anxiety. The present study suggested that the mindfulness attitude change brain structure and psychological state recursively.

Poster 74

AFFECTIVE RANGE VS. MEAN: A NOVEL METHOD FOR UNDERSTANDING ATYPICAL AFFECTIVE MODULATION OF STARTLE

C. Daniel Hornyik1, Jared P. Dempsey1, David E. Lovett1, Elizabeth D. Eldridge1, Ashley N. Junghans1, Ronni G. Grigsby1, Brooke N. Hill1, Charles I. Abramson1, & Lee M. Cohen2 1Oklahoma State University, 2Texas Tech University

Descriptors: affective modulation of startle, atypical startle modulation, self-assessment manikin

In Affective Modulation of the Startle Reflex (AMSR), the common method of assessing differences in affective reactions involves comparing averaged EMG startle values across valence categories: pleasant to neutral and unpleasant to neutral pictures. The current investigation assessed the utility of analyzing these variables in a more linear fashion. Affective ranges were created: neutral scores were subtracted from unpleasant scores (Negative Affective Range - NAR), and neutral scores were subtracted from pleasant scores (Positive Affective Range - PAR). These new variables allow for easy identification of atypical affective modulation in both the positive and negative direction. The NAR and the PAR variables were used to split participants into 4 groups with typical vs. atypical response patterns. These groups were then compared on their subjective ratings of affect and arousal of the same images used in gauging AMSR. Participants with both atypical NAR and PAR showed blunted subjective experience for both positive and negative images, in comparison to the other 3 groups. Specifically, pleasant images were rated much less positively F(3, 39) 5 3.551, p 5 .024, and more dull, F(3, 39) 5 2.512, p 5 .073 (trend). Aversive images were also rated less negatively and dull; however these differences did not reach significance. The current poster will detail the methodologies used to calculate the ''affective range'' categories, as well as the results of their relationship to several other psychological and physiological variables.

Poster 75

THE INDEPENDENT CONTRIBUTION OF ANXIETY IN NICOTINE WITHDRAWAL-INDUCED CARDIAC DECELERATION

Ashley N. Junghans1, Jared P. Dempsey1, Kasey R. Claborn1, Sasha D. Jaquez1, David E. Lovett1, William Lechner1, & Lee M. Cohen2 1Oklahoma State University, 2Texas Tech University

Descriptors: nicotine withdrawal, heart rate, anxiety

The robust psychophysiological responses to nicotine withdrawal are well known, including increased anxiety and deceleration of heart rate, hypothesized to be a homeostatic response to withdrawal. The current exploratory study was conducted to better understand the changes in HR and anxiety across three levels of nicotine withdrawal - Ad lib smoking, Brief Abstinence (3.5 h) and Extended Abstinence (18 h). While several studies have examined this relationship previously, none have assessed the trajectory of change across multiple points within abstinence period. Participants remained in the laboratory for 4h, with assessments conducted every half-hour. Anxiety was assessed using the Profile of Mood States (POMS). Participants were grouped based on POMS, into those who increased in anxiety (IA), and those who stayed the same or decreased in anxiety (DA), for each abstinence segment. For Extended Abstinence, no significant change was found for the IA group, while the DA group showed an expected decrease in HR across time, F(1, 16) 5 3.06, p < .05. For Brief Abstinence, the expected deceleration in HR was seen for both the IA and DA groups, F(1, 15) 5 13.30, p < .001, F(1, 10) 5 5.72, p < .05, respectively. For ad lib, the DA group did not show a significant change in HR. However, the IA group showed a significant HR deceleration, similar to a deprived state, while still smoking ad lib, F(1, 11) 5 13.40, p < .01. Poster details the independent variance contributed by anxiety and the decrease of HR associated with nicotine withdrawal.

Poster 76

COTININE AS A POTENTIAL PREDICTOR OF INCREASED ANXIETY DURING NICOTINE WITHDRAWAL

Kasey R. Claborn1, Jared P. Dempsey1, Sasha D. Jaquez1, Ashley N. Junghans1,

Brooke Hill1, William Lechner1, Lee Cohen2, & Mustafa al'Absi3 1Oklahoma State University, 2Texas Tech University, 3University of Minnesota Medical School

Descriptors: cotinine, anxiety, nicotine withdrawal

Cotinine is a metabolite ofnicotine that is reliably associated with changes in tobacco use. Little is known about the relationship between cotinine and anxiety, with limited information suggesting that cotinine may enhance nicotine's anxiolytic properties during withdrawal. Anxiety in response to withdrawal is well researched. However, no studies could be identified which utilized biomarkers of tobacco reduction (or lack thereof) for potentially identifying differential anxiety-withdrawal reactivity. The present investigation

used the biological marker ofsalivary cotinine as an indicator ofability to reduce smoking among 30 nicotine dependent smokers with no desire to quit smoking who participated in several levels of abstinence sessions. During the extended abstinence session (18 hrs), those showing a 50% or greater reduction in cotinine from a typical smoking day differed from those showing less than 50% reduction. During the 4-hour laboratory stay, ending the 3.5 hour abstinence period, those with > 50% cotinine change did not increase in level of anxiety over the 5 assessment points of the study, F(1, 11) 5 1.91, p > .05). Results suggest that those nicotine dependent individuals able to abstain from tobacco for an extended period will likely differ in psychological reaction to the state of withdrawal.

Poster 77

SOCIAL DEVIANCE AND STARTLE MODULATION: DIFFERENT RESULTS FOR DIFFERENT MEASURES OF PSYCHOPATHY

Elizabeth D. Eldridge1, Jared P. Dempsey1, Sara T. Hughes1, David E. Lovett1, C. Daniel Hornyik1, & Lee M. Cohen2 1Oklahoma State University, 2Texas Tech University

Descriptors: affective modulation of the startle response, psychopathy, California psychological inventory

In affective modulation of the startle reflex (AMSR), psychopathic traits are associated with decreased startle potentiation when viewing aversive images. While AMSR methodology has stayed fairly consistent across these studies, there are numerous measures available to assess psychopathy, the most common being the Psychopathic Checklist Revised and the Psychopathic Personality Inventory. It is currently unknown whether various measures of psychopathy differentially influence this AMSR-Psychopathy connection. The current investigation was conducted to explore the relationship between the California Psychological Inventory - Socialization Scale (CPI-So) and the AMSR-Psychopathy link. The CPI-So is a less frequently utilized, yet validated measure of psychopathy. It was hypothesized that greater levels of psychopathy (assessed via CPI-So) would be correlated with lower levels of potentiated startle, while viewing aversive images. Surprisingly, results showed a significant relationship in the opposite direction, with the higher scores of psychopathy (lower CPI-So) being associated with greater potentiation, r (43) 5 — .35, p < .05. Further, those over cut-off for psychopathic traits had significantly higher levels of startle potentiation, F(1, 33) 5 5.62, p < .05. Given that previous studies have found the psychopathy-AMSR relationship among both clinical and non-clinical populations, it does not appear that the present findings are due to the non-clinical sample utilized. Rather, it seems more likely that the findings are associated with the specific measure, CPI-So.

Poster 78

ATYPICAL AFFECTIVE MODULATION OF STARTLE AND SYMPTOMS OF DEPRESSION

David E. Lovett, Jared P. Dempsey, Ashley N. Junghans, C. Daniel Hornyik, Elizabeth D. Eldridge, Jason M. Kaplan, & Lee M. Cohen Oklahoma State University

Descriptors: affective modulation of startle reflex, depression, atypical startle modulation While researchmethodology has varied, it has been well established that depression symptoms are associated with atypical Affective Modulation of the Startle Reflex (AMSR). The level of depression seems to be influential, with severity impacting aversive-image augmentation, pleasant-image inhibition, or both. While replication of methodology will help disentangle these differences, the presentstudy sought to examine this relationship from a different angle. A small, yet consistent number of participants in the vast majority ofAMSR studies show atypical AMSR. The present study investigated this depression-AMSR relationship by grouping those with typical vs. atypical affective modulation, rather than by depression level. Results indicated that those with atypical aversive-picture modulation reported more symptoms of depression, in comparison to those with the expected pattern of aversive-picture modulation, F(1,39) 5 9.05, p < .01). Those with atypical pleasant-picture modulation showed higher levels of depression, albeit at trend level F(1,39) 5 3.1, p < .09). Further, aversive-image modulation had a moderate correlation with symptoms of depression, R(41) 5 .40, p < .01. Results suggest that sub-clinical levels of depression and aversive-image response may be more tightly connected than pleasant-image response. This presentation will discuss the potential need for covariance of even sub-clinical depression scores in AMSR, as well as steps towards using AMSR to track pharmacological treatment effectiveness in depression.

Poster 79

BLUE LED PREPULSE INHIBIT MORE IN PPI OF HUMAN STARTLE EYE BLINK REFLEX

Fumio Yamada, & Shin'ichi Nakano Osaka University of Human Sciences

Descriptors: PPI, LED

Purpose: Startle response is inhibited by weak prepulse, either auditory or visual, presented 100-ms before the onset of startle eliciting loud noise. This phenomenon is

called PPI. The purpose of this experiment was to compare the effect of color of visual stlimuli on PPI. Procedure: Subjects were 12 students (6 males, 6 females). Stimulus conditions: Prepulse was an onset of LED (Light Emitting Diode) with 50-ms duration. Intensity of the startle noise was set at 110 dB(A), duration 50-ms, and rise/fall time less than 1-ms. Noise was presented via headphones. Subjects received 25 trials with 5 blocks of 5 trials including four prepulse-noise pair conditions (SOAs 50-, 100-, 150-, and 500-ms), and noise alone control condition. The order of presentation was modeled after the 5 by 5 Latin Square. ITIs were randomly varied from 25 to 35-s with mean of 30-s. Subjects received two sessions, one using red LED and the other using blue LED. Six subjects initially received red condition and another 6 subjects blue. Startle response was assessed by EMG recordings of the M. orbicularis oculi. An independent measure of reflex magnitude was defined as an integrated value from 20-to 120-ms time windows after noise onset. Result and discussion: Results showed that mean magnitude of blink reflexes were inhibited under SOAs of 100-, 150-, and 500-ms conditions in both color conditions, however the inhibition was more intense in the blue than in the red condition at 500-ms SOA condition. These results suggest that blue LED-prepulse has more attentional effects on stimulus sensation than red LED-prepulse.

Poster 80

ATTENTIONAL STARTLE MODULATION: IT TAKES MORE THAN PAIRS OF TWO DIGITS

Sakinah S.J. Alhadad, & Ottmar V. Lipp University of Queensland

Descriptors: attention, startle eyeblink reflex

Attentional startle modulation is modality specific in continuous performance tasks (CPT) and modality nonspecific in trial-structured tasks. The first study assessed whether the interstimulus interval (ISI) between cue and target affects the nature of attentional startle modulation. Participants responded by pressing a button to a 7 when preceded by a 3. In one task block, the ISI was 5,000 ms, resembling a differential reaction time (DRT) paradigm, whereas in the second it was 1,650 ms designed to resemble a CPT. A trend towards modality specificity emerged in the CPT-variant and a trend towards modality nonspecificity in the DRT-variant. In a follow-up study, participants were explicitly informed of the predictive relationship in the task. This abolished the apparent trends, suggesting that the different ISIs employed in previous studies were unlikely to determine the nature of attentional startle modulation. Moreover, it suggests that a 2-digit sequence is insufficient to support attentional startle modulation. The second study assessed this. One group was presented with 3-7 digit pairs embedded in a 6-digit stream. A second group, matched on time on task, was presented with discrete 2-digit pairs. As before, modality specific attentional startle modulation was found in the first group. No evidence of attentional startle modulation emerged in the 2-digit task. This suggests that a digit sequence consisting of more than the target pair may be necessary for attention to modulate the startle eyeblink reflex.

Poster 81

CARDIOVASCULAR PATTERNS ASSOCIATED WITH APPETITIVE AND DEFENSIVE ACTIVATION DURING AFFECTIVE PICTURE

VIEWING

Patrick Gomez, & Brigitta Danuser Institute for Work and Health

Descriptors: cardiovascular patterns, emotion, affective pictures

In this study we assessed blood pressure (BP), heart rate (HR), stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR) in response to 13 picture series in 18 men and 19 women in order to investigate their hemodynamic responses associated with activation of the appetitive and defensive motivational systems underlying emotional experience. Skin conductance level (SCL) was also recorded. BP and SV increased with increasing self-rated arousal both for appetitive and defensive activation, whereas HR decelerated more in response to negative than positive and neutral pictures. TPR showed a general increase from baseline to picture processing but was unrelated to self-rated valence and arousal. These findings suggest that affective modulation of the cardiovascular response to affective pictures is primarily myo-cardial. The observed response pattern is consistent with a configuration of cardiac sympathetic-parasympathetic coactivation. The relationships between self-reported arousal, BP and SV were mainly exhibited by men suggesting that increases in the sympathetic inotropic effect to the heart with increasing self-rated arousal might be larger in men than in women. In contrast, SCL covaried positively with self-rated arousal both in men and women. This suggests that sex differences in the affective modulation of the responses to pictures may be restricted to specific cardiovascular parameters and support the contention that the sympathetic nervous system does not discharge as a whole.

MUSIC PERFORMANCE ANXIETY (MPA): CARDIORESPIRATORY ACTIVITY IN HIGH- AND LOW-ANXIOUS PROFESSIONAL MUSIC STUDENTS BEFORE A PERFORMANCE SITUATION

Regina Studer1, Danuser Brigitta1, Horst Hildebrandt2, Marc Arial1, & Patrick Gomez1 1Institute for Work and Health, 2Swiss University Centre for Music Physiology

Descriptors: music performance anxiety, respiration, hyperventilation Surveys indicate that high-anxious musicians may suffer from hyperventilation (HV) before or during performance. Reported symptoms include shortness of breath, fast/ deep breathing and thumping heart. However, no study has yet tested if these self-reported symptoms reflect actual cardiorespiratory activity. The main goal of this study was to determine if MPA is manifested physiologically in specific correlates of cardio-respiratory activity associated with HV. We studied 74 professional music students from Swiss Music Academies. In this study, we compared the most anxious students (high-anxious; n 5 20) with the least anxious students (low-anxious; n 5 23) based on their self-reported performance anxiety. We measured cardiorespiratory patterns with the Lifeshirt system, end-tidal CO2 with a capnograph (EtCO2, a good non-invasive estimator of HV), self-perceived physiological activation and affective experience in three situations on different days: baseline, performance without audience, and performance with audience. Comparing measures for the private vs. the public concert, high- compared to low-anxious students showed a significant drop in EtCO2 before the public concert and reported larger increases in anxiety, tension, palpitations and breathing difficulties. In contrast, heart rate, respiratory rate and volume did not differ significantly between groups. The results of this study support the hypothesis that MPA may be associated with a tendency to hyperventilate and, thus, point to a potential hyperventilation problem in high-anxious music students.

Poster 83

EFFECT OF INTENSITY IN CHOICE REACTION TIME TASKS: AN EEG STUDY

Izabela Szumska, Edyta Sasin, & Piotr Jaskowski University of Finance and Management

Descriptors: intensity, lateralized readiness potentials, processing stages Long reaction times (RT) paradoxically occur with extremely loud auditory stimuli (Van der Molen and Keuss, 1979, 1981), or with ultra bright and large visual stimuli (Jarekowski & W3odarczyk, 2006) when the task requires a response choice. Van der Molen and Keuss (1981) hypothesized that this effect of intensity results from an arousal-driven elongation of response-selection processes. We tested this hypothesis using visual stimuli and chronopsychophysiological markers. The results showed that latency of both early (P1 recorded at Oz) and late (P300) evoked potentials decreased monotonously with intensity. In contrast, the latency of stimulus-locked lateralized readiness potentials (LRP) abruptly increased for the most intense stimuli, thus mirroring the reaction time-intensity relationship. Response-locked LRPs revealed no dependence on intensity. These findings suggest that the processes responsible for the van der Molen-Keuss effect influence processing stages that are completed before the LRP's onset. Hence, the van der Molen-Keuss effect likely occurs later than those represented by early sensory potentials. This is in keeping with van der Molen-Keuss' hypothesis.

Poster 84

CROWDED TARGETS DO NOT CAPTURE ATTENTION: AN EEG STUDY

Marcin Ciesielski, & Piotr Jaskowski University of Finance and Management

Descriptors: crowding, visuo-spatial attention, lateralized parietal potential Crowding has been shown to be a very efficient method of masking. There is also evidence that masked information is processed in the visual cortex (V1 and V5). One hypothesis (attentional resolution) assumes that crowding constrains resolution of attention (i.e. the minimum spacing at which observers can select individual items). We tested this hypothesis by studying the lateralized parietal potential (LPP). Two letters (the main stimulus) were displayed on the right or left of a fixation point. Participants' task was to indicate as quickly as possible whether the letter S was displayed. The main stimulus was preceded by a pair of'curvilinear' letters (S, C, B) displayed for 32 ms, each of them surrounded by four 'straight-line' letters (e.g. X, T, A), presented simultaneously on the left and right of fixation. 75% of the trials (go trials) were compatible (S-letters on the same side in both stimuli) or incompatible (S-letters on different sides). In the remaining 25% of the trials (no-go trials) no target letter was shown, and participants were not supposed to provide an answer. In go trials, LPP was observed in the post-prime time window of 310-430 ms. This potential was identical in the compatible and incompatible trials. No LPP was found in no-go trials. Assuming that LPP represents attentional shift to a relevant stimulus, a conclusion can be drawn that stimuli masked by crowding do not attract participants' attention. This finding corroborates the attentional resolution hypothesis.

ATTENTION NETWORKS IN THE LEFT AND RIGHT HEMISPHERES: A SPATIO-TEMPORAL EEG STUDY

Edyta Sasin, Izabela Szumska, & Piotr Jaskowski University of Finance and Management

Descriptors: attention, hemispheric specialization, LORETA

Attention can be conceptualized as a system of three specialized neuronal networks associated with alerting, orienting and executive control. However, evidence is scant about hemispheric specialization for these networks. To clarify hemispheric contributions to these processes, we performed an experiment in which visual targets were displayed in the left or right visual hemifield. Participants had to identify the direction of an upward or downward pointing arrow which was flanked by 4 arrows (2 below and 2 above the target arrow). Flanking arrows pointed either in the same direction (congruent trials) as the target or in the opposite direction (incongruent trials). Targets were preceded by either a centrally presented cue or a cue presented at target location (valid cue). EEG was analyzed using low resolution tomography (LORETA). Hemispheric differences in the processing of stimuli presented in the left and right hemifields were found for both executive control and orienting in the superior frontal gyrus (SFG). In the case of executive control, the left SFG activation was independent of hemifield and congruency, while the right SFG was more active 590 - 690 ms post-stimulus in congruent trials when the left visual hemifield was stimulated. The opposite pattern was observed in incongruent trials. With orienting, larger activity was found for central than for valid cues in the right SFG whereas the activity of left SFG was irrespective of cue location. These findings indicate that LORETA is well suited for investigating attent-ional networks in the left and right hemispheres.

Poster 86

ATTENTIONAL FACTORS IN CROSSED-UNCROSSED DIFFERENCE: AN EEG STUDY

Tadeusz Kononowicz1, Piotr Wolski2, & Piotr Jaskowski1 1University of Finance and Management, 2Jagiellonian University

Descriptors: crossed-uncrossed difference, interhemispheric transfer, attention Crossed-uncrossed difference (CUD) is widely believed to reflect the time of interhemi-spheric transfer (IH). However, Weber et al. (2005) showed that attention significantly modulates CUD. In our study, we wanted to shed some light on this influence using evoked related potentials. We manipulated attention by varying the proportion of crossed and uncrossed trials (75/25 or 25/75). CUD was calculated from the P1 latencies for several homotopic electrode sites. Larger CUDs were obtained for O1/O2, P3/P4, CP1/CP2, C3/ C4 than for FC1/FC2 and F3/F4. No effect of attention was found for O1/O2. Leftward attentional bias (AB; 75% trials on the left side) increased CUD for C3/C4 and F3/F4. Rightward AB (75% trials on the right side) reduced CUD estimate of IH from left to right hemisphere and leftward attentional bias reduced the CUD estimate of IH from the left to the right hemisphere for C1/C2 and FC1/FC2. For P3/P4, right AB shortened the left-to-right CUD estimate of IH but did not affect the right-to-left CUD. Different CUDs for different electrode pairs suggest the existence of different callosal circuitries: A faster anterior and a slower posterior channel. While AB did not affect CUD calculated from the occipital sites, leftward AB increased CUD for all electrode pairs except the parietal ones for which an increased CUD was noted with rightward AB. Therefore, our results suggest that attention can modulate interhemispheric transfer and, moreover, this modulation seems to be different for different callosal channels.

Poster 87

SPATIAL-NUMERICAL ASSOCIATION INTERFERES WITH ORIENTING AND EXECUTIVE ATTENTIONAL PROCESSING

Malgorzata Gut, Marzena Wasilewska, Izabela Szumska, & Piotr Jaskowski University of Finance and Management

Descriptors: attention, spatial-numerical association, mental number line Brain representations of numbers are spatially organized according to the so-called mental number line (MNL). We investigated the relationship between attentional processes and this spatial-numerical association. In Task 1 participants indicated the position (left/right) of an earlier displayed digit within a centrally presented four-digit number. The position of digit was either congruent with its localization on the MNL (e.g. 8 on the right) or in-congruent (e.g. 9 on the left). In Task 2 subjects were asked to assess the parity of the central digit within five-digit numbers (right key 5 even; left key 5 odd). The condition was referred to as congruent when the reaction side corresponded to the digit position on the MNL, and as incongruent when there was no such correspondence. In both tasks results showed more accurate and faster reactions in the congruent than in the incongruent conditions. This finding confirms the interaction between orienting attention shifting and digit representations. Moreover, the incongruence between the correct response (left/right) and the digit location on MNL induced a conflict which proves that also executive attention can be evoked by digits. LORETA results showed greater activation in the incongruent than in the congruent trials: (1) in parietal cortex 400 ms post-stimulus in the orienting attention task, as well as (2) in parietal and cingulate areas 500 ms post-stimulus in the executive

attention task. These activation patterns in conjunction with behavioral results confirm functional relationship between attention and numbers processing

Poster 88

CRAVING AND AFFECTIVE EVALUATION OF TOBACCO STIMULI WITH VIRTUAL ENVIRONMENTS: STARTLE BLINKING MODULATION IN SMOKERS ON PROCESS OF CHANGE

Miguel A. Muñoz1,2, Sofía Mohamed2, Ignacio Cifre1,3, María I. Viedma-del-Jesus2, Carolina Sitges1, Pedro Montoya1, & Jaime Vila2 1University of Islas Baleares, 2University of Granada, 3University of Barcelona

Descriptors: startle reflex, virtual environment, smoking addiction The paper reports the results of a study on emotional modulation of the startle reflex in female smokers with a double objective: (a) to test the effectiveness of virtual environments versus traditional image presentation to induce affective states and (b) to examine how motivation to quit smoking is a relevant factor in the affective evaluation of tobacco stimuli, independent of craving. Participants were 32 university students who smoked more than 10 cigarettes daily. They underwent a psychophysiological test to assess the modulation of the startle reflex and completed several scales and questionnaires to measure craving, motivation to quit smoking, and subjective reactivity to the stimuli. Results show no differences between virtual environments and traditional images. However, motivated smokers showed greater blink magnitude to tobacco cues compared with non-motivated smokers. These results indicate that virtual environments are effective in inducing emotional states and craving and that motivation to quit smoking affects the subjective assessment of the stimuli and the modulation of the startle reflex.

Poster 89

SOMATOSENSORY ACTIVITY MODULATION DURING OBSERVATION OF OTHERS' PAIN

Mercedes Martínez Jauand, Ana Maria Gonzalez Roldan, Ignacio Cifre, Carolina Sitges Quiros, Miguel Angel García Muñoz, & Pedro Jose Montoya Jimenez University of Balearic Islands

Descriptors: EEG, emotions, empathy

Previous studies have demonstrated that observation of others' pain can modulate the affective and sensory components of the pain network. In the present study, we examined whether brain activity elicited by tactile stimulation could be also modulated by the observation of pain and touch delivered to a model's hand. Twenty healthy female volunteers (aged 19-23 years) participated in the study. Somatosensory-evoked potentials elicited by non-painful pneumatic stimulation of the right hand were recorded when subjects were viewing video clips depicting either a static right hand, a needle penetrating the dorsum of the right hand (painful stimulation), or a Q-tip touching the dorsum of the right hand (non-painful stimulation). Subjects were asked to evaluate both pain intensity and unpleasantness supposedly felt by the model. Results indicated that observation of video clips depicting painful stimulation enhanced P50 amplitudes at electrodes located over the hemisphere contralateral to the stimulation site (C3, CP3, P3, P5) as compared to viewing either a static hand or non-painful stimulation. Our data are consistent with previous results suggesting that neural substrates for empathic experiences also involve early sensory components of the pain network. Moreover, these findings suggest that observation of others' pain might modulate the processing of somatosensory information independently of the kind ofsomatosensory stimulation (electrical or pneumatic) used to examine brain activity.

Poster 90

ERPS ELICITED BY PAIN AND ANGER FACES WITH DIFFERENT INTENSITIES OF EMOTIONAL EXPRESSION

Ana Maria Gonzalez Roldan, Mercedes Martinez Jauand, Miguel Angel Muñoz García, Carolina Sitges Quiros, Ignacio Cifre, & Pedro Montoya Jimenez University of Balearic Islands

Descriptors: facial expression, EEG, pain

Previous studies have shown differences in brain activity between facial expressions of negative and positive emotions. There is, however, no information about how brain activity is modulated by the observation of faces with different levels of emotional expression. A forced-choice affective judgment task was used to investigate brain activity elicited by pain and anger faces with three intensity levels of emotional expression (high, medium, low). Stimuli were obtained from 1-second video clips depicting actors expressing from neutral to the peak expression of pain and anger. Single frames were grabbed from video clips at following times: 0, 200, 400, 600, 800 and 1000 ms. Participants were asked to rate the valence and arousal for each facial expression. ERPs elicited by faces were recorded using 64 electrodes in 20 females. A significant effect of expression intensity was found on valence and arousal ratings for both pain and anger, indicating that faces with high and medium intensities were judged as more unpleasant and arousing than faces with low levels of expression intensity. In addition, a N230 component was observed in frontal regions, which was differentially modulated by emotional faces and intensity level of the facial expression. ERP analyses showed that pain faces elicited greater amplitudes for low levels

of expression intensity than for high levels; whereas angry faces elicited greater amplitudes for high levels as compared to low. These findings indicate that brain activity elicited by affective faces is also modulated by the intensity of the facial expression.

Poster 91

SLEEP ONSET AND CARDIOVASCULAR MODIFICATIONS IN INSOMNIA

Naima Covassin, Massimiliano de Zambotti, Giuliano de Min Tona, & Luciano Stegagno University of Padova

Descriptors: insomnia, sleep onset, cardiovascular

The transition from wakefulness to sleep is typically characterized by a shift from sympathetic to parasympathetic prevalence. Previous investigations have shown cardiovascular and electroencephalographic hyperactivity before and during sleep in insomniacs compared to normal sleepers. Few studies have investigated cardiovascular activity during sleep onset in primary insomnia. The purpose of this study was to compare cardiac response during 3 minutes before and after falling asleep in 10 insomniacs who met DSM-IV criteria for primary insomnia and 10 normal sleepers. Measures of heart rate (HR), stroke volume (SV), cardiac output (CO), pre-ejection period (PEP) and left ventricular ejection time (LVET) were collected using impedance cardiography during a night of polysomno-graphic recording. Significantly decrement of HR, CO and increase of SVand LVET was found in both groups after sleep onset compared to wakefulness. Differently, PEP showed an increase after sleep onset in controls while it remained unchanged in insomniacs. Moreover, PEP was significantly lower in insomniacs than normal sleepers in both conditions. Physiological data are also consistent with longer sleep onset time and higher scores at the Pre Sleep Arousal Scale found in insomniacs. Results suggest that in sleep onset, normal sleepers followed the expected progressive autonomic drop, whereas insomniacs demonstrated a constant sympathetic hyperactivation. These findings support the hypothesis that physiological hyperarousal can be involved in falling asleep.

Poster 92

CARDIAC ACTIVATION AND ATTENTIONAL PERFORMANCES IN INSOMNIACS AND NORMAL SLEEPERS

Giuliano De Min Tona, Massimiliano de Zambotti, Naima Covassin, Sandro Bettella, & Luciano Stegagno University of Padova

Descriptors: insomnia, cardiac, attention

Several investigations have shown cardiovascular and electroencephalographic hyperactivity before and during sleep in insomniacs compared to normal sleepers. In contrast, little evidence of cognitive impairment in primary insomnia has been found. This study evaluated cardiac activation during a cognitive task measuring heart rate (HR), high and low frequency bands of heart rate variability (HRV), stroke volume (SV), cardiac output (CO) and pre-ejection period (PEP). Participants were twenty university students, 10 normal sleepers and 10 meeting DSM-IV criteria for primary insomnia. Cardiovascular parameters were measured by impedance cardiography during a task that involves alerting, orienting, and executive control (Attentional Network Test). Two sessions were run, before and after a night of polysomnographic recording. The results on the main cardiac parameters recorded during the baseline before the cognitive task suggest a generalized hyperactivation in the evening for the insomniacs. Also, a significant increase in cardiovascular activation was found in insomniacs in the morning. No differences between groups were found in task performance in both sessions. These findings suggest that global hyperactivation in insomniacs before sleep allows obtaining an attentional performance comparable to normal sleepers. Differently, insomniacs need a greater cardiac mobilization than controls to perform the task in the morning.

Poster 93

ASSOCIATIONS BETWEEN EEG AND FMRI MEASURES DURING INSTRUCTED EMOTION REGULATION

Elisabeth L. Kallenberger, Philip C. Burton, Dongju Seo, Christopher J. Patrick, & Edward M. Bernat University of Minnesota

Descriptors: emotion regulation, EEG, fmri

The neurophysiological correlates of emotion regulation have been investigated in studies using either ERP and fMRI measures, but few have investigated the relationship between ERP and fMRI measures from the same subjects during emotion regulation tasks. The current study evaluated ERP and fMRI data from separate sessions using an emotion regulation paradigm in which participants were instructed to down-regulate emotion using a reappraisal strategy (cf. Jackson et al., 2000). Previous ERP research has found a higheramplitude Late Positive Potential (LPP; indexed from 400 ms to 700 ms post-stimulus onset) during the down-regulation of emotion, compared with a viewing condition (Bernat et al., 2009). In the same study, startle-locked P300 was increased during the down-regulation of emotion, suggesting that these efforts were associated with a down-modulation of attention towards the stimulus. The current study replicated these LPP and startle P300 results during the regulation of positive emotion. Previous fMRI research has indicated that the Prefrontal

cortex and the Anterior Cingulate Cortex are recruited in the regulation ofemotion (Ochsner et. al., 2004), effects which replicated with the fMRI data in the current study. Results of the combined EEG/fMRI analysis indicated that the observed differences in the LPP as well as the startle-locked P300 correlated with fMRI regulation differences in the prefrontal cortex. These results suggest that multimodal studies utilizing EEG and fMRI measures provide both unique and interrelated information about processes involved in emotion regulation.

Poster 94

THE FUNCTIONAL LOCUS OF THE SNARC EFFECT: AN ERP INVESTIGATION

Ian G. Mackenzie1, Hanna Fechner2, & Hartmut Leuthold1 1University of Glasgow, 2Humboldt University, Berlin

Descriptors: erps, SNARC

The Spatial Numerical Association ofResponse Codes (SNARC) effect refers to the finding of faster parity judgments (odd vs. even) with the left hand to small numbers and the right hand to large numbers, even though number magnitude is irrelevant. As the processing architecture underlying the SNARC effect (single-route versus dual-route models) and its locus within information processing are still debated, the main aim of the present study was to inform this debate using event-related brain potentials (ERPs). EEG was measured while participants performed parity judgments to centrally presented numbers in different response modality conditions (left vs. right hand, simultaneous hands vs. feet). P300 peak latency and the onset and amplitude ofthe lateralized readiness potential (LRP) in stimulus-locked (S-LRP) and response-locked (LRP-R) waveforms were analyzed. For unilateral hand responses, we replicated the standard SNARC effect in RT, whereas chronometric ERP measures indicated a SNARC effect only in the S-LRP onset. Also, there was no evidence of initial incorrect activation in both S-LRP and LRP-R waveforms for incompatible SNARC trials. Simultaneous hand (foot) responses were faster (slower) to small numbers than hand (foot) responses to large numbers, while the proportion of first left vs. right responses was not influenced by number size, both results disagreeing with the traditionally assumed left-right mental number line. In conclusion, our findings strongly support a single-route model of the SNARC effect with its locus at the response selection stage.

Poster 95

INTERHEMISPHERIC EEG ASYMMETRIES OF ERP OLD/NEW EFFECTS IN VISUAL PERCEPTION OF SIMPLE NONVERBAL STIMULI

Alexander Ya Kaplan, Ekaterina V. Levichkina, & Alexander Yu Zhigalov Moscow State University

Descriptors: perception, ERP, priming

The meanings of affective words normally modulate cerebral functional asymmetry (Thierry et al., 2008 and others). This study investigated the asymmetry effect of nonsemantic context on the perception of simple nonverbal visual stimuli in 10 healthy volunteers by the evoked potential (EP) method. The nonsemantic context was specified by the formation of a memory trace of a test visual stimulus via its repeated presentation without any instruction. This stimulus randomly alternated with control stimuli that did not form memory traces before their presentation. Results indicated significant differences (p < .05) within the 260 - 340 ms in the EP amplitudes in response to test stimuli and other types of stimuli. In this interval, the test-induced EPs with preliminarily formed memory traces were more negative than the EPs caused by repeated stimuli and more positive than the EPs in response to control stimuli. The control stimuli did not differ from one another. This old/ new effect was distributed predominantly in the right hemisphere and has a focus in the right centroparietal area, which is in agreement with the data on lateralization of the old/ new effect in the case of the presentation of word stimuli and object image stimuli. Thus, in the absence of a subject's attention to any characteristic of a stimulus that has no semantic and verbal attributes, its multiple repetition results in the formation of a nonsemantic context, which can be seen as the differences in the EPs induced by stimuli that are relevant and irrelevant to the context formed.

Poster 96

CONFLICT SIGNALS IN THE EXPLICIT WORD STEM COMPLETION TASK

Lars Kuchinke, Markus Hofmann, Benny Briesemeister, Nik Krumm, & Arthur M. Jacobs Free University of Berlin

Descriptors: word stem completion, cognitive conflict, ERP

The word-stem completions task is characterized as a situation of underdetermined responding: Word stems associated with several completions do not uniquely specify the appropriate response, and should lead to greater cognitive conflict. We tested this central assumption of the conflict monitoring theory (CMT; Botvinick et al., 2001) in an event-related potentials (ERP) study wherein conflict is expected to lead to an enhanced N2 component. Subjects learned word stems with one completion and word stems with three completions. In a test phase, all word stems were presented again and subjects were ask to

name a learned completion. ERPs (29 channels) were recorded during the test phase and the first 500 ms post stimulus onset were analyzed. Word stems with three completions elicited increased naming latencies and a higher frontal P200 compared with word stems associated with one possible completion. Thus, the behavioral data support the assumptions of the CMT, whereas the P200 finding does not. Thus, the condition that was expected to be associated with greater conflict did not reveal a more negative going deflection in the ERP during the first 500 ms. Because a higher P200 is discussed to indicate higher activation in the mental lexicon, we think these results are best explained with higher lexico-semantic conflict in the mental lexicon in the three completions condition.

Poster 97

ASSESSING THE IMPACT OF STIMULUS SIMILARITY ON THE P300 DURING A CARD-PLAYING DECEPTION DETECTION TASK

Yannick Marchand1, Pauline C. Inglis2, & Celeste D. Lefebvre3 institute for Biodiagnostics (Atlantic), 2Dalhousie University, 3IWK Health Centre

Descriptors: P300, lie detection, malingering

The use of event-related potentials (ERPs) has been investigated in both forensic and clinical contexts as a tool for the detection of guilty knowledge or malingering. Study designs generally involve presenting probes (e.g. crime-related information) embedded within a series of irrelevant items. However, the impact of the irrelevant items has been given little attention. Thus, the present study investigated the impact of stimulus overlap of the irrelevant items with the probe. Twenty participants completed a computerized card-playing task with 156 trials. For each trial, participants were shown a ''match'' card followed by the sequential presentation of six "test" cards, one of which was the same as the match card (i.e. the probe). Participants were asked to either identify the probe when it appeared (truth condition) or to deny recognition of the probe (lie condition). The test cards varied in terms of shared features (e.g., suit and/or face value) with the probe. An accurate identification of the probe for each participant was determined if the P300 amplitude elicited to the probe was larger compared to the irrelevant test card that evoked the largest P300 response. Recognition of the probe card was found in 95% of participants in the truthful condition and in 80% of participants in the lie condition. In addition, the P300 elicited to the test cards was found to be modulated by stimulus similarity, whereby the majority of participants showed a statistically significant pattern of increased P300 amplitude as the overlapping features with the probe card increased.

Poster 98

ERP P3 AMPLITUDE CHANGE OVER TRIALS DURING THE PERFORMANCE OF A WORKING MEMORY N-BACK TASK IN OLDER AND YOUNGER ADULTS

David W. Shucard, Trevor L. Chichelli, Wing H. Lee, Tom J. Covey, Jeff T. Lee, & Janet L. Shucard University at Buffalo

Descriptors: working memory, habituation, age

A previous event-related potential (ERP) study from our laboratory showed increased frontal activity during a working memory (WM) n-back task in healthy aging adults relative to younger adults. As WM load increased, frontal ERP P3 amplitude increased and parietal P3 amplitude decreased. Here, we examined P3 amplitude change across trials at frontal and parietal scalp sites during an n-back task in older and younger adults. ERPs were recorded for 3 levels of task difficulty (load): 0-, 1-, and 2-back. We hypothesized that there would be greater habituation of the frontal P3 (amplitude decrement over trial blocks of 15 stimuli per block) in younger versus older adults with increased WM load, and that the opposite pattern would be observed for parietal P3 amplitude. An Age Group x WM Load x Scalp Site x Block ANOVA yielded a significant 4-way interaction. The 3-way and simple effects within the first two blocks indicated that younger, but not older, participants showed habituation at Fz during the greatest WM load condition (2-back). For all 10 blocks, only a Group x Lead interaction was present during the 2-back condition, indicating that the older group had greater frontal amplitude compared to the younger group. These findings lend support to our previous results that more difficult WM tasks recruit more frontal neuronal resources, and more so in older versus younger adults. The relationship between frontal and parietal scalp sites is reflective of resource allocation during WM. Habituation occurs early in the more difficult task in younger versus older adults.

Poster 99

MODULATION OF PARIETO-FRONTAL FEEDBACK LOOPS IN CONTINUOUS VISUOMOTOR LEARNING IDENTIFIED BY EVENT-RELATED POTENTIALS

Holger Hill Goethe University

Descriptors: visuomotor learning, feedback loop, tracking

Sensory feedback is essential for visuomotor learning. The posterior parietal cortex should analyze the success of error corrections by integrating visual, kinesthetic, and internal (efference copy) feedback. This information should be used by premotor

areas to improve motor programs. The present study addressed the evaluation of the spatio-temporal pattern ofthis parieto-frontal circuitry in a continuous visuomotor task using ERP measures. In three experiments (between-subjects designs), subjects tracked a computer-controlled target with either a mouse (Exp. 1) or a joystick (Exp. 2+3) controlled cursor. Visuomotor gain was varied to increase difficulty and to create implicit and explicit learning conditions. The initial tracking error and its reduction (reflecting visuomotor learning) was largest in the explicit joystick task, followed by the implicit joystick and the implicit mouse task. Error reduction was achieved by a continuous offset (target-cursor-distance) reduction. Two ERP components were modulated by visuomotor learning: 1) A fronto-central positive ERP component, peaking about 100 ms after the change of target direction and related to movement programming and execution showed an activity shift, that is an earlier onset and offset of the component, and 2) In the time range around 250 to 500 ms after error correction, ERP activity at centroparietal sites was shifted to more positive values. Data from these three experiments support our previously formulated hypothesis (Hill & Raab, 2005).

Poster 100

CHANGES IN EEG THETA ACTIVITY AFTER WORKING-MEMORY STRATEGY TRAINING ON A DIFFICULT PLANNING TASK

Kimberly Horn, Naveen Reddy, Dana Byrd, & W. Keith Berg University of Florida

Descriptors: strategy training, theta activity, working memory

For those with working memory deficits it would be very beneficial if training could improve this ability, especially if there was information on the brain changes accompanying the improvement. In this study, we explored the differences in EEG theta frequency before and after specific strategy training in healthy young adults (N 5 24) to begin to understand the changes in spectral power resulting from such training. Participants were asked to solve multiple trials of the Tower of London (TOL), a difficult spatial planning task, pre- and post-strategy training. Before the post-training session, participants were taught a strategy which reduced working memory load by chunking several moves together. Three types of problems were presented: directly trained problems, indirect problems (those which could be solved if participants transferred the strategy), and control problems that could not be solved using the strategy. Behavioral results indicate significant improvement on both the direct and indirect problems and less so for the control problems. EEG data, taken during a time in which participants were likely to be applying the strategy, showed an increase in power across midline leads at the post-training session, especially for the frontal cortex. Frontally situated lateral leads show greater theta power in the right hemisphere than the left. Additional regression analyses will assess the relationship between performance and theta activity.

Poster 101

GENETIC AND DEVELOPMENTAL INFLUENCES ON EEG BAND POWER AND ANTERIOR ALPHA ASYMMETRY IN ADOLESCENCE

Andrey P. Anokhin, Simon Golosheykin, & Sean D. Kristjansson Washington University School of Medicine

Descriptors: EEG, asymmetry, heritability

Previous studies have demonstrated heritability of brain oscillations as reflected in the resting electroencephalogram (EEG) in children and adults, however, the little is known about genetic influences on the human EEG in early adolescence. Here we examined heritability of resting EEG power, anterior EEG asymmetry, and coherence in a longitudinal sample of 752 twins (including 169 MZ and 203 DZ pairs, 48% females) tested at ages 12 and 14. Linear structural equation modeling of longitudinal data showed that heritability of EEG band power was very high at both ages, with 82 to 91 % of the observed variance in total alpha power explained by genetic factors. Developmental stability of alpha power was very high, with test-retest correlations between the two ages ranging from .80 to .89. Importantly, individual differences in the rate of developmental changes in EEG frequency spectrum were also heritable (up to 61%). Anterior EEG asymmetry showed substantial within-session test-retest reliability (r 5 .46-.68), but modest developmental stability(r 5 .39). Heritability ofthe asymmetry measure was modest but significant (21% and 28% for ages 12 and 14, respectively), consistent with our previous findings in young adults. Finally, developmental changes, stability, and heritability of coherence measures depended both on the frequency band and topographical locations.

Poster 102

DISSOCIATING FUNCTIONAL LOCI OF SPATIAL AND NON-SPATIAL SIMON EFFECTS: A PRP/LRP STUDY

Carola Lehle1, Asher Cohen2, Joerg Sangals1, Werner Sommer1, & Birgit Stuermer1 1Humboldt University, Berlin, 2Hebrew University of Jerusalem

Descriptors: dual task, priming, conflict

In Simon tasks, task-irrelevant stimulus features prime corresponding responses. If the primed response is incompatible to the required one, RT is longer compared to the compatible assignment (Simon-effect). Recent dual task studies revealed that Simon

effects in spatial versions of the task interact differently with stimulus onset asynchrony (SOA) compared to color versions: The color Simon effect was independent of SOA, whereas the spatial effect decreased with SOA. This signals a specific role of spatial compared to non-spatial features in response conflicts. In order to elucidate the mechanisms of this dissociation, we combined the dual task design with the Lateralized Readiness Potentials (LRP). Performance confirmed additivity of the Simon effect and SOA for the color task, and underadditivity for the spatial version. Importantly, an early LRP-deflection reflecting the priming by the irrelevant feature was absent in the color Simon task and confined to the spatial version. Here, the early LRP-deflection indicating incorrect response priming was unaffected in its onset latency, but strongly diminished for short SOAs. Therefore, the color Simon effect seems to emerge during response selection and to be resource-invariant. In contrast, the spatial Simon effect, related to location-dependent response activation via the dorsal stream in the brain, appears to arise during pre-bottleneck processing and seems to be resource-dependent.

Poster 103

INTERVALS OF QUASI-STABLE EEG PHASE SYNCHRONY CORRELATED WITH PERCEPTION

Andrey R. Nikolaev1, Sergei Gepshtein2, Pulin Gong3, & Cees van Leeuwen1 'RIKEN Brain Science Institute, 2Salk Institute for Biological Studies, RIKEN Brain Science Institute, 3University of Sydney, RIKEN Brain Science Institute

Descriptors: perception, phase synchrony, inter-area communication Brain activity is characterized by alternating episodes of irregular and regular activity. We studied scalp EEG synchrony in local brain areas, using chains of closely-spaced scalp electrodes extending over an area of 8 cm of occipital cortex. We measured the durations of synchronized episodes in perceptual groupings which were in accordance with the law of proximity. We used dot lattices which perception depends on aspect ratio (AR: ratio of the two shortest inter-dot distances in the lattice) as well as on the property of the participants: individual sensitivity to spatial proximity between the dots. Among the nine studied EEG frequency bands, we found that the durations were systematically related to AR in the beta frequency band (~20 Hz). The shortest interval duration (~ 140 ms) was observed in AR 5 1.0. The durations gradually prolonged with increasing AR and reached the maximum at the maximal AR used. The durations were also longer in participants whose sensitivity to proximity was higher than others. Thus, in relation to both stimulus property and individual characteristic of participants the longer intervals correspond to sufficiency of information for the perceptual judgment. We propose the episodes of quasi-stable phase synchrony constitute the coherence intervals: the temporal windows in which the result of a single perceptual or cognitive computation is communicated to the rest of the brain (van Leeuwen and Bakker 1995; van Leeuwen 2007).

Poster 104

EEG STUDY OF CREATIVITY

Maria Starchenko Institute of the Human Brain of the Russian Academy of Sciences

Descriptors: creativity, eeg power

Distinguished are 3 psychological parameters of creativity: fluency, flexibility and originality (Guilford, 1971). These parameters of creativity are important characteristics to understand how successful creativity proceeds. In order to investigate EEG-correlates of separate creativity parameters, four types of original tasks (Fluency, Flexibility, Originality and Control) were developed. 26 healthy volunteers underwent computer EEG registration while being tested. EEG was recorded from 19 sites (10-20 system). Mean values of EEG power for each subject in each state were calculated in frequency bands d (1,5-3,5 Hz), q (4-7 Hz), a1 (7,5-9,5 Hz), a2 (10-12,5 Hz), b1 (13-18 Hz), b2(18,5-30 Hz) and g (30-40 Hz). Statistical analysis was conducted using multi-way ANOVA and a within subjects design. Frequency bands, states and zones were considered effective factors. Greenhouse-Geisser correction was applied. Statistically significant differences between means in certain frequency bands, states and zones were found with post hoc tests. Statistically significant results were revealed in gamma and beta bands for all creative components vs control. Fluency and Flexibility tasks are characterized by increasing of EEG power in gamma and beta bands in frontal and temporal areas, while the Originality task is characterized by decreasing in the same bands in parietal area.

Poster 105

HIGH-DENSITY ERPS ELICITED BY HUMAN AND ANIMAL FACES AND POLYMORPHISM OF 5HT2A GENE

Elena V. Mnatsakanian1, Natalia V. Maluchenko2, & Alexander G. Tonevitsky3 1Institute of Higher Nervous Activity and Neurophysiology of the Russian Academy of Sciences, 2Moscow State University, 3Russian Research Institute of Sport and Physical Education

Descriptors: ERP, implicit recognition, individual differences

We aimed at studying individual differences in brain electrical activity underlying processing neutral and emotional pictures of humans and animals in healthy humans.

Complex cognitive processes cannot be explained by a single gene effect, however, a correlation between certain gene polymorphisms and some cognitive task performance may be informative and stimulating for further research. We were interested in 5HT2A receptor gene (polymorphism T102C). Thirty-four right-handed male volunteers participated in this study: 17 of them had two C alleles of the 5HT2A gene (CC-group) and the others had CT genotype (CT-group). 256-channel EEG was recorded with 500 Hz digitization rate while our participants performed dual-choice visual task. The stimuli were monochrome photographs of humans and animals. The instruction was to press button 1 for a human and button 2 for an animal. Half of images in either group were neutral and halfwere showing aggressive people or animals (aggression/treat directed to the observer). No explicit recognition of emotions was required. Reaction times (RT) for emotional vs. neutral images were longer for both humans (p 5 .02) and animals (p 5 .08) in CT-group. For CC-group, differences were only for animals (p 5 .002). Major ERP-differences between CC and CT-group were around 200 ms widespread on the scalp, prominent in the central and frontal areas of the right hemisphere, and also around 300 ms in the posterior regions. There were also inter-group differences for human vs. animal conditions and for neutral vs. aggressive conditions (implicit emotion recognition).

Poster 106

RESTING EEG-CHARACTERISTICS AND HUMAN WORKING EFFICIENCY

Sergii A. Kryzhanovskyi, Igor G. Zyma, Sergij V. Tukaev, Andrii O. Cherninskyi, & Natalja G. Piskorska Taras Shevchenko National University of Kyiv

Descriptors: EEG, short-term memory, sensomotor task

The aim of this study was to find the human rest EEG-characteristics, which can enable us to make assumptions about the efficiency and the features of further adaptation to various types of the cognition activity. EEG of 48 healthy 18 - 22-year-old volunteers were registered during resting wakefulness and performing the sensomotor (n 5 21) and short-term memory (n 5 27) tasks with eyes closed. We used audio stimuli in both tests. Spectral power density (SPD) of all frequencies from .2 to 25 Hz (.2 Hz step) was estimated for each state. We found that sensomotor reaction time strongly negatively correlated with right parietal EEG-frequencies of 11 -12 Hz SPD (r 5 — .6).

Poster 107

DOES ERROR DETECTION SYSTEM IMPACT TO LIE PROCESSING? AN ERP STUDY

Maxim Kireev, Sergey Pakhomov, & Svyatoslav Medvedev Institute of the Human Brain of the Russian Academy of Sciences

Descriptors: deception, error detection, ERP

The brain's detection of deception is one of the intriguing issues for neuroscience research. Its behavioral manifestations are complex and contemporary powerful neuroscience methods of lie detection are however weak and not reliable. A possible way of progress in this direction is related to a possibility of discovering the fundamental brain mechanisms corresponded to lying processes. The error detection system (Be-chetereva N.P. 1968, 2005) is sensitive to involuntary incorrect actions, however, the deceptive action in relation to subjective knowledge about the true is incorrect. The issue concerning involvement of an error detection mechanism in such voluntary incorrect actions remains scantily explored. In present study we recorded event related potentials (ERP) while subjects performed ''True-False'' analog card game with voluntary deceptive and truthful responses. 13 subjects participated in present study. The EEG (bandpass .5-30 Hz, digitized at 250 HZ) was recorded from 19 scalp sites in accordance with extended 10-20 system. All electrodes were referenced to linked ear lobes. Impedance was kept below 5 KOhm. Amplitudes of extracted ERP components were subjected to two-way ANOVA analysis. The amplitude of negative deflection of ERP locked to responses with latency over 200 ms was higher for deceptive ones in comparison with truthful responses. This finding could be considered as evidence supporting the idea of involvement of an error detection mechanism in the brain's processing of deception.

Poster 108

THE P300 BCI IS MORE THAN AN ODDBALL AND MORE THAN A P300 BCI

Sergei L. Shishkin, Ilya P. Ganin, & Alexander Ya Kaplan M. V. Lomonosov Moscow State University

Descriptors: BCI, ERP, attention

One of the most popular BCI paradigms was developed by Farwell & Donchin (1988) as a variation of the oddball task, and is usually called P300 BCI. Recently, it was noted that, in addition to P300, an earlier posterior negative component also differentiated target vs. nontarget responses in P300 BCI (e.g., Krusienski et al., 2008). No studies, however, have directly compared this component in P300 BCI and oddball paradigms. We made such a comparison using the BCI2000 system (Schalk et al., 2004) in 10 healthy

adults. In a BCI P300 paradigm, the amplitude of the first large posterior negative component (N1; peak latency in our settings in the range of approx. 200 - 300 ms) of the target-nontarget difference curves was larger.

Poster 109

ELECTROPHYSIOLOGICAL CORRELATES OF REFERENCE MEMORY IN A TIME DISCRIMINATION TASK: AN ERP AND ERD/ERS STUDY

Vincenza Tarantino, Anahita Goljahani, Costanza D'Avanzo, Sparacino Giovanni, & Bisiacchi S. Patrizia University of Padova

Descriptors: time perception, reference memory, ERD/ERS

In the present study we investigated Event Related Potentials (ERPs) and Event Related Desynchronization/Synchronization (ERD/ERS) responses in brain activity during a time discrimination task, in which stimulus interval length was modulated. EEG was recorded in 12 subjects (21-27 years) from 32 electrodes. The task consists on two successively presented pairs ofvisual stimuli. The first stimulus (standard interval) lasted either 500, 1000 or 2000 ms; the second stimulus (comparison interval) could have duration of the 30% shorter or longer than the standard one. Participants were required to compare the duration of the two stimuli and to determine whether the comparison one was shorter or longer than the standard. ERPs and ERD/ERS changes in the delta, theta, alpha and beta EEG frequency bands were examined. ERPs data showed a negative slow wave during the comparison interval in centro-frontal sites, which, only for intervals longer than the standard, terminates before the end of the stimulus, after a duration equal to the memorized standard one. A P150 was found at the offset of the comparison interval in parietal sites, which linearly increased with the absolute interval length. In addition, an increase of theta power for durations longer than the standard was found in parietal sites, at the offset of the comparison interval. The ERS increase was supposed to reflect the retrieval of the memorized interval. ERD/ERS together with ERPs results provide further insight on the involvement of a specific memory process (reference memory) in time perception tasks.

Poster 110

MOTHERS! EEG ACTIVITY DURING BABIES! CRYING AND NURSING

Yolanda del-Rio-Portilla1, Julieta Ramos-Loyo2, Consuelo Arce1, & Maria Corsi-Cabrera1 1National Autonomous University of Mexico, 2Neuroscience Institute, University of

Guadalajara

Descriptors: eeg, emotion

In a previous study, we found an increase of theta and a decrease of alpha relative power while listening to classical music and an opposite pattern during listening to a baby's crying recording. The present work was conducted to explore changes in brain electrical activity (EEG) during own baby's crying and nursing in first time mothers. EEG was recorded in 8 healthy mothers, between 21 and 38 years old, with babies of 3 months or less, in 10 locations referred to the ipsilateral earlobes, according to the 10-20 International System. 20 segments (2 sec each) with opened eyes were recorded during: baseline (BL), while the baby was crying because of hungry (BC) and while nursing (NU). Signals were analyzed by means of the Fast Fourier Transform, obtaining absolute power (AP), as well as inter- and intra-hemispheric (rTRA) correlation for each EEG band. Theta1 AP was higher during NU and BC than BL in T4. Delta AP difference was higher during NU than BC in T4 and P3. AP difference was higher during BC than NU in T3 for alpha2 and beta1. rTRA was higher during NU than BL between C4-P4 theta2, F3-C3 alpha2 and F3-C3, F4-P4 and C4-P4 in beta2. Theta1 AP increment in right temporal region is in agreement with the emotional involvement in both conditions vs BL. CR in contrast to NU could have act as a disorganizer emotional stimuli, increasing beta1 in left temporal zone. Nursing induced an increment in temporal coupling between different areas of left and right hemisphere.

Poster 111

QUALITATIVE AND QUANTITATIVE EEG ABNORMALITIES IN ALCOHOL DEPENDENCE VIOLENT OFFENDERS

Ana Calzada-Reyes1, & Alfredo Alvarez-Amador2 1Legal Medicine Institute, 2Cuban Neuroscience Center

Descriptors: EEG, offender, alcohol dependence

Resting eyes closed electroencephalogram was studied in a group of violent offenders evaluated at Psychiatric Department of the Legal Medicine Institute in Cuba (14 with alcohol dependence diagnosis, and 13 without psychiatric diagnosis). Characteristics of the EEG visual inspection and the use of frequency domain quantitative analysis techniques (narrow band spectral parameters) are described. Both groups were compared to Cuban normative database. High incidences of electroencephalographic abnormalities

were found in both groups of violent offenders. The most frequent were: electrogenesis alterations, attenuated alpha rhythm and theta and delta activities increase in the frontal lobe. In the quantitative analysis theta and delta frequencies were increased and alpha activity was decreased in both groups. Differences appear for the topographical patterns present in subjects of both groups. EEG abnormalities were more severe in alcohol dependece group than in control group. The results provides a strong lead for examining the electrophysiological differences between offender groups, the neurotoxic effect of drugs on the brain and to establish possible relations between the deficiency in information processing capacity of central nervous system how one of possible mechanisms related to increase the likelihood of criminal act in offenders with this diagnosis.

Poster 112

FRONTAL ALPHA AND BETA EEG POWER ASYMMETRY AND IOWA GAMBLING TASK PERFORMANCE

Richard T. Amoss, & Michael J. Owren Georgia State University

Descriptors: EEG, alpha, IGT

Frontal electroencephalographic (EEG) alpha asymmetry may index the activation of lateralized affect and motivation systems in humans. Resting EEG activation was measured and its relationship to Iowa gambling task (IGT) performance was evaluated. No effects were found for power asymmetry. However, beta power, an alternative measure of resting EEG activation asymmetry, was associated with the number of risky decisions made in the early portion of the task. IGT deck selection patterns show three styles of responding, high, random, and low. Interestingly, high performers' power asymmetry contradicts expectations of IGT performance that were based on lateralized frontal emotion and motivation systems.

Poster 114

PREDICTION OF TRANSITION TO SCHIZOPHRENIA IN AT-RISK INDIVIDUALS BASED ON EEG SPECTRAL POWER AND NEGATIVE SYMPTOMS

Ronan Zimmermann1, Ute Gschwandtner1, Frank H. Wilhelm2, Marlon O. Pflueger1, Anita Riecher-Rossler1, & Peter Fuhr1 1University Hospital Basel, 2University of Basel

Descriptors: quantitative eeg, prediction of schizophrenia, negative symptoms Patients in an "at risk mental state for schizophrenia'' (ARMS) can be detected based on specific as well as unspecific prodromal signs. Since only about 40% of ARMS identified by ultra high risk studies develop frank psychosis it is important to identify further factors contributing to the prediction of beginning psychosis. Quantitative EEG (along with neuroimaging and neuropsychological evaluation) may provide information on vulnerability in addition to clinical assessment. We examined a sample of 13 neuroleptic-na'ive ARMS who developed psychosis and 15 that did not during a follow-up period of at least 4 years from the "Basel prediction and early detection of psychosis study.'' Psychopathology was rated with the Scale for the Assessment of Negative Symptoms (SANS) and EEGs were recorded using a 10-20 configuration. Logistic regression analysis was used to predict transition to schizophrenia based on SANS score and EEG spectral power over the fronto-central scalp area controlling for confounding factors (age, gender, medication, cannabis use and daytime of EEG recording). Neither SANS score nor EEG power scores alone were predictive of a transition to schizophrenia.

Poster 115

IMPLICIT PROCESSING OF FACIAL FEATURES: EVIDENCE FROM HUMAN ELECTROPHYSIOLOGY

Irene Leo1, Michela Sarlo1, & Francesca Pesciarelli2 1University of Padova, 2University of Modena

Descriptors: face processing

In this study, we used ERPs to investigate neural correlates of face processing. More specifically, we utilized a masked priming paradigm to investigate implicit processing of the eyes and mouth in upright and inverted faces, using a prime duration of50 ms. Three types of prime-target pairs were used: 1. congruent (e.g., open eyes only in both prime and target); 2. incongruent (e.g., open eyes only in prime and open mouth only in target) and 3. dual (both mouth and eyes open in the prime only followed by either type of target, i.e., either eyes or mouth but not both, open). The identity of the faces changed between prime and target. Participants pressed one button to indicate whether the target face's mouth was open, and an other if the eyes were open. The behavioral results indicated a congruent priming effect for both upright and inverted faces. In addition, we found an enhanced negativity at about 200 ms after target presentation. The amplitude of the N200-like component depended on the relation between prime and target, being smaller when the stimuli were congruent in both upright and inverted faces. This N200-like component was followed by a P300 component, which was influenced by the three conditions, with incongruency and dual producing a smaller positivity than congruency in both upright and inverted faces. Moreover, when the stimuli were presented upside

down, the N200 and the P300 effects took place about 30 ms later. The functional significance of these ERP effects is discussed in relation to unconscious perception and configural face processing.

Poster 116

HOW LEARNING TYPE AND REWARD MODULATE THE ERP CORRELATES OF ERROR PROCESSING

Nicola K. Ferdinand, & Axel Mecklinger Saarland University

Descriptors: error-induced learning, learning type, reward

An important electrophysiological marker of error monitoring is the error-related negativity (ERN), an event-related potential (ERP) component visible after subjects commit an error or receive negative feedback. Interestingly, earlier studies showed that not only negative feedback, but also the way it is processed, influences error monitoring: The ERN is more pronounced for subjects that learn better from negative feedback (negative learners) than for subjects that learn better from positive feedback (positive learners). Additionally, the ERN is larger when learning incentives like monetary rewards are given. A functionally similar negativity, the N2b, is elicited by perceived errors (deviant events). The aim of the present study was to explore whether the N2b, in a similar way as the ERN, is modulated by learning type and incentives. We conducted a sequence learning experiment with deviants inserted into a repeating sequence. A neutral and a rewarded condition were realized with groups of positive and negative learners. This allowed us to examine ERP correlates of committed errors (ERN) and perceived errors (N2b). Surprisingly, in contrast to previous studies we did not find ERP differences in error monitoring between positive and negative learners. However, our results show that ERP differences between correct and erroneous responses and between regular and deviant stimuli are larger when incentives are given during learning. This might imply that the error monitoring system is engaged more strongly in conditions in which errors are more important and rewards are expected.

Poster 117

THE FUNCTIONAL SIGNIFICANCE OF THE PARIETAL ODDBALL N2 OBTAINED IN AUDITORY EXPERIMENTS

Janos Horvath Institute of Psychology, Hungarian Academy of Sciences

Descriptors: oddball paradigm, n2p, p3b

Recently a number of studies reported a negative parietal event-related potential to auditory oddball stimuli in the N2 latency range (N2p), however, a functional characterization of this component is still missing. Because a common feature of most studies reporting an N2p was that the eliciting oddball stimuli were well-identifiable members of a behaviorally significant stimulus category, it seems possible that N2p reflects identity-based processing of the stimulus (as opposed to a rule-based evaluation of the task-relevant feature). In the present study, this hypothesis was tested by varying the plausibility of reducing the task-rules to a stimulus identification-based stimulus-response association. A sequence of tone-pairs was presented. Participants responded according to the direction of within-pair pitch change (50% going lower - 50% higher). On oddball trials (10%), the spectral width of the second tone of the pair was changed. In the ''identity'' condition, the magnitude of pitch change was always seven semitones; in the "feature rule'' condition it was six or eight semitones (randomly). Whereas the ''identity'' condition should foster identity-based processing, the variability and use of less frequent musical intervals should give better support to rule-based processing of the task-relevant feature-dimension. Reactions were delayed in oddball trials. N2p and N2b were only elicited in the ''identity'' condition, whereas P3b was present in both conditions. These results support the hypothesis that N2p is related to the identity-based processing of the stimuli.

Poster 118

WAVELET-BASED EOG ARTIFACT CORRECTION OF EEG

Benoit Decarie1, Philippe Robaey1, & Jean-Marc Lina2 1Children's Hospital of Eastern Ontario, 2Ecole de technologie supeerieure

Descriptors: eog correction, wavelet, multiscale analysis

Electroencephalogram (EEG) is profoundly affected especially at frontal sites by electro-oculogram (EOG) artifacts originating by eye movement, blinks or eyelid movements. This is even more dramatic with children who cannot prevent themselves to blink or to move their eyes. Therefore, EOG correction techniques are of primary importance in the study of brain electrical sources related to cognitive processes in children. Different approaches have been used to correct EOG artifacts, all estimating for each EEG channel the proportion of ocular contamination and by subtracting EOG scaled by the estimated proportion from the original EEG signals. The proportion of ocular contamination is usually estimated from the temporal correlations between the amplitude variations of the EEG and the EOG channels. We developed an alternative approach based on the correlations between the different frequency sub-bands obtained by a multi-scale analysis (discrete wavelet transform) of the EEG and the EOG channels. The technique was utilized for the detection and spectral

characterization of transient (artifact) and background processes (true EEG). The EEG is estimated in the wavelet space, using an appropriate weighted mixture of raw signal and the EOG channel where the artifact is modeled. This is combined with an unusual shrinkage technique to avoid discontinuities in the reconstruction of the EEG. EEG obtained in children and corrected by these two different approaches (temporal or multi-scale) will be compared in order to assess the reliability and effectiveness of EOG correction methods.

Poster 119

EEG INVESTIGATION OF SPATIAL CREATIVE THINKING COMPONENTS

Zhanna V. Nagornova Institute of the Human Brain of the Russian Academy of Sciences

Descriptors: EEG, spatial creativity

The aim of the study was to reveal EEG correlates of creative thinking components -fluency, flexibility and originality (Guilford, 1950; Torrance, 1974) during performance of figural Torrance test (1974). Twenty-one healthy subjects took part in our EEG study. In FLUENCY task volunteers drew as many pictures as possible. In FLEXIBILITY task volunteers drew pictures from different classes (animals, flowers, equipment). In ORIGINALITY task volunteers drew any original, creative pictures. In CONTROL task volunteers drew lines without any system. EEG was recorded from 19 scalp electrodes (10-20). We calculated spectral power in B1 (13-18 Hz), B2 (18.5-30 Hz), G (30.5-40 Hz) bands, used ANOVA for analyzing the interaction, and obtained significant EEG power differences.

Poster 120

THE N200 IS SENSITIVE TO CONCEALED INFORMATION AND ADDS TO THE DETECTION EFFICIENCY OF SKIN CONDUCTANCE RESPONSES

Matthias Gamer1, & Stefan Berti2 1University Medical Center Hamburg-Eppendorf, 2University of Mainz

Descriptors: guilty knowledge test, N200, response monitoring

Previous studies on the Guilty Knowledge Test (GKT) demonstrated that event-related brain potentials (ERPs) and skin conductance responses (SCRs) can be used to reliably detect concealed knowledge. However, the contribution of memory- and task-related processes to this response pattern remains unclear and it has not been tested whether SCR measures provide incremental validity in addition to EPRs. We implemented variations of the GKT in two experiments while simultaneously measuring SCRs and ERPs. Participants were required to conceal knowledge of a specific playing card (probe) while viewing a randomized sequence of probes and irrelevant items. In experiment 2, another playing card was merely memorized but not specifically instructed to be concealed. Task relevance was manipulated by requiring participants to press a different response key for rare targets (experiment 1) or catch items (experiment 2). We found that P300 amplitudes were specifically enhanced for items requiring a deviant behavioral response but they were not sensitive to concealed knowledge. In contrast, N200 amplitudes differed between memorized and irrelevant items in both experiments. SCR measures reflected a combined influence of task relevance and probe recognition and they provided incremental validity above N200 amplitudes. These results suggest that the P300 mainly reflects task relevance in the given experimental setting while the N200 amplitude is sensitive to previously encoded information and potentially linked to response monitoring processes.

Poster 121

ELECTROPHYSIOLOGICAL CORRELATES OF DIRECTED ATTENTION TO FACE FEATURES

Joseph P. McCleery1, Chandni Singh2, Gillian Petrozziello2, & Charles A. Nelson1 1Harvard Medical School, 2Children's Hospital Boston

Descriptors: face, N170

Decades of research has shown that the N170, a negative-going component recorded from electrodes occipital-temporal cortex, is consistently of larger amplitude and of shorter latency in response to faces versus objects. More recently, a number of studies have shown that individuals with psychiatric disorders, including autism, exhibit atypical N170 responses to face stimuli. However, these studies have not accounted for the possibility that atypical face viewing patterns might account for some, or all, of the observed processing differences. In the current experiment, we used simple visual stimuli (e.g., a small spinning square) to direct normal adult participants to look at a particular area of the screen. Then, faces were presented such that the participant was viewing either the eye or mouth region when the face was presented and the N170 recorded, with object stimuli included as comparison stimuli. Results indicate that there were no differences in the amplitude of the N170 component when participants viewed the eye versus the mouth region, F(1, 12) 5 1.80, p 5 .20. However, N170 latencies were significantly shorter in response to viewing the eye region versus the mouth region, F(1,

12) 5 6.44, p 5 .026; but not for viewing the top versus the bottom of objects, F(1, 12) 5 .38, p 5 .55). These results suggest that location of initial visual focus on full face stimuli affects the latency of the face-sensitive N170 component.

Poster 122

BRAIN POTENTIALS ELICITED BY GARDEN-PATH ARITHEMETIC EXPRESSIONS

Nai-yi Wang1, & Yue-jia Luo2 1Capital Institute of Basic Education Research, Beijing Normal University, 2National Key Lab of Cognitive Neuroscience and Learning, Beijing Normal University

Descriptors: garden path effect, arithmetic, P600

It has been shown that ''garden-path'' sentences elicit the P600, which may reflect structural reanalysis occurring at a critical word indicating that the preceding ambiguous sentence structure was complex. We carried out an experiment where ''garden-path'' (temporarily ambiguous and eventually complex structure), ''main-path'' (temporarily ambiguous and eventually simple structure) and control (unambiguously simple structure) arithmetic expressions were presented. The second operators serve as the critical element disambiguating expression structures in ''garden-path'' and ''main-path'' expressions. Results showed that by comparing second operators in ''garden-path'' to control expressions, two posterior late positive components (LPC) within 350 - 500 and 500-900 ms were elicited. The first LPC could have been a P300, reflecting detection of error in the previously preferred analysis. The second LPC was analogous to the P600, which may reflect structural reanalysis in ''garden-path'' arithmetic expressions. Additionally, a central LPC within 350 - 500 ms was elicited by second operators in ''main-path'' relative to control expressions. It is likely that a P300 represented a confirmation of correctness in the previously preferred analysis. The present study suggests that processing of both ''garden-path'' arithmetic expressions and language sentences may have common neurophysiological processes.

Poster 123

TEMPORAL MODULATION OF N1 VISUAL COMPONENT IN A STROOP MATCHING TASK

Isabel A. David1, Eliane Volchan1, Jaime Vila2, Aydamari Faria-Jr3, Pandelis Perakakis2, Leticia Oliveira4, Mirtes G. Pereira4, & Walter Machado-Pinheiro4 1Federal University of Rio de Janeiro, 2University of Granada, 3Universidade Federal do Amapa, 4Fluminense Federal University

Descriptors: ERP, stroop, attention

Top-down attentional control is required when subjects must attend to one of conflicting stimulus features, such as in the Stroop task. Performance may be improved when such control is implemented in advance of an imperative stimulus. We investigate the temporal dynamics of attentional control on early perceptual processing in a Stroop matching task. Two stimuli were presented simultaneously or with SOAs (Stimulus Onset Asynchrony) of 400 and 1200 ms. The first stimulus (S1) was a colored word in yellow, red or blue ink (the Stroop stimulus) and the second (S2) was a color word in white ink. In trials with SOA, S1 stayed on the screen until S2 onset. Volunteers (N 5 40) were told to compare the color ink of S1 to the word of S2 and to press a key if they had the same meaning. The N1 ERP component was measured as a marker of stimuli early perceptual processing. The Stroop effect was maximal during simultaneous presentation, was reduced at SOA 400 and was inverted at SOA 1200. This indicates that attention modulates Stroop conflict during SOAs. ERP findings parallel the effects observed in reaction times. N1 mean peak amplitude was greater for congruent stimuli than incongruent during simultaneous presentation. This effect was attenuated at SOA 400 and at SOA 1200 an inversed pattern was observed (incongruent stimuli elicited a greater N1). The results provide evidences that anticipatory attentional modulation has a major role in Stroop interference acting even on early stages of processing.

Poster 124

THE INFLUENCE OF PERFORMANCE FEEDBACK IN BLINDSIGHT - AN ERP STUDY

Jessica Sanger, & Petra Stoerig Heinrich-Heine-University of Duesseldorf

Descriptors: blindsight, feedback, ERP

Lesions of the primary visual cortex cause homonymous fields of cortical blindness in the contralateral hemifield. Nevertheless, patients who claim that they do not see visual stimuli presented within their field defect may respond much better than expected by chance guessing when forced to guess whether or where a stimulus has briefly been presented. This 'Blindsight' has been shown to improve with practice. As performance feedback may accelerate the improvement, we tested the effect of trial-by-trial response feedback on detection performance in two hemianopes. A 3.2°, 80 ms disk of — .5 log contrast was presented in pseudo-random alternation with a blank stimulus, and patients indicated 'target' or 'blank' by keypress. Each response was followed by a cen-

trally presented visual icon that signaled response correctness. Detection performance improved consistently over 1,200 trials, reaching a d' of 3.4. To learn how stimuli, responses, and feedback are reflected in the electroencephalographic brain activity, we recorded event-related potentials (ERPs) while the participants performed the detection task in the contralesional hemifield. Results show differential ipsi- and contralesional modulations of the target-related N1 in response to blind-field targets. Moreover, a response-related negativity for correct responses suggests integration of stimulus and response information even in the absence of stimulus awareness. Finally, feedback signaling the relatively rare errors resulted in a fronto-central positivity that may play a role in improving the implicit performance.

Poster 125

ERP-P3 FOR PICTURES VARIES IN AMPLITUDE ACCORDING TO STIMULUS CONTENT

Aki Akamine1, & Mitsuro Kida2 1Nagoya University of Arts and Sciences, 2Aichi Gakuin University

Descriptors: ERP-P3, pictures, stimulus probability

It has been demonstrated by using a simple oddball task that P3 amplitudes vary as a function of stimulus probability. Using a discriminative reaction time task, this study explored whether ERP-P3 varies according to picture content. In the Stop-Cars condition, pictures in five categories; cars, people, electronics, flowers, and landscapes, were presented randomly at probabilities of .40, .30, .10, .10, and .10, respectively. Participants were asked to react to every stimulus that was not a car. In the Stop-Figures condition, simple geometric shapes replaced the car stimuli, with all other procedures being identical. ERPs for stimuli of electronics, flowers, and landscapes that were presented equiprobably were analyzed. Two types of P3s were observed in the waveforms. The first component (early P3) observed about 380 ms after stimulus onset had a parietal maximal and seemed equivalent to P3 (P3b). The second component (late P3) observed about 520 ms after the stimulus onset was more anterior distributed. In the Stop-Cars condition, early P3 amplitudes were largest for flowers, followed by that for landscapes and electronics. Neither early P3 elicited by flowers, nor that elicited by landscapes were different between the two conditions. However, the stimuli of electronics in the Stop-Figures condition yielded a large early P3 that was similar to that yielded by stimuli of flowers. These results suggest that in a discriminative reaction time task, the P3 amplitude for complex pictures is sensitive to the content of picture rather than to the probability.

Poster 126

INFLUENCE OF AROUSAL STATE ON MOVEMENT-RELATED BRAIN ACTIVITY

Marta Bortoletto, Marianna Lemonis, & Ross Cunnington School of Psychology and Queensland Brain Institute, University of Queensland

Descriptors: movement-related potentials, arousal, skin conductance Voluntary movements are preceded by pre-movement cortical activity associated with the planning and readiness for action. Previous studies have suggested that movement-related brain activity is affected by higher cognitive functions such as attention and motivation. In this study, we investigated the effect of arousal on pre-movement activity by examining the Readiness Potential (RP) under conditions of relatively high and low physiological arousal. Eighteen participants performed a Readiness Potential paradigm in which they executed self-paced voluntary movements approximately every 4 - 5 s. The arousal state was manipulated by the experimenter through interaction with participants during rest breaks. 64 channels EEG, skin conductance level and heart rate were recorded. Skin Conductance level was significantly different between high and low arousal conditions, showing that the experimental manipulation effectively altered arousal state. The RP amplitude was significantly higher under conditions of low arousal compared with high arousal, with no change in the RP scalp topography. Moreover, arousal level differently modulated the early and the late component of the RP. Results exclude the hypothesis of a positive linear relationship between Readiness Potential and arousal. Therefore neural mechanisms associated with increasing arousal are unlikely to directly influence the premotor pathways important for the preparation and readiness for action.

Poster 127

ACC THETA OSCILLATION AND THE FEEDBACK-ERN

Bai Yu, & Ohira Hdeki Nagoya University

Descriptors: ERN, ICA, decision-making

The feedback-error related negativity (ERN) is a medial frontal negative deflection which peaks at around 300 ms, elicited by informative feedback about the correctness of a response when the subject does not know which response is correct. The feedback ERN does not just index error or conflict detection, but may play a role in reward related learning. The putative generator of the feedback-ERN is the anterior cingulate cortex (ACC), that a region also known as the generator of the ERN. In another study, we

found that the ERN consists of more than one component using independent component analysis (ICA). In the present study, ICA is applied to multichannel EEG data from an experiment in which subjects engaged in a probabilistic reinforcement learning task which we manipulated. Behaviorally, all subjects quickly adapted their decision-making to maximize rewards. Cluster-analysis applied to the normalized scalp topographies and power spectra of the ICA data identified two classes of contributing components, an ACC cluster and a Pe cluster. Time-frequency analysis revealed that ACC cluster responses to losses, compared to wins, were associated with enhanced power and phase coherence in the theta (4-7 Hz) frequency band. These findings suggest that the neural mechanisms of feedback processing may differ between wins and losses while the theta oscillation may reflect the difference.

Poster 128

RESPONSE ACTIVATION AND INHIBITION IN CHOICE RESPONSES: A LAPLACIAN ERP ANALYSIS

Maria C. van de Laar1, Wery P.M. van den Wildenberg1, Geert J.M. van Boxtel2, & Maurits W. van der Molen1 1University of Amsterdam, 2University of Tilburg

Descriptors: response activation, response inhibition, laplacian erp Recent studies using laplacian-transformed EEG showed that manual choice responses involve a negativity recorded over the contralateral primary motor cortex (M1), representing the central motor command to the involved hand. This activation is accompanied by a positivity over the ipsilateral M1, preventing activation of the non-involved hand. This pattern is preceded by activation recorded over the supplementary motor area (SMA), which is thought to reflect a hierarchically organized control system upstream of M1. We further explored this pattern by comparing Laplacian estimations derived from four different choice responses in a stop-signal task. Participants were required to respond with the left or right hand to primary go signals (white arrows) that occasionally changed to blue or pink. Blue (ignore) signals could be ignored in favor of the go response, whereas the ongoing response should be stopped when presented with a pink (stop) signal. We compared EMG-locked responses on go trials, on unsuccessful stop trials, and fast and slow responses to ignore stop trials. The Laplacian results showed that the negativity (i.e., activation) over the contralateral M1 did not differentiate between the four response types. However, the ipsilateral inhibition ofM1 varied with response speed and was greatly reduced for slow responses. Interestingly, SMA activation was absent preceding slow responses. This pattern of findings supports the notion that the positivity over the ipsilateral M1 represents a control function that prevents choice errors, guided by the SMA.

Poster 129

THE INFLUENCE OF TRAIT ANGER, CORTISOL, AND AGGRESSION RESTING CORTICAL ACTIVITY

Katja Bertsch1, Judith Trenz1, Robina Khan1, Menno R. Kruk2, Steffen Richter3, & Ewald Naumann1

1University ofTrier, 2Leiden University, 3Institute ofPsychobiology, University ofTrier Descriptors: EEG, aggression, cortisol

Animal as well as clinical studies indicate a strong relationship between stress and aggression. There is evidence that in healthy individuals, trait as well as state anger are associated with an increased left-prefrontal and a decreased right-prefrontal brain activity. Moreover, a few recent studies have shown that the administration of cortisol also has an impact on resting cortical activity. Exogenous cortisol administration has been shown to alter global cortical activity as well as frontal asymmetries. As changes in resting cortical activity might therefore be an important link in the relation of stress and anger/aggression, we investigated the influence of trait anger, cortisol, and experimental provocation on resting cortical activity. Therefore, we administered either 20 mg hydrocortisone (cortisol group) or a placebo (placebo group) to a group of healthy participants and provoked aggressive behavior in half of the participants of each group with the Taylor Aggression Paradigm. Resting EEG was measured before and after the provocation for four minutes. Preliminary results indicate effects of trait anger, cortisol, as well as aggression on alpha and beta activity. Data indicate that changes in resting cortical activity might play an important role within the 'vicious circle of stress and aggression'.

Poster 130

THE USE OF HIGH RESOLUTION EEG TECHNIQUES TO IMPROVE THE ESTIMATION OF CORTICAL ACTIVITY AND CONNECTIVITY

Craig Tenke New York State Psychiatric Institute

Descriptors: surface laplacian, high resolution eeg, connectivity estimation In the last decade, the possibility to noninvasively estimate cortical activity and connectivity has been highlighted by the application of the techniques known as high resolution EEG. These techniques include a subject's multi-compartment head model (scalp, skull, dura

mater, cortex) constructed from individual magnetic resonance images, multi-dipole source model, the use of spherical and realistic surface Laplacian and regularized linear inverse source estimates of cortical current density. Here, we present some applications of such estimations in different high resolution EEG data sets, related to the movement and cognition in healthy humans. We observed that the proposed de-blurring technology was able to unveil the direction of the information flow between the cortical regions of interest. The conclusion was that modern de-blurring techniques have to be used to generate reference-independent, high spatial resolution data from raw EEG recordings.

Poster 131

WHAT DO WE MEASURE - CREATIVITY OR TASK COMPLEXITY?

Natalia V. Shemyakina, Zhanna V. Nagornova, & Sergey G. Danko Institute of the Human Brain of the Russian Academy of the Sciences

Descriptors: creativity, task complexity, EEG

When investigating creative thinking, even ifwe use a test-control approach, it is difficult to balance tasks by their complexity level, and some differences can be obtained because of different tasks' complexity levels. We carried out an EEG study in order to reveal and separate correlates of creative task performance and the noncreative factor of task difficulty (subjective complexity). Fifty right-handed healthy subjects took part in our EEG study. We found that creative and non-creative verbal tasks of the same SCL differed in their EEG spectral power correlates.

Poster 133

CONTINUOUS RATING AND PSYCHOPHYSIOLOGICAL MONITORING OF EXPERIENCED AFFECT WHILE WATCHING EMOTIONAL FILM CLIPS

Robert Schleicher1, & Niels Galley2 1Deutsche Telekom Laboratories, Berlin, 2University of Cologne

Descriptors: valence & arousal, film clips, facial emg

Subjective rating on the dimensions of valence and arousal is common for affective sounds, pictures and movies alike. Usually the rating is done after presentation, which may be insufficient for dynamic stimuli. We modified an existing software to continuously rate stimuli ('EMuJoy') such that the axes of valence and arousal were superimposed as thin crosshairs on the playing clip and rating could be done while watching, using a PC mouse. Sixty subjects watched 14 clips that evoked joy, sadness, disgust, anger, and fear as well as a neutral scene. Facial EMG, EKG and skin conductance (SC) were recorded during presentation. All data were analyzed using time-aggregated values for all clips and considering temporal course for the most effective clip for each emotion. Joy could clearly be distinguished from the negative emotions due to its valence, while sadness had a significant lower arousal rating than anger, disgust and fear. Facial EMG distinguished between positive and negative emotions and differentiated disgust from anger and fear. Fear was accompanied by stronger electrodermal reactions than anger. SC decreased during presentation for all negative emotional stimuli and only increased during abrupt changes in plot typical for disgust and fear. While the standard deviation of inter-beat-intervals initially decreased for all emotions, it only re-increased for the joyful clip. These changes became only apparent when looking at the temporal course. We thus conclude that continuous rating and analysis of the course of change may provide new insights for emotion research

Poster 134

PERSONALITY, EMOTION, FEELINGS & PHYSIOLOGY: HOW PERSONALITY MODERATES THE EFFECT OF EMOTION INDUCTION ON PHYSIOLOGY AND FEELINGS

Corinna E. Bonhage, Christin Burgdorf, & Gerhard Stemmler University of Marburg

Descriptors: positive emotion, personality, cardiovascular

How does personality influence the effects of emotions on cardiovascular variables? We evoked positive feelings ofwarmth/liking (and the opposite) in subjects which were engaged in a romantic partnership. Forty heterosexual couples were studied in a virtual ball game (''Cyberball''), in which one of the partners was instructed to play with his or her partner plus another unknown couple on a computer. Cyberball allows researchers to experimentally modulate social inclusion and exclusion. Variables in this experimental design included Emotion (positive/negative), Group (experimental/control) and Gender, in addition to certain personality traits used as covariates. Traits like affiliation, harm avoidance, positive emotionality, and achievement orientation influenced physiological variables (ECG, skin temperature, skin conductance) and subjective feelings of warmth/liking. Personality specifically moderated the impact of emotion induction and resulting effects on physiological parameters. For example, participants high in affiliation showed larger P-Q times, which marks a higher vagal influence, in the negative experimental group compared to negative controls. Results emphasize the importance of taking personality variables into consideration when the psychophysiology of emotion is studied.

EMOTIONS IN MOTION: THE PERCEPTION OF DYNAMIC AND STATIC EMOTIONAL FACIAL EXPRESSIONS INVESTIGATED BY ERPS AND FMRI CONSTRAINED SOURCE ANALYSIS REVEAL DIFFERENT SPATIO-TEMPORAL NEURAL NETWORKS

Sina A. Trautmann1, Judith Domínguez-Borras2, Carles Escera2, Thorsten Fehr1, & Manfred Herrmann1 1University of Bremen, 2University of Barcelona

Descriptors: dynamic vs. static faces, fmri constrained source analysis, disgust The aim of the present study was to examine emotion-specific event-related components and to apply discrete regional source models based on corresponding fMRI activation patterns complemented with additional fitted sources. Data were obtained during the perception of static and dynamic emotional face stimuli. Healthy women (N 5 19) passively watched videos and photos of different facial expressions (neutral, disgust, happiness). ERP data of static facial expressions showed a stronger deflection of the N170 in right posterior regions for emotional compared to neutral faces. LPP over centro-parietal areas for emotional compared to neutral faces could be shown for static and dynamic modality. For static facial expressions, predominantly additionally fitted regional sources showed distinct source signals for emotional compared to neutral stimuli. Aside from posterior regions, the source model of static faces revealed a potential emotional modulation of the insula indicated by enhanced source signal for disgust compared to neutral face processing between 300 and 350 ms. Dynamic emotional stimuli compared to neutral ones yielded increased source signals in posterior, inferior frontal and medial frontal regions, hence, a topographically more distributed network. The data support the view that (1) a combined fMRI and EEG approach of studying emotional perception enhances our knowledge about the time course of activation of different sources and reveals sources in regions not identified by fMRI procedures, and that (2) static emotions, compared to dynamic emotions, recruit different neural networks.

Poster 136

CIGARETTE SMOKING REDUCES NEGATIVE AFFECT IN ADOLESCENT SMOKERS: CONCORDANCE ACROSS SELF-REPORT AND PSYCHOPHYSIOLOGAL MEASURES

Jennifer C. Veilleux, Jon D. Kassel, Margaret C. Wardle, Adrienne J. Heinz, Justin Greenstein, Daniel P. Evatt, Ashley Braun, Linda Roesch, Eisuke Segawa, & Michael L. Berbaum University of Illinois, Chicago

Descriptors: adolescent, nicotine

Whereas most adult smokers report that smoking cigarettes reduces negative affect (NA), the extent to which NA reduction occurs in adolescent smokers is unclear. Many adolescent smokers do attribute their smoking to affect regulation, yet there is little research that empirically supports this claim. Hence, the current study compared changes in emotion (as measured by the Positive and Negative Affect Schedule, acoustic startle eyeblink latency and amplitude, and skin conductance) and craving in adolescents (N 5 198, mean age 15.7, 54.7% girls). Changes in emotional response were assessed from pre-post smoking and compared to the same smokers in a non-smoking condition and to a group of never-smokers. Participants attended 2 sessions, approximately 6 weeks apart, wherein smokers were randomized to smoke at one of the two sessions. Using SAS PROC MIXED, results revealed that, relative to non-smokers or the no-smoke condition, smoking a nicotine cigarette significantly: (1) increased startle onset latency, (2) decreased skin conductance level, (3) decreased self-reported NA and craving. Smoking exerted a near-significant reduction on startle eyeblink amplitude. Overall, results suggest that even among young, light (12.5 days smoked in the past 30 days, 3.4 cigarettes smoked per day) smokers, cigarette smoking reduces NA as assessed via both self-report and psychophysiology.

Poster 137

THE CLOSED CIRCLE OF EMPATHY: OBSERVING OUTGROUPS DOES NOT RESULT IN SENSORIMOTOR MU SUPPRESSION

Jennifer N. Gutsell, & Michael Inzlicht University of Toronto

Descriptors: empathy, prejudice, EEG

Empathy facilitates prosocial behavior and social understanding. Here, however, we suggest that empathy is bounded to the ingroup because the neural system underlying empathy is less responsive to outgroups than ingroups. Generally, we empathize with others by simulating their bodily states in shared neural networks for experience and perception. Observing others' emotional expressions activates motor areas responsible for the same expressions, which then elicits the associated physiological states and emotions - the foundation for empathy is laid. As an indicator of this simulation process we measured motor neuron activity during actual actions and the observation of others' actions. We defined motor neuron activity as the suppression of EEG oscillations in the mu frequency (8-13 HZ) over sensorimotor cortex (mu suppression at electrodes at scalp locations C3, Cz and

C4). During EEG recording, 31 White participants watched videos of ethnic ingroup and outgroup members performing an action and then performed the action themselves. Supporting our hypothesis, participants showed mu suppression when performing the action and when observing ingroup members. Importantly, they did not show mu suppression when observing outgroup members. Moreover, individual level of prejudice predicted mu suppression in response to outgroup members. These findings provide evidence from brain activity for the concept of bounded empathy: Empathy may be restricted to close others and, without active effort, may not extend to outgroups, making them likely targets for prejudice and discrimination.

Poster 138

EMOTIONS IN VOICE AND MUSIC: SAME CODE, SAME EFFECT?

Nicolas Escoffier, Jidan Zhong, Anqi Qui, & Annett Schirmer National University of Singapore

Descriptors: voice, music

Scientists and philosophers have highlighted many similarities in the way humans convey emotions through voice and music. Some have speculated that these emotional messages recruit similar perceptual processes and affect listeners in the same way. We investigated this proposition in a functional magnetic resonance imaging (fMRI) study during which participants listened to musical excerpts and spoken sentences composed of pseudowords. Musical excerpts and the pseudospeech could vary in emotional connotation from neutral to sad or from neutral to happy. In two different tasks, participants tracked either pitch or emotion changes in these stimuli by using a joystick. Subtracting the low-level pitch task from the emotion task revealed an area in the medial prefrontal cortex that was activated for both music- and voice-emotion judgments, which prior research has implicated in the ability to infer others' emotional and mental states. However, contrasting stimuli rated as neutral, happy or sad indicated differential effects for music and voice. Thus, it seems that although the mechanism of extracting emotional information from these two types of stimuli is comparable, its effect on the listener is not. Moreover, differential responses to emotional messages conveyed in music and voice may point to the different roles these two media play in human communication.

Poster 139

EFFECTS OF COMPLETELY PREDICTABLE AND UNPREDICTABLE AVERSIVE STIMULI ON STARTLE RESPONSES

Brady D. Nelson, & Stewart A. Shankman University of Illinois, Chicago

Descriptors: emotion, predictability, startle reflex

Anticipation of aversive stimuli can yield two types of emotional states: fear and anxiety. One characteristic of aversive stimuli that differentiates these emotions is whether the stimuli are predictable or unpredictable, such that fear is elicited by predictable aver-siveness and anxiety is elicited by unpredictable aversiveness (Davis, 1998; Grillon et al., 2004). When empirically examining predictability, it is important to include conditions where the aversive stimuli are either completely predictable or unpredictable. However, in most studies the predictable condition contains aversive stimuli that are more predictable than the unpredictable condition, but their occurrence is not certain. Therefore, we examined fear and anxiety-potentiated startle in 51 participants who anticipated no (N), predictable/certain (P), and unpredictable (U) aversive stimuli. This study also examined whether the effects of predictability were similar for two types of aversive stimuli (shocks and unpleasant noises). Startle blink reflex was measured using the orbicularis oculi muscle and elicited using a 95 dB acoustic white noise probe. Results indicated that completely predictable shocks (but not unpleasant noises) potentiated fear, while unpredictable shocks and unpleasant noises potentiated anxiety. Our results support predictability as an important feature of aversive stimuli that can differentiate fear and anxiety. However, not all aversive stimuli will induce fear when completely predictable.

Poster 140

EMOTION REGULATION AND THE CHRONOMETRY OF EMOTION-EVOKED ZYGOMATICUS MAJOR ACTIVITY PATTERNS

Ashley Warren, & Keith W. Burton University of Illinois, Springfield

Descriptors: affective chronometry, emotion regulation

The role played by individual difference variables in the processing of emotional stimuli and in their subsequent emotional outputs (e.g., facial expressions) has been relatively unexplored. Emotion regulation is one such individual difference variable and describes efforts undertaken to modulate the experience of emotions, often with the goal of downregulating negative emotion. We examined the role that emotion regulation strategies play in the types of emotional expressions elicited by a standard set of emotional pictures, and in the time course of those emotional expressions. Sixty-three participants (32 women) were recruited, and we assessed two major methods of emotion regulation: cognitive reappraisal and expressive suppression. Participants viewed 36 emotionally salient pictures (12 positive, 12 neutral, and 12 negative) while electromyographic recordings were made of their zygomaticus major muscle activity (i.e., the "smiling" muscle along the cheek). Self-re-

port ratings of the emotion experienced while viewing the images was also recorded. We found that expressive suppression was unrelated to facial expression patterns or time course. Cognitive reappraisal interacted significantly with picture type to produce different patterns of activity over time, with a ''grimace'' pattern of zygomaticus major activity seen during the first three seconds of picture viewing in those who were less likely to engage in cognitive reappraisal to regulate their emotions. This was not seen in those more likely to engage in cognitive reappraisal.

Poster 141

SUBLIMINAL EXPOSURE TO BIOLOGICALLY RELEVANT STIMULI ON AFFECTIVE AND PHYSIOLOGICAL STATES

Pedro J. Rosa1,2, Patricia Arriaga2, & Francisco Esteves2 1Universidade Lusofona de Humanidades e Tecnologias, 2Instituto Superior de Ciencias do Trabalho e da Empresa (ISCTE)

Descriptors: subliminal exposure, fear of snakes, anxiety

A large body of evidence indicates that conscious perception of a stimulus is not a required condition to obtain an emotional response. Exposure to fear-relevant stimuli, even when presented very briefly, can produce an intense negative emotional response. Research also suggests that repeated subliminal exposure to phobic stimuli may lead to affective habituation. Based on the reciprocal inhibition principle, the aim of the present study was to test if subliminal exposure to snakes paired with supraliminal incongruent stimuli (pleasant) might reduce negative affective experience (anxiety and subjective report) and physiological arousal. The role of fear of snakes as a moderating variable was analyzed. Eighty participants, 22 male and 58 female, were randomly assigned to one of the following three experimental conditions: 1) supraliminal exposure to pleasant images preceded by subliminal snake images; 2) supraliminal exposure to neutral images preceded by subliminal snake images; and 3) supraliminal exposure to pleasant images with no subliminal exposure). Heart rate (HR) and skin conductance response (SCR) were recorded. Participants who were exposed to snakes subliminally showed a higher SCR compared to the condition with no subliminal exposure. However, no significant differences were found between the three groups on subjective emotional responses. Taken together, the results are in line with research that suggests an emotional processing of fear-relevant stimuli below threshold of consciousness.

Poster 142

PSYCHOPHYSIOLOGICAL MEDIATION EFFECTS OF EMOTIONAL FACES IMPACT IN TIME PERCEPTION

Alexandre C. Fernandes, & Teresa Garcia-Marques Instituto Superior de Psicologia Aplicada

Descriptors: time perception, emotion, faces

The duration of emotional stimuli is frequently overestimated (in comparison with duration estimates of neutral stimuli). This effect has been attributed to physiological arousal. According to internal-clock and attention-gate timing models, attention focus on stimulus and arousal elicited by the stimulus have opposite impacts on time perception. It is likely the main reason of why previous research reveals inconsistent effects on time perception of emotional valence and arousal manipulations. The present study sought to clarify these inconsistencies in an examination of the physiological mediation effects of emotional dimensions' impacts on time perception. Using a 7-point timing scale, participants estimated the duration (.4 to 1.6 s) of negative and positive emotional faces (valence) with low and high expressivity (arousal). Heart rate (HR), skin conductance (SC) activity, and facial EMG activity of corrugator supercilii (CS) and zygomatic major (ZM) muscles were measured. Duration ratings were higher for high arousing faces, but no overall effect for valence was found. As expected, negative faces, as compared to positive faces, evoked a larger CS activity, whereas positive faces evoked a larger ZM activity. Furthermore, HR deceleration was higher for negative faces, and SC was greater for high emotional faces. Regression analysis only showed an overall mediation effect of SC between stimuli intensity and time perception. These data demonstrated that SC response (arousal index) evoked by emotional stimuli mediates its impact in time perception; and suggests a central role of arousal over attention and valence.

Poster 143

UNCONSCIOUS AFFECT AND ECONOMICS BEHAVIOR: FMRI EVIDENCE FOR STRONGER SUBLIMINAL THAN SUPRALIMINAL AFFECTIVE PRIMING EFFECTS ON FINANCIAL CHOICES

Julie L. Hall1, Richard Gonzalez1, Chandra Sripada1, & Oliver C. Schultheiss2 1University of Michigan, 2Friedrich-Alexander University of Erlangen

Descriptors: affect, unconscious processes, neuroeconomics

Traditional economic models assume that individuals are always rational when they make financial decisions. However, the current study suggests that affect plays an important role in financial decisions and that these processes are occurring at an unconscious level.

Using fMRI, 24 participants viewed happy, angry, and neutral affective primes presented under subliminal and supraliminal conditions followed by an investment task where they had to decide between risky, high-payoff stocks and safe, low-payoff bonds. Our results indicate that both subliminal and supraliminal presentations of affective primes influence financial investment decisions and anticipatory neural activation in the nucleus accumbens. As predicted, participants showed greater nucleus accumbens activation and made more risky investment decisions after happy versus neutral face primes. Furthermore, this effect was stronger for subliminal versus supraliminal affective primes. In conclusion, our results demonstrate that affective primes, even when they are not consciously perceived, can influence investment decisions and neural markers of anticipatory arousal. Our findings point to the role of unconscious affect in decision processes and suggest that ne-uroeconomics research may foster a more comprehensive model of decision making, one that incorporates emotion both consciously and unconsciously, and is able to dissociate the processes involved in decision making.

Poster 144

THE RELATIONSHIP BETWEEN CORTISOL CONCENTRATION, ANXIETY AND ROCK CLIMBING MOTOR PERFORMANCE

Christopher I. Hodgson1, Claire West1, Terry McMorris1, Ian Coleman1, & Nick Draper2 1University of Chichester, 2University of Canterbury

Descriptors: stress, cortisol, motor control

Previous research indicates that cortisol concentrations can relate to subjective anxiety experience during rock climbing. This study examined whether cortisol concentrations might also relate to the quality of a climber's motor performance. Seven climbers completed two identical horizontal climbing problems maintaining consistent heights (.01 m and 2.40 m) on an indoor rock wall. A familiarization, to reduce learning effects, took place on the low route (low stress condition) and the two experimental trials were then completed in random order. Stress levels of climbers were identified through cortisol concentrations assayed from pre and post climb salivary samples and self reported scores on a ten point anxiety thermometer scale. Motor performance variables were climbing time and distance traveled by the climber's center of mass. As expected movement performance was impaired in the higher, increased stress, condition with significant differences showing increased climbing time and distance traveled by the center of mass. Subjective anxiety rating was significantly higher in the high stress condition. Although cortisol concentrations were higher prior to the high stress condition, this difference was not significant. Regression analyses were significant, indicating strong relationships between cortisol concentration and subjective anxiety ratings, and also between climbing time and distance traveled by center of mass in both high and low stress conditions. It seems that cortisol concentrations may be related to subjective experience and motor performance during rock climbing.

Poster 145

AMYGDALA ACTIVATION TO FEARFUL FACES UNDER ATTENTIONAL LOAD

Martin Mothes-Lasch, Wolfgang H.R. Miltner, & Thomas Straube Friedrich Schiller University of Jena

Descriptors: faces, attention, amygdala

While some functional imaging studies have suggested an automatic activation of the amygdala to fearful faces, recent studies have shown the absence of amygdala activation to fearful faces under conditions that induced high perceptual load by means of a distracting task. The present functional magnetic resonance imaging study demonstrates activation of the amygdala to fearful vs. neutral faces even under high perceptual load, when the saliency of fearful faces is increased by manipulating the eyes of the faces. In particular, the removal of iris and pupils of eyes in half of the trials led to a differential activation to fearful vs. neutral normal faces, which was not observed when only normal faces were shown. These findings suggest a relative automaticity of the activation of the amygdala to fearful faces depending on attentional resources and salience of fearful eyes.

Poster 146

ACUTE SOCIAL STRESS MODULATES PASSIVE BUT NOT MOTIVATED VISUAL ATTENTION - A MEG STUDY

Ludger Elling, Janine Bayer, & Markus Junghoefer University of Munster

Descriptors: emotion & attention, stress, MEG

It is widely accepted that stressful experiences profoundly influence cognitive and emotional functioning. However, the ability of stress to modulate emotional perception and emotional learning remains to be determined. Recent studies demonstrated the impact of stress on several processes of sensation, cognition and neurocrine states. According to this, we expected acute stress to modulate passive as well as motivated attention to task-irrelevant emotional pictures. In particular, we predicted a non-specific enhancement of passive

attention in the C1, P1 and N1 time range, and enhanced sensory processing of emotional pictures in the EPN time interval (120 - 300 ms). Healthy subjects were exposed to a potent and a weak social evaluative stressor, while being presented with emotional slides. Event Related Fields were recorded with whole head 275 sensor MEG. Peripheral, endocrine and self-assessment data were used to verify the stressor and stratify our sample. As a main effect of stress, we observed markedly enhanced occipital cortical activity in the expected time range. With respect to correlates of emotional processing, however, no modulation whatsoever emerged. We discuss our data in terms of external attraction for attention and competition for processing resources.

Poster 147

ENGAGING IN A COGNITIVE TASK INHIBITS NEGATIVE EMOTION

Saea Iida, & Hideki Ohira Nagoya University

Descriptors: emotion regulation, unpleasant emotion, IAPS

In the present study, we investigated whether or not engaging in a cognitive task can inhibit subsequent negative emotion automatically. For this purpose, we measured self report (PANAS) and physiological responses (HR and SCL) to three cognitive tasks. Forty students participated in this study, and were divided into three experimental groups (the n-back group, the go/no-go group, and the WCST group) and one control group. Participants underwent four stages within one session: baseline (10 min), cognitive task (5 min), emotion induction task (10 min), and recovery (10 min). At the baseline stage, all participants were asked to stay calm. At the cognitive task stage, all participants were presented with the same stimulus sequence, but participants in three experimental groups were asked to engage in one of three cognitive tasks, and participants in the control group were asked to view the stimulus sequence passively. At the emotion induction task, all participants were asked to evaluate the unpleasantness of affective pictures. At the recovery stage, all participants were asked to stay calm again. We collected self reports of unpleasant emotion between the stages, and measured physiological responses through the whole session. Results showed that, compared with the control group, the three experimental groups showed inhibited negative-emotion-related responses in self report and physiological responses after and during the emotion induction task, respectively. These results suggest that engaging in cognitive tasks can be used to regulate our unpleasant emotion automatically.

Poster 148

THE HEART OF THE MUSIC: MUSICAL TEMPO AND CARDIAC RESPONSE

Robert J. Ellis, John J. Sollers III, Bradley M. Havelka, & Julian F. Thayer Ohio State University

Descriptors: heart rate variability, phasic heart rate, music

Purpose: Empirical investigations of heart rate (HR) responses to music date back over 125 years. Most have examined differences in mean HR in response to music, with inconsistent results. Two less-frequently investigated measures (HR variability and phasic HR) that index beat-to-beat changes in HR (rather than mean HR) may provide better windows into cardiac response to music. HR variability is a sensitive measure of parasympathetic nervous system activity; higher resting levels of HR variability have been consistently linked with greater health, emotional well-being, and cognitive flexibility. Phasic HR is considered to index adjustments in attention and emotional processing. METHODS AND RESULTS: We varied the tempo (60, 90, 120 beats per minute) of computer-generated (MIDI) performances of ragtime piano music. Experiment 1 examined HR variability to 2.5-min excerpts of music, and revealed significant differences in HR variability but not mean HR. Experiment 2 examined phasic HR responses to 12 - 16-s excerpts of music, and revealed that phasic responses increased in magnitude as tempo increased, suggesting that tempo differentially affects HR within a few moments of music onset. Additionally, intersubject differences in phasic HR were related to baseline levels of HR variability, suggesting that HR variability indexes the potential for cardiac flexibility.

Poster 149

EMOTIONAL AND PSYCHOPHYSIOLOGICAL RESPONSES TO FOOD STIMULI

Isabel Santos1, Ameerico Baptista1, & Francisco Esteves2 1Universidade Lusofona de Humanidades e Tecnologias, 2Instituto Superior de Ciencias do Trabalho e da Empresa (ISCTE)

Descriptors: emotion, psychophysiology, food

Emotional and psychophysiological responses under the visualization of food stimuli were studied using self-report and physiological, (facial EMG, SCR and HR) measures. Participants (N 5 56), viewed three visual stimuli categories (neutral objects, high caloric and low caloric food) that were presented with equal probabilities, and had to evaluate the images using the Self Assessment Manikin. Subjects reported more valence to the visualization of low caloric food and demonstrated more activation when they

visualized the high caloric food stimuli. No differences were found for the EMG (co-rrugator and zigomatic), SCR and HR response. Subjects were then divided in two groups (higher disgust sensitivity and lower disgust sensitivity). Contrarily to the SAM evaluation, no differences were found in psychophysiological responses in function of the stimuli category. These findings suggest that the category of the stimuli is relevant for the emotional response but not for significant psychophysiological differences. Results will be discussed according to the theoretical models.

Poster 150

VISUAL SCANPATHS AND PUPIL RESPONSES TRIGGERED BY EMOTIONAL FACIAL EXPRESSIONS ARE DIFFERENTIALLY AFFECTED BY TASK DEMANDS

Elisa Scheller1, & Matthias Gamer2 1University of Mainz, 2University Medical Center Hamburg-Eppendorf

Descriptors: facial expression, emotion, eye tracking

Previous studies showed differences in visual scanpaths when viewing happy versus fearful facial expressions: whereas subjects fixated more often on the mouth region for the former, they showed enhanced gaze preferences for the eye region ofthe latter. In the current study, we wanted to examine to what degree these gaze orientations depend on picture presentation time and type of task. Fearful, happy and neutral faces were presented to 24 participants either for 150 or 2000 ms. Three different tasks had to be accomplished in separate blocks: emotion classification, gender discrimination and passive viewing. A high speed eye tracking system was used to measure eye movements as well as pupil responses after picture onset. Across all tasks and presentation times, participants showed a strong bias to shift their gaze towards the eye region. However, this response pattern was modulated by facial expression and was strongest for fearful and neutral faces. Poststimulus pupil dilatation - an index of sympathetic nervous activity - was largest for fearful faces when participants were explicitly required to identify the depicted emotion. No such modulation was found for the gender discrimination or the passive viewing task. These findings indicate that reflexive gaze orienting towards the eyes is modulated by the facial expression irrespective of task demands. Differential sympathetic activity, however, is selectively enhanced when the emotional expression is required to be processed explicitly. The hypothesized role of the amygdala in mediating these effects will be discussed.

Poster 151

EMOTIONAL BEHAVIOR IN SUBCLINICAL PSYCHOPATHY

Kristen L. Godenick, & Paul E. Haerich Loma Linda University

Descriptors: emotion, startle, psychopathy

The unique interpersonal qualities of individuals who fall on the so-called 'psychopathic spectrum' have been regularly documented since Cleckley's observations. The literature reflects the importance of understanding individuals who have high and low levels of psychopathic personality traits for research, clinical and risk assessment purposes through bringing forth the position that psychopathic traits can fall on a continuum. The purpose of this study was to investigate the association between psychopathic personality traits in the general population and deficits in emotion modulated psycho-physiological responses as well as deficits in emotionally influenced decision making. Results indicated that individuals with higher levels of Fearless Dominance, as measured by the Psychopathic Personality Inventory, Revised had attenuated fear responses (r 5 — .26; Chi-square 5 5.286, p < .05), but there were no significant abnormalities in responses to other emotional conditions. There was no association between psychopathic personality traits and emotionally influenced decision making as measured by the Iowa Gambling Task suggesting that at subclinical levels, psychopathic personality traits have a negligible influence on an individual's use of somatic markers to guide behavior.

Poster 152

CARDIOVASCULAR AND EEG INDICATORS OF ANGER AND CONTROL/NO CONTROL STATES

Elena Spiridon, & Stephen H. Fairclough Liverpool John Moores University

Descriptors: anger, control, psychophysiology

Psychophysiological responses during states of anger can be confounded with reactions associated with the perception of control. The aim of the study was to identify psy-chophysiological markers of anger in combination with levels of control during a laboratory task. Forty participants were split into four experimental groups: anger/no control, anger/control, neutral/no control and neutral/control. Anger (anger state vs. neutral state) was manipulated via an experimenter effect (i.e., rude vs. polite experimenter). Participants were exposed to a computer-based problem-solving task where the keyboard either worked correctly (control) or malfunctioned (no control). Various psychophysiological variables (blood pressure, cardiovascular impedance and frontal EEG asymmetry) were obtained in addition to subjective data. Self-report measures indicated that the manipulation of anger and control was successful. Systolic blood pressure increased significantly during the anger/no control state only. Cardiovascular

impedance measures were not sensitive to the experimental conditions. The frontal polar site showed the expected right-brain activation in the anger/no control condition. In conclusion, systolic blood pressure and frontal polar brain site are indicators ofanger in combination with the perception of a state of no control, suggesting that emotion and motivation interact with each other intensifying psychophysiological reactions.

Poster 153

EFFECTS OF NICOTINE AND BUPROPION ON P3-INDEXED DISTRACTION BY AFFECTIVE AND SMOKING-RELATED PICTURES

David G. Gilbert, Chihiro Sugai, Swetha Murali, & Elizabeth Kreke Southern Illinois University Carbondale

Descriptors: smoking, pharmacotherapy, emotion

While nicotine replacement therapy (NRT ) and bupropion SR (BUP) are the two most widely used and studied drug treatments for smoking cessation, little is known about the psychobiological mechanisms associated with the efficacy of these two medications. Thus, 37 smokers were randomly assigned to NRT, BUP, or placebo (PLA) during smoking abstinence. The ability of negative, positive, neutral, and smoking-related pictures to attenuate P3 responses to occasionally occurring target digits immediately subsequent to picture offset was assessed. Post-quit Day 3 and Day 24 change scores of P3 amplitude from pre-quit/pre-drug baseline revealed a significant Treatment Type x Distractor Picture Type x Electrode (4 midline levels: central through occipital) interaction, F(18, 306) 5 2.68, p 5 .001. Follow-up analyses revealed that, relative to PLA, BUP enhanced P3 amplitude to target digits preceded by emotionally negative pictures and targets preceded by smoking pictures. That is, BUP reduced distraction by negative and smoking-related pictures as indexed by reduced P3 attenuation. In contrast, relative to PLA and BUP, NRT reduced distraction by emotionally positive pictures at the occipital electrode. While the finding that BUP reduced distraction by negative and smoking-related stimuli is consistent with the reported ability of BUP to reduce smoking urges and negative affect, the failure of NRT to produce similar effects suggest that the two smoking cessation drugs differ in the means by which they help smokers refrain from smoking.

Poster 154

ATTENTIONAL REDEPLOYMENT AS AN EFFECTIVE EMOTION REGULATION STRATEGY IN DEPRESSION

Martin J. Herrmann1, Maike Georgs2, Andreas Muhlberger3, Alexandra Rebhan2,

Paul Pauli3, & Andreas J. Fallgatter1 1University of Wurzburg, Clinic for Psychiatry, Psychosomatics and Psychotherapy, 2University of Wurzburg, 3University of Wurzburg, Institute of Psychology

Descriptors: emotion, ERP, attention

Recent studies have shown that cognitive reappraisal can be used as an effective emotion regulation strategy in healthy controls, leading to decreased amygdala activity and to less pronounced late positive potentials (LPP) in the EEG. In contrast, depressive patients fail in effective top-down control of negative emotions by reappraisal strategies (Johnstone et al., 2007). A recent study (Dunning and Hajcak, 2009) showed that cues leading the visual attention to a non-emotional focus within unpleasant images can also reduce the LPP. Therefore, attentional redeployment might be another emotion regulation strategy, which might be effective in depressive patient. To test this hypothesis we measured the even-related potentials (ERPs) in 20 depressive patients and 20 healthy controls during emotional picture processing. The instruction to look at a non-emotional part within the pictures lead to a significant reduction in the LPP (and even earlier in time course) compared to the instruction to look at the hot spot of the emotional pictures. Interestingly, we found this reduction not only in healthy controls but also in depressive patients. Our study suggests that simply instructing subjects to look at the non-emotional part of a picture/scene might be a useful emotion regulation strategy, not only for healthy controls but also for depressive patients.

Poster 155

SLEEP DEPRIVATION POTENTIATES PHYSIOLOGICAL REACTIVITY TO NEGATIVE AFFECTIVE STIMULI IN HEALTHY YOUNG ADULTS

Peter L. Franzen, Daniel J. Buysse, Denise N. Duryea, Annette Wood, & Greg J. Siegle University of Pittsburgh

Descriptors: sleep deprivation, emotional reactivity, pupil dilation We used pupil dilation as an objective, physiological indicator of emotional reactivity responses to standardized affective picture and sound stimuli in two tasks. Using a within-subjects crossover design, healthy young adults 18-25 years old were tested under two experimental conditions separated by 1 week: sleep deprivation (SD; following a night of total SD) and rested wakefulness (RW; following a night of normal sleep). For the sound task (n 5 8), negative, neutral, and positive sounds (14 each) were randomly presented for 6 s followed by an 8 s ISI. Pupil dilation was significantly larger in response to negative compared to non-negative sounds during both SD (F(1,7) 5 10.4, p

5 .015) and RW (F(1,7) 5 8.6, p 5 .022). SD impacted the time course of this response; significant differences between the negative versus non-negative pupil dilation waveforms emerged earlier (.8 s) and persisted longer (.5 s) longer in SD compared to RW. For the picture task (n 5 11), 24 negative and neutral stimuli were randomly presented for 2 s followed by an 8 s ISI. During SD, negative pictures resulted in a sustained and exaggerated pupil dilation response compared to neutral pictures (F(1, 10) 5 42.9, p < .05).

Poster 156

ATTENTIONAL RESOURCES AND NEGATIVITY BIAS

Yu-Xia Huang, & Yue-Jia Luo Beijing Normal University

Descriptors: emotion, attention, late positive component

The current study aimed to explore the relationship between attentional resources and the emotional negativity bias. A cue-target paradigm was used to manipulate attention. In the valid cueing condition subjects could obtain sufficient attention resources, while in the invalid cueing condition resources were relatively insufficient. It was noteworthy that both attention levels in the current experiment were far more beyond attention scarceness. Positive, neutral and negative pictures from the International Affective Picture System and the Chinese Affective Picture System were transformed into upper and lower adjacent patchworks of the normal scene and its inverted copy. Seventeen undergraduate students participated in the study. They were instructed to pay attention to the structure of the patchworks and to judge whether the normal scene was located in the upper or lower part of the whole patchwork. Significant interactions between emotion and attention were found in LPC difference waves. In the sufficient attention condition, there was no obvious difference between 'positive minus neutral' and 'negative minus neutral'. In contrast, the LPC amplitude of 'negative minus neutral' was significantly larger than that of 'positive minus neutral' when the attention resource was relatively inadequate. This study suggests that when enough attention resources are available, positive information can be processed in the same way as negative information. The processing superiority of negative events is more likely to take effect in situations that attention resource is not adequate.

Poster 157

DECISION-MAKING IN THE ULTIMATUM AND DICTATOR GAMES

Johannes Hewig1, Nora Kretschmer1, Ralf H. Trippe1, Holger Hecht1, Michael G.H.

Coles2, Clay B. Holroyd3, & Wolfgang H.R. Miltner1 1Friedrich Schiller University of Jena, 2FC Donders Centre for Cognitive Neuroimaging (FCDC), 3University of Victoria

Descriptors: decision-making, feedback negativity, skin conductance In the Ultimatum Game a proposer splits an amount of money and offers a share to a receiver. The receiver decides whether to accept the share or to reject it. Rational choice theory predicts that human receivers always accept all offers. However, unfair offers are rejected in 50% of trials if the share offered is 20% of the total amount. We used the Ultimatum and Dictator games to examine the affective correlates of decision-making in psychophysiological and subjective emotional parameters. We measured event-related potentials and skin conductance responses of receivers during both games. In addition, participants provided subjective emotional ratings towards offers. Participants showed increased feedback negativity, skin conductance responses, and negative emotional ratings to unfair offers. Furthermore, the decision to reject offers in the Ultimatum Game was related to participants' increased negative emotional reactions, to their increased activity in the autonomous nervous system, and to their increased feedback negativity. The findings suggest that emotion is a very important factor in economic decision-making.

Poster 158

EMOTIONAL PROCESSING AND AUTONOMIC RESPONSES IN PATIENTS WITH AUTONOMIC HYPERACTIVITY

Satoshi Umeda1,2,3, Neil A. Harrison4,5, Marcus A. Gray5, Christopher J. Mathias3,6,

& Hugo D. Critchley5 1Keio University, 2Institute of Cognitive Neuroscience, University College London, 3Autonomic Unit, National Hospital for Neurology and Neurosurgery, University College London, 4Institute of Cognitive Neuroscience, University College London, 5Brighton and Sussex Medical School, University of Sussex, 6Neurovascular Medicine Unit, Imperial College London at St Mary's Hospital

Descriptors: autonomic hyperactivity, emotion

Previous functional imaging studies provide evidence for neural integration of human emotions and autonomic bodily responses. However, it remains unclear how primary autonomic disorders influence emotional processing. The present functional MRI study investigates how heightened bodily reactivity shapes excessive emotional responses. We recruited patients with autonomic hyperreactivity (postural tachycardia syndrome, POTS) and age-matched normal controls. Participants were scanned with heart rate recording when judging emotional pictures, consisting of five emotion-specific categories of faces and scenes. The POTS patients showed an excessive rise in heart rate from onset of each stimulus presentation, when compared to controls. The results of the fMRI data showed much greater deactivation within ventromedial prefrontal cortex (VMPFC, BA11) and right dorsolateral prefrontal

cortex (BA9) in the patients compared to controls. In contrast, greater activation in midline structures; precuneus (BA7), anterior prefrontal cortex (BA10), and rostral anterior cingu-late cortex, were found in the patients compared to controls. Further investigations showed that globus pallidus (GP), pons, and VMPFC were significantly correlated with higher state anxiety in the patients. Overall findings suggest that hyperreactive bodily states trigger disruptive emotional status by increased attenuation of activity within VMPFC impacting on GP function. Our study highlights the possible neural mechanisms for understanding emotional disturbance in autonomic hyperreactivity disorders.

Poster 159

AFFECTIVELY-MODULATED STARTLE REFLEX PATTERNS ARE INFLUENCED BY USE OF HORMONAL ORAL CONTRACEPTION

Keith W. Burton, Lindsey Kucera, Jeanine Sellman, Dawn Tompkins, Sarah Wolsfeld, & Ashley Warren University of Illinois, Springfield

Descriptors: startle reflex, ovarian hormones

Ovarian cyclic hormones have previously been shown to influence emotions (e.g., premenstrual dysphoric disorder), yet few studies have examined how these hormonal changes influence basic emotion processing. This study examined the influences of menstrual cycle phase (luteal vs. follicular) and use of hormonal oral contraception on several measures of emotional experience and physiology. Twenty-seven participants were tested during luteal or follicular phases of their menstrual cycles, nine of whom were using oral contraception. Participants viewed 36 emotionally salient images (12 positive, 12 neutral, and 12 negative) and reported their experiences of emotional valence and arousal after each. During image presentation EMG recordings were made of corrugator superscilii, zygomaticus major, and orbicularis oculi startle reflex activity. Corrugator and zygomatic EMG patterns and emotional valence and arousal ratings were unaffected by menstrual cycle phase or contraception use. The traditional linear valence pattern of startle reflex modulation (negative > neutral > positive) was observed in those not using oral contraception, but a quadratic pattern (negative and positive > neutral) of startle reflex modulation was observed in those using oral contraception.

Poster 160

OCCUPATIONAL EXPOSURE TO A CONDUCTIVE ENERGY DEVICE: EFFECTS ON CARDIOVASCULAR PARAMETERS

Kirsten M. VanMeenen1, Michael T. Bergen1,2, Neil S. Cherniack1, & Richard J. Servatius1,2 1University of Medicine & Dentistry of New Jersey-New Jersey Medical School (UMDNJ-NJMS), 2Department of Veterans Affairs New Jersey Health Care System

(VA-NJHCS)

Descriptors: stress, autonomic, electromuscular interference

Conductive energy devices (CED) are popular for incapacitating individuals for short periods of time. The impact of these devices on cardiovascular parameters during exposure in humans is relatively controversial. Resolving these controversies is difficult. A primary reason is obtaining direct measures of electrical activity of the heart (e.g., electrocardiogram) during exposure is made impractical given the voltage, frequency and capacitance of the discharge of CEDs. Recent advances in pulse oximetry offered the promise of obtaining derived heart rate from a measure unaffected by the CED itself. In the occupational setting, law enforcement officers undergoing training for the use of CED volunteered to participate in data collection involving pulse oximetry (continuous), temperature, respiration, and ECG (discontinuous) before, during and after exposure to the device discharge. Discharge was typically 5-s in duration. Heart rate increased dramatically in the minutes leading to exposure. Heart rate, derived from pulse oximetry obtained from the earlobe, was relatively unchanged over the 5-s discharge in 50/55 participants; there was no evidence of missed beats. Heart rate variability showed increased sympathetic power in the period leading to discharge and shortly thereafter while parasympathetic power was relatively low and unchanged during this period of time. These data suggest that while anticipation of exposure to CEDs is a potent stimulator of the heart, exposure to the actual discharge shows relatively little impact on these parameters.

Poster 161

INTEROCEPTIVE SENSITIVITY MODULATES IMPLICIT MEMORY OF EMOTIONAL WORDS

Natalie S. Werner, Isabella Peres, & Rainer Schandry Ludwig Maximilian University of Munich

Descriptors: interoception, emotion, memory

The ability to perceive bodily signals (''interoceptive sensitivity'') has gained in importance in theories of emotion. Consistent with these theories, numerous studies have shown that individuals with a higher sensitivity to bodily signals experience emotions more intensely. The present study explored the influence of interoceptive sensitivity on implicit memory performance of emotional information. It was predicted that participants with high interoceptive sensitivity show a bias to emotional material. In our study, we exposed 30 participants with high interoceptive sensitivity and 30 participants with low interoceptive sensitivity to positive, negative and neutral words. During word presentation, heart rate and skin conductance

responses were measured. After a subsequent filler task, participants were asked to complete primed and unprimed word stems. Implicit memory was assessed in terms of accuracy for completion. The results demonstrate that participants with high interoceptive sensitivity recalled significantly more positive and negative words, whereas no differences were found between the groups for neutral words. Participants with high and low interoceptive sensitivity did not differ with respect to physiological measures, which have previously been shown to mediate memory. Our findings suggest that the perception of bodily signals enhances unconscious recall of emotional words. We assume that this effect is modulated by better access to "somatic markers'' which arise in emotional situations and support emotion processing.

Poster 162

A NOVEL PARADIGM FOR EXAMINING ADOLESCENTS' NEURAL RESPONSE TO PARENTS' AFFECT

Erika E. Forbes1, Lisa B. Sheeber2, & Nicholas B. Allen3 University of Pittsburgh, 2Oregon Research Institute, 3University of Melbourne

Descriptors: adolescent development, affect regulation, brain function Affect in the family environment is critical to healthy functioning and risk for psycho-pathology during adolescence. Because functional magnetic resonance imaging (fMRI) paradigms for studying affect-related brain function typically rely on static images of strangers, which have little ecological validity, we developed an fMRI paradigm using dynamic, personally relevant stimuli: video clips of participants' parents expressing neutral, pleasant, dysphoric, and aggressive affect during an actual parent-adolescent interaction. Eleven healthy adolescent girls underwent fMRI in a 3T Siemens Allegra scanner. Stimuli were obtained from an earlier assessment in which participants and their parents discussed a conflict-eliciting topic and a future vacation. Data were analyzed in SPM2. When viewing parents expressing neutral affect compared with a stranger, adolescents exhibited reactivity in the anterior cingulate, prefrontal cortex, striatum, and insula. During parents' affect, adolescents exhibited reactivity to parents' affect in a set of regions including the striatum, anterior cingulate, insula, medial prefrontal cortex, and dorsolateral prefrontal cortex. Adolescents' depressive symptoms were related to medial prefrontal reactivity during parents' pleasant affect and inversely related to insula reactivity during parents' dysphoric affect. This paradigm appears to be feasible and potentially valuable for investigating adolescents' affective responses to the family environment.

Poster 163

ABBERANT SOCIAL AND CEREBRAL RESPONDING IN A COMPETITIVE REACTION TIME PARADIGM IN PSYCHOPATHS

Martin Lotze1, Ralf Veit2, Sven Sewing2, H. Missenhardt3, Tilmann Gaber2, & Niels Birbaumer2

1Functional Imagining Unit, Center for Diagnostic Radiology and Neuroradiology, University of Greifswald, 2Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, 3Center of Psychiatry, Bad Schussenried

Descriptors: psychopathy, reactive aggression, prefrontal lobe

Emotional and interpersonal deficits are core features of psychopathy. In this study we investigated behavioral and neural responding of psychopathic individuals during a painful physical provocation task. Ten subjects from a forensic psychiatric institution participated in a functional magnetic resonance imaging study using an interactive competitive reaction time paradigm, involving putative mutual physical punishment for slow reaction time. Prior to scanning, subjects were clinically screened for psychopathy and completed several self report scales of aggression and psychopathy. For retaliation trials, the comparison between high and low pain intensity adjustments revealed activations in an aggression associated circuitry (hypothalamus, inferior orbitofrontal cortex). The intensity of physical aggression showed a positive correlation with hypothalamic activation. Medial prefrontal areas, associated with emotional control and conflict management, found in healthy volunteers, were inactive in psychopathic subjects. During observation the opponent, activations in the dorsal and ventral medial prefrontal cortex were strongly modulated by impulsivity and antisocial behavior but showed no relation with the callous unemotional features of psychopathy. The present study supports the notion that reactive aggression is rather related to antisocial behaviour and anger management than to emotional and interpersonal characteristics of psychopathy.

Poster 164

ANXIETY'S DOUBLE-EDGE: A MEG STUDY

Brian R. Cornwell, Sven Mueller, Raphael Kaplan, Christian Grillon, & Monique Ernst National Institutes of Mental Health

Descriptors: MEG, threat, saccades

Background: Anxiety is mostly recognized as an impediment to cognitive performance. However, opposite effects are also noted. Anxiety associated with the threat of shock modulates top-down attentional control that determines orienting behavior. This modulation can serve to enhance rapid responses to potentially dangerous stimuli, but can interfere with ongoing cognitive processes. The neural mechanisms underlying this double-edged influence of anxiety on cognition remain unclear. Our goal was to examine these mechanisms. Methods: Using magnetoelectroencephalography (MEG), seventeen healthy adults performed a saccade eye-movement task in a threat (electric shock) and a safe

condition. The saccade task permitted us to assay both rapid, prepotent (prosaccades) and controlled, non-prepotent behavioral responses (antisaccades). Results: As expected, threat, relative to safe, conditions facilitated prepotent responses (reduced prosaccade latency) and impeded controlled responses (lengthened antisaccade latency). The [threat vs. safe] contrast differentiated the neural modulation by anti- and prosaccade of the dorsal stream (prefrontal and parietal regions) and the ventral stream (occipitotemporal region) of attentional systems, superior colliculus and rostral anterior cingulate cortex (ACC). Conclusion: Anxiety by threat of shock facilitated stimulus-bound responses and hindered controlled responses by influencing information processing via the dual attentional system, conflict monitoring via ACC, and saccade inhibition via superior colliculus.

Poster 165

ASYMMETRIES OF EMOTIONAL PERCEPTION IN WOMEN WITH HISTORY OF DEPRESSION

Gina M. Grimshaw, Amy Walsh, Matt Crawford, & Kathryn Campbell Victoria University of Wellington

Descriptors: emotion, depression, laterality

Depression is associated with a rightward shift in frontal activation as measured with EEG, and a shift toward right hemisphere language processing as assessed with perceptual asymmetries. Hemispheric changes are trait dependent, and continue to be observed in previously-depressed individuals in remission. Previous research has focused on the assessment of language asymmetries; the present study examined asymmetries in the processing of lexical, prosodic, and facial emotion. Participants were 32 women who reported previous therapy for depression, and 32 controls who reported no history of depression. None exhibited clinical depression at the time of assessment, and the two groups did not differ in depression or anxiety. In the first session, participants completed a dichotic listening task which assessed lateralization for the processing of words and emotional prosody, a divided visual task which assessed reading of emotional words, and a chimeric faces task which assessed asymmetries in the perception of facial expression. In a follow-up session, four minutes of resting EEG were collected, yielding an asymmetry index that reflected hemispheric difference in alpha power at midfrontal and lateral frontal sites. Differences between groups were observed on all measures. Compared to controls, previously-depressed women were less lateralized for processing speech, and more lateralized for processing lexical and facial emotion. Groups did not differ in processing of emotional prosody. Findings suggest a relationship between cognitive and neurological asymmetries in depression.

Poster 166

EVIDENCE FOR SEX DIFFERENCES IN CEREBRAL LATERALITY: EXAMINING CHANGES IN SYSTOLIC BLOOD PRESSURE REGULATION AND TIME ESTIMATION BEFORE AND AFTER EXPOSURE TO A COGNITIVE STRESSOR

Alissa K. Holland1, Joseph E. Carmona2, David W. Harrison2, Brooke T. Hunter1,

Leah S. Leak1, Caroline Nunnery1, & Terri Polenski1 1University of South Carolina Lancaster, 2Virginia Polytechnic Institute and State University

Descriptors: cerebral laterality, sex differences, time estimation

Cerebral laterality plays an important role in cardiovascular regulation in response to stressors. Lateralization of function differs in men and women on a variety of neuropsy-chological tasks (Harrison et al., 1990). It was expected that men would exhibit increased cardiovascular reactivity to stress as evidenced by greater resting levels of systolic blood pressure (SBP), leading to longer time estimations for men after exposure to a cognitive stressor. Twenty-seven undergraduate right-handed men and 13 women were recruited for participation. Each participant completed six consecutive 30-second time estimations before and after completing the Ruff Figural Fluency Test. Blood pressure was taken after each manipulation. A Sex x Condition interaction was found (F(1, 38) 5 4.15, p < .05), indicating a relative increase in SBP in women in the post stress condition. Moreover, there was a Sex x Trial interaction for perseverations (F(5, 241) 5 3.5, p < .01), indicating longer time estimations for men in later trials relative to women. These findings have implications for sex differences in the ability to estimate time concurrent with regulation of right hemisphere stress. The Sex x Trial interaction may indicate greater relative activation of the right hemisphere when estimating short periods of time concurrent with regulating right-lateralized stress. Although women evidenced greater SBP after undergoing right-lateralized cognitive stress, time estimations remained shorter across trials indicating greater involvement of the left hemisphere in the post stress condition.

Poster 167

THE EFFECTS OF FACIAL FEEDBACK ON SPONTANEOUS EYEBLINKING WHILE RECEIVING PLEASANT-UNPLEASANT VISUAL STIMULI

Yasuko Omori, & Yukiko Tatsuhira Jin-ai University

Descriptors: spontaneous eyeblink, facial feedback, pleasant-unpleasant visual stimuli The purpose of this study was to investigate the effects of facial feedback on spontaneous eyeblink rates during pleasant-unpleasant visual stimuli. While spontaneous eyeblinking

reflects inner states (i.e., arousal, anxiety, stress, and attention), some studies have recently been made on the relations between eyeblinking and emotions or interpersonal factors. The participants were 23 university students, 12 males and 11 females. They were presented with a series of 36 photos on a 20-inch monitor, divided into two categories of pleasant and unpleasant photos, consisting of 18 photos respectively. The participants' facial expressions of happiness, neutrality and sadness were manipulated when looking at the pictures. After each stimulus presentation, participants rated their own emotions and the degree of difficulty regarding manipulated facial expressions. They repeated two sessions, with a 6-second duration of each stimulus. Eyeblinks were identified with the video recordings of the participants' faces, and heart rates were measured with ECG recordings. The results of the blinking rates sorted in descending order were: neutral condition, happy one and sad one. Eyeblinks occurred frequently during pleasant stimuli, which was remarkably notable when the neutral expression was manipulated. Furthermore, heart rates were significantly lower in the neutral condition than those in the sad one. Therefore, it is suggested that spontaneous eyeblinking can be used as a reliable physiological index to exhibit emotions in terms of facial feedback.

Poster 168

AFFECTIVE MODULATION OF STARTLE EYE-BLINK TO EMOTIONAL PICTURES OF VARYING AROUSAL LEVEL IN BORDERLINE PERSONALITY DISORDER PATIENTS WITH AND WITHOUT COMORBID SUBSTANCE USE AND CONTROLS

Joseph S. Baschnagel1, Scott F. Coffey2, Larry W. Hawk, Jr3, & Julie A. Schumacher2 1Rochester Institute of Technology, 2University of Mississippi Medical Center, 3University at Buffalo

Descriptors: borderline personality disorder, emotion, startle reflex Affective dysregulation is theorized to be a central feature of Borderline Personality Disorder (BPD), yet limited research has directly assessed this feature. Bilateral startle eyeblink data were collected to measure affective responses during presentation of, and recovery from, emotional pictures varying in valence (positive, negative) and arousal (low, medium, high) and neutral pictures. Participants included 33 BPD patients with comorbid substance use disorder (BPD-SUD), 13 BPD patients without SUD, and 45 healthy controls. Startle data were aggregated across 3 & 5 s trials and 7 & 9 s trials to create picture and recovery trials respectively. There was a significant affect x arousal x group interaction, with the BPD and control groups exhibiting significantly greater startle magnitude during high arousal negative trials compared to high arousal positive valence trials; the BPD-SUD group showed no differences between affect or arousal conditions. The startle response affect x arousal x group interaction was not moderated by picture versus recovery condition. The results will be discussed in relation to theories of affective dysregulation and the role of substance use in BPD.

Poster 169

EMOTIONAL MODULATION IN PSYCHOPHYSIOLOGICAL DISORDERS

Alfonso Salgado1, & Almudena Duque2 1Pontificia University of Salamanca, 2Complutense University of Madrid

Descriptors: stress disorders, emotion, cardiac reactivity

Some theoretical models (Everly, 1989; Farmer and Crespo, 1993; Salgado et al., 2006) propose that automatic defensive processing is one of the factors involved in the genesis of psychophysiological disorders associated with stress, so these types of subjects usually present more autonomic and somatic reactivity than normal subjects. Differences between normal subjects and patients with different psychophys-iological disorders -with cardiovascular implications- were examined in terms of cardiac reactivity and startle eyeblink during emotional picture viewing. IAPS slides (CSEA, 2006) were used, and they were selected in accordance with the Spanish version (Molto et al., 1999) Groups were compared in cardiac maximum deceleration, cardiac maximum acceleration and startle eyeblink. Greater cardiac acceleration and cardiac deceleration were observed in subjects with psychophysiological disorders, suggesting effects on cardiac reactivity. However, no significant differences were observed in startle eyeblink. Theoretical and applied implications for these results are discussed.

Poster 170

AUTOMATIC AND CONTROLLED PROCESSING IN STRESS DISORDERS

Almudena Duque1, & Alfonso Salgado2 1Complutense University of Madrid, 2Pontificia University of Salamanca

Descriptors: stress disorders, emotion, cardiac reactivity

Lang's theoretical and experimental model was applied to establish emotional stimuli differences between subjects with psychophysiological disorders and normal subjects. Pleasant, unpleasant and neutral stimuli were selected from IAPS (Spanish version, Molto et al., 1999). A white noise burst was used (500 msec/ 60 dB) to measure startle reflex while subjects viewed the pictures. Emotional modulation was measured in cardiac reactivity and

startle eyeblink, registering EMG changes from the orbicularis oculi. In addition, differences in affective valence, arousal and dominance ratings were estimated employing the Self Assessment Manikin (SAM, Lang et al., 2001). Successive MANOVAs were conducted. Significant differences were observed in autonomic changes and startle eyeblink for different types of stimuli. The same results were observed in controlled processing. Two different patterns were revealed in emotional modulation ofthe cardiac reactivity and startle eyeblink when both samples of subjects were compared. When controlled processing of pictures were analyzed, there were no significant differences between groups. Theoretical and applied implications for these results are discussed.

Poster 171

VOICE PARAMETERS, HEART RATE CHANGES, AND SKIN CONDUCTANCE RESPONSES IN ANIMAL FEAR

Anders Flykt1, Tanja Banziger1,2, & Sofie Lindeberg1 1University of Gavle, 2University of Geneva

Descriptors: fear, animals, voice

Participants fearful of snakes or spiders viewed color photographs of snakes, spiders, and rabbits presented on a computer screen. Arrow-shaped probes were sometimes superimposed on the animal pictures, and the task of the participants was to say ''upp'' (up) if the arrowhead was pointing upwards or ''ner'' (down) if the arrowhead was pointing downwards. Participants were asked to answer quickly without jeopardizing the accuracy of their answers. The probes were presented with stimulus onset asynchronies (SOAs) of 300 or 600 ms from the picture onsets. Excerpts from voice, also ECG and SC were recorded. The results showed effects of exposure to the fear animal when probed at SOA 600 ms, but not at 300 ms. The results question that fear is activated fast, or if it is activated fast, the results question if a fear response follows its course once initiated.

Poster 172

HEART RATE VARIABILITY CHANGES AT COMPUTER SIMULATION OF AGGRESSIVE ENVIRONMENT

Lusineh Stepanyan, Anna Stepanyan, & Vilena Grigoryan Yerevan State University

Descriptors: heart rate variability, aggression, stress index

Dynamic changes of heart rate variability were investigated in teenagers with different levels of aggressiveness. Computer simulation of aggressive environment was achieved by the use of ''aggressive'' computer games. The Bus-Durkee and Eysenck questionnaires, as well as drawing a non-existing animal and Wagner's Hand tests were used to determine the level of aggressiveness. Participants were divided into two groups: examinees with high or low level of aggressiveness. Then, the influence of aggressive computer game play was investigated. A Lusher test was used to determine the anxiety level before and after the experiment. Heart rate variability and a stress index were obtained from the electrocardiogram. This allowed us to consider the development of favorable emotional state for this group of examinees. Among teenagers with a low level of aggression, authentic changes of heart rate variability are not observed. This testifies about minimal emotional effort during aggressive gameplay.

Poster 173

MAGNETOCORTICAL CORRELATES OF THE AFFECT MODULATED LPP

Stephan Moratti1, Cristina Saugar2, & Francisco del-Pozo1 1Polytechnic University of Madrid, 2Complutense University of Madrid

Descriptors: arousal, late positive potential, magnetoencephalography An enhanced late positive potential (LPP) for high arousing emotional pictures has been consistently observed in affective ERP research. The scalp topography of the affect modulated LPP is widely distributed and the underlying cortical source configuration is not well understood. The current study investigated if a mag-netocortical correlate of the LPP, can be recorded with MEG. A slow magnetic field wave over right and left temporo-parietal sensors between .4 and .65 seconds after stimulus onset was observed. Further, this slow magnetocortical response was enhanced for high arousing pleasant and unpleasant compared to low arousing neutral pictures. Minimum norm source reconstruction using a quasi realistic head model indicated that cortical activity was arousal modulated in right and left lateral and medio-temporal brain regions. Further, right supramarginal gyrus activity was also modulated by emotional picture category. However, although an arousal modulation was observed, high arousing unpleasant pictures provoked the greatest slow wave magnetocortical responses. The current findings are discussed in the light of previous LPP studies using EEG.

REDUCED PREFERENTIAL PROCESSING OF EMOTIONAL STIMULI FOLLOWING EMOTION-MEDIATED RESPONSE CONFLICT

Marco Steinhauser, Tobias Flaisch, & Harald Schupp University of Konstanz

Descriptors: cognitive control, emotion, response conflict

Theories on conflict control assume that the detection of response conflict leads to increased conflict resolution on the subsequent trial. For emotion-mediated response conflicts, it has been suggested that conflict resolution acts by suppressing activity in the amygdala. However, many studies have shown that emotional stimuli are preferentially processed already in early sensory pathways. Based on these findings, the present fMRI-study investigated whether emotion-mediated response conflict is also resolved by reducing preferential sensory processing of emotional pictures. Participants discriminated between emotional words while ignoring simultaneously presented face dis-tractors. These included neutral, as well as emotional facial expressions which were either congruent or incongruent to the target word. Preferential processing of emotional stimuli was measured as enhanced BOLD-activity when comparing emotional to neutral face distractors. Results indicate that enhanced processing of emotional faces in early visual pathways is eliminated following response conflict. This suggests that emotionmediated response conflict is resolved by reducing preferential sensory processing of emotional stimuli.

Poster 175

LEARNING TO FEAR OTHERS THROUGH PAVLOVIAN CONDITIONING AND SOCIAL PUNISHMENT

Andreas Olsson, Daniel Fürth, Madlen Derbsch, Evelyn Andersson, Armita Golkar, Tina Lonsdorf, & Arne Ohman Karolinska Institute

Descriptors: pavlovian fear conditioning, social punishment, fear potentiated startle Social punishment is a powerful means of shaping our behavior and we might learn to fear those who are punishing us. Recent research suggests that Pavlovian conditioning can serve as a model for socially acquired fears, but the mechanisms underlying learning from social punishment are unknown. Here, we used a within-subjects design to examine the acquisition and extinction of fear responses to pictures of faces (CSs) in two separate experimental sessions using the fear-potentiated startle reflex as our primary measure: (1) In the Pavlovian conditioning session, faces were either paired (CS+) or unpaired (CS —) with a mild electric shock (tactile US). During the extinction phase that followed, all CSs were presented without shocks; (2) In the social punishment session, faces that were believed to depict co-participants were either paired (CS+) or unpaired (CS-) with repeated social exclusion (social US) during an interactive virtual ball tossing game (Cyberball). During the subsequent extinction phase, participants passively watched un-reinforced presentations of the pictures of the alleged co-players. Our results showed that both Pavlovian conditioning and social punishment affected verbal evaluations of the CS+s vs. CS-s negatively. In addition, both Pavlovian conditioning and social punishment resulted in an enhanced fear-potentiated startle response that resisted extinction to the CS+ vs. CS — . These results suggest that tactile and social USs can be equally powerful, and that they both are likely to draw on overlapping mechanisms ofPavlovian fear conditioning.

Poster 176

THE VALENCE OF EMOTIONAL ANIMAL VOCALIZATIONS MODULATES ELECTROPHYSIOLOGICAL CORRELATES OF THE HUMAN ORIENTING RESPONSE

Anna S. Hasting1, Marina Scheumann2, Elke Zimmermann2, & Sonja A. Kotz1 1Max Planck Institute for Human Cognitive and Brain Sciences 2University of Veterinary Medicine, Institute for Zoology, Hannover

Descriptors: emotional vocalizations, orienting response, cross-specific Since Darwin (1892) it is postulated that emotional expressions contain universals that are retained across species by evolutionary mechanisms. In the auditory modality, behavioral studies gathered evidence that humans are able to distinguish the emotional valence of vocalizations of dogs, cats or macaques above chance level. Furthermore, a recent fMRI study showed that emotional animal vocalizations activate the same neuronal network as human emotional vocalizations. However, to date it is unclear whether this cross-specific perception of emotion is actually based on phylogenetic relation, or whether it is rather effected by the familiarity of the acoustic signals. To investigate the relative contribution of these factors, we presented affiliative and agonistic vocalizations of four different species as novels in a three-stimulus oddball paradigm. 24 vocalizations per category were recorded from human babies, chimpanzees, dogs and tree shrews, thus varying the degree of phylogenetic relation and familiarity with respect to the human

recipient. Participants engaged in a target detection task on a tone deviating in frequency from the standard tone and were uninformed about the occurrence of the novels. Event-related potentials to the novels showed the typical pattern of an orienting response comprising N1, P3a and P3b components, whose characteristics varied depending on species and emotional context. These time-sensitive data provide first indications of temporally differentiated effects of phylogenetic relation and acoustic familiarity on emotional perception in man.

Poster 177

THE ROLE OF ALEXITHYMIA IN MODERATING RAPID FACIAL RESPONSES TO FACIAL EMOTIONS

Yong Peng Why, & Denise LiJuan Liu National University of Singapore

Descriptors: alexithymia, facial electromyography, facial emotions Individuals with alexithymia have been observed to have limited or incongruent facial expressions during therapy. This current research examines the relationship between alexithymia and Rapid Facial Responses to animated faces displaying sadness, anger and happiness. Alexithymia was measured using the two subscales of the Toronto Alexithymia Scale (Difficulty Identifying Feelings and Difficulty Describing Feelings) and faces from the Facial Expressions of Emotions - Stimuli and Tests (FEEST; Younger et al., 2002) were used to create animated faces displaying sadness, anger and happiness at 25%, 50%, 75%, and 100% intensities. Corrugator supercilii (frowning) and zygomaticus major (smiling) electromyographic activity were measured. Results indicate that participants high in Difficulty Identifying Feelings had attenuated corru-gator activity that was non-specific to emotion or intensity of the facial expressions presented. Participants high in Difficulty Describing Feelings had corrugator activity that was non-specific to facial emotions presented. Such three-way interactions (sub-scale of Alexithymia, emotion and intensity) were not present for zygomaticus activity. The findings provide support that individuals high in Difficulty Identifying Feelings have paucity in facial emotional expressions while those high in Difficulty Describing Feelings have incongruent facial expressions.

Poster 178

FRONTAL EEG ASYMMETRY IN INITIAL RESPONSE TO AFFECTIVE PICTURES IS ASSOCIATED WITH SUSTAINED NEGATIVE AFFECT

Christine L. Larson, & Jordan S. Robinson University of Wisconsin, Milwaukee

Descriptors: frontal eeg asymmetry, emotion modulated startle

A growing body of work suggests that individuals who show sustained responses to negative stimuli in the first few seconds following stimulus offset are more likely to be anxious or depressed. Sustained negative affect has also been linked with relative right-frontal resting EEG asymmetry, a pattern linked with both anxiety and depression. In the present study we examined whether EEG asymmetry during affective challenge is associated with sustained negative affect, as evidenced by continued potentiation of startle blink reflexes following picture offset. 99 participants completed a picture viewing paradigm during which both EEG and emotion-modulated startle blink data were recorded. Visual stimuli consisted of 126 IAPS pictures, 42 each of positive, negative, and neutral images. Images were presented for 6 s, with acoustic startle probes presented at four time points: 1.5, 4.5, 7.5, and 9 s post-stimulus onset. Frontal asymmetry during the first three seconds of both unpleasant and pleasant pictures was associated with sustained blink potentiation following the offset of negative pictures. Specifically, individuals who showed stronger potentiation to negative pictures at both 7 and 9 seconds following picture offset (compared to both of the mid-picture probes) exhibited more relative right frontal EEG activation (less right-sided alpha power) at a number of frontal sites, most strongly F7-F8 (r's 5 — .198 to — .262). These data indicate that frontal asymmetry during initial reactivity to affective stimuli is linked with prolonged maintenance of negative emotion.

Poster 179

DIFFERENCES IN THE CENTRAL PROCESSING AND VOLUNTARY REGULATION OF EMOTIONS IN ALEXITHYMIA - AN EEG STUDY

Olga Pollatos Ludwig Maximilian University of Munich

Descriptors: alexithymia, emotion regulation, IAPS

Emotion regulation and the abiltiy to voluntarily suppress feelings, especially negative feelings, is an important tool in social life and social interactions. Empirical data suggest that there are deficits in voluntary suppression of feelings in many psychiatric disorders. Data on alexithymia and suppression of negative feelings are rare and suggest that there are problems in voluntary regulation of feelings in alexithymia as compared to controls. We present EEG data using IAPS pictures showing that

participants with high vs. low scores of alexithymia have differences in the central processing of emotional stimuli, especially in the modulation of central processing. In the used task participants were asked to either attentively watch or to suppress upcoming feelings during the presentation of negative pictures as compared to neutral ones. Differences between both groups of participants were significant during the N200 and P300 time intervals. EASI source reconstruction suggests that activity in underlying brain structures and activity patterns differ between participants with high vs. low scores of alexithymia. These results highlight potential mechanisms involved in social difficulties in alexithymia.

Poster 180

ALEXITHYMIA, PERIPHERAL REACTIVITY AND EMOTION REGULATION DURING A SOCIAL STRESS TASK

Ellen Matthias Ludwig Maximilian University of Munich

Descriptors: alexithymia

Dealing with social stress is an essential ability to successfully cope with many critical social situations. Social difficulties and differences in the experience of social stress as well as differences in peripheral reactivity are described in alexithymia. We chose a public speaking task to induce social stress and assessed peripheral reactivity as well as subjective unpleasantness and externally rated signs of social stress in subjects differing in their degree of alexithymia. Our data suggest that reactivity as assessed by EDA and heart rate during social stress and recovery time is related to the degree of alexithymia. Additionally, although subjects with high scores of alexithymia described a higher degree ofunpleasantness and stress during the chosen task, there was an inverse correlation between externally rated social stress and alexithymia. Theses results indicate differences in the reactivity to social stress, perceived distress and socially communicated aspects of stress in alexithymia.

Poster 181

AUTOMATIC PROCESSING OF PHONOTACTICALLY ILL-FORMED SYLLABLES INDEXED BY MISMATCH NEGATIVITY (MMN)

Johanna Steinberg1, Hubert Truckenbrodt2, & Thomas Jacobsen1 1University of Leipzig, 2Centre for General Linguistics (ZAS)

Descriptors: phonology, speech processing, mismatch negativity

In this MMN study, the effects of language-specific phonotactic restrictions on pre-attentive auditory speech processing were investigated using event-related potentials. In German grammar, the occurrence of the velar [+back] and the palatal [-back] dorsal fricatives is limited by the phonotactic restriction of Dorsal Fricative Assimilation (DFA), which demands a vowel and a following dorsal fricative to agree in articulatory backness [ + back], e.g. ''Koch'' (cook) or ''echt'' (real). Combinations of a front vowel and a following velar dorsal fricative within a syllable lead to phonotac-tically incorrect sequences. For passive oddball stimulation, three phonotactically correct Vowel + Fricative syllables and one phonotactically incorrect syllable violating DFA were used. Stimuli were contrasted pair-wise in reversed oddball blocks such that they shared the initial vowel while differing regarding the fricatives (Oddball contrast 1: [o + coronal sibilant] versus [o + velar dorsal fricative]; Oddball contrast 2: [e + coronal sibilant] versus the incorrect sequence n[e + velar dorsal fricative]). The phonotactic violation coincided with the change of the fricatives and had to be processed additionally. Significant stronger MMN responses to the incorrect deviant were observed compared to the MMN elicited by the analogously constructed correct deviant. As our data showed, the phonotactic violation of DFA affected the pre-attentive processes in terms of a modulation of the MMN amplitude. This indicates that implicit phonotactic knowledge is activated and applied even pre-attentively.

Poster 182

FAILURE IN PHONOLOGICAL MONITORING? ERP EVIDENCE OF LATE, RATHER THAN EARLY, DIFFERENCES BETWEEN DYSLEXIC AND CONTROL READERS' PHONOLOGICAL TASK RESPONSE

Nicola Savill, & Guillaume Thierry Bangor University

Descriptors: ERP, dyslexia

This study used event related potentials (ERPs) to examine when dyslexic readers show sensitivity to the phonological and orthographic properties of visual pseudoword stimuli whilst performing a task with high phonological demand. We compared responses of dyslexic and non-dyslexic adults to pseudoword-word pairs, for which phonological similarity (homophonic match/mismatch) and orthographic similarity (orthographic neighbour/non-neighbour) had been manipulated. Participants responded whether word targets sounded the same as the previously presented pseudoword. ERPs time-

locked to target word onset showed main and interactive effects of phonological and orthographic similarity on N2 and P300 modulations with no significant group differences, suggesting that both groups' early sensitivity to the stimuli's relative phonological and orthographic properties were intact. However, analysis of later modula-tions—within the P600 range—showed a significant group x similarity-priming interaction with respect to amplitude change: Whilse the control group showed clear stimuli differentiation—with largest P600 amplitudes to homophonic mismatching, non-neighbouring stimulus pairs and weakest to matching, neighbouring pairs—the dyslexic group's P600 response was significantly attenuated. As P600 modulations are associated with linguistic monitoring and reanalysis, it is suggested that poor phonological task performance typically found with adult dyslexic readers may be more related to inefficient engagement with phonological processing, rather than poor sensitivity per se.

Poster 183

SEMANTIC VIOLATIONS AND ANIMACY VIOLATIONS ELICIT DIFFERENT BRAIN RESPONSES

Jakub Szewczyk1, & Herbert Schriefers2 1Jagiellonian University, 2Radboud University Nijmegen

Descriptors: language perception, animacy, P600

Many linguistic and psycholinguistic theories treat animacy as a special ''grammati-calized'' semantic feature, because animacy is involved in grammatical distinctions in many languages. The present experiment employs the ERP technique to examine whether animacy information has a special status in syntactically canonical and unambiguous sentences. Participants were presented with 120 short stories in Polish. They were constructed in such a way that for half of them an animate direct-object-noun in the story's final sentence was highly expected, and for the other half an inanimate noun. The critical noun occurred in (1) a congruent condition - semantically congruent with the preceding context (tested by a cloze test); or (2) a semantic violation condition -introducing a semantic violation while still being congruent with respect to the animacy/ inanimacy expectation induced by the story; or (3) an animacy violation condition -introducing a semantic violation which in addition violated the animacy/inanimacy expectation induced by the story. The critical nouns in both the semantic violation condition and in the animacy violation condition (conditions 2 and 3) elicited an N400 effect relative to the congruent condition. In addition, both types of violations elicited a P600 effect, relative to the congruent condition. The P600 effect for animacy violations had significantly higher amplitude than that of semantic violations.

Poster 184

ELECTROPHYSIOLOGICAL MARKERS OF BOTTOM-UP AND TOP-DOWN INFLUENCES ON TEMPORAL ORDER PERCEPTION IN SPEECH

Shin-Yi Fang, & James S. Magnuson University of Connecticut & Haskins Laboratories

Descriptors: temporal order

How does a listener tell ducks from dusk? Temporal order processing is a crucial but surprisingly poorly understood aspect of speech perception and spoken word recognition. Such seemingly trivial distinctions may depend on bottom-up (auditory and phonetic sensitivity) and top-down (language-specific phonology and vocabulary) details. In this study, we used a passive auditory oddball paradigm to measure electro-physiological responses to temporal and phonological change. We compared a standard phonological sequence (/apta/) to multiple deviants where the two internal segments were manipulated: reversed-order (/atpa/), same-onset (/apka/), same-offset (/akta/), or unrelated (/afla/). Items were repeated in random order with a ratio of 60:10 (standard:each deviant type) for a total of 900 trials. The difference waveform (deviant -standard) showed a negativity between 200-300 ms after deviance point with distribution similar to the MMN except for same-onset. All conditions showed an N400-like posterior negativity 400-500 ms post deviation. The MMNs were strongest in the first half of the trials and were weak or absent in the second half. The N400 was weak in the first half, and became strong in the second half. This suggests that temporal order deviants were initially perceived as variants of the standard, but with repeated exposure, all items began to be lexicalized. This suggests this paradigm may be useful for understanding bottom-up and top-down contributions to the perception of temporal order.

Poster 185

ELECTROCORTICAL SIGNATURE OF EMOTION VERB PROCESSING

Javier Rodriguez-Ferreiro1, Brendan Weekes2, Robert Davies3, & Fernando Cuetos1 1University of Oviedo, 2University of Sussex, 3Oxford Brookes University

Descriptors: semantics, verbs, EEG

Motion verbs elicit patterns of anterior electrocortical activity that are assumed to reflect the involvement of the motor cortex in the representation of their meaning.

However, little is known about other semantic categories such as verbs that refer to emotional actions. In order to explore how these verbs are represented, we compared the electrocortical activity generated by the identification of forty emotion verbs (e.g., ''to yearn'') and forty motion verbs (e.g., ''to twirl'') matched on lexical frequency, orthographic neighborhood size and length, but different in emotional valence. Event related potentials from ten healthy students were recorded while they performed a lexical decision task in which the target verbs were presented along with eighty pseudoverbs (e.g., ''to scrout''). EEG was recorded using a 128-channel Net (EGI, Eugene, Oregon). Impedance was kept below 50 kOhm. Sampling rate was 250 Hz. EEG was band-pass filtered between .3 and 40 Hz and segmented from 100 ms before to 600 ms after stimulus onset. Segments were baseline corrected and re-referenced to the mastoids. Emotion verbs appeared to be associated with larger positive amplitudes than motion verbs at early (150-200 ms) and late (450-500 ms) time-windows. Furthermore, the effect of verb category significantly interacted with electrode position at intermediate stages (250 -350 ms), with emotion verbs eliciting a much larger positivity than motion verbs at anterior compared to posterior electrodes. We conclude that semantic processing of emotion-related verbs is reflected in anterior brain activation.

Poster 186

MULTIPLE VARIABLES IN PICTURE NAMING STUDIED USING PARAMETRIC MEG ANALYSIS

Olaf Hauk1, Friedemann Pulvermuller1, & Michele Miozzo2 1MRC Cognition and Brain Sciences Unit, University of Cambridge, 2University of Cambridge

Descriptors: picture naming, MEG, parametric analysis

We investigated MEG responses in a picture naming paradigm using multiple linear regression. We reduced an initial set of 14 variables to a final set of 4 predictor variables: Visual Complexity (VC), Semantic Features (SF), Action-Features (AF), and Name Frequency (NF). Participants overtly named objects presented as line drawings on a computer screen. Regression coefficients were obtained for each of the 4 predictor variables at each latency and each sensor. Data for individual participants were interpolated to a standard sensor geometry, and source estimates were computed in a standardized boundary element model. Statistical analysis was performed in sensor space using the SPM5 approach based on random field theory. In contrast to previous studies, we found evidence for a contamination of MEG data by preparatory articulatory activity. Distributed source analysis localized this activity to orbito-frontal and anterior-temporal brain structures. Localization results for those brain areas should therefore be interpreted with care. The VC variable affected posterior brain areas around 90 and 140 ms. SF and AF activated bilateral per-isylvian cortical areas between 150 and 300 ms. NF showed effects as early as 130 ms, and activation of left pre-central areas around 260 ms. These data provide evidence for overlapping visual, semantic and phonological processes within the first 300 ms of picture naming. They also demonstrate the value of parametric analysis techniques for the investigation of effects of multiple intercorrelated variables in the same set of participants.

Poster 187

LISTENING TO RELAXING MUSIC PRIOR TO A SOCIAL STRESSOR: EFFECTS ON THE PSYCHOLOGICAL AND PHYSIOLOGICAL STRESS RESPONSE

Mirjam V. Thoma, Ulrike Ehlert, & Urs M. Nater University of Zurich

The experience of stress and its biological consequences may dramatically influence health. Music has been suggested to beneficially impact health via stress-reducing effects. However, the exact mechanisms through which music impacts the psycho-biological stress system are poorly understood. Sixty healthy female volunteers (m 5 25.37 y) were exposed to a laboratory social stress test after having been randomly assigned to one of three different conditions prior to the stressor: 1) relaxing music (''Miserere'', Allegri), 2) water sound (WS) and 3) rest (R) (i.e. without acoustic stimulation). Psychological stress perception (VAS) salivary cortisol, as well as salivary alpha-amylase were continuously measured in all subjects. The stressor caused significant changes in perceived stress, cortisol and alpha-amylase in all three groups over time. The three conditions significantly differed regarding cortisol responses (p 5 0.025). Contrary to our expectations, the music intervention did not result in a significant attenuation of perceived stress and cortisol, whereas the WS condition did. In the recovery phase, listening to music resulted in lower amylase levels compared to the other two conditions (p 5 0.005). Listening to music prior to a significant stressor does not influence the subsequent psychological and endocrine, but the sympathetic stress response. Listening to water sound seems to be effective in responding to a stressor with an attenuated stress response. These findings bear potential implications for the scientific study of the effectiveness of music interventions.

INTERACTION BETWEEN THE TASK AND THE BACKGROUND: A VISUAL MISMATCH NEGATIVITY STUDY

Istvan Czigler and Istvian Sulykos Institute for Psychology, Hungarian Academy of Sciences

Descriptors: visual perception, visual mismatch negativity, and task-background relationship Irrelevant changes in the visual background elicited a posterior negative event-related potential component in the 120-200 ms latency range. We identified this component as visual mismatch negativity (vMMN). The background change was either the color or orientation of the elements of textures with oblique line segments. Participants responded to a changing shape on the center of the visual field. This task-relevant change was either the orientation or the color of the shape. Reaction time increased in sequences with identical dimension of background and task change (color change of the shape and irrelevant color change in the background; orientation change of the shape and irrelevant orientation change in the background). This effect was independent of the temporal proximity between the irrelevant and relevant changes. However, the opposite pattern emerged in the vMMN, i.e., this ERP component was larger when the change of the background and the task-relevant change were different (color change of the shape and irrelevant orientation change in the background; orientation change of the shape and irrelevant color change in the background). Accordingly, registrations of background change and target detection were not independent. Direction of the RT effect corresponded to the contingent capture principle, while direction of the vMMN changes indicated the top-down control of feature-specific mechanisms of information processing.

_POSTER SESSION II_

Poster 1

ELECTROCORTICAL CORRELATES OF INTRA-SUBJECT VARIABILITY OF REACTION TIMES

Chris W.N. Saville, David Daley, James Intriligator, Stephan Boehm, & Christoph Klein Bangor University

Descriptors: reaction time variability, ADHD, N2

Intra-subject variability of reaction times (ISV) has recently emerged as an important area of research within biological psychiatry. ISV is now being investigated as a putative endo-phenotype for a number of psychiatric disorders including attention-deficit hyperactivity disorder, schizophrenia, and autism; with patients demonstrating significantly greater ISV than healthy controls on a range of tasks (eg. Klein et al., 2006). While theories on its neural underpinnings have emerged (Sonuga-Barke & Castellanos, 2007), data on the electro-cortical correlates of ISV remain sparse. This poster presents event-related potentials (ERPs) from two groups of healthy participants, one exhibiting high ISV (n 5 13) and one exhibiting low ISV (n 5 13), on working memory oddball tasks. Striking differences between groups in the ERPs for oddball trials were found, with only low scorers showing an N2 component in response to these stimuli. These findings suggest specific differences in neural processing of rare events between high and low scorers.

Poster 2

ENABLING COMMUNICATION IN COMPLETELY PARALYSED BY SEMANTIC CLASSICAL CONDITIONING: A PILOT STUDY

Adrian Furdea1, Carolin Ruf1, Armin Walter1, Dimitria Pagania1, Tamara Matuz1, Jeremy Hill2, Femke Nijboer3, Christoph Braun1, Boris Kotchoubey1, & Niels Birbaumer1 1University of Tübingen, 2Max Plank Institute for Biological Cybernetics, 3Fatronik - Tecnalia

Descriptors: EEG, BCI, classical conditioning

The aim of the study was to investigate the applicability of a semantic conditioning paradigm in a BCI setting to enable basic yes/no communication. The experiment consisted of two phases: acquisition and extinction. In the first block of the acquisition phase, true and false sentences were randomly presented in an auditory fashion. The conditioned stimuli (CS) comprised thinking on either ''yes'' or "no", according to the type of the sentence. For ''yes'' and "no" conditioning two different unconditioned stimuli (UCS) were used: a pink noise - immediately following a true sentence and a white noise - following a false sentence. In the next two blocks, one of every 10th CS, respectively, one of every 5th CS, at random, was not paired with the UCS. Physiological responses were continuously measured by means of electroencephalogram, electrocardiogram and galvanic skin response. The Self Assessment Manikin scale was used to assess the valence and the arousal that each subject associated to its affective reaction to UCS. Ten healthy subjects were measured with preliminary results suggesting differ-entiable responses for the CS. Further analysis will be carried out to assess conditioned reaction. The employment of the auditory modality and of a paradigm which consumes fewer attentional resources and voluntary efforts may be an alternative for the locked-in patients to learn BCI skills and to transfer these to the completely locked-in state (CLIS). To confirm these we intend to carry out a longitudinal study.

MAPPING THE CORTICAL HUBS IN THE TINNITUS DISTRESS NETWORK

Winfried Schlee, Nadia Muller, Thomas Hartmann, Julian Keil, Isabel Lorenz, & Nathan Weisz University of Konstanz

Descriptors: tinnitus, MEG, cortical hubs

Tinnitus is the conscious perception of a phantom sound in the absence of any physical source. Approximately 5% of the population experience such a tinnitus for more than 6 months and about 1% report the ongoing perception of the sound as bothering, leading sometimes to severe psychological distress. Until now, most of the research in tinnitus has concentrated on the auditory cortices. Some experimental work and theoretical considerations, however, have also suggested the involvement of non-auditory cortices that might form a large-scale cortical network. We aimed to investigate this network using magne-toencephalographic recordings of chronic tinnitus patients and healthy controls in the resting state. A beamforming technique was applied to reconstruct the brain activity at source level and the directed functional coupling between all voxels was analyzed by means of Partial Directed Coherence. Within a cortical network, hubs are brain structures with a rich functional connectivity to other brain regions. By mapping the cortical hubs in tinnitus and controls we report fundamental group differences in the global networks, mainly in the gamma frequency range. The prefrontal cortex, the subgenual cortex and the parieto-occipital region were core structures in this network. The information flow from this global network to the auditory cortex correlated positively with the strength of tinnitus distress.

Poster 4

AN MRI-DTI STUDY OF MONOZYGOTIC TWINS DISCORDANT FOR OBSESSIVE-COMPULSIVE SYMPTOMS

Anouk den Braber1, Dennis van't Ent1, Danielle C. Cath2, Dorret I. Boomsma1, Marina Barysheva3, Agatha D. Lee3, Lara C. Foland-Ross3, Jason L. Stein3, Paul M.

Thompson3, & Eco J.C. de Geus1 1Vrije University - Amsterdam, 2Utrecht University, 3University of California, Los Angeles, School of Medicine

Descriptors: magnetic resonance imaging, diffusion tensor imaging, obsessive compulsive disorder

Obsessive-compulsive disorder (OCD) is characterized by recurrent, persistent, and intrusive anxiety-provoking thoughts or images and subsequent repetitive behaviors. Recent diffusion tensor imaging (DTI) studies reported abnormalities of fractional anisotropies (FA) in OCD patients compared to unaffected controls. However, there are still inconsistencies in the results. This could be due to the differential impact of genetic and environmental risk factors for OCD that do not necessarily lead to identical underlying neurobiological changes. Here we used MRI-DTI to scan 19 monozygotic twin pairs (age range 18 - 60) discordant for OC symptoms (OCS) to highlight white matter brain regions linked to OCS that are particularly susceptible to environmental factors. Voxelwise comparison, using a paired t-test, was performed to indicate regions of significantly altered FA in the OCS high-scoring twins compared to their OCS low-scoring co-twins. Relative to OCS low-scoring twins, OCS high-scoring twins exhibited significantly decreased FA in the left inferior parietal lobe and right occipital lobe and increased FA in the left medial frontal lobe and multiple regions of the right temporal lobe. These results generally overlap with FA abnormalities reported in previous DTI studies of OCD patients. Therefore, our findings suggest that neurobiological changes underlying the environmentally-mediated risk for OCD, partly, correspond with the neurobiological abnormalities that originate from a combination of adverse genetic and environmental influences.

Poster 5

TEMPORAL CHANGES IN BRAIN ACTIVITY ELICITED BY CONDITIONED AND UNCONDITIONED STIMULI IN AN ASSOCIATIVE LEARNING PARADIGM

Noemi Sanchez-Nacher1, Carolina Sitges1, Miguel Angel Mufioz1,2, Ignacio Cifre1,3, Jose Javier Campos-Bueno4, & Pedro Montoya1 1University of Balearic Islands, 2University of Granada, 3University of Barcelona, 4Complutense University

Descriptors: associative learning, erps, habituation

Classical theories on associative learning predict higher affective strength between conditioned stimuli and unconditioned stimuli, as well as an enhancement of early attent-ional processes during the course of conditioning. The aim of the present study was to examine temporal changes in brain activity associated with the presentation of conditioned and unconditioned stimuli in a differential conditioning task. In this task, a red square was followed by an aversive visual stimulus (IAPS slides) (A+) and a yellow square was followed by a blank screen (B — ). Event-related potentials (ERPs) elicited by the two types of stimuli were recorded from 32 electrodes. In the experiment participated nineteen right-handed volunteers (mean age 22 years). A late positive complex (LPC)

was observed between 500 and 700 ms after stimulus onset and was more prominent at electrode Pz. Statistical analyses revealed that LPC amplitudes elicited by A+ stimuli were progressively diminishing over time, whereas ERP amplitudes elicited by B- stimuli remained stable at central, parietal, and occipital electrodes (p's < .05). Thus, the present findings revealed that habituation effects were present only for A+, but not for B — following repeated exposition to affective stimuli. Our data suggest that differential classical conditioning could be a useful tool for examining brain correlates of learning processes involved in affective disorders, such as phobia or chronic pain.

Poster 6

INDUCED GAMMA BAND RESPONSES: NEURONAL ORIGIN OR EYE MOVEMENT ARTIFACT?

Uwe Hassler, & Thomas Gruber University of Osnabrück

Descriptors: induced gamma band, microsaccade, EEG

Findings of induced gamma band responses (iGBRs) in the human electroencephalogram (EEG) were challenged by the work of Yuval-Greenberg et al. (2008) who stated that iGBRs are an artifact caused by microsaccades (MSs). According to Yuval-Greenberg et al., MSs are accompanied by short spike potentials (SPs) (with a steep gradient), which are the true source of iGBRs. In our present study we recorded EEG-signals and eye movements while participants performed a familiar-unfamiliar task (for details see Busch et al., 2006), which allowed us a clear identification of MS-related SPs in the EEG data. In order to remove the SPs, we applied a method based on spline interpolation at the affected data points in each contaminated trial. A wavelet-analysis of the resulting data revealed an ongoing narrowband oscillation in the gamma band range (30-80 Hz) at posterior sites after SP removal. We also replicated previous findings stating that familiar objects elicit a higher iGBRs compared to unfamiliar objects. These specific characteristics of the remaining iGBR are corresponding with intra-cranial recordings in animals as well as with extra-cranial recordings in humans (Fries et al., 2008). Moreover, a narrow-band and ongoing oscillation makes an underlying electromyogenic artifact very unlikely. Accordingly, we conclude that the artifact free iGBR has a neuronal source and consequently is a reliable tool for investigating cognitive processes.

Poster 7

ENCODING OF MULTIPLE TIME SCALES OF ACOUSTIC REGULARITIES AS A FUNCTION OF EXPECTANCY AS REVEALED BY HUMAN EVOKED POTENTIALS

Jordi Costa-Faidella, Sabine Grimm, Francisco Diaz-Santaella, Lavinia Slabu, & Carles Escera University of Barcelona

Descriptors: auditory processing, regularity encoding, event-related potentials Acoustic regularity encoding has been traditionally linked to the mismatch negativity (MMN) event-related potential (ERP), elicited to any auditory event violating a rule, and recently, to another ERP component termed Repetition Positivity (RP), which increases in amplitude with stimulus repetition. Here we aimed to explore the effects of stimulus expectancy in human auditory system automatic responses, by means of amplitude changes of the MMN and RP components to multiple time scales of stimulation history. ERPs to standard and deviant stimuli differing in frequency were studied in 19 healthy subjects using a fixed oddball sequence design embedding multiple acoustic regularities defined as: Repetition, consisting of trains of 2, 6 and 12 simple tones of the same frequency (standards), each train followed by a frequency deviant; Run, consisting of two successive Repetition sequences; and Switch, consisting of two successive Run sequences, with the second one switching roles between standard and deviant frequencies. Another sequence was used to control for deviant refractoriness effects by replacing standards with random tones. Our results show an increase of the controlled MMN amplitude (135-155 ms) for deviants and an increase of RP for standards (80 -180 ms) with an increased number of previous standard repetitions. A simple linear model, taking into account both local and global aspects of stimulation history, revealed that standard and deviant stimuli ERP amplitudes in the controlled MMN time range (135 -155 ms) increased linearly as a function of stimulus expectancy.

Poster 8

AGE-RELATED DECLINE IN THE DIMENSIONALITY OF ERROR-RELATED EEG ACTIVITY: AN INDEPENDENT COMPONENT ANALYSIS

Sven Hoffmann, & Michael Falkenstein Leibniz Research Centre for Working Environment and Human Factors

Descriptors: executive functions, errors

Recent studies report an amplitude reduction of error-related potentials (Ne/ERN and Pe) in elderly participants. It is not clear whether this a result of true functional alterations or if the reduction is due to artifacts in common analysis procedures, i.e. the averaging procedure. The amplitude reduction might well result from a larger latency jitter

in the single-trial ERPs in the elderly. In the present study we investigated the component structure of the single-trial ERP after a response in two age groups with two qualitatively different tasks by means of Independent Component Analysis (ICA) and non-linear measures like the Hurst exponent. The first task was a modified flanker task and the second a mental rotation task. In both tasks the response deadline was adapted with respect to the error rate. This should prevent speed-accuracy trade-off and yield comparable error rates in both age groups. Further, nested in the two age groups, two different instruction types (''respond as precise as possible'' and ''respond as fast as possible'') were given to the participants. This manipulation should balance the possibility that the age groups might systematically use different response strategies. ICA yielded in both age groups one single component accounted for most of the variance in erroneous and correct responses. Further, the results indicate a true age-related decline in component activity accounting for error-related activity. In addition the component structure in general, the dimensionality of the signal was significantly altered in elderly subjects.

Poster 9

EXECUTIVE FUNCTIONS AND CONTROL OF AGGRESSION: AN ERP STUDY

Robert P.J. Kopyciok1, Ulrike M. Kramer2, Sylvia Richter1, & Thomas F. Miinte1 1Otto-von-Guericke University of Magdeburg, 2University of California, Berkeley

Descriptors: aggression, executive functions, ERP

Research suggests that there is a relation between executive control and aggression. Recording ERPs in the Taylor aggression paradigm (TAP) we found an enhanced frontal negativity in participants of high trait but low experimental aggressiveness, possibly indicating executive control of the impulse to react aggressively. To test this hypothesis 32 healthy high trait aggressive participants completed a combined flanker/stop task, providing measures of executive functions, and the Taylor aggression paradigm (TAP), comprising a provocation and an outcome phase. In the provocation phase of the TAP we observed an enhanced frontal negativity during low relative to high provocation in participants with high experimental aggressiveness. We suggest that this finding reflects reduced aggression control during high provocation in these subjects. The error related negativity to errors in the flanker task was larger for less aggressive participants, which also showed similarly high stop-N2 componentes for successfully stopped reactions and forced errors implying that less aggressive participants have increased action monitoring and inhibitory processes relative to participants with experimental aggessiveness. These findings further strengthen the proposed link between executive functions and control ofaggression.

Poster 10

IMAGINING THE UNKNOWN: ERP INVESTIGATIONS OF SEMANTIC KNOWLEDGE EFFECTS AND THE TIME COURSE OF VISUAL IMAGERY

Johannes Rost, & Rasha Abdel Rahman Humboldt University, Berlin

Descriptors: visual imagery, semantic knowledge effect, ERP

Previous research on knowledge scale effects in object recognition has revealed knowledge-induced modulations not only of semantic analyses but also of early perceptual processes. In event-related brain potentials these effects are reflected in the N400 time window (associated with meaning access) and in the P100 component (associated with early stages of visual analysis). The present study investigates whether comparable knowledge scale effects could also be observed in visual imagery. It has often been argued that perception and imagery share common brain regions and processes. However, while the neural basis of imagery is well-investigated, little is known about its time course. Here, we employ event-related brain potentials to investigate the temporal dynamics of imagery of objects associated with in-depth or minimal semantic knowledge. In a learning paradigm the amount of knowledge about existing but rare objects was manipulated while perceptual factors were held constant. In a subsequent test session participants saw the pictures or formed visual images of the objects. Replicating previous results, in-depth semantic knowledge was associated with amplitude modulations in the N400 and P100 time window when object pictures were presented. During object imagery the same N400 and a similar but weaker P100 effect were observed. Behav-iorally, the formation of mental images was enhanced in the in-depth compared to the minimal knowledge condition. These results suggest that imagery is a function of the visual system and that semantic knowledge facilitates visual imagery.

Poster 11

ON THE NEURAL CORRELATES OF EYE GAZE ADAPTATION

Nadine Kloth, & Stefan R. Schweinberger Friedrich Schiller University of Jena

Descriptors: face perception, eye gaze, high-level adaptation

Recent research shows a strong effect of adaptation on gaze perception: Adaptation to faces with eye gaze constantly diverted in one direction subsequently impairs the perception of that gaze direction. In a previous study on the neural correlates of this effect, N170 amplitudes to

test faces were strongly attenuated when these were presented following adaptation to faces irrespective of gaze direction. ERP modulations as a function of gaze direction adaptation, however, were found only later (250 - 350 ms). In the present study, we used a new paradigm to study the exact nature of both the gaze direction-invariant N170 attenuation effect and the direction-specific effects in later time windows. We compared the ability to classify left, direct, and right gaze direction before and after adaptation to direct gaze (control condition) or to eye gaze diverted to the right (adaptation condition). The behavioral results clearly replicated earlier findings of impaired perception of eye gaze directed to the adapted side. The ERP analysis confirmed an insensitivity of the N170 to gaze adaptation, and suggests that reported attenuations were a result of adaptation to generic face information irrespective of gaze direction. Occipito-temporal ERPs ~ 250 - 350 ms showed direction-specific modulations with most positive amplitudes in response to stimuli gazing in the direction of adaptation. A similar, yet polarity reversed, effect was observed in the parietal P3 component, which may be a neural correlate of adaptation-induced novelty detection.

Poster 12

ALCOHOL DOSE EFFECTS ON FEAR CONDITIONING WITH VARYING LEVELS OF THREAT INTENSITY

Christine A. Moberg, Stefanie M. Weber, Jason N. Jaber, Allison M. Grant, & John J. Curtin University of Wisconsin, Madison

Descriptors: alcohol, startle, fear conditioning

Use of use of alcohol to reduce stress predicts subsequent problems with alcohol (Schroder & Perrine 2007). Research on the alcohol-stress relationship has been guided for decades by the Stress-Response Dampening (SRD) model, which proposed that alcohol reduces emotional response to aversive stimuli generally, across drinkers and blood alcohol concentrations (BACs). Research has not consistently supported this thesis. In order to clarify the nature of SRD effects, the current project parametrically varied BAC and included a novel manipulation of threat intensity to examine the main and interactive effects of these factors on stress response. Ninety-two participants were assigned to one of four BAC groups (target BACs of 0%, .04%, .075%. or .011%) and viewed a series of 6s cues, in alternating shock and no-shock blocks. During shock blocks, shocks were administered at the termination of each cue and the intensity of the shock (mild, moderate, or intense) was indicated by cue color. Fear-potentiated startle (FPS; startle during shock cues relative to no-shock cue) was used to index stress response to each shock cue. FPS increased with increasing shock cue intensity. A significant main effect of BAC was observed with FPS decreasing as BAC increased. Shock intensity moderated this BAC effect such that the BAC effect on FPS was strongest at the highest shock intensity. These results suggest that the stress response is attenuated at higher BACs and that this alcohol dose response effect is more robust when the stress-eliciting stimulus is highly potent.

Poster 13

PSYCHOPHYSIOLOGICAL VARIABLES AS PREDICTORS OF TREATMENT OUTCOME FOR ANXIETY DISORDERS

Marlen Figueroa-Varela, Angela J. Mufloz, Sonia Rodriguez-Ruiz, Blanca Ortega-Roldan, Clara Homar, Ana I. Perez, Sandra Diaz, & Jaime Vila University of Granada

Descriptors: anxiety disorders, treatment outcome, autonomic responses The present study was aimed at testing whether a psychophysiological assessment protocol prior to a cognitive-behavioral treatment for anxiety disorders would provide reliable predictors of treatment outcome. A group of 22 anxiety patients (8 specific phobia, 5 social anxiety, 5 generalized anxiety, and 4 panic) completed the ADIS clinical interview and a set of questionnaires (BDI, STAI-T, and PSWQ) before and after treatment. The psycho-physiological protocol included three reactivity paradigms: cardiac defense, the startle probe paradigm with pleasant, neutral and unpleasant pictures, and mental imagery with personalized clinically relevant scenes. In addition to eye-blink startle, heart rate and skin conductance were recorded throughout the three paradigms. Results showed: (a) significant negative correlations between tonic levels of both heart rate and skin conductance, and treatment outcome such that patients with higher tonic levels had poorer prognosis; and (b) significant positive correlations between heart rate and skin conductance indices of reactivity and treatment outcome, such that patients with greater reactivity had better prognosis. These results underscore the importance of using a psychophysiological assessment protocol within the standard clinical evaluation of anxiety disorders.

Poster 14

SOURCE ESTIMATION OF THE N2, ERN, AND FERN IN A TACTILE TIME-ESTIMATION TASK

Theo O.J. Grundler1, Markus Ullsperger1, Christo Pantev2, & Rene J. Huster2 1Max Planck Institute for Neurological Research, 2Institute for Biomagnetism and Biosignalanalysis, University of Munster

Descriptors: ERP, source localization

The N2, error-related negativity (ERN), and feedback-related negativity (fERN) are event-related brain potentials (ERP) sharing similar scalp topographies and possible

functional concordances. The N2 is elicited by stimuli that call for response inhibition in a context of frequent responding, the ERN by action slips, and the fERN by reward prediction errors after receiving feedback. To investigate the question as to whether these components represent the same functional phenomenon and have the same neural generator we recorded EEG from participants engaged in a modified tactile time-estimation task combined with a stop-signal paradigm. In addition to the analysis of scalp topographies, current density reconstructions were computed using the sLORETA-weighted accurate minimum norm inverse solutions algorithm. Realistic head models as well as an individualized solution space were estimated from structural T1-weighted images. The ERN, the fERN and the N2 all exhibited comparable negative fronto-central scalp topographies. Consistent with previous observations, the fERN amplitude was augmented with unexpected as compared to expected feedback stimuli. Similarly, the N2 exhibited larger amplitudes with increased difficulty of the time-estimation procedure. The ERN, on the other hand, was not strongly affected by task characteristics. All three potentials were predominantly generated by the dorsal anterior cingulate cortex. However, source estimations of the N2 additionally revealed activations in the inferior-frontal region.

Poster 15

ERROR-RELATED NEGATIVITY PREDICTS ACADEMIC PERFORMANCE

Jacob B. Hirsh, & Michael Inzlicht University of Toronto

Descriptors: ERN, self-regulation, post-error slowing

Activity in the Anterior Cingulate Cortex (ACC) has been linked to the processes of error detection and conflict monitoring, along with the subsequent engagement of cognitive-control mechanisms. The error-related negativity (ERN) is an electrophysiolog-ical signal associated with this ACC monitoring process, occurring approximately 100 ms after an error is made. The magnitude of the ERN has recently been related to a number of real-world behavioral outcomes related to self-regulation and cognitive control. The current study extended this research by examining the relationship between the ERN and academic performance. Undergraduate students completed a color-naming Stroop task while their neural activity was recorded via electroencephalogram. Results indicated that a larger ERN following errors was significantly correlated with better academic performance as measured by official student transcripts. This relationship was mediated by increased post-error slowing on the Stroop task, indicating improved behavioral regulation. A greater ability to monitor performance and engage cognitive control mechanisms when needed thus appears associated with improved real-world performance in the academic domain.

Poster 16

WHAT CAUSES THE ERRORLESS LEARNING BENEFIT? EVIDENCE FROM FEEDBACK-RELATED BRAIN ACTIVITY

Benjamin J.G. Ernst, & Marco Steinhauser University of Konstanz

Descriptors: errorless learning, feedback-relatednegativity

It has been shown that learning is improved when errors due to guessing are prevented. This errorless learning benefit is attributed to the fact that errors are learnt which impairs subsequent performance. The goal of the present study was to investigate the mechanisms underlying the errorless learning benefit by considering behavioral data and the feedback-related negativity (FRN), an event-related potential peaking shortly after feedback indicating a wrong choice. We examined whether the errorless learning benefit requires that guessing is avoided or that the execution of an erroneous response is avoided. To this end, participants learned German-Swahili word pairs during a learning phase. Whereas an errorful learning condition required that participants responded to multiple-choice items, an errorless learning condition required that the same items were passively inspected only. In both conditions, immediate feedback about the correct response was provided which could be used for learning the word pairs. In both conditions, the learning phase was followed by a test phase in which learning success was assessed. As a result, better performance was achieved in the errorless learning condition, indicating an errorless learning benefit. Moreover, a marked FRN was found for negative feedback during errorful learning. Crucially, however, an even stronger FRN was found for feedback during errorless learning. This indicates that participants made a covert choice during errorless learning and that the errorless learning benefit merely reflects the absence of an overt response.

Poster 17

WHEN HYPER BECOMES HYPO: PANIC DISORDER AND AMYGDALA ACTIVATION TO MASKED STIMULI

Cristina Ottaviani, Valeria Nucifora, Daniela Cevolani, Raffaele Agati, Rosita Borlimi, Gianni Brighetti, & Marco Leonardi University of Bologna

Descriptors: amygdala, backward masking, panic disorder

Previous functional neuroimaging studies have demonstrated amygdala activation in response to fearful faces even if they are presented below the threshold of aware visual

perception. However, chronic hyperarousal in panic disorder (PD) may diminish the emotional response reflected in reduced amygdala activation. The aim of the present study was to test if amygdala reactivity to fearful stimuli is weakened in PD when fearful stimuli are presented below the level of awareness. A sample of 13 PD patients (7 female, 6 male; mean age 5 28.1 (SD 5 2.7) and 15 healthy volunteers (9 female, 8 male; mean age 5 26.2 (SD 5 3.3) were presented human faces with fearful vs. neutral expressions (17 ms) using a backward masking procedure during a 3T fMRI scanning. Awareness was confirmed by a forced-choice fear detection task. Whereas controls showed a significant bilateral activation within the amygdala for fearful masked faces, patients failed torespond, t(2,26) 5 2.40; p 5 .02; for the left amygdala and t(2,26) 5 2.88; p 5 .01) for the right amygdala. The cognitive activity of worry can be responsible for the inhibition of the limbic system and interfere with the evaluation of threatening visual stimuli, thus becoming maladaptive.

Poster 18

TACTILE CAPTURE OF AUDITORY LOCALIZATION: AN EVENT-RELATED POTENTIAL STUDY

Patrick Bruns, & Brigitte Roder University of Hamburg

Descriptors: multisensory, auditory localization, posture change

The well-known ventriloquist illusion arises when sounds are mislocalized toward a synchronous but spatially discrepant visual stimulus. A similar effect of touch on audition has also been reported. Recently, we demonstrated that this audio-tactile ventriloquism effect predominantly operates in an external coordinate system, i.e. auditory localization was biased toward the external location, rather than toward the side of the anatomical hand to which the tactile stimuli were applied. Using ERPs, the present study investigated the neural correlates of this audio-tactile ventriloquism effect. ERPs elicited 260 ms following stimulus onset suggest a biasing of cortical activity towards the external side of the tactile stimulus. This effect was only seen for trials in which a ventriloquist illusion was elicited. Moreover, this effect was reduced when participants adopted a crossed hands posture, which corresponds to the behavioral finding of a reduced audio-tactile ventriloquism effect when external and anatomically-centered reference frames were in conflict.

Poster 19

AMYGDALA-DEPENDENT ASSOCIATIVE LEARNING IN HUMANS IS MODULATED BY THE BDNFVAL66MET POLYMORPHISM

Tina B. Lonsdorf1, Almut I. Weike2, Armita Golkar1, Martin Schalling1, Alfons O.

Hamm2, & Arne Ohman1 1Karolinska Institute, 2University of Greifswald

Descriptors: fear conditioning/ extinction, BDNF, polymorphism The Brain derived neurotrophic factor (BDNF) is critically involved in neuroplasticity as well as the acquisition, consolidation and retention of hippocampal- and amygdala-dependent learning. A common A/G single nucleotide polymorphism (BDNFval66met) in the pro-domain of the human BDNF gene is associated with abnormal intracellular trafficking and reduced activity-dependent BDNF release specifically in neuronal cells. We studied the effect of this functional polymorphism in an aversive differential fear conditioning, and a 24-hours delayed extinction paradigm in fifty-seven healthy participants. Pictures of male faces were used as stimuli and fear learning was quantified by fear potentiated startle responses (FPS) and skin conductance responses (SCR). A postacquisition interview was used to assess whether participants could correctly report the conditioning contingencies. Aware BNDF met-carriers show a behavioral deficit in amygdala-depended associative learning as indicated by an absence of FPS responses in the last acquisition block, p 5 .004. This deficit is maintained in the first block of extinction, (p 5 .05). No genotype differences were found in conditioned SCR discrimination. These data present provide evidence for the involvement of BDNF signaling in human amygdala-dependent learning and may have important implications for the genetic risk of developing affective pathologies. We suggest that the BDNF met-allele may have a protective effect that is mediated via reduced synaptic plasticity in the amygdala induced by negative life experience.

Poster 20

OXYTOCIN BUFFERS CORTISOL RESPONSES TO STRESS IN INDIVIDUALS WITH IMPAIRED COPING ABILITIES

Rainer Duesing, Markus Quirin, & Julius Kuhl University of Osnabrück

Descriptors: oxytocin, cortisol, coping

Oxytocin facilitates stress regulation but little is known about individual differences in these effects. The present study investigates whether the effect of intranasal oxytocin on stress-contingent cortisol release differs between individuals with high vs. low efficiency in coping with stress. In a double-blind study thirty-seven healthy male students with either high or low coping abilities (action- vs. state-oriented individuals, respectively)

were randomly assigned to receive intranasally 24 International Units oxytocin or placebo. Cortisol was measured at several times before and after a social stressor (public speaking). Individuals with impaired coping abilities show an reduced cortisol response to stress after oxytocin but an increased cortisol response after placebo application. The results suggest that healthy individuals with low stress coping abilities benefit from intranasal oxytocin application. The findings are discussed with respect to their relevance for neuropharmacological treatment of psychiatric disorders with impaired coping abilities such as depression, anxiety or borderline disorder.

Poster 21

THE PERCEPTION OF HIV RISK: AN ERP ANALYSIS OF INTUITIVE PROCESSES

Ralf Schmalzle, Britta Renner, & Harald Schupp University of Konstanz

Descriptors: risk perception, intuition, affect

Recent models of health risk perception emphasize the role of intuitive affective processes, assuming that risk perception comprises more than cognitions about probabilities and expected consequences. The present study attempted to demonstrate that health risk perception processes conform to two key features of intuition: speed and affective evaluation. As a new approach to shed light on intuitive processes in health risk perception, event-related potentials (256 channels) were measured while participants (N 5 40) judged the risk of HIV-infection (Human Immunodeficiency Virus) of 120 persons based on their physical appearance. ERP potentials differentiated between high-and low-risk stimuli around 350 ms post-stimulus, too early to reflect elaborate cognitions about risk. Furthermore, high-risk stimuli elicited enlarged late positive potentials, supporting the notion of affective evaluation in risk perception. Control analyses established that these results cannot be explained by several confounds, such as different stimulus probabilities. Considering previous research in affective neuroscience, it is proposed that risky faces attain higher salience early during information processing, and guide selective attention. The present findings show that neuroscientific methods are able to trace down intuitive processes of health-related risk perceptions.

Poster 22

EFFECT OF DIFFERENT FORMS OF CONTINGENCY AWARENESS ON SUBJECTIVE, ELECTRODERMAL, AND NEURAL CORRELATES OF FEAR CONDITIONING

Christian J. Merz1,2, Katharina Tabbert2, Dieter Vaitl2, Rudolf Stark2, & Oliver T. Wolf3

1Ruhr-University Bochum, 2Bender Institute of Neuroimaging, University of Giessen, 3Ruhr-University Bochum

Descriptors: fear conditioning, contingency awareness

In classical conditioning, a conditioned stimulus (CS) is paired with an unconditioned stimulus (UCS). Contingency awareness, i.e. the cognitive representation of the CS-UCS relationship, has been shown to influence the conditioned responses (CR). However, there are different ways to achieve contingency awareness (i.e. instruction vs. learning) that may influence CR but have not been studied in detail yet. We conducted a differential fear conditioning experiment with transcutaneous electrical stimulation as UCS and geometric figures as CS. One figure was always paired (CS+), whereas the other (CS —) was never paired with the UCS. Nineteen subjects did not notice the contingencies between CS and UCS (unaware), whereas 19 subjects did (learned aware). The third group of 19 subjects was informed about the contingencies in advance (instructed aware). Analyses of subjective ratings and electrodermal activity revealed CR in the two aware groups only. Regarding neural activity in the contrast CS+ > CS —, the unaware group showed significant thalamus activity and a trend in the amygdala. The instructed aware group showed enhanced activations in the insula and prefrontal structures (e.g. anterior cingulate). The learned aware subjects yielded differential responses in the same regions and additionally in the amygdala, hippocampus, thalamus, ventral striatum, occipital, and orbitofrontal cortex. Thus, learned and instructed aware participants showed similar subjective and electrode-rmal responses but differed with respect to the underlying neural activity.

Poster 23

DOES BARO-AFFERENT FEEDBACK RESPOND TO PROCESSES OF CLASSICAL CONDITIONING?

Thomas M. Schilling, Andre Schulz, Anna M. Stertz, Nadine Jutz, Rebecca Schierbaum, Stefanie Schmitt, & Hartmut Schachinger University of Trier

Descriptors: classical conditioning, visceral afferences, baroreflex Classical conditioning of visceral functions is a well known phenomenon. However, it has not been described for baro-afferent feedback. This circuitry plays a crucial role in the regulation of the cardiovascular system, especially the interbeat-interval (IBI). Its afferent signals (US) originate from baroreceptors located in large arteries proximal to the heart. An increased loading of baroreceptors causes increased baro-afferent feed-

back and ultimately a longer IBI (UCR). In the first part of this experiment we established an association in 20 participants (15 w, age 20-27) between the baro-afferent signal (US) and a formerly neutral acoustic stimulus (CS+) by repeated simultaneous presentation. The acoustic stimulus was paired 40 times with the early cardiac cycle phase (R-wave + 230 ms). As a control condition, a second acoustic stimulus (CS — ) was presented 40 times along with the late cardiac cycle phase (R-wave +530 ms). The success ofthis conditioning process was assessed in the second part ofthe experiment by randomized presentation of both stimuli and a third neutral acoustic stimulus right at the R-wave. The CS + leads to a significantly reduced IBI (CR), but neither the CS-, nor the neutral stimulus had an impact on the heartbeat. This finding may indicate an out-of-phase trace conditioning process and requires further discussion.

Poster 24

HAPPY END: THE OFFSET OF ANGRY FACIAL EXPRESSIONS ACTIVATES THE HUMAN REWARD SYSTEM

Matthias J. Wieser, Andreas Muhlberger, Antje B.M. Gerdes, Monika C.M. Frey, Peter Weyers, & Paul Pauli University of Wurzburg

Descriptors: emotion, facial expressions, dynamics

Research on face processing has mostly used still pictures of facial expressions. In everyday life, however, emotional expressions are changing dynamically, and recent studies have shown enhanced processing of dynamic facial expressions. Dynamic information such as the onset and the offset of the same emotional expression may be processed differentially due to its different signaling character: Whereas the offset of a happy expression might signal potential threat, the offset of an angry expression might signal stress relief. To investigate the neuronal correlates of these dynamic features of facial expressions, video clips showing onsets and offsets of happy and angry facial expressions were presented to 18 participants while brain activity was measured by means of fMRI. The offset of the happy expressions and the onset of the angry expressions showed strong common activations in the left amygdala and insula, while both offset of the angry and onset of the happy expressions induced significant activations in the left dorsal striatum. Interaction analysis indicated that the offset of an angry facial expression and to a minor part the onset of a happy facial expression were associated with activity in the left ventral striatum. This difference was confirmed by strong ventral and dorsal striatum activations in response to the offset of angry facial expressions. In sum, our study highlights the significance of dynamic changes of facial emotional expressions, which result in different activities in emotion and motivation-related brain areas.

Poster 25

ALCOHOL INTOXICATION: SELECTIVE REDUCTION OF ANXIETY IN THE FACE OF UNCERTAIN THREAT

Kathryn R. Hefner, Jason N. Jaber, Allison M. Grant, & John J. Curtin University of Wisconsin, Madison

Descriptors: alcohol, anxiety, predictability

Research indicates that fear and anxiety are distinct, separable processes. Experimental procedures administering predictable vs. unpredictable shock elicit fear vs. anxiety, respectively. Our lab has recently demonstrated that alcohol selectively reduces anxiety but not fear. To further specify which stimulus characteristics are most relevant to anxiety elicitation and anxiolytic effects of alcohol, we developed a novel paradigm to vary threat probability while holding temporal precision of threat constant. Intoxicated (.08% BAC) and placebo participants viewed a series of visual cues. Shock probability varied across blocks. High probability (100%) shock cues matched predictable shock cues eliciting fear in earlier research, while lower probability (20% & 60%) shock cues were designed to elicit anxiety. Inter-trial intervals (ITIs) modeled anxiety in anticipation of uncertain, distal shock. Startle potentiation (SP) relative to matched cue and ITI in no-shock blocks indexed affective responses. All shock cues produced robust SP. Alcohol reduced SP monotonically during shock cues as a function of shock probability. Sustained SP was observed during ITIs in shock blocks despite no imminent threat in this period. Alcohol significantly reduced SP during ITIs in all shock blocks. This builds on research suggesting that fear and anxiety are discrete affective responses, and indicates that threat probability as well as temporal uncertainty elicits anxiety. Due to high rates of comorbidity between anxiety disorders and alcoholism, this work has important clinical relevance.

Poster 26

CARDIAC REACTIONS TO PSYCHOLOGICAL STRESS: THE INFLUENCE OF VAGAL TONE AND SOCIAL SUPPORT

Gabriela G.L. Souza1, Pandelis Perakakis2, Pedro Guerra2, Jose Luis Mata2, Evandro F.S. Coutinho3, Ivan Figueira1, Jaime Vila2, & Eliane Volchan1 1Federal University of Rio de Janeiro, 2University of Granada, 3Oswaldo Cruz Foundation

Descriptors: heart period, psychological stress, individual variability

Flexibility is related to ability in effectively regulating emotions and in successfully

coping with challenging daily experiences. Previous studies showed that social support

availability and vagal tone are associated with active engagement and orientation toward the challenge accompanied by a more efficient coping response. Here we investigated ifbiological (vagal tone) and psychological (social support) predispositions, and emotional priming (affective pictures) influence the cardiac reactions to a psychological stress. Seventy-one students filled out a social support scale (MOS) and had calculated the resting high frequency power of heart rate variability (vagal tone) from 5 minutes recordings during the baseline. Electrocardiogram was recorded throughout the experiment. After baseline the participants viewed either a sequence ofpleasant or unpleasant pictures to induce positive or negative mood respectively. Then they were instructed to prepare and deliver a speech about a pre-determinated theme in front of a video-camera. Psychometric measure of social support correlated both with cardiac reactivity (p 5 .03) and with cardiac recovery from stress (p 5 .01). Resting vagal tone also correlated with reactivity (p 5 .01) and recovery from stress (p 5 .01). The emotional priming did not modulate the cardiac reactions to stress. In conclusion, participants presenting high vagal tone and those presenting high social support availability seemed to be more flexible inasmuch as they react more and recover faster from stress.

Poster 27

DECREASED PRE-MOTOR VOLUME IN VICTIMS OF URBAN VIOLENCE WITH PTSD

Vanessa Rocha-Rego1, Mirtes G. Pereira2, Mateus Joffily1, Leticia Oliveira2, Adriana Fiszman1, Carla Marques-Portella1, Mauro Mendlowicz2, Ivan Figueira1, & Eliane Volchan1 1Federal University of Rio de Janeiro, 2Fluminense Federal University

Descriptors: post-traumatic stress disorder, VBM/DARTEL, pre-motor cortex In the monkey brain, electrical stimulation of pre-motor cortex evokes defensive-like withdrawing or blocking movements. Graziano (2006) suggests that a major emphasis of these areas is the construction of a margin of safety around the body and the selection and coordination of defensive behaviour. Our study employed VBM (DARTEL) to detect brain anatomical differences in victims of urban violence with PTSD (n 5 16) relative to trauma-exposed controls (n 5 16) by analysing T1-weighted magnetic resonance images. Direct group comparisons using t-test showed reduced gray matter volume in right pre-motor cortex.

Poster 28

ASYMMETRICAL FRONTAL CORTICAL ACTIVITY, COMMITMENT TO ACTION, AND RESISTANCE TO PERSUASION

Raymond N. Serra, Philip A. Gable, & Eddie Harmon-Jones Texas A&M University

Descriptors: frontal asymmetry, approach motivation, attitudes

The action-based model of dissonance predicts that commitment to an action evokes an approach motivational state (Harmon-Jones, 1999, 2000). This approach motivational state assists with the implementation ofaction and associated cognitive responses and has been associated with increased left pre-frontal cortical activity (LFA). A common way to manipulate commitment is through the induced compliance paradigm, which traditionally uses counter-attitudinal behaviors. The current experiment examines whether or not commitment to pro-attitudinal behavior would increase approach motivation, measured through increased LFA, and would increase resistance to persuasion. To manipulate commitment, participants were told (low choice) or asked (high choice) to write that they enjoyed chocolate. Immediately after this commitment manipulation, EEG was recorded. Participants then read an article extolling the health problems of chocolate; this article was designed to pressure readers to change their attitudes toward chocolate. Finally, self-reported liking of chocolate was measured. As compared to participants in the low-choice condition, participants in the high-choice condition had increased relative LFA (inverse of EEG alpha power) and more positive attitudes toward chocolate, indicating that committed participants resisted persuasive arguments more than participants in the low-choice condition. These results indicate that commitment to pro-attitudinal behavior evokes approach motivation that may underlie resistance to persuasion.

Poster 29

SYMPATHY MODULATES N170 RESPONSE TO FEAR VS. NEUTRAL FACIAL EXPRESSIONS

Laura C. Gravens, Philip A. Gable, & Eddie Harmon-Jones Texas A&M University

Descriptors: emotion, sympathy, ERP

The emotion of sympathy underlies much prosocial behavior and has even been found to cause altruistic behavior (Batson, 1990). The current experiment sought to extend research on sympathy by examining rapid neural responses to faces of other individuals who were in a distressed state. Participants were first told they would view pictures of individuals who had been in an experiment on electric shock (fearful facial expression) or in a control condition of the same experiment (neutral expressions). Then, to manipulate sympathy, participants were instructed to imagine what the individuals in the pictures

were going through (high sympathy); or they were instructed to try to remain objective while viewing the pictures (low sympathy). Participants then viewed pictures of faces displaying neutral or fearful expressions. Event-related potentials were extracted from the occipito-temporal regions and analyzed at approximately 170 ms after stimulus onset. Within the high sympathy condition, a significant facial expression (fear vs. neutral) X sex of expressor (male vs. female) interaction emerged. It indicated that N170 amplitude was greatest to male faces expressing fear. No significant effects emerged in the low sympathy condition. Thus, as predicted, N170 amplitude was increased by sympathy for individuals in distressed states. Possible interpretations of the sex of expressor effect will be considered.

Poster 30

ASYMMETRICAL FRONTAL LATE POSITIVE POTENTIAL (LPP) RELATES TO LOCAL VS. GLOBAL ATTENTIONAL PRECEDENCE FOLLOWING DESIRE VS. SADNESS PRIMES

Philip A. Gable, & Eddie Harmon-Jones Texas A&M University

Descriptors: emotion/motivation, local-global attention, late positive potential Decades of research has suggested that positive affect broadens attention, whereas negative affect narrows attention. This past research failed to consider the importance of motivational intensity. Recent research revealed that positive affects low in approach motivation broaden attention but positive affects high in approach motivation narrow attention. The present research was designed to test whether negative affects low in approach would also broaden attention and whether frontal LPP asymmetry is related to attentional precedence. Previous research has suggested that relatively greater left cortical activity is associated with local attentional bias and relatively greater right activity is associated with global attentional bias. The current experiments examined LPPs to pictures evoking desire, sadness, or neutral affect, and then assessed the relationship of asymmetrical LPPs to local vs. global attentional bias following the affective picture primes. Results revealed that desire pictures caused greater relative left frontal LPP amplitudes, which predicted more local bias following desire pictures. In contrast, sad pictures caused greater relative right frontal LPP amplitudes, which predicted more global bias following sad pictures. These results provide the first evidence that asymmetric LPPs over frontal cortical regions are associated with attentional biases induced by emotions of desire and sadness.

Poster 31

PTSD AND IMMOBILITY: A POSTUROGRAPHIC STUDY

Camila M. Franklin, Carlos E. Norte, Billy E.M. Nascimento, Willian Berger, Adriana Fiszman, Ana Carolina F. Mendonca-de-Souza, Gabriela G.L. Souza, Ivan Figueira, &

Eliane Volchan Federal University of Rio de Janeiro

Descriptors: stabilometry, immobility, PTSD

Employing psychometric measures, previous studies from our group revealed the occurrence of peritraumatic tonic immobility in humans and indicated an association with symptoms severity of post traumatic stress disorder (PTSD). Here we investigated the postural profiles of PTSD patients taking into account the reports of peritraumatic immobilization. Victims of urban violence with PTSD (n 5 18) and trauma exposed controls (n 5 15) stood on a force platform which recorded the displacement of center of pressure. Experimental session consisted of four consecutive blocks (60s duration each): (i) audiotaped neutral script presentation; (ii) blank interval; (iii) audiotaped traumatic script presentation (iv) blank interval. Reports of immobility during the experiment were documented through standardized questions. Area of sway was calculated for each block. Amplitude of body sway during the experiment was estimated by adding the areas of the 4 blocks. The area of sway in patients increased significantly during the presentation of traumatic script compared to controls. On the other hand, in patients, the intensity of reported immobility was inversely correlated with the total amplitude of body sway (r 5 _ .55; p 5 .01). These findings suggest that subjective reports of peritrau-matic postural immobility in PTSD patients may have a somatomotor substrate.

Poster 32

LOOKING FOR A CARDIAC MARKER OF PERITRAUMATIC TONIC IMMOBILITY IN PTSD

Carlos E. Norte, Gabriela G.L. Souza, Camila M. Franklin, Alessandra A. Lima, Carla Marques-Portella, Ivan Figueira, & Eliane Volchan Federal University of Rio de Janeiro

Descriptors: heart rate variability, immobility, PTSD

Violence-related trauma has increased dramatically in recent years potentially raising the risk for Posttraumatic Stress Disorder (PTSD). During the trauma, the defensive cascade is activated and the victim can display reflexive motor inhibition (tonic immobility), the last-ditch defense under life threat. Previously, our group showed that peritraumatic tonic immobility is a strong predictor of the severity of PTSD symptoms. Additionally,

PTSD patients reporting this reaction responded very poorly to standard pharmacological treatment. The objective of the present work is to investigate a potential cardiac marker of tonic immobility. Nineteen PTSD patients underwent a symptom provocation session. Electrocardiographic recording while listening to a personalized trauma-related script was analyzed. The square root of the mean of the sum of the squares of differences between successive adjacent interbeat intervals was computed as a measure of heart rate variability. Reports of immobility during the experiment were documented through standardized questions. We found that heart rate variability was negatively correlated with the reported degree of immobility (r 5 — .48; p < .05). Patients who reported intense immobility exhibited the lowest indices of heart rate variability during the symptom provocation. This finding suggests that decreased heart rate variability may be a putative candidate for a cardiac marker of peritraumatic tonic immobility.

Poster 33

CORTISOL CORRELATES WITH TONIC IMMOBILITY SYMPTOMS AS A RESPONSE TO LIFE THREATENING SITUATIONS IN HEALTHY SUBJECTS

Thais M. Gameiro1, Ana Carolina F. Mendonca-de-Souza1, Nastassja L. Fischer1, Camila M. Franklin1, Gabriela G.L. Souza1, Evandro S.F. Coutinho2, Ivan Figueira1, & Eliane Volchan1 1Federal University of Rio de Janeiro, 2Oswaldo Cruz Foundation

Descriptors: cortisol, immobility reactions, fear responses

The activity of the Hypothalamo-Pituitary-Adrenocortical (HPA) system is known to be related to behavior in the face of threat. Glucocorticoid hormones are the main product of HPA axis and have been implicated in fear responses. Higher basal levels of those hormones in animals were found to be related to more fear paralysis responses, like freezing and tonic immobility. Here we investigated if basal cortisol levels would be related to the degree of immobility felt during a real life threatening situation. We tested 15 trauma-exposed healthy subjects. Saliva samples were collected between 2 pm and 5 pm in the laboratory. To assess the occurrence of peritraumatic tonic immobility we employed the Tonic Immobility Scale (TIS) a 10-item seven-point likert scale. Final scores on the TIS were considered to indicate immobility symptoms felt during or immediately after the trauma. We used non-parametric correlations to test the relationship between cortisol levels and immobilization during a traumatic event. Immobility self-reports were significantly related to basal levels of cortisol (r 5 .58; p 5 .02). The result showed that, in a sample of healthy subjects there is a positive correlation between cortisol basal levels and immobility symptoms felt as a response to real life threatening situations. These findings suggest that in humans, as observed in animals, glucocorticoids are importantly related to immobility responses in the face of danger.

Poster 34

RESILIENCE AND HUMANITARIANISM IMPACT ON MORNING SECRETION OF CORTISOL AND DHEA IN PEACEKEAPERS

Nastassja L. Fischer1, Ana Carolina F. Mendonca-de-Souza1, Wanderson F. Souza2, Thais M. Gameiro1, Antonio Fernando A. Duarte3, Evandro S.F. Coutinho2, Ivan

Figueira1, & Eliane Volchan1 1Federal University of Rio de Janeiro, 2Oswaldo Cruz Foundation, 3Physical Research Institute of Brazilian Army

Descriptors: cortisol, DHEA, resilience

Peacekeeping duty has evolved in ways that individuals are faced with many psychological challenges. However, the shared experience and sense of purpose that arises from being part of an organized structure may mitigate the potentially traumatizing effects of exposure to the negative elements of peacekeeping. Here we evaluated cortisol and DHEA levels in 24 healthy peacekeepers from the Brazilian army after deployment. Saliva samples were taken 0, + 30, +45 and + 60 min after awakening. The extent to which individuals found activities related to their duties to be positive/rewarding was evaluated through a self-reported questionnaire (Positive Humanitarian Subscale). The Resilience Scale measured positive psychological outcome after serious risk experiences. Correlation analysis revealed that the positive hu-manitarianism was inversely associated with morning cortisol reactivity (r 5 — .48).

Poster 35

THE LATE POSITIVE POTENTIAL AS A BIOMARKER FOR ANXIETY-RELATED ATTENTIONAL BIASES

Jennifer M. DeCicco-Augello1, Melanie Hong2, Daniel Otap2, Greg Hajcak3, George Bonnano4, & Tracy A. Dennis2 1The Graduate Center, The City University of New York, 2Hunter College, The City University of New York, 3Stony Brook University, 4Teachers College, Columbia University

Descriptors: late positive potential, anxiety, memory

The late positive potential (LPP) reflects attention to emotion and is greater in response to emotional versus neutral stimuli. Thus, the LPP is ideal for examining the time course of affective processing and its impact on other cognitive processes such as memory. For example, anxiety is characterized by threat biases, including attention biases, behavioral

disengagement, and disrupted memory for emotional material. Changes in the LPP should reflect such threat biases, but few studies have examined links among anxiety, the LPP, and memory. The present study (N 5 25) predicted that high trait anxiety (HTA) will be associated with an attentional bias to unpleasant pictures as measured by increased LPP amplitudes in three time windows (early 350-500, middle 550-750, and late 750 -1000 ms). In addition, this bias will be reflected in decreased LPPs later in the processing stream, reflecting attentional disengagement. Finally, as LPPs decrease, memory for emotional pictures will also decrease. As predicted, HTA was associated with increased LPPs in the early window (r 5 .47).

Poster 36

CHANGES IN THE LATE POSITIVE POTENTIAL PREDICT ATTENTION TRAINING EFFECTS ON THE THREAT BIAS

Laura O'Toole1, Meg Reuland2, Kai Monde1, Andrey Syroyezhkin3, & Tracy Dennis3 1The Graduate Center, The City University of New York, 2Teachers College, Columbia University, 3Hunter College, The City University of New York

Descriptors: attention bias, affective processing

Anxiety is characterized by an attention bias towards threat. This bias can be increased or decreased via attention training, but such training may only succeed when affective processing of threat is altered. The late positive potential (LPP) is ideal for capturing attention to threat because its magnitude is greater for emotionally arousing versus neutral stimuli. Few if any studies have used the LPP to examine attention training and anxiety-related attention biases. Participants were a non-clinical sample of 37 adults trained to attend selectively to angry or happy faces using the dot probe task. The attention bias score was the reaction time to probes in the location ofhappy - angry faces (higher scores indicate faster responses to angry faces). Before and after training, EEG was recorded while emotional faces were viewed. The LPP was quantified in an early (300 - 500 ms), middle (550-750 ms), and late window (800-1000 ms). There were no significant changes in the attention bias score or LPPs due to training. However, when participants were divided into two groups based on whether their LPPs to each face type increased or decreased after training a significant change in attention bias emerged. Those in the attend-happy group who showed a post-training decrease in early-window LPPs to angry faces showed reduced attention bias scores, F(2, 26) 5 5.10, p < .05).

Poster 37

THE LATE POSITIVE POTENTIAL AS A BIOMARKER FOR GENDER DIFFERENCES IN AFFECTIVE PROCESSING RELATED TO EMOTION REGULATION

Melanie Hong1, Jennifer DeCicco-Augello2, Emily Haroz3, & Tracy A. Dennis1 1Hunter College, The City University of New York, 2The Graduate Center, The City University of New York, 3Teachers College, Columbia University

Descriptors: late positive potential, emotion

The late positive potential (LPP) reflects attention to emotion: it is enhanced to emotional versus neutral stimuli. In one study, boys versus girls showed larger LPPs in response to negative stimuli, which in turn was related to maternal report of emotion regulation (ER). Thus, the LPP might be a useful biomarker for affective processing style and be sensitive to gender differences. However, no studies have examined links between the LPP and complex ER behaviors, particularly in children. The present study (N 5 39) explored whether girls and boys showed distinct patterns of affective processing during passive viewing of positive, negative, and neutral pictures measured via the LPP (divided into early 300 - 600 ms, middle 600 -1200 ms, and late 1200-2000 ms windows) and whether the LPP was associated with observed ER (frustration and persistence during a challenging task). Overall, boys and girls did not differ in LPPs to emotional pictures or persistence and frustration. For boys viewing negative pictures, as early window LPPs increased persistence increased (r 5 .47, p < .05), whereas as middle window LPPs increased frustration increased (r 5 .63, p < .05). In contrast, for girls viewing positive pictures, as late window LPPs increased, frustration decreased (r 5 — .55, p < .05). Findings suggest gender differences in the implications of affective processing for ER such that boys' early attention to negative stimuli may underlie the ability to persist even while frustrated, whereas girls' later-developing attention to positive stimuli may underlie the ability to control frustration.

Poster 38

...AND THEY ALL LIVED HAPPILY EVER AFTER: FACTORS INFLUENCING RECOVERY FROM NEGATIVE EMOTION IN YOUNG CHILDREN

Jennifer A. DiCorcia, & Heather L. Urry Tufts University

Descriptors: emotion regulation, recovery, temperament

Recovery from negative emotions is an important facet of emotion regulation but little is known about the factors that moderate recovery. In the first study, 4- to 6-year-olds watched two blocks of three film clips. Each block consisted of a happy scene (PE1), a negative emotion (sad, fear) scene (NE), and a second happy scene (PE2) that resolved the

previous negative scene. Self-reports and expressions of negative emotion increased from PE1 to NE along with heart rate and skin conductance, thereby indicating negative emotion elicitation. With the exception of skin conductance, all measures decreased from NE to PE2 which demonstrated children recovered. Although there was no difference in the pattern of recovery from each negative emotion, higher effortful control was associated with recovery. But was the resolution necessary? In a second study the presence of a resolution was manipulated. In one series, PE2 resolved the previous fearful scene and in the second series it did not. As in Study 1, fear was again elicited. Recovery was also observed in self-report, expressivity, and heart rate regardless of the resolution presence. Again, higher levels of effortful control and surgency predicted recovery from fear. Taken together, the implications of these studies extend to both the clinical and theoretical realms. How children react to and ultimately recover from negative emotions may be related to risk for later psychopathology. Also, understanding how children recover from negative emotions may help to better understand the role positive emotions play in emotion regulation.

Poster 39

EXTENDING THE SCOPE OF SOCIAL NEUROSCIENCE TO EXPLORE THE RELATIONSHIP BETWEEN VAGAL TONE AND EVENT-RELATED POTENTIALS IN RESPONSE TO AN AFFECTIVE PICTURE TASK

Michele Dufey1, Ana M. Fernandez1, Esteban Hurtado1, & Agustin M. Ibanez2 1Universidad Diego Portales, 2Universidad Diego Portales, Chile/Institute of Cognitive Neurology (INECO-CONICET)

Descriptors: ERP (N1, EPN, LPP), vagal tone, international affective picture system (iaps) The present study is the first to investigate the relationship between vagal tone level and event-related potentials (ERP) in adults. Several studies have shown a relationship between vagal tone and individual differences in a variety of psychophysiological, affective and social outcomes. This suggests that vagal tone can be related to how people process relevant affective social information in the brain. This study aimed to assess whether the ERP responses to affective information varied between high and low vagal tone groups. Two groups (n 5 30, matched by gender, age and educational level) were separated according to their vagal tone level. Differences in vagal tone were obtained with the Porges method, through respiratory sinus arrhythmia from ECG and respiratory activity of participants under resting conditions. ERPs were recorded while individuals performed an affective picture task (IAPS) that included positive, neutral, and negative emotional stimuli. Differences between the high and low vagal tone groups were observed at the negative category (N1), the early posterior negativity (EPN) for both positive and negative valences, and at the late positive potential (LPP) for all the categories. This would imply that a higher vagal tone is associated with a more accurate strategy to encode and discriminate affective relevant information in relation to a lower vagal tone. To our knowledge, this is the first report that inquires into the relationship between vagal tone level and the cerebral response in adults to affectively salient information assessed by ERPs.

Poster 40

ERPS OF EMOTIONAL PROCESSING IN SCHIZOPHRENIA: N170 EVIDENCE OF STRUCTURAL PROCESSING AND EMOTIONAL DISCRIMINATION DEFICITS IN PROBANDS AND FIRST DEGREE RELATIVES FROM MULTIPLEX SCHIZOPHRENIA FAMILIES

Esteban Hurtado1, Migdyrai Martin Reyes2, Rodrigo Riveros1, Alvaro Navarro1, Josefina Escobar3, Viviana Vergara4, Sofia Cereceda1, Isabel Pizarro1, Valeria Valdivia1, & Agustin Ibanez5

1Universidad Diego Portales, 2Unidad de Hospitalization Psiquiatrica, Hospital Virgen

del Camino, 3Universidad Diego Portales/P. Universidad Catolica de Chile, 4Universidad Diego Portales/Universidad de Valparaiso, 5Universidad Diego Portales/ Institute of Cognitive Neurology (INECO-CONICET)

Descriptors: ERP (N170 VPP), possible endophenotype of multiplex schizophrenia families, implicit attention test

In schizophrenia research, endophenotypes are receiving an increasing interest due to their usefulness in identifying the functional importance of genetically transmitted brain-based deficits in this desease. ERPs have been considered in that research and proven relevant. Recently, we reported the first N400 evidence of processing deficits (significantly reduced N400 amplitude for congruent categories) in probands and first degree relatives during a picture semantic-matching task. This suggested a probable contextual semantic deficit (Guerra, S, Ibanez, A, Bobes, A., Martin, M et al., In press). In order to explore in which ways ERP accounts of emotional processing could also be compromised, unaffected first-degree relatives of patients, DSM-IV diagnosed schizophrenia probands, and control subjects, matched by age, gender and educational level performed an implicit attention test (IAT) that involved the categorization of pleasant and unpleasant words, along with faces of anger and happiness, giving place to a congruent condition (when happy faces were implicitly associated to pleasant words) and an incongruent condition (otherwise). An N170 component present in relatives and control subjects was largely reduced in patients, not only for faces, but also for words, suggesting a deficit in structural processing of stimuli. Consistent with our previous report of N170 in a race-IAT, control subjects show N170 modulation by the association imposed by IAT blocks. However, this discrimination effect appears clearly reduced in both patients and relatives.

EXPECTED VALUE MODULATES FEEDBACK CORRECT-RELATED POSITIVITY: AN ERP STUDY ON COGNITIVE PROCESSING OF MONETARY GAINS AND LOSSES

Rene San Martin1, Esteban Hurtado2, Fernando Sandoval2, Alvaro Navarro2, Pablo Isla3, Facundo Manes4, & Agustin Ibanez5 1Universidad Diego Portales, Universidad de Chile, 2Universidad Diego Portales, 3Universidad Federico Santa Maria, 4Institute of Cognitive Neurology (INECO), 5Universidad Diego Portales/Institute of Cognitive Neurology (INECO-CONICET)

Descriptors: fern:feedback error-related negativity, fcrp: feedback correct-related posit-ivity, expected value and reinforcement learnig

The feedback error-related negativity (fERN) has been referred to as similar to a negative deflection in the event related potential (ERP) that distinguishes between wins and losses. The reinforcement learning theory of the fERN postulates that the difference between actual and expected outcomes would be transmitted, like a training signal, from the midbrain dopamine system to the anterior cingulate cortex, generating the fERN. A growing body of evidence suggests greater modulation of fERN amplitude for win vs. loss feedback, suggesting that the neural mechanism of feedback processing may differ between wins and losses. Furthermore, it has been suggested that the observed modulation of the fERN by valence of the feedback is due to the superposition of a positive-going deflection for the win trials, the so-called feedback correct-related positivity (fCRP). We used a roulette-like gambling task to study the effect of the expected value on the amplitude of fERN and/or fCRP. The results indicate that, although the ERP associated to the feedbacks distinguishes between wins and losses, changes in size and probability of rewards impacted the amplitude of fCRP. Furthermore, larger expected value of wins was associated with greater positivity following win feedback. No significant difference was observed when changes did not affect the expected value. These findings support the existence of two independent systems for the processing of positive and negative feedback, since only the positive feedback responses were modulated for the expected value of conditions.

Poster 42

GESTURE INFLUENCES THE PROCESSING OF FIGURATIVE LANGUAGE IN NON-NATIVE SPEAKERS: ERP EVIDENCE

Agustin M. Ibanez1, Josefina M. Escobar2, Facundo Manes3, Natalia Trujillo4, & Esteban Hurtado2

1Universidad Diego Portales/Institute of Cognitive Neurology (INECO-CONICET), 2Universidad Diego Portales/P. Universidad Catolica de Chile, 3Institute of Cognitive Neurology (INECO), 4University of Antioquia

Descriptors: second language, video gesture, ERP N400 LPC

In spoken language, gestures and contextual cues are very closely connected. Gestures are used concurrently with words and help convey the meaning of spoken language. This is particularly evident in figurative language, in which a considerable amount of contextual information is required for understanding. Gestures should play an important role in second language acquisition and comprehension. In this study, two components of event-related potentials, the N400 and the Late Positive Complex (LPC), were evaluated in a task involving the observation of videos showing utterances accompanied by gestures. Spanish native speaker studying advanced (n 5 15) and basic (n 5 15) German as a second language participated. The utterance-gesture congruence and metaphoric meaning of content were manipulated during the task. As in previous reports, the N400 and LPC elicited by metaphors were highly sensitive to their gesture-context. Our report shows that the level of L2 proficiency affects the neuronal processing of semantic meaning constructed from the gesture type (congruent or incongruent) and the type of expression (literal or metaphoric). Also, our results suggest that semantic processing is robust in the early learning of a second language, although the amplitude modulation and latency might depend on the speaker's proficiency level. This paves a new path for studying the electrophysiological correlates of multimodal, paralinguistic cues and figurative language in L2 learners.

Poster 43

SOURCE ANALYSIS OF N400 WAVEFORM GENERATORS OBTAINED WITH A CROSS-MODAL PRIMING PARADIGM

Margarita M. Baez-Martin1, Maria L. Bringas1, Mayelin Borrego2, Marilyn Zaldivar-Bermudez1, Abel Sanchez-Coroneaux1, Ivette Cabrera-Abreu1,

& John F. Connolly3 international Center for Neurological Restoration, 2Cuban Neuroscience Center, 3McMaster University

Descriptors: event-related potentials, language, attention

The aim of the present study was to evaluate the distribution of current sources inside the brain that generate the N400 waveform obtained during the performance of a computerized version of the Peabody Picture Vocabulary Test- Revised (PPVT-R), which

was maximal in centroparietal and frontal derivations. Twenty-two healthy control subjects (mean age 5 38.6 years) free of neurological, psychiatric, visual or audio-logical disorders were instructed to watch pictures and hear a word that matched or mismatched (.5 probability) the semantic content of the picture. Participants were instructed to judge silently whether the picture and the word were congruent or not (passive task) or to press a button after the auditory stimulus presentation if picture and word were incongruent (active task). An image of the underlying brain electrical activity for the individual scalp topography for each task in the first level ofvocabulary ofPPVT-R was estimated by the Bayesian Model Averaging (BMA) ofdifferent EEG inverse solutions, which were visualized using the Brain Electrical Tomography (BET) viewer software (La Habana, Neuronic S.A.). The activation was maximal in the superior and middle frontal gyri in the left hemisphere, the left middle temporal gyrus, and the angular gyrus bilateraly during the active task, but it was different with the passive one. Our results confirm the participation ofbrain areas that are related to the processing oflanguage and attention, and the involvement ofboth hemispheres in the studied paradigm.

Poster 44

INFLUENCE OF SEMANTIC KNOWLEDGE ON EPISODIC MEMORY PERFORMANCE IN SCHOOL-AGED CHILDREN WITH INFANT FEBRILE SEIZURES

Martina K. Becker, Kerstin H. Kipp, & Axel Mecklinger Saarland University

Descriptors: memory development, event-related potentials, infant febrile seizures This event-related potentials (ERP) study examined semantic and episodic memory in school-aged children with a history of infant febrile seizures (a risk factor for hippocampal sclerosis) and age-matched controls. To date, it is unclear how semantic and episodic memory interact and whether this interaction is modified by ontogenetic development. The possibility that infant febrile seizures distort normal memory development is even more controversial. We focused on the N400 component, indexing the access to semantic knowledge, and its correlation with episodic memory processing as reflected in the early frontal and late parietal old/new effects. We used a semantic paired-associate learning task with related vs. unrelated pictures to induce different amounts of semantic processing at learning. Thereafter a recognition memory test was performed. The groups differed neither in reaction times and accuracy nor in the expected N400 effect during study. We found similar early fronto-central and late parietal old/new effects in both groups, the putative ERP correlates of familiarity and recollection. An additional ERP effect at around 400 ms varied between both groups. For controls, semantically related items were more positive-going than new objects, while the risk group showed more positive-going waveforms for unrelated relative to new items. Moreover, the late parietal effect correlated with the N400 effect only in the controls. These findings suggest that the risk group's episodic memory was supported to a lesser extent by pre-existing semantic knowledge than in normal controls.

Poster 45

DEVELOPMENTAL ASPECTS OF FAMILIARITY AND RECOLLECTION: INSIGHTS FROM A CROSS-SECTIONAL EVENT-RELATED POTENTIAL STUDY OF RECOGNITION MEMORY

Volker Sprondel, Kerstin H. Kipp, & Axel Mecklinger Saarland University

Descriptors: memory, development, erps

Throughout childhood, familiarity-based remembering seems to develop earlier than recollection-based remembering. However, previous studies failed to demonstrate an early frontal old/new effect, an event-related potential correlate for familiarity, in children. Instead, they showed a frontal negativity (Nc) at 400 ms that is elicited by new and old items and by this insensitive to memory status. In infants, the Nc is thought to reflect novelty-induced attention processes. In our study, we examined the sensitivity of the Nc to generic novelty and how the Nc is modulated by memory status. Secondly, we analyzed age-related changes in strategic recollection, here operationalized by means of successful rejection of non-target events. In two runs of a continuous recognition memory task, children, adolescents, and adults saw pictures of familiar objects and unfamiliar non-objects, each item repeated once per run. Subjects judged the old/new status of the items separately in each of the runs, that is, in the second run, new items and items repeated from the first run (non-targets) had to be rejected as new. Relative to adolescents and adults, children were selectively impaired in rejecting non-targets. In children and adolescents the Nc to new items was larger for non-objects than for objects, and also attenuated for repeated stimuli, with both effects differing in scalp topography. This suggests that different portions of the Nc are modulated by generic novelty and by memory status. Only adults showed a late parietal positivity for non-targets indexing strategic recollection.

EVIDENCE FOR AN ERP CORRELATE OF FAMILIARITY PROCESSING IN 7-10 YEAR-OLD CHILDREN

Nicole Brunnemann, Kerstin H. Kipp, & Axel Mecklinger Saarland University

Descriptors: memory, development, erps

According to dual-process models of recognition memory, retrieval can be based on familiarity and on recollection. Event related potential (ERP) studies revealed that the late parietal old/new effect, the putative ERP correlate of recollection, is highly similar for adults and children. However, the early mid-frontal old/new effect, the putative ERP correlate of familiarity, so far, has not been reported for children, even though some behavioral studies suggest that children in early school age use familiarity. In the present study we used a response-deadline procedure to examine whether children show familiarity processing (and its putative ERP correlate) if they are hindered to use recollection. In a fast response block participants were instructed to make old-new decisions for objects within a limited time. In the slow response block they had unlimited time, allowing recollection-based retrieval. The behavioral findings suggest that item recognition improves with age. ERPs showed similar old/new effects for children (age 7 to 10) and for adults. In the slow response block we found a late parietal old/new effect between 500 and 650 ms for both groups. In the fast response block there was an early fronto-central old/new effect between 350 and 500 ms for adults and for children. The data demonstrate that, under conditions where children are forced to make the old/new decision quickly and, in turn, recollection is hindered, they show an early mid-frontal old/new effect associated with familiarity-based retrieval.

Poster 47

NEURAL NETWORK EVALUATION OF MULTI-MODAL STARTLE EYEBLINK MEASUREMENTS

Christopher T. Lovelace1, Reza Derakhshani1, & Judee K. Burgoon2 1University of Missouri, Kansas City, 2The University of Arizona

Descriptors: neural networks, startle, deception

Psychophysiological measurements like startle eyeblink can provide information about the state of an individual with respect to sensory, cognitive, and affective processing. A drawback to using such techniques, especially outside the laboratory, is the laborious process of feature extraction (e.g., ''peak picking''). An alternate approach is to use existing data to train a neural network to classify novel responses as, say, indicative of psychopathology, modulated by attention or a prepulse, etc. No manual feature extraction is needed. In two pilot experiments, we measured startle eyeblinks using EMG and high-speed video in prepulse inhibition (PPI) and detection of deception paradigms. After training, the neural networks were able, based only on the response waveforms, to determine whether a trial had contained startle or prepluse+ startle stimuli in 72% of EMG trials (15 participants) and 80% of video trials (4 participants). In a mock crime experiment, neural networks correctly classified 85% of participants (7 deceptive, 29 truthful) as having answered a crime-related question truthfully or untruthfully. With larger datasets, neural network performance should improve. Additionally, because neural networks operate on entire response waveforms, they can capture effects that would be missed by conventional feature extraction. Compared to conventional methods, the data-driven neural network technique represents a more efficient and flexible approach to the understanding and evaluation of the data generated in some psycho-physiological studies.

Poster 48

FICTION ATTENUATES FEAR: NEUROIMAGING EVIDENCE

Izabela Mocaiber1, Fatima S. Erthal2, Tiago A. Sanchez3, Draulio B. Araujo3, Mateus

Joffily1, Eliane Volchan1, Mirtes G. Pereira1, & Leticia Oliveira1 1Federal University of Rio de Janeiro, 2Fluminense Federal University, 3University

of Sao Paulo

Descriptors: emotion regulation, amygdala, fmri

The role of the amygdala in emotional processing has been often demonstrated, especially for aversive stimuli. Here, we employed fMRI to investigate whether amygdala responses to mutilation pictures could be modulated by experimental context. 24 participants (13 male)tookpartinthestudy. Theywerescannedina1.5 T SiemensVisionwhileperforming an emotion discrimination task. Participants viewed a display containing a neutral or an unpleasant picture. They had to respond to the stimuli as quickly and accurately as possible, pressing one of two keys if they judged the stimuli as emotional or neutral. Neutral pictures consisted of photographs of people, and unpleasant pictures consisted of photographs of mutilated bodies. Each trial began with a fixation cross (3s) at the center of the screen, followed by a picture (200 ms). The task was performed in two contexts: (1) fictitious, where participants were instructed that pictures had been obtained from movies and (2) real, where they were instructed that pictures had been obtained from day-life

situations. Data analysis was performed using SPM5. In the real context, we found increased BOLD response in the right amygdala (x 5 34, y 5 _ 2, z 5 124) when participants viewed aversive pictures as compared to neutral pictures.

Poster 49

EMOTIONAL PROCESSING OF LOVED FACES: FAMILIARITY VERSUS AFFECT

Rafaela R. Campagnoli1, Cynthia Vico2, Maria Isabel Viedma2, Pedro Guerra2, Lourdes Anllo-Vento2, Leticia Oliveira3, Mirtes G. Pereira3, Eliane Volchan1, &

Jaime Vila2

1Federal University of Rio de Janeiro, 2University of Granada, 3Fluminense Federal University

Descriptors: emotional processing, face processing, affect

Background: Neuroscience research on face processing has focussed on the cognitive mechanisms of face recognition and emotional expression. Little research has been conducted on the emotional processing associated with the recognition of facial identity. The aim of the present study was to replicate previous findings concerning emotional processing of loved faces, using both central and peripheral physiological measures, and controlling for differences in familiarity. Method: Thirty-five volunteer female students viewed five photographs of faces in black and white and with neutral emotional expression corresponding to the following categories: boyfriend, father, control boyfriend, control father, and baby. Faces were presented for 4 seconds with a random intertrial interval of8-12seconds. Each photograph was presented 20 times in counterbalanced order using a Latin square procedure. Results: Loved faces produced larger responses of skin conductance, heart rate, zygomatic activity, and positive components of Event-Related Potentials (P300 and LPP) replicating previous findings; no differences were found as a function of familiarity (boyfriend versus father). Larger response for boyfriend than for father was shown for zygomatic activity. Discussion: The findings support the hypothesis that the neurophysiological mechanisms underlying the processing of loved faces include peripheral and central components that are specifically affective and independent of its cognitive components.

Poster 50

NEURAL CORRELATES OF CONCEPTUAL JUDGMENTS OF LYING AND TRUTH-TELLING: AN ERP STUDY

Dingcheng Wu1, Fen Xu1, & Kang Lee2 1Institute of Cognitive Neuroscience and Learning, 2Institute of Child Study

Descriptors: lie, conceptual judgment, ERP

Extensive behavioral research has shown that people readily make accurate judgments about whether a statement is a lie or the truth. However, little is known about the neural correlates of such conceptual judgment. In this study, we used high-density ERP to provide information about the time course of the brain activities associated with the conceptual judgments of lies and truths. We found a significant amplitude divergence between conceptual judgment of lie and truth-telling in frontal left and posterior right ERP components peaked at about 400 ms after the presentation of the test stimuli. Judgments of lying elicited higher ERPs compared with that of truth-telling. Also, the amplitude difference between the anti-social lying and modesty lying appeared at 400 ms in the frontal left and posterior right sites. Judgments of anti-social lying evoked higher ERPs relative to those of modesty lying. As expected, there was no ERP difference between the two types of truth-telling. The late positive component as the 400 ms ERP component in the present study was thought to reflect valence evaluation (e.g., Cunningham et al., 2005). Therefore, our findings suggest that conceptual judgment of lying contains processing of valence evaluation. In the studies of lie judgment, in addition to conceptual judgments, participants appeared to automatically make moral judgments when they read lying stories.

Poster 51

OBJECTIVE MEASUREMENT OF PLACEBO ANALGESIA BY EVENT RELATED POTENTIALS

Peter Solvoll Lyby, Martin Bystad, Elisabeth Sjolie, Line Solbakken, June Thorvaldsen, Sara M. Vambheim, Magne Arve Flaten, & Per M. Aslaksen University of Troms0

Descriptors: pain, placebo analgesia

Placebo analgesia refers to reduced pain report after administration of a placebo with information that it is a painkiller. This study investigated whether placebo analgesia could be observed as a reduced cortical response to pain, and whether placebo analgesia could be related to reduction in stress. Thirty-three participants (17 females) were exposed to phasic contact heat pain at 510C before and 10-30 minutes after administration of capsules containing lactose with information that the capsules contained a powerful painkiller. In a control condition the participants were exposed to the same painful stimuli, but the capsules were not administrated. The placebo and control conditions were separated by a minimum of 24 hours, and the order of the conditions was balanced. Pain report was recorded on a visual analogue scale, and cortical activity to

painful stimulation was recorded by electroencephalography from 32 electrodes with linked ears reference. Only data from the Cz electrode are reported here. Phasic painful stimulation reliably generates cortical activity that can be observed as a positive component at about 200 - 300 ms after stimulus onset in the event related potential. The results showed significantly lower pain unpleasantness, and a significantly reduced P2 component in the placebo condition. Placebo analgesia was also related to a decrease in stress levels. The findings indicate that placebo analgesia is due to a reduced nociceptive signal to the cortex, or to reduced processing of the nociceptive signal in the cortex.

Poster 52

HOW FAST IS FEAR? AUTOMATIC AND CONTROLLED PROCESSING IN CONDITIONED FEAR

Ole Asli, & Magne Arve Flaten University of Troms0

Descriptors: fear potentiated startle, fear conditioning

The minimum latency of potentiated startle after delay and trace fear conditioning was investigated. Delay conditioning is hypothesized to be mediated by automatic processes, whereas trace conditioning, where there is a gap between the conditioned stimulus (CS) and the unconditioned stimulus (US), is hypothesized to involve controlled cognitive processes. Previous research has found that the latency of the conditioned fear reaction in humans is about 100 ms following delay conditioning. In delay conditioning a tone CS signaled an electric shock US presented 1000 ms after CS onset. In trace conditioning a 200 ms tone was followed by an 800 ms gap prior to US presentation. The CS and US were explicitly unpaired in two control groups. Fear-potentiated startle was assessed by 95 dB noise presented 10, 30, 100, 150, 500 and 1500 ms after CS onset. It was hypothesized that fear-potentiated startle should be observed at shorter intervals after delay conditioning compared to trace conditioning. The results showed increased startle in the delay paired group compared to the delay unpaired group 100 and 150 ms post CS onset. The trace paired group showed increased startle at 1500 ms after CS onset. These findings support the hypothesis that delay conditioning is mediated by automatic processing, whereas trace conditioning is dependent on controlled processing.

Poster 53

BRAIN CORRELATES OF STRESS-INDUCED ANALGESIA

Pinar Yilmaz, Martin Diers, Slawomira Lipinski, Michele Wessa, & Herta Flor Central Institute of Mental Health

Descriptors: pain, stress analgesia, mechanical stimulation

Stress-induced analgesia (SIA) has been described as a reduced nociceptive response after stress exposure, which is mediated by descending pain-inhibitory circuits and may be an indicator of adequate pain control. We used functional magnetic resonance imaging to assess SIA in 21 healthy participants. Series of painful pressure stimuli midway between pain threshold and tolerance were applied to the left m. flexor digiti minimi at a frequency of 1 Hz. Stimulation was carried out in a block design, with 6 stimulation blocks each lasting 10 echo planar sequences and 7 rest blocks where no stimulation was applied. Mental arithmetic combined with noise was used as stressor. Verbal ratings as well as changes in blood pressure and heart rate confirmed that the stressor was perceived as stressful. The stress induction led to a significant increase in pain threshold and in pain tolerance as well as decreased pain and unpleasantness ratings. In the pre as well as in the post stress condition the pain matrix was activated. Post stress, pain inhibitory areas such as the periaqueductal grey and the anterior insula were additionally activated. In the post versus pre comparison the anterior insula was significantly more activated in line with its role in pain inhibition. To further investigate the opoid mediation of this stress analgesia we extended our design to the administration of naloxone during functional imaging and will also report on these data.

Poster 54

INFORMATION PROCESSING BIAS FOR ANXIETY-RELATED STIMULI IS ASSOCIATED WITH AN AVERSIVE CONDITIONED ACTIVATION OF AFFECTIVE BRAIN FUNCTIONS IN A SAMPLE OF HEALTHY ADOLESCENTS

Frauke Nees1, Karl Mann1, Gunter Schumann2, & Herta Flor1 1Central Institute of Mental Health, 2Institute of Psychiatry, King's College London

Descriptors: aversive conditioning, adolescents, affective cognitive processing Changes in conditionability of primary reinforcers have been shown to covary with activation of core brain regions involved in the processing of emotional and motivational stimuli in a number of mental disorders (e.g. anxiety disorders, drug addiction). The present study assessed to what extent Pavlovian aversive conditioning is related to affective information processing in a sample of healthy adolescents. A differential conditioning paradigm with an aversive sound, used as unconditioned stimulus, and pictures of male faces, used as conditioned stimuli, were employed in 14 year old healthy adolescents (N 5 15). We used functional magnetic resonance imaging, and self-report

measures to assess the differential conditioned responses as well as an Affective Go-NoGo (AGN) task including positive and anxiety-related words. Increased activity after the conditioned stimulus (CS+) relative to the CS — in amygdala, insula, frontal cortex, and putamen during acquisition and in anterior cingulate, frontal cortex, thalamus, and putamen during extinction was found to be related to enhanced information processing for anxiety-related stimuli during the AGN task. These results provide evidence for the important role of affective cognitive processing in brain activation during aversive learning in adolescents and may be of theoretical and clinical significance for generation and persistence of mental disorders in adult age.

Poster 55

TREATMENT RELATED CHANGES IN BRAIN ACTIVATION IN PATIENTS WITH FIBROMYALGIA SYNDROME

Diers Martin, Pinar Yilmaz, Mariela Rance, Kati Thieme, & Herta Flor Central Institute of Mental Health

Descriptors: fibromyalgia syndrome, operant behavioral therapy, pain Little is known about the effects of successful treatment on brain functions in chronic pain. The present study aimed to identify changes in brain activation following operant behavioral therapy (OBT) in fibromyalgia patients. Using functional magnetic resonance imaging, brain activation to painful mechanical stimuli was assessed in 10 patients with fibromyalgia (FMS) and 10 healthy controls (HC). The FMS patients were again scanned after treatment. Before treatment, brain activation compared to the HC showed higher activation in the bilateral insula, bilateral striatum, right orbitofrontal cortex (OFC) and left thalamus. OBT significantly reduced interference from pain and pain severity in the FMS patients. After treatment the FMS, brain activation compared to the HC showed higher activation in the left insula and the right OFC. The contrast of brain activation post- compared to pre-treatment correlated significantly with the amount of reduction in interference related to pain and pain severity in the bilateral insula, bilateral striatum, left thalamus and the primary somatosensory cortex contralateral to the stimulated side. These data suggest that effective behavioral treatment activates brain regions involved in pain inhibition.

Poster 56

THE WHY OF ACTION MATTERS: EXTRINSIC MOTIVATION INCREASES THE NEURAL RESPONSE TO REWARD

Michele Wessa1, Andrea V King1, Andre Bongers2, & Julia Linke1 1Central Institute of Mental Health, 2Mediri GmbH

Descriptors: reward, fmri, emotion

Motivation does not only vary in quantity, but also in its orientation, being either primarily extrinsic (acting because it leads to a separable outcome, e.g., grades, money) or intrinsic (acting because it is inherently interesting or enjoyable, e.g., gain in knowledge, stimulation). So far, no study has investigated whether intrinsically or extrinsically motivated persons respond differently to reward on a neurobiological level although this might give new insights in pathological gambling. We investigated the relationship between extrinsic and intrinsic motivation toward gambling and the neural response to reward in a functional magnetic resonance imaging task on reward learning in 33 healthy, right-handed volunteers (19 females, 14 males; mean age 22.8 years). This task evokes increased activation in the reward network (orbitofrontal cortex, anterior cingu-late cortex, amygdala, putamen) to rewarding trials. Participants also completed a questionnaire on gambling motivation, assessing intrinsic and extrinsic motivation as well as illusion ofcontrol. We observed a significant relationship between the orientation of motivation (extrinsic vs. intrinsic) and the neural response to reward: Extrinsically motivated people showed an augmented and intrinsically motivated persons a diminished neural response to monetary reward in the aforementioned brain network. This modulation of reward responsiveness by the motivational orientation might be highly relevant for the understanding of pathological gambling and might be an important target for psychological treatments.

Poster 57

MODULATION OF NEURAL RESPONSES TO REWARD AND PUNISHMENT BY SAD MOOD INDUCTION IN HEALTHY VOLUNTEERS

Julia Linke1, Andrea V. King1, Andre: Bongers2, & Michele Wessa1 1Central Institute of Mental Health, 2Mediri GmbH

Descriptors: mood, fmri, reward

Mood states are dispositions that alter the activity of the resting state brain networks. Increased activation in prefrontal and limbic brain regions at rest have been observed in healthy volunteers after sad mood induction. These brain regions are crucial for the processing of reward and punishment and due to the altered sensitivity to reward and punishment in depression, we assumed that the induction of sad mood would alter the activity in those regions during reward and punishment. Using a functional magnetic

resonance imaging (fMRI) task on probabilistic reversal learning we assessed neural responses to reward and punishment in 35 healthy, right-handed volunteers. Participants were randomly assigned to negative (n 5 17) or neutral (n 5 18) mood induction through film clips. As compared to neutral mood induction, negative mood induction led to significantly greater activity in the medial orbitofrontal cortex (mOFC), the anterior cingulate cortex (ACC) and the dorsolateral prefrontal cortex (dlPFC) in response to punishment. These brain structures have been associated with the identification of emotional stimuli and the generation of an emotional response (mOFC, ACC), thus strengthening the hypothesis that negative information are intensified by congruent mood states. Additionally, the increased neural response in the dlPFC, a structure involved in the regulation of emotional states, might be interpreted as healthy mechanism to suppress the increased emotional response to punishment and thus to avoid further negative mood and sadness.

Poster 58

REDUCED PREPULSE INHIBITION IS SENSITIVE TO A WIDE RANGE OF PSYCHOPATHOLOGIES, BUT SPECIFIC TO NONE OF THEM

Joseph C. Franklin University of North Carolina, Chapel Hill

Descriptors: prepulse inhibition, psychopathology, theory

Combining Graham's (1975) protection theory of PPI with McGhie and Chapman's (1961) theory of early information processing deficits in psychosis, Braff et al. (1978) investigated and confirmed prepulse inhibition (PPI) deficits in patients diagnosed with schizophrenia. Since then, hundreds of studies have replicated and extended this finding, with many researchers insisting that PPI deficits are a specific indicator of psychosis. This belief is maintained by some despite extensive findings of reduced PPI in various internalizing (e.g., Grillon et al., 1996), externalizing (e.g., Kumari et al., 2005), and autism spectrum disorders (Perry et al., 2007), among many others. This lack ofdiscriminant validity has been explained away by some as PPI deficits indicating some form of psychosis within each of these disorders. Given that PPI is modulated by many different areas of the brain (e.g., midbrain, striatum, limbic and cortical areas) and several forms of psychopathology with no accepted association with psychosis are associated with abnormalities in these areas, PPI should be sensitive to many psycho-pathologies, but specific to none of them. Although this brain-based view has been promulgated by three of the most prominent PPI researchers (Swerdlow, Braff, & Geyer, 2000), the psychosis-specific assumption remains dominant, severely limiting the application of PPI as a broad psychophysiological tool. The purpose of this review is to more formally challenge this assumption and to aid in the development of a more valid notion of the clinical implications of reduced PPI.

Poster 59

THE ASSOCIATIONS BETWEEN PREPULSE INHIBITION OF STARTLE AND DIMENSIONS OF OBSESSIVE-COMPULSIVE DISORDER: CLEARER RESULTS UNDER STRESS

Joseph C. Franklin, Michael G. Wheaton, Elenda T. Hessel, & Jonathon S. Abramowitz University of North Carolina, Chapel Hill

Descriptors: obsessive-compulsive disorder, prepulse inhibition, stress Previous studies have shown that obsessive-compulsive disorder (OCD) is associated with reduced prepulse inhibition (PPI); however, given that OCD is comprised of several heterogeneous symptom dimensions with distinct neural correlates, this association may be specific to certain OCD subtypes. Additionally, given that OCD is more prominent under stressful conditions, we hypothesized that these associations would be stronger under stress. To test this, we measured OCD symptomatology with the OCI-R across various dimensions (hoarding, washing, checking, obsessing, ordering, and neutralizing) in 42 undergraduates and then measured their PPI (70 dB background, 85 dB prepulse, 100 dB startle stimulus; 6 prepulse and 6 startle-alone trials in each condition) both at baseline and while preparing for a stressful speech task. Baseline results showed that Ordering was associated with reduced PPI.

Poster 60

PREPULSE INHIBITION OF ACOUSTIC STARTLE IS DECREASED BY BOTH STRESS AND PAIN

Joseph C. Franklin, Elenda T. Hessel, Rachel V. Aaron, Michael S. Arthur, Eleanor K. Hanna, John D. Guerry, & Nicole Heilbron University of North Carolina, Chapel Hill

Descriptors: prepulse inhibition ofacoustic startle, stress, pain

Although Grillon and Davis (1997) and Lietner (1989) respectively suggest that prepulse inhibition (PPI) decreases under stressful and painful conditions, these effects have yet

to be directly demonstrated in humans. To test this possibility, the present study measured PPI in 56 healthy undergraduates at baseline, during preparation for a stressful speech task (a one minute speech on a controversial topic), and immediately after an experimental pain stimulus (cold pressor task [CPT]; placing the hand in ice water until it becomes intolerable), and again during preparation for another speech task and after another CPT administration (i.e., a baseline-A-B-A-B design). A within-participants Analysis of Variance (ANOVA) revealed a significant main effect of condition.

Poster 61

LATENT GROWTH CURVE MODELING PROVIDES A MORE PRECISE ACCOUNT OF STARTLE HABITUATION

Joseph C. Franklin1, Ruth E. Mathiowetz1, Michael G. Wheaton1, Nicole Heilbron1, Elenda T. Hessel1, John D. Guerry1, & Terry D. Blumenthal2 1University of North Carolina, Chapel Hill, 2Wake Forest University

Descriptors: startle habituation, latent growth curve modeling, methodology Although some studies have shown that startle habituation - an index of information processing - is associated with psychopathology, these findings have been inconsistent. We propose that this may be due, in part, to the use of means-based techniques (e.g., t-tests, ANOVAs) to index habituation. Accordingly, we hypothesized that employing an advanced statistical technique specifically designed to index change over time (Latent Growth Curve Modeling [LGCM]) would provide a more powerful and detailed account of startle habituation. Habituation data from two samples (original: N 5 53, 105 dB startle stimulus; cross-validation: N 5 56, 100 dB startle stimulus; each had 8 trials) were quantified with the two most commonly used means-based techniques to quantify startle habituation (i.e., t-test [here, 4 trials per block] and ANOVA [here, 2 trials in each of the four blocks]) and LGCM.

Poster 62

INVESTIGATING AND EXPLAINING HABITUATION OF PREPULSE INHIBITION OF ACOUSTIC STARTLE

Joseph C. Franklin, Ruth E. Mathiowetz, Michael G. Wheaton, Nicole Heilbron, John D. Guerry, Elenda T. Hessel, & Terry D. Blumenthal University of North Carolina, Chapel Hill

Descriptors: startle, prepulse inhibition, habituation

To investigate the presence of, and reason for, habituation of prepulse inhibition (PPI), in a sample of 53 healthy undergraduates we examined PPI habituation with an advanced statistical technique specifically designed to measure change over time (latent growth curve modeling) across three different prepulse/background signal-to-noise ratios (+ 5, 10, and 15 dB above 70 dB background noise). There were 8 startle alone (105 dB) trials, and 8 trials per SnR condition, resulting in a total of 32 randomly ordered trials. Results revealed that there was PPI habituation in the +10 and +15 conditions (i.e., significant positive linear trends), but not in the +5 condition (i.e., significant intercept/flat trend). Raw startle reactivity on prepulse trials (i.e., the magnitude ofresponses to startle stimuli on these trials before being quantified with a PPI formula that references startle-alone reactivity), however, indicated the opposite trend: reactivity in the +5 condition closely followed the quadratic trend of startle-alone reactivity whereas reactivity in the + 10 and + 15 conditions displayed flat trends .As +5 reactivity varied systematically with startle-alone reactivity and +10/15 reactivity did not, quantifying PPI in reference to startle-alone reactivity (i.e., proportion of difference from control method) led to a flat trend in the + 5 condition and a linear trend (indicating habituation) in the + 10/15 conditions. Accordingly, PPI habituation appears to exist, but it may be an artifact of quantifying PPI in reference to startle-alone reactivity.

POSTERIOR VERSUS FRONTAL EEG THETA ACTIVITY AS A BIOLOGICAL MARKER FOR DOPAMINERGIC EXTRAVERSION

Mira-Lynn Chavanon, Jan Wacker, & Gerhard Stemmler University of Marburg

Descriptors: EEG, theta, extraversion

In their psychobiological theory Depue and Collins (1999) linked the agency facet of Extraversion (aE; i.e. assertiveness, dominance, ambition, positive emotionality) to functional properties of the mesocorticolimbic dopamine system, creating individual differences in incentive motivation and positive emotion. In a recent pharmacological study, we identified posterior versus frontal theta activity in the electroencephalo-gramm (EEG) as a possible biological marker for aE, which was also sensitive to pharmacological manipulation of central dopamine activity using 200 mg Sulpiride. The present study aimed to replicate these results and extend our work by specifying the mechanisms (dose-response-curves, differences in the time course of drug effects) underlying those aE-related EEG effects. To this end, we measured the EEG intermittently for about five hours after healthy male volunteers extremely high or low in aE (N 5 74) had received either placebo or 50 mg, 200 mg, or 400 mg Sulpiride. Conceptually replicating our earlier findings, we again observed (1) more posterior (versus frontal) theta activity in individuals high versus low in aE, and (2) aE-related differences in drug-induced changes. Based on the dose-response and time course data we will discuss possible mechanisms and their implications for psychobiological theories of extraversion.

Poster 65

BARORECEPTOR CARDIAC REFLEX FUNCTION IS DEFICIENT IN FIBROMYALGIA SYNDROME AND CORRELATES WITH CLINICAL PAIN REPORTS

Sergio Garrido1, Angeles Pulgar1, Stefan Duschek2, & Gustavo A. Reyes del Paso1 1University of Jaeen, 2University of Munich

Descriptors: baroreflex sensitivity, fibromyalgia syndrome, pain

This study analyzed autonomic cardiovascular regulation in fibromyalgia syndrome (FMS) both at rest and under mental stress. Thirty-five FMS patients and 29 healthy controls performed an arithmetic task after a baseline period. Cardiovascular variables were assessed through electrocardiography, impedance cardiography and finger continuous blood pressure. As an estimate of clinical pain severity, participants completed the McGill Pain Inventory. Results showed reduced baseline levels of baroreceptor cardiac reflex sensitivity, RR interval, stroke volume, left ventricular ejection time, and RR interval variability in all frequency bands in FMS. Blunted or aberrant responses to stress were found for baroreceptor reflex sensitivity, RR interval, diastolic blood pressure and left ventricular ejection time. Baroreceptor reflex sensitivity and blood pressure negatively correlates with clinical pain reports, both across the whole sample and in the two groups. This data suggest deficiencies in autonomic cardiovascular regulation in FMS in terms of reduced sympathetic and parasympathetic influences, as well as impairments in adjustment to acute stress. We conclude that a main source of dysautonomia in FMS is the aberrant functioning of the baroreflex, including an inhibition of the baroreceptor-mediated antinoceptive mechanism. In line with the reduced baroreflex function in FMS, one may assume deficient ascending pain inhibition arising from the cardiovascular system, which may contribute to the hyperalgesia characterizing the disorder.

Poster 63

THE N2 EFFECT IN TRUTHFUL AND DECEPTIVE RESPONSES TO AUTOBIOGRAPHICAL INFORMATION

Xiaoqing Hu, Genyue Fu, & Haiyan Wu Zhejiang Normal University

Descriptors: ERP, deception, frontal central n2

Although previous ERP-based lie detection studies have successfully utilized P300 to identify concealed information, relatively little is known about the executive function and the corresponding neural mechanisms underlying deception. Here, event-related potentials were recorded while twenty-one participants (eleven males) were performing a differentiation of deception paradigm (DDP) task which orthogonally manipulated response type (deceptive and truthful) and stimuli type (autobiographical and non-autobiographical information). Behavioral results showed that deception requires longer RT, larger response variance and more errors compared to truth. Analysis of ERP data had found that deception elicited an enhanced frontal-central N2, which peaks around 320 ms post-stimulus, relative to truth, F(1, 20) 5 15.64, p < .05).

Poster 66

PHYSICAL EXERCISE LEVEL MODULATES RELATIONSHIPS BETWEEN BARORECEPTOR REFLEX SENSITIVITY AND COGNITIVE PERFORMANCE

Maria Martin, Jose: L. Mata, & Gustavo A. Reyes del Paso University of Jaen

Descriptors: baroreceptor reflex sensitivity, cognitive performance, physical exercise The baroreceptors are implicated in a negative feedback pathway to the brain by which cardiovascular activity modulates central nervous system (CNS) functions. We have previously shown that baroreceptor reflex sensitivity (BRS) negatively predicts cognitive performance during an arithmetic task. In the present study we evaluated this relationship controlling for a) the numeric aptitude of the participants measured by the Thurstone's PMA, b) the degree of effort implemented in the task rated on a 10-point VAS, and c) differences in physical exercise. Twenty-three exercise-trained and 20 sedentary students performed a serial arithmetic task. BRS was assessed by the spontaneous sequence method. Results of the stepwise regression analysis of the whole

sample showed that cognitive performance was predicted by a model with two predictors.

Poster 67

EFFECTS OF PHYSICAL EXERCISE LEVEL ON THE DYNAMICS OF THE CARDIAC BAROREFLEX: A COMPARISON WHEN BLOOD PRESSURE IS RISING AND FALLING

Maria Martin, & Gustavo A. Reyes del Paso University of Jaen

Descriptors: baroreceptor reflex sensitivity, up and down sequences, physical exercise The baroreceptor reflex is the main mechanism for short term regulation of blood pressure. In the analysis of baroreceptor reflex sensitivity (BRS) through the sequence method in the time domain, spontaneous cardiac sequences are sought in which systolic blood pressure (SBP) increases are accompanied by an increase in heart period (HP; up sequences), or in which a decrease in SBP is accompanied by a decrease in HP (down sequences). The regression line between the SBP and the HP values produces an estimate of BRS in ms/mmHg. Up sequences are associated with vagal activation, and down sequences are associated with vagal inhibition. This study evaluated the effect of physical exercise on BRS assessed in up and down sequences. Twenty-three physically fit and 20 sedentary students performed a serial arithmetic task after a baseline period.

Poster 68

MOOD IMPACT ON CARDIOVASCULAR REACTIVITY UNDER CONDITIONS OF UNFIXED TASK DIFFICULTY: THE MODERATING EFFECT OF TASK CONTEXT

Michael Richter1, & Antonia Friedrich2 1University of Geneva, 2University of Hamburg

Descriptors: cardiovascular reactivity, mood

Gendolla and colleagues demonstrated that mood effects on effort-related cardiovascular reactivity are context-dependent if task difficulty is fixed and clear (see Gendolla, Brinkmann, & Richter, 2007, for a review). However, for tasks with unfixed performance standards, they found stable effects: Negative mood resulted in higher cardiovascular reactivity than positive mood. Drawing on this finding, we investigated the moderating impact of task context on the mood-cardiovascular response relationship. Participants (N 5 45) worked on an unfixed memory task in a 2 (mood valence: negative vs. positive) x 2 (task context: demand vs. reward) between-persons design. As predicted, mood impact on cardiovascular response was moderated by the task context. Negative mood resulted in higher PEP and SBP reactivity than positive mood if participants had rated task demand before performing the task. If participants had rated task reward before performance, the pattern was reversed. This finding extends previous research by demonstrating context-dependent mood implications under conditions of unfixed task difficulty.

Poster 69

MOOD, HEDONIC INCENTIVE, AND EFFORT-RELATED CARDIOVASCULAR REACTIVITY

Nicolas Silvestrini, & Guido H.E. Gendolla University of Geneva

Descriptors: mood regulation, cardiovascular reactivity, resource mobilization This experiment investigated the impact of mood (negative vs. positive) and hedonic incentive (pleasant vs. unpleasant) on effort-related cardiovascular reactivity during task performance. Cardiovascular and facial EMG reactivity of 40 participants were assessed during a baseline period, mood inductions, and a moderately difficult attention task with either pleasant or unpleasant consequences of success. For unpleasant consequences, we anticipated rather low cardiovascular reactivity in both positive and negative moods because in this condition incentive of success was negative and thus only low effort was justified. Given that resource mobilization is proportional to subjective task demand as long as success is perceived as worthwhile (Brehm & Self, 1989; Wright, 1996), we also expected relatively low cardiovascular reactivity in the pleasant-consequences/positive-mood condition, because subjective task demand should be perceived as lower in a positive mood compared to a negative mood. In contrast, we predicted stronger cardiovascular reactivity in the pleasant-consequences/negative-mood condition because here incentive of success was positive and justified the high effort required in a negative mood due to the high experienced demand. The results were as expected. Moreover, facial EMG reactivity indicated efficient mood manipulations. In summary, the findings further support the predictions of the mood-behavior-model (Gendolla, 2000).

DYSPHORIA AND EFFORT MOBILIZATION: REFLECTING ON PERFORMANCE STANDARDS LEADS TO REDUCED CARDIOVASCULAR RESPONSE

Kerstin Brinkmann, & Guido H.E. Gendolla University of Geneva

Descriptors: depression, effort mobilization, performance standards Previous research has shown that mental tasks without fixed performance standards elicit stronger cardiovascular reactivity in participants with manipulated negative com versus positive mood, and in subclinical participants with higher versus lower depression scores (Brinkmann & Gendolla, 2007). The present study (N 5 29) extended this research by explicitly asking dysphoric and nondysphoric students to indicate their performance expectation and minimal performance standards just before performing a memory task without predefined standard. Effort mobilization during task performance was operationalized as sympathetically mediated cardiovascular response. Consistent with previous research, dysphoric participants did not show the normal positive discrepancy between self-efficacy expectations and minimal performance standards. In contrast to previous studies, however, the focus on performance expectations and standards reversed the effect on cardiovascular response: Compared to nondysphoric participants, dysphoric participants showed a weaker reactivity of pre-ejection period, as well as systolic, diastolic, and mean arterial pressure. Thus, this study presents evidence that focusing dysphoric participants' attention on performance standards leads to disengagement from the task. Consistent with the notion that mood effects are highly context-dependent, the previous and present studies show that different task contexts (i.e., focus on task difficulty vs. focus on performance expectations and standards) lead to different patterns of effort-related cardiovascular reactivity.

Poster 71

VISUOSPATIAL WORKING MEMORY PROCESSING OF FACIAL EMOTIONAL STIMULI: AN ERP STUDY

Andres A. Gonzalez-Garrido, Adriana L. Lopez-Franco, Fabiola R. Gomez-Velazquez, & Rodrigo Guzman-Anaya Institute of Neurosciences, University of Guadalajara

Descriptors: spatial working memory, emotion, ERP

Face-specific processing is gated by visual spatial attention, while maintenance of vis-uospatial information in memory has been shown to be accomplished through a sustained shift of spatial attention to a memorized location. With the aim to evaluate the effects of facial emotional content on spatial working memory processing, twenty healthy young adults performed a three-back task while recording EEG, using pictures with different facial emotional expressions -happy, fearful, neutral- or squares as stimuli. Behavioral results showed that response times were significantly shorter for trials corresponding to fearful faces. Early ERP differences -starting from N170- were observed between facial emotional conditions, followed by a fronto-parietal positivity peaking at 220 ms. This positive waveform showed higher parietal voltage amplitude during happy facial condition, but its amplitude was higher for fearful facial stimuli at frontal regions. P220 was followed by a P3-like slow positive centro-parietal component which was significantly higher for happy and fearful facial series with respect to the neutral ones. Results are interpreted as part of the separation phenomenon between locations and objects in visual working memory, where intrinsically relevant stimuli could recruit additional cognitive processing resources.

Poster 72

THE EFFECT OF NUMERICAL DISTANCE ON ERP COMPONENTS ELICITED BY NUMERICAL INCONGRUENCIES IN MENTAL ARITHMETIC OPERATIONS

Fabiola R. Gomez-Velazquez, Andres A. Gonzalez-Garrido, Josefina Ortiz, Minerva Altamirano, & Daniel Zarabozo-Hurtado Institute of Neurosciences, University of Guadalajara

Descriptors: arithmetic processing, numerical distance, ERP

Previous research has shown that incongruent solutions of simple multiplication problems elicit an arithmetic N400 effect whose amplitude seems to depend on the relatedness of the solution (errors that are either table-related or table-unrelated to the preceding operands). However, there is not enough information regarding the probable cost of different nearness between incongruent and valid solutions on arithmetic N400 effects. Fourteen healthy young adults (22-27 years-old) evaluated the correctness of successive single digit arithmetic problems (addition, subtraction and multiplication) while EEG was simultaneously recorded. Behavioral results showed a significantly higher amount of correct responses for subtraction and multiplication with respect to addition operations. Correct responses were higher for more distant incongruent results. A fronto-central negativity with maximum over 280 ms appeared for erroneous solutions, reaching greater voltage amplitude for

distant than for closer errors. This component is interpreted as related to the detection of expectation violation. A following slow parietal positive waveform peaking over 340 ms showed significantly higher amplitude for correct solutions, probably reflecting subsequent succeed in stimulus categorization. These results seem to point out that neural systems involved with processing numerical magnitudes could support different cognitive strategies depending upon stimuli presentation and task demands.

Poster 73

SUBTYPES MATTER: BIASES AND INDIVIDUAL DIFFERENCES IN ELECTROCORTICAL RESPONSE TO SPECIFIC EMOTIONAL PICTURE CATEGORIES

Anna Weinberg, & Greg Hajcak Stony Brook University

Descriptors: LPP, picture subtypes, individual differences

The Late Positive Potential (LPP) is sensitive to the emotional content ofstimuli, increasing in amplitude to both pleasant and unpleasant compared to neutral stimuli. However, insufficient attention has been paid to the construction of the broad stimulus categories. The present study utilized subtypes of IAPS images to examine a) evidence for a negativity bias, and b) individual differences in the magnitude of the LPP. ERPs were recorded while 67 participants viewed pictures. Examination of broad categories (pleasant, neutral, unpleasant) revealed that unpleasant images elicited a larger LPP than pleasant images and that individuals reporting more affective distress were less reactive specifically to unpleasant images. When subtypes were examined, however, differences emerged: images of erotica and mutilation elicited the largest, but comparable, LPPs; affiliative and threat images also elicited a comparable LPP. Exciting images (e.g., images of sports) and disgusting images elicited smaller LPPs than other emotional images, on par with or smaller than neutral images containing people. When these three anomalous categories (exciting, disgusting, and neutral scenes with people) were excluded, unpleasant images no longer elicited a larger LPP than pleasant images. Thus, the inclusion of exciting images may drive electrocortical data suggesting a negativity bias. In addition, affective distress was negatively correlated with the magnitude ofLPPs to both erotic and mutilation images, suggesting that distressed individuals may be less reactive to the most arousing images.

Poster 74

HEMISPHERIC ASYMMETRY OF EXOGENOUS ORIENTING OF ATTENTION: INFERENCES FROM REACTION TIME, P1 AND N1 AMPLITUDE

Paola Spera1, Ian Mackenzie2, Mariaelena Tagliabue1, & Hartmut Leuthold2 1University of Padova, 2University of Glasgow

Descriptors: spatial attention, reaction time, erps

The effect of exogenous orienting of attention on reaction time (RT) critically depends on the stimulus onset asynchrony (SOA) between cue and target: RT is shorter for cued target locations (facilitation) when the SOA is short, whereas this RT effect reverses when the SOA is long (inhibition). In the present study we were primarily interested in the later-alization of exogenous visuospatial attention mechanisms, as these are known to depend in right-handers predominantly on the right hemisphere. Specifically, we recorded event-related brain potentials (ERPs) to investigate how hemispheric lateralization of attention modulates facilitation and inhibition effects. Thirty right-handed participants performed a Posner-like cueing task (p(valid) 5 .50) using SOAs of 200 and 800 ms, in which go-nogo responses were demanded to the visual target stimulus. RTs showed an asymmetric facilitation effect that was larger for right visual field targets. Visual ERP components over lateral occipito-temporal sites (P1, N1) indicated that facilitation and inhibition influenced already early stages of visual processing. Crucially, for the short SOA, it was only for targets displayed in the left visual field that the contralateral P1 was enhanced for valid trials. Moreover, no hemispheric asymmetries, neither in RT nor in P1 and N1 amplitudes, were observed with the long SOA. In conclusion, present findings support the assumption that the right hemisphere plays a dominant role in exogenous orienting of visuospatial attention.

Poster 75

A NEW ODDBALL PARADIGM TO INVESTIGATE THE TIME COURSE OF CHINESE SINGLE SPOKEN WORD RECOGNITION

Jingjing Zhao1, Jingjing Guo2, Fengying Zhou2, Jie Xi2, & Hua Shu2 1University of Connecticut & Haskins Laboratories, 2Beijing Normal University

Descriptors: spoken word recognition, N400, oddball paradigm

Recent studies about the time course of English spoken word recognition indicate that segmental information is used incrementally. The time course of Chinese spoken word recognition might differ from English, since in Chinese, a single character always corresponds to a monosyllable, and meaningful syllables mainly have one-to-one correspondence with morphemes. In the present study, we developed a new oddball paradigm to investigate the time course of Chinese single spoken word recognition. Forty-three pictures and 215 Chinese single spoken words were used in this study. In each trial, a picture was presented

for 2 seconds with a Chinese character representing its name below it. Then a single spoken Chinese word was presented. The relationship between the spoken word and the name of the picture was varied. In the match condition the spoken word was exactly the name of the picture. The other four conditions were different types of mismatch: three partial mismatches (onset, rime and tone mismatch) and one complete mismatch (syllable mismatch). After 3 seconds, another picture was presented. Participants were asked to do a semantic categorization task: judge whether the first picture and the second picture were in the same semantic category or not. ERPs from 17 Mandarin native speakers were averaged according to the onset of the spoken words. Results showed that the syllable mismatch condition elicited earlier and stronger N400 than partial mismatch conditions, which implies that syllable level might be more important for Chinese single spoken words recognition.

Poster 76

PERCEIVED STRESS INCREASES ALERTING AND INFLUENCES VIGILANCE TO FEARFUL FACES DURING AROUSED MOODS

Jeffrey L. Birk1, Tracy A. Dennis2, & Heather L. Urry1 1Tufts University, 2Hunter College, The City University of New York

Descriptors: perceived stress, attention networks

Perceived stress, like trait anxiety, disrupts the executive control of attention. The effects of perceived stress on alerting and vigilance to threat, however, are less well studied, and the modulation of these stress-attention effects by current mood state remains largely unexplored. The present study addressed these issues by inducing a high-arousal mood (happy or anxious) and a low-arousal mood (neutral) in 27 undergraduates. Alerting and executive control were assessed using a modified version of the Attention Network Task (ANT), which participants completed after each induction. ANT trials were preceded by either a fearful or a neutral facial expression for 50 ms, enabling assessment of vigilance to threat. Electromyography levels over the corrugator supercilii muscle and changes in self-reported affect confirmed the success of the mood inductions. Participants were grouped according to totals on the 10-item Perceived Stress Scale. Although high-stress participants had significantly faster reaction times (RTs) than low-stress participants across all trial types, high-stress participants showed slower RTs in aroused moods than low-stress participants during trials preceded by fearful faces. Furthermore, high-stress participants had significantly higher alerting ANT scores than low-stress participants, but only for aroused moods. Executive control of attention did not differ between the two groups. The results suggest that perceived stress influences attention in ways generally similar to trait anxiety and that aroused mood may play a role in facilitating these effects.

Poster 77

I SHOW YOU HOW YOU FEEL: MIMICRY AS A FUNCTION OF ASSIGNED EMOTIONAL STATE

Stephanie Houde, Annie Simard, & Ursula Hess University of Quebec at Montreal

Descriptors: emotion expression, mimicry

Facial mimicry - the imitation of the facial expressions of others - has been described as both an automatic mirroring reaction to the observed facial expressions of others, and as a communicative signal that serves to signal understanding and acceptance. Whereas the first view necessarily implies that mimicry can only occur when another person's facial expression is observed, the second view allows for the possibility that mimicry can be elicited in the absence of a visible expression, by the simple knowledge that another person feels a certain emotion. To assess this latter possibility, participants were shown neutral facial expressions and told that the target persons were actually experiencing sadness, anger or joy. Their task was to rate the intensity of that emotion. Assigned emotional state for each face was counterbalanced across participants. Facial mimicry was assessed using EMG at the Co-rrugator Supercilii, Orbicularis Oculi, and Zygomaticus Major sites. Preliminary analysis showed no effects for Orbicularis Oculi, and no mimicry of purportedly sad faces. In contrast, when seeing faces of individuals purported to experience anger, participants showed greater activation of Corrugator Supercilii and less activation of Zygomaticus Major. Conversely, when the target individuals were purported to experience joy, the reverse pattern was observed. These pattern of facial expressions are congruent with facial mimicry and support the notion that facial mimicry has a communicative function and does not depend on the actual perception of an expression.

Poster 78

WILL YOU STILL MIMIC ME WHEN I AM 64? MIMICRY OF OLDER FACES

Marie Lasalle, Annie Simard, & Ursula Hess University of Quebec at Montreal

Descriptors: emotion expression, mimicry

Mimicry is the imitation of others' nonverbal behavior. One function of mimicry is to serve as "social glue,'' that is, as a means to foster affiliation. However, we may not want to affiliate with everyone we interact with. Congruent with this notion, recent studies suggest that the facial expressions of members of an outgroup are mimicked to a lesser degree than

expressions by the ingroup. Older people may be perceived as outgroup members by younger individuals, and hence be mimicked to a lesser degree. Because interactions in which mimicry occurs are perceived as more pleasant, and the mimicking interaction partner is perceived as more warm and approving, this may have a negative impact on interactions between younger and older adults. The present study aimed to assess whether facial expressions by older people are mimicked to the same degree as expressions by younger people. Participants under the age of 30 saw facial expressions of anger and happiness, shown by the same movie actor under the age of 30 and when older than 60. Facial mimicry was assessed using facial EMG at the Corrugator Supercilii, Orbicularis Oculi, and Zygomaticus Major sites. Preliminary analyses suggest that overall, participants showed increased Corrugator Supercilii and decreased Zygomaticus Major activity when looking at the older actors and the reverse pattern when looking at younger actors. Whereas smiles by younger actors were mimicked, smiles by older actors were not. The implications of this for intergenerational interactions will be discussed.

Poster 79

CORRELATION BETWEEN PSYCHOLOGICAL REACTIONS TO A NEGATIVE EMOTIONAL VIDEO AND AMPLITUDES OF SKIN POTENTIAL RESPONSE COMPONENTS

Olena V. Bogdanova1, Volodymyr B. Bogdanov1, Dmytro S. Gorlov1, Yuriy P. Gorgo2, Mykola Yu Makarchuk1, & Jean Schoenen3 1Taras Shevchenko National University of Kyiv, 2National Technical University of Ukraine, 3University of Liege

Descriptors: reduser-augmenter scale, differential emotions scale, skin potential response The skin potential response (SPR) is a fast change in the electric potential on the palmar surface attributed to an autonomic sudomotor reaction. Positive fast and negative slow components of SPR (pSPR and nSPR) can be distinguished. They are thought to be associated with goal-directed and defensive reactions respectively (Edelberg, 1970) but their precise behavioral correlates are not clear. We studied the SPR in 21 healthy volunteers (10 males, 11 females, age 19-23 years) and compared individual pSPR and nSPR differences induced by fast deep inspiration with scores on the Reducer-Augmenter scale (RAS; Dragutinovich, 1987) in high arousal states. Emotional arousal was induced by a negative emotional video and assessed by the Differential Emotions Scale (DES; Izard, 1993). pSPR and nSPR during the video were +5.5+1.3 and — 5.1 + 1.1 mV. Augmenters had greater pSPR (R 5 .49).

Poster 80

ALEXITHYMIA, EMPATHY AND DIFFERENCES OF SKIN POTENTIAL LEVEL AMPLITUDES UNDER AFFECTIVE STIMULATION

Volodymyr B. Bogdanov1, Dmytro S. Gorlov1, Yuriy P. Gorgo2, Mykola Yu Makarchuk1, Olena V. Bogdanova1, & Jean Schoenen3 1Taras Shevchenko National University of Kyiv, 2National Technical University of Ukraine, 3University of Liege

Descriptors: skin potential level, alexithymia, empathy

Alexithymia (ALT) is characterized by a reduced ability to recognize and describe one's own emotions. Patients with ALT often have impaired empathy (EPT) ability. ALT is associated with somatization. Tonic electric activity which is called skin potential level (SPL) reflects the gradual changes in arousal mediated by sympathetic regulation of skin sweat glands. We compared relationships of individual scores of ALTand EPT with SPL during a continuous 9-minute computer game or negative valence video in 21 volunteers. SPL was measured as the electric DC potential negativity in the surface of palmar skin. SPL increased for 5-7 mV after the onset of stimulations in accordance with the increases in subjective arousal. During the negative emotional video, SPL increased more in volunteers with higher levels of ALT or EPT (Spearman rank order correlation, r 5 .51 and r 5 .52 respectively). In the computer game test, such a correlation was found only for EPT level (r 5 .52). ALT was also related to sustained high SPL negativity (slow habituation) during computer game (r 5 .49). Conversely, EPT was associated with fast habituation to the emotional video (r 5 _ .48). We suggest the existence of some common mechanisms that underlie individual differences of empathy and alex-ithymia. Deficient emotional habituation can explain amplification of somatic sensations in alexithymia that may lead to somatization disorders.

Poster 81

IMPAIRED CORTICO-STRIATAL CONNECTIVITY FOR LOSS IN THE REWARD CIRCUITRY OF OBSESSIVE-COMPULSIVE DISORDER (OCD)

Christian Kaufmann1, Jan-Carl Beucke2, Daniela Simon1, & Norbert Kathmann1 1Humboldt University, Berlin, 2Massachusetts General Hospital/Harvard Medical School

Descriptors: psychophysiological interaction, obessive-compulsive disorder, reward circuitry A brain circuit model of OCD emphasizes an imbalance of the direct and indirect path within the cortico-basal ganglia-thalamo-cortical paths resulting in dysfunctional, most likely

hyperactive, brain structures of the basal ganglia and cortical areas. The disease is associated with overactive performance monitoring persumably related to hyperac-tivity of the anterior cingulate cortex (ACC), brain grey and white matter abnormalities in the dorsal ACC (dACC), and also to higher sensitivity to avoid punishment or loss. We challenged the brain's reward circuitry, including the ACC, with a monetary incentive delay task and measured haemodynamic signals in 19 OCD patients and 19 well-matched healthy controls with event related FMRI. We were interested in the functional connectivity of the dACC with other brain regions during anticipation of potential (monetary) gain or loss and carried out a psychophysio-logical interaction (PPI) analysis. PPI is a method for finding out whether the correlation of activity between two distant brain areas differs in different psychological contexts. Patients and controls showed comparable BOLD responses in the dACC but PPI analysis revealed that OCD patients had significantly less connectivity between the dACC and the ventral striatum during anticipation of loss. The extent of reduced connectivity between dACC and ventral striatum correlated positively with symptom severity (as indicated by Y-BOCS scores). These results are direct evidence of a dysfunctional cortico-striatal network which is associated to the sensitivity for loss in OCD.

Poster 82

INCREASING PERCEPTUAL LOAD DISRUPTS RIGHT HEMISPHERIC VISUOSPATIAL BIAS - AN EVENT-RELATED POTENTIAL STUDY

Redmond G. O'Connell1, Dana Schneider2, Robert Hester3, Jason B. Mattingley2, & Mark A. Bellgrove2 1Trinity College, Dublin, 2University of Queensland, 3University of Melbourne

Descriptors: perceptual load, spatial attention, N1

The right hemisphere plays a dominant role in both spatial and non-spatial aspects of attention. Here we explore how increasing the demand on non-spatial attention affects visual orienting asymmetries. Forty-four normal healthy participants performed a visual detection task on a continuous rapid successive visual presentation of number and letter stimuli at a fixed central location and simultaneously monitored two bilateral peripheral place holders for the appearance of an additional target stimulus. Participants performed the task under three levels of perceptual load achieved by varying the difficulty of central target detection. Increasing load produced a significant slowing of response times to peripheral stimuli and there was an over all trend towards faster responding to stimuli presented in the left visual field. Visual-evoked potentials were time-locked to the onset of the peripheral stimuli. The earliest effect of perceptual load on orienting was seen on the posterior N1 (160 ms) component. When perceptual load was low, the N1 was enhanced over occipito-parietal sites contralateral to the visual field of stimulus presentation and exhibited broad right hemisphere dominance which was confirmed by source analysis. Spatial selection was primarily disrupted over right hemisphere with increasing load. These early effects were followed by an attenuation of the occipito-parietal P2 (240 ms) and the centro-parietal P3 (400 ms). These data demonstrate that increasing perceptual load has a disproportionate effect on visual orienting in the right hemisphere.

Poster 83

ELECTROPHYSIOLOGICAL INDICES OF ATTENTIONAL DECREMENTS IN MILD COGNITIVE IMPAIRMENT

Simon P. Finnigan, Redmond G. O'Connell, Richard B. Reilly, & Ian H. Robertson Trinity College, Dublin

Descriptors: mild cognitive impairment, cognitive decline, attention Amnestic mild cognitive impairment (aMCI) is classified primarily via substantial episodic memory deficits in the absence of a dementia diagnosis. We investigated the degrees to which attentional versus memory encoding decrements might contribute to such deficits, by analyzing event-related potentials acquired during encoding trials of a modified Sternberg word recognition task with low (4 items) and high (8 items) memory load conditions. These measures and memory accuracy data were compared between 15 participants with aMCI (ages 58-84) and 15 matched, healthy older adults (ages 57-81). Recognition accuracy was significantly higher in controls than aMCI participants, in the high-load condition. In posterior ERPs the N1 was significantly larger and the P2 significantly smaller, in controls versus aMCI participants. These differences were most pronounced in the high-load condition. Neither P1 amplitude nor any peak latency differences were observed between the samples. We interpret these outcomes to primarily reflect attentional decrements in aMCI, albeit these do not preclude memory encoding/retrieval deficits. Differing current source patterns were revealed (using standardized LORETA) between the groups for the N1 component only; occipito-parietal N1 sources were identified bilaterally in the controls but unilaterally in the aMCI sample. These and other data indicate that healthy older adults generally can recruit additional brain regions, via top-down control, to successfully maintain a certain level of cognitive performance; whereas aMCI individuals generally may not.

TASK PREPARATION AND MENTAL DEMAND DURING A VISUALLY CUED ATTENTION TASK IN YOUNG AND OLDER PARTICIPANTS AS REFLECTED IN THE CONTINGENT NEGATIVE VARIATION

Nele Wild-Wall, Melanie Hahn, & Michael Falkenstein Leibniz Research Centre for Working Environment and Human Factors

Descriptors: aging, task preparation, CNV

An age-related decline for task preparation has been found in several studies. Other results suggest increased task preparation by older subjects possibly reflecting compensatory effort under high task demands. The present study aimed to explore age-related differences in task preparation in a highly demanding task. Younger (N 5 25, M 5 25 years) and older subjects (N 5 24, M 5 65 years) performed a dual task including continuous tracking and a visually cued attention task. In the cued attention task, the stimuli, following 2500 ms after the cues, called either for a response or not. Alongside the EEG was recorded. The P300, reflecting controlled processing of the cue, and the Contingent Negative Variation (CNV), reflecting task preparation, were assessed in the cue-stimulus interval. Older participants responded more slowly and committed more target errors, missings and false alarms. The P300 to cues was higher and the CNV started earlier and was increased for the older compared to the young subjects. Exploratory correlations showed a relation between an increased CNVand a lower rate of missed responses in the older but not in young group. For both groups there was a relation between an increased CNV and higher subjective mental demand at the end of the task as measured with the NASA-TLX questionnaire. The results suggest a compensatory increase in task preparation in this highly demanding task for the older subjects, which was reflected in increased P300 and CNV amplitudes. In addition, the CNVproved to be useful as a correlate of mental task preparation under high task demands.

Poster 85

AGE-RELATED DIFFERENCES IN STIMULUS PROCESSING IN A DUAL TASK AS REFLECTED IN THE P300

Melanie Hahn, Nele Wild-Wall, & Michael Falkenstein Leibniz Research Centre for Working Environment and Human Factors

Descriptors: ERP, aging, dual task

Several studies showed increased difficulties of older people in dual task situations that require simultaneous motor and cognitive performance. Furthermore older people showed lower P300-amplitudes and longer latencies in complex tasks where divided attention is needed. The aim of the present study was to investigate the information processing of relevant and irrrelevant stimuli in a dual task situation in two age groups (20 - 33 and 57 -70 years old). EEG was recorded while the 49 participants were performing a dual task consisting of a compensatory tracking task and a visual attention task with different types of stimuli (relevant targets, irrelevant targets, relevant non-targets, irrelevant non-targets). Participants were asked to perform both tasks as correctly and as quickly as possible. Older participants generally responded more slowly and committed more errors in the visual attention task. Contrary to expectations, they did not show lower P3-amplitudes overall, but there was a significant interaction between age and the stimulus type presented: Whereas young participants showed the expected increased P3-amplitude after relevant targets compared to other types of stimuli, there was no difference of P3-amplitude between different types of targets/non-targets in older participants. The results suggest that older people's difficulties in dual tasks may be related to a reduced ability to differentiate between relevant and irrelevant stimuli in situations that require divided attention.

Poster 86

EYE-BLINK STARTLE RESPONSE IS POTENTIATED BY COLD PRESSOR PAIN BUT INHIBITED BY CO2-INDUCED BREATHLESSNESS

Steven de Peuter, Erik Ceunen, Ilse Van Diest, Omer Van den Bergh, & Johan W.S. Vlaeyen University of Leuven

Descriptors: emg eye-blink startle, pain, interoceptive

Eye-blink EMG startle potentiation is observed in negative situations and negative emotional states, as well as in defensive responding to threat. The existing evidence supporting EMG startle potentiation as a defensive response is mainly based on exteroceptive stimuli - e.g., pictures or electrical stimuli. Evidence concerning EMG startle modulation in response to physical threat is however scarce, although EMG startle potentiation has been observed in response to heat pain. We investigated EMG startle modulation in response to cold pressor pain (n 5 16; 1 minute 2°C immersion of non-dominant hand) and CO2-induced breathlessness (n 5 13; 1 minute 10% CO2-enriched air inhalation). Six auditory startle probes were presented: two probes during the minute preceding the challenge (baseline), two probes during the challenge and two further probes during the minute following the challenge (recovery). The first probe of each phase was presented in the first 30 seconds, the second probe in the last 30 seconds. No differences in EMG startle responding were observed during baseline or recovery. The challenge resulted in EMG startle potentiation in reaction to cold pressor pain and EMG startle inhibition in response to CO2-induced breathlessness. The latter

may be due to breathlessness - in contrast to pictures, electrical stimulation or pain -being an interoceptive stimulus, directing attention inwards and reducing attention to external threats. In contrast, CO2-induced breathlessness may be experienced as a circa-strike situation in which EMG startle modulation is generally reduced.

Poster 87

NEUROIMAGING OF DECEPTION IN A FREE-CHOICE GUILTY KNOWLEDGE TEST (GKT) AFTER A MOCK CRIME SCENARIO

Markus Schneider, Bailint Varcuti, Ahmed A. Karim, Sitharam Ranganatha, & Niels Birbaumer University of Tübingen

Descriptors: lie detection, moral cognition, fmri

A major limitation of studies in the field of psychophysiological detection of deception is the lack of ecological validity of lab studies. Recent neuroimaging studies (e.g. Spence et al., 2008) took that into account, for example, by using a free answer format and revealed a bilateral higher activation of the ventrolateral prefrontal gyrus during lies. Constitutive to that approach the aim of this study was to further increase ecological validity by performing a mock crime scenario in which the participants had to steal money from a wallet, and subsequently by using videos of an interrogator known to the subjects in a GKT. Sixteen healthy subjects participated in the experiment. In addition to acquiring functional magnetic resonance imaging (fMRI) signals, sympathetic skin conductance response (SCR) was measured. Data driven independent component analysis (ICA) revealed a prefrontal component (medial and lateral prefrontal cortex and anterior cingulate cortex) and a parietal/insular component, both related to the deception task. Moreover, lies also led to higher SCRs than truthful answers, which indicated the effectiveness of the experimental procedure. These results support findings of a recent neurostimulation study (Karim et al., 2009) that showed that inhibition of the prefrontal cortex modulates deceptive behavior and sympathetic arousal.

Poster 88

MAGNETOENCEPHALOGRAPHIC EVIDENCE FOR RAPID

AND HIGHLY RESOLVING AFFECTIVE EVALUATION OF SHORT ENVIRONMENTAL TONES IN THE ABSENCE OF CONTINGENCY AWARENESS

Ann-Kathrin Broeckelmann, & Markus Junghoefer Institute for Biomagnetism and Biosignalanalysis, University of Münster

Descriptors: MEG, auditory conditioning, motivated attention

Accumulating evidence suggests a modulation of neural activity in the presence of emotionally significant stimuli by motivated attention already on early processing stages. Previous studies proposed that rapid affective evaluation is strongly mediated by the amygdala via bottom-up pathways into sensory cortex. Using magnetoencephalo-graphy, we investigated the spatial extent, time-course, and resolution of the neural network underlying rapid selective affective attention in a highly demanding classical conditioning procedure. Environmental tones of only 20 ms duration (conditioned stimuli; CS) were paired with high-arousing pleasant, high-arousing unpleasant or neutral realistic auditory scenes (unconditioned stimuli; UCS). Associations among 14 unique CS-UCS pairings for each valence category were conditioned within only three learning instances, rendering each of 24 subjects unaware of the contingent relationship between CS and UCS. We found evidence for rapid affective differentiation already at 20 ms after CS onset and modulation within the time range of the auditory N100m. Source estimation for the underlying neural activity revealed amplified affective CS processing after learning within frontal and parietal cortex regions. Our findings argue for a highly efficient distributed neural network with impressive learning capacity, capable ofalmost instantaneous differentiation of motivationally significant from negligible stimuli, even in complete absence of contingency awareness.

Poster 89

ELECTROPHYSIOLOGICAL INSIGHTS INTO THE DETECTION OF PERSONALLY SIGNIFICANT SOUNDS

Anja Roye1, Thomas Gruber2, Thomas Jacobsen1, & Erich Schroger1 'University of Leipzig, 2University of Osnabrück

Descriptors: electrophysiology, auditory processing, long-term memory Personally and emotionally significant sounds play an outstanding role in our acoustic environment. We notice our mobile phone ringtone apparently independent of its current relevance or of our ongoing activity. The present study used electrophysiological methods to investigate whether the human brain differentiates sounds by their personal significance even if the auditory input is not relevant for the current ongoing activity and even though no physical auditory change detection mechanism could have triggered deeper semantic processing. For that purpose, we analyzed the evoked gamma band activity (GBA) as well as event-related potentials (ERP) to a personally significant sound (own ringtone) compared to a non-significant sound (ringtone of another participant). Both sounds occurred rarely in an auditory sequence of 12 different randomly played ringtones. The data revealed differences due to the experimental variation in the

evoked GBA starting after 40 ms. Those were followed by differences in ERPs after around 200 ms. We suggest that the evoked GBA activity reflects the first match of every incoming stimulus with memory templates. Based on that initial match, a regularity may have been extracted that enables the auditory system to detect a deviating stimulus even solely based on features stored in long-term memory.

Poster 90

TOWARDS A TRUE HABITUATION PARADIGM: A NEONATAL/FETAL MEG STUDY

Tamara Matuz1, Rathinaswamy B. Govindan2, Hubert Preissl1, Eric R. Siegel2, Pamela Murphy2, Maureen Ware2, Curtis L. Lowery2, & Hari Eswaran2 1University of Tübingen, 2University of Arkansas for Medical Sciences

Descriptors: fetal, habituation, MEG

Habituation is defined as a response decrement that occurs as a result of repeated stimulation. To distinguish habituation from sensory fatigue, a different stimulus (dish-abituator), meant to account for response recovery, needs to be inserted between trains of repeated stimuli. In this study we aimed to (i) develop a habituation paradigm that allows the investigation of both response decrement and response recovery, and (ii) examine its applicability for measuring the habituation of the visually evoked responses (VERs) in neonatal and fetal magnetoencephalographic (MEG) recordings. Our paradigm consisted of a train of four light flashes with an interstimulus interval of 2 s followed by a 500 Hz burst tone 5s after onset of the 4th light flash. This sequence was repeated 90 times. Healthy pregnant women (N 5 22), with fetuses ranging in GA from 30 to 38 weeks, participated in the study. Sixteen mothers returned with their babies for a neonatal investigation. In 11 of 13 neonates we found a response decrement in amplitude from the 1st to the 4th light flash. The statistical analysis showed significant differences between the amplitudes of the five stimuli and the pairwise comparison of tone to 4th flash confirmed the response recovery. The prenatal response rate of the cortical responses on the 1st light was 45.5%, much lower than in the neonates (84.61%). Five out of the 15 fetuses who responded to the 1st light flash also showed detectable VERs on the 2nd flash. In four of them, a response decrement has occurred, while in the fifth, the response amplitude was the same.

Poster 91

MODULATION OF DECEPTION WITH PREFRONTAL TRANSCRANIAL DIRECT CURRENT STIMULATION (TDCS)

Ahmed A. Karim1, Markus Schneider1, Martin Lotze2, Ralf Veit1, Paul Sauseng3, & Niels Birbaumer1 1Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, 2Center for Diagnostic Radiology and Neuroradiology, University of Greifswald, 3University of Salzburg

Descriptors: lie detection, moral cognition, neuroethics

Recent fMRI studies have indicated a predominant role of the frontopolar cortex (FPC; BA 9/10) in deception and moral cognition, yet the functional contribution of the FPC remains elusive. Here we demonstrate the effect of prefrontal tDCS on deception. Three experiments were conducted to test the specificity of the transcranial stimulation effect. In the first experiment subjects participated in a mock crime and a subsequent interrogation with the Guilty Knowledge Test. Remarkably, inhibition of the FPC did not lead to an impairment of deceptive behavior but rather to a significant improvement. This effect manifested in faster reaction times in telling lies, but not in telling the truth, a decrease in sympathetic SCR and feelings of guilt while deceiving the interrogator and a significantly higher lying quotient reflecting skilful lying. In the second experiment reversing the stimulation polarity had no effect on deceptive behavior, confirming the specificity of the applied polarity. In the third experiment the Stroop-test was used as a control task. Our results demonstrate that although the incongruent condition is cog-nitively more demanding than the congruent one, tDCS of the FPC had no effect on performance, suggesting a specific effect on deceptive behavior and not on cognitively demanding tasks in general. Our findings support the notion that a dysfunction of the FPC may underlie certain psychopathological disorders (i.e., psychopathy) that are characterized by the absence of sympathic arousal while performing an antisocial act such as deceiving in a criminal interrogation.

Poster 92

P300 BCI PERFORMANCE PREDICTION USING AN AUDITORY STANDARD ODDBALL

Sebastian Halder1, Eva-Maria Hammer1, Sonja C. Kleih1, & Andrea Kubler2 1University of Tübingen, 2University of Würzburg

Descriptors: BCI, EEG, P300

Brain-Computer Interfaces (BCIs) enable paralyzed people to communicate with their environment. Differences in performance between users and sessions remain largely unexplained, as does the question as to why communication in the complete locked-in-state (CLIS) has not been possible. A reliable performance indicator would allow an

analysis of subject-to-subject and session-to-session performance differences and serve as and indicator of the capacity to use a BCI during the progression of a disease. A study with 40 healthy participants was conducted to determine the viability of performance indicators. All participants performed a single 20 symbol visual (VP300) and auditory P300 (AP300) BCI session. Additionally, an auditory oddball was recorded from each subject. Using the amplitudes of two samples at 395 ms on CPz and CP1 correlations (Pearson) with performance of r 5 .57 were found. This result shows the viability of the auditory standard oddball to predict individual BCI performance and suggests that the long-term tracking of the P300 elicited by the auditory oddball will lead to a better understanding of BCI performance degradation in the CLIS.

Poster 93

DOES GRANGER CAUSALITY ANALYSIS OF THE INTERACTIVITY

OF INDEPENDENT COMPONENTS TELL US SOMETHING PLAUSIBLE ABOUT TIME-LAGGED CO-REGULATION PATTERNS?

Balint Varkuti, Colleen Dockery, Sitaram Ranganatha, & Niels Birbaumer Institute of Medical Psychology and Behavioral Neurobiology

Descriptors: connectivity, methodology, DTI

Information about the time-lagged interactions of functional networks increases our understanding of large-scale connectivity in the brain. To further investigate the feasibility of various methods for this purpose, sixteen subjects participated in a Tower of London task during a time-resolved fMRI measurement (TR 5 1.4 s). High-resolution DTI data were additionally acquired. The data were analyzed with Group-ICA and results indicate involvement of the expected networks - best discrimination of task-complexity (one to five move problems were used) was reached by time-course analysis of IC 1 (precuneus, ACC and bilateral BA 45 - stronger activity left) and various visual ICs - which bespeaks task-complexity dependent activation of these functional networks. Statistical interactions of all identified ICs were analyzed using multivariate Granger Causality Modelling (mGCM). The resulting session-specific interactivity profile assesses the interactions of various noise types and the hemodynamic reflections of neural activity. When analyzing this network (nodes: ICs, edges: significant mGCM connections) the ICs with the highest cluster coefficients correspond to the ICs with highest task-complexity based activation-sensitivity (e.g. precuneus to frontal action monitoring areas, DLPFC to medial prefrontal areas). Results from the correspondence of graph edges with anatomical connectivity - based on DTI-based probabilistic fibre tractography - are presented. This data-driven method allows for the assessment of the role of certain ICs in specific time-lagged co-regulation networks.

Poster 94

GASTRIC DISTENSIONS ENHANCE AROUSAL RATINGS OF VISUAL FOOD CUES

Diana F. de Si1, Lukas Degen2, Christoph Beglinger2, & Hartmut Schachinger1 1University of Trier, 2University of Basel

Descriptors: gastric distensions, food cues, arousal

Gastric sensations play an important role in the control offood intake, as well as during the experience ofhunger and satiety. They are believed to influence the appraisal offood, but it is unclear how gastric sensations affect arousal ratings of food cues, which are known to increase during hunger and food restriction. Therefore, 8 healthy males who were restricted from food intake for 12 hours preceding the experiment, rated arousal of 18 food pictures presented during supra-, sub-liminal, and zero-control barostat balloon distension of the gastric antrum. Responses were averaged per subject and distension level. Arousal ratings of food pictures were higher during supra-liminal gastric distension as compared to zero-control (p 5 .059) and sub-liminal (p 5 .024) distension, but did not differ between subliminal and zero-control conditions. Electrodermal responses remained unaffected. In summary, perceived gastric distensions enhance arousal ratings offood cues, but distension intensities below the conscious perception thresholds do not have an affect. Our data corroborate previous research demonstrating that visceral sensations contribute to the appraisal of affectively relevant cues.

Poster 95

PREPULSE INHIBITION OF CARDIOVASCULAR STARTLE REACTION

Christian E. Deuter1, Andre Schulz1, Steffen Richter1, Kurt Krauchi2, & Hartmut

Schachinger1

1University of Trier, 2Psychiatric University Clinic Basel Descriptors: PPI, skin perfusion, heart rate

Startle elicits an increase in skin conductance as well as changes in heart rate, blood pressure and skin perfusion. It has clearly been demonstrated that startle-induced blinking and electrodermal responses can be inhibited when weak stimuli precede the startle stimulus (prepulse inhibition, PPI). The aim of the current study was to investigate PPI-effects on the startle responses of the cardiovascular system and skin per-

fusion. Therefore, we measured beat-to-beat changes in heart rate by ECG, blood pressure by non-invasive Finapres and skin perfusion of the fingertip by laser doppler flowmetry in 16 young healthy female subjects. Startle stimuli were (103 dB, white noise, 50 ms, instantaneous rise time, binaural) presented 32 times (mean inter stimulus interval: 14 s). Half of the startle stimuli were preceded by a prepulse (75 dB, 1200 Hz Sinus, 50 ms, SOA 5 120 ms, binaural). The startle responses of heart rate, blood pressure and skin perfusion were significantly affected by prepulses. Our results indicate the existence of a prepulse inhibition effect on the cardiovascular startle response, but may contradict Lacey's environmental intake-rejection hypothesis.

Poster 96

DO HUMANS PREFER SIMILAR OR DISSIMILAR MATES? FACIAL SELF-RESEMBLANCE INFLUENCES PHYSIOLOGICAL REACTIONS BUT NOT SUBJECTIVE RATINGS TO EROTIC STIMULI

Johanna Lass-Hennemann1, Christian E. Deuter1, Linn K. Kuehl1, Andre Schulz1, Terry D. Blumenthal2, & Hartmut Schachinger1 1University of Trier, 2Wake Forest University

Descriptors: affective startle modulation, erotic stimuli, kin recognition Cues of kinship are predicted to increase prosocial behavior due to the benefits of inclusive fitness, but to decrease sexual attraction due to the potential costs of inbreeding. Previous studies have shown that facial resemblance, a putative cue of kinship, increases prosocial behavior. However, the effects of facial resemblance on mating preferences are equivocal, with some studies finding that facial resemblance decreases attractiveness in a sexual context, while other studies show that individuals choose mates partly on the basis ofsimilarity. To investigate this question we conducted an experiment in which 30 male volunteers viewed pictures of erotic female nudes while startle eye blink EMG responses to binaural bursts of white noise were recorded. The female nude pictures were digitally altered so that the face either resembled the male participant or another participant, or were not altered, and non-nude neutral pictures were also included. The digital alteration was undetected by the participants. We also assessed pleasure and arousal ratings of all pictures. Erotic pictures reduced startle eyeblink magnitudes as compared to neutral pictures. Furthermore, participants showed a greater startle eyeblink inhibition to self-resembling female nudes than to other-resembling female nudes or non-manipulated female nudes. However, subjective pleasure and arousal ratings did not differ between the three erotic picture categories. Our data suggest that facial resemblance with the participant increases the attractiveness of erotic female nudes instead of decreasing it.

Poster 97

ORAL CORTISOL IMPROVES IMPLICIT SEQUENCE LEARNING WHEREAS ORAL METYRAPONE SHOWS NO EFFECT

Sonja Roemer1, Frauke Nees2, Andre Schulz1, Steffen Richter1, & Hartmut Schachinger1 1University of Trier, 2University of Heidelberg

Descriptors: implicit sequence learning, glucocorticoids, hippocampus Medial temporal lobe structures are suggested to be essential for explicit memory. Recent studies show that the medial temporal lobe (including the hippocampus) is also active in implicit sequence learning. Since glucocorticoids affect memory function via receptors in the hippocampus, we investigated implicit sequence learning after glucocorticoid manipulation. In Experiment 1, oral cortisol (30 mg) was given to 29 healthy subjects, whereas 31 control subjects received placebo. In Experiment 2, oral metyrapone (1500 mg; blocker of cortisol production) was given to 27 healthy subjects, whereas 27 control subjects received placebo. At the expected peak period of treatment all volunteers performed 5 blocks of a 5-choice serial reaction time task by responding to colored lights by pressing buttons of the same color. The subjects responded without knowing to a stimulus sequence, including higher-order sequential regularities. The reaction speed of every button-press (100 per block) was determined and difference-scores to initial values were calculated as a proof of learning. We found a significant interaction of treatment and block number in Experiment 1 which indicated a better learning performance of the cortisol group compared to the placebo group, but there was no effect of metyrapone on implicit sequence learning. The effect of cortisol might reflect hippocampus-involvement. This favorable effect is in line with studies which observed enhanced memory after pre-learning cortisol-treatment in the afternoon and might be due to retrieval blockade of distracting memories.

Poster 98

STARTLING FACTS ABOUT EYE BLINK CONDITIONING

Carina M. Zech1, Frauke Nees2, Terry D. Blumenthal3, & Hartmut Schachinger1 1University of Trier, 2Central Institute of Mental Health, 3Wake Forest University

Descriptors: startle, corneal air puff, trace conditioning

Recently, it was shown that intense versions of tones that had been paired at lower intensities as prepulses with aversive acoustic white noise stimuli induced significantly larger

startle eye blinks than did unpaired tones. In this study we asked whether similar effects occur after pairing with corneal air puffs. Fifty-one healthy subjects participated in a differential trace eye blink conditioning study (US: air puffs, 10 psi, 50 ms; CS+/CS x : binaural tones, 400 ms, 70 dB, pitch of 1200 or 1600 Hz). The empty interval was 550 ms. Pairing of CS+ was done in 6 blocks of 10 trials, and conditioned eye blink response (CR) probability was assessed by EMG in the 550 to 950 ms interval after CS onset. CS- was presented randomly and equally as often as the CS+. Learning was indicated by a significant increment of CR probability after CS+. During the extinction phase, intense (105 dB) and brief (50 ms) startle-eliciting versions of CS+ and CS x were presented in randomized order, counter-balanced across subjects, and peak EMG eye blink responses were measured immediately (20 to 150 ms) after CS onset. Startle eye blink responses were stronger when induced by the intense versions of CS+ than CS _ (p 5 .016). However, this difference did not correlate with learning during the acquisition phase. Thus, previous pairing with blink inducing air puffs enhances the ability of a tone to induce startle. This effect is not redundant with learning during acquisition, and may help to differentiate aversive and non-aversive associative learning in eye blink conditioning studies.

Poster 99

MODULATION OF THE STARTLE REFLEX BY ARTERIAL AND CARDIOPULMONARY BARORECEPTORS

Steffen Richter1, Andre Schulz1, Johannes Port2, Terry D. Blumenthal3,

& Hartmut Schachinger1 1University of Trier, 2University of Stuttgart, 3Wake Forest University

Descriptors: baroreflex, lower body negative pressure, cardiac cycle Arterial baroreceptor afferent feedback originating from the high pressure vascular system inhibits the startle eye blink. However, it is not known, whether cardiopulmo-nary baroreceptor signaling originating from the low pressure vascular system exerts a similar effect. We used Lower Body Negative Pressure (LBNP) with gradients of 0, _ 10, _ 20, and _ 30 mmHg to gradually unload cardiopulmonary baroreceptors. For the modulation of high pressure afferent feedback, we took advantage of spontaneous loading and unloading of the arterial baroreceptor over the cardiac cycle. White noise bursts were delivered 230 and 530 ms after spontaneous R-waves. We measured eye blink responses by EMG, and psychomotor reaction time by button pushes to startle stimuli. Startle eye blink responses were enhanced during unloading of either cardio-pulmonary (p 5 .01) or arterial (p 5 .05) baroreceptors. An interaction effect on psychomotor reaction times (p 5 .05) indicated facilitation with combined unloading of both baroreceptor types. These results demonstrate that the loading status of cardio-pulmonary baroreceptors has an impact on brainstem and cortical CNS processes.

Poster 100

STRESS INDUCES A TIMESHIFT OF THE BARO-AFFERENT-MEDIATED REDUCTION IN STARTLE

Andre Schulz1, Debora E. Plein1, Terry D. Blumenthal2, & Hartmut Schachinger1 1University of Trier, 2Wake Forest University

Descriptors: baroreflex, startle eye blink, cold pressor stress

Eye blink responses to acoustic startle stimuli are smaller when startle stimuli are presented during the cardiac systole (R-wave +230 ms) than during the diastole (R +530 ms). This effect relies on intact baro-afferent neural traffic, which is enhanced during the early cardiac cycle phase (systole). Stress is known to reduce the pre-ejection period (PEP), thereby shifting the beginning ofthe systolic phase to earlier time points in the cardiac cycle. However, there is no data on whether the expected shift of baro-afferent feedback would impact the pattern of startle modulation within the cardiac cycle. 38 healthy volunteers (24 f, mean age: 23.3 y) received acoustic startle stimuli (105 dB) at 6 different latencies relative to the R-wave (R +0, 100, 200, 300, 400, 500 ms), each before and immediately after either a cold pressor (n 5 19) or a control intervention (n 5 19). Autonomic parameters were increased in the cold pressor group right after the intervention (BP: +15/10 mmHg). Pre-intervention startle responses were lowest for latencies of R +200 and +300 ms. Immediately after the cold pressor test, startle responsiveness was lowest for earlier latencies (R +100 and +200 ms; significant 3-way interaction: p < .05). We conclude that the cardiac modulation of startle is sensitive to altered temporal baro-afferent feedback characteristics induced by stress and autonomic activation.

Poster 101

STRESS INDUCED REDUCTION IN HIGH FREQUENCY HEART RATE VARIABILITY CANNOT BE EXPLAINED BY RESPIRATORY FREQUENCY CHANGES

Linn K. Kuehl, Steffen Richter, Andre Schulz, & Hartmut Schaechinger University of Trier

Descriptors: stress, heart rate variability, respiration

Stress is well known to affect the function of the sympathetic and parasympathetic nervous systems. It has been suggested that stress induces vagal withdrawal of cardiac

control, thereby reducing parasympathetically-mediated high frequency heart rate variability (hf-HRV). However, reduced hf-HRVunder mental stress may also be explained by stress-related increases of respiratory frequency, since respiratory frequency is a strong determinator of hf-HRV with higher respiratory frequency being associated with reduced hf-HRV. The current study asked whether the stress induced decrease in hf-HRV may be explained by respiratory frequency changes. Nine healthy subjects aged between 21 and 27 years underwent repetitive assessment of cardiovascular beat-to-beat data while their breathing was paced according to auditory tape instructions at defined frequencies between .15 and .45 Hz. Afterwards, a resting period with free breathing and a 5 min period of a stressful adaptive choice-reaction-time task were assessed. HRV was calculated by WinCPRS software in the frequency range of .15 to .45 Hz. Hf-HRV significantly decreased during stress (81.5 ms2/Hz) as compared to rest (676.5 ms2/Hz), while respiratory frequency increased from .27 (SD 5 .04) to .43 (SD 5 .06) Hz. Individual adjustment according to the subject's respiratory frequency - hf-HRV relationship showed that this stress-induced reduction in heart rate variability cannot be explained by respiratory frequency changes, and are thus likely attributable to true stress-induced vagal withdrawal of cardiac control.

Poster 102

AUDITORY NOVELTY PROCESSING IN OBSESSIVE-COMPULSIVE

DISORDER

Moritz Ischebeck, Tanja Endrass, Rüdiger Spielberg, & Norbert Kathmann Institute of Psychology, Humboldt-University,Berlin, Germany

Descriptors: novelty-p3, obsessive-compulsive disorder, dopamine Heightened arousal and hypervigilance have often been observed clinically in patients with obsessive-compulsive disorder (OCD). Thus, we hypothesized that OCD patients, relative to mentally healthy control participants, will exhibit an enhanced involuntary shift of attention toward novel stimuli. To test the hypothesis of an enhanced orienting response in OCD patients, we measured the auditory event-related novelty-P3 during performance ofa three-stimulus novelty oddball task in 20 OCD patients and 20 control participants. We did not find the expected increase of the novelty-P3 in the total group of OCD patients. However, patients with early age at illness-onset showed enhanced amplitudes of the novelty-P3 compared to patients with a late illness-onset and control participants. This result might reflect a more severe biological vulnerability ofpatients with early illness-onset. As dopamine plays a central role in the generation of the novelty-P3, this vulnerability might be specifically related to alterations in the dopaminergic system.

Poster 103

ACTION MONITORING DYSFUNCTIONS AS AN ENDOPHENOTYPE IN OBSESSIVE-COMPULSIVE DISORDER

Anja Riesel, Tanja Endrass, Christian Kaufmann, & Norbert Kathmann Institute of Psychology, Humboldt University, Berlin

Descriptors: obsessive-compulsive disorder, error related negativity, endophenotype Action monitoring dysfunctions in patients with obsessive-compulsive disorder (OCD) have been repeatedly reported. Event-related brain potentials (ERP) and functional magnetic resonance imaging (fMRI) studies consistently showed increased error-related brain activity in OCD patients. The enhancement of the error-related negativity (ERN) seems to be independent from state-related changes in OCD symptoms. Thus, the ERN is considered as a potential endophenotype marker of OCD and therefore might also be observed in unaffected first-degree relatives. Endophenotype models help to improve aetiological understanding of complex disorders such as OCD. The aim of the present study was to examine whether unaffected first-degree relatives of OCD patients show larger ERN amplitudes and/or larger amplitudes of the correct-related negativity (CRN). ERPs were recorded from unaffected first-degree relatives of OCD patients, OCD patients and healthy controls during performance of a modified flanker task. Preliminary results indicate enhanced ERN amplitudes in first-degree relatives and OCD patients compared to healthy controls. These data support the existence of action monitoring dysfunctions not only in OCD patients but also in their unaffected first-degree relatives. Thus, overactive action monitoring could represent a potential neurocognitive endophenotype in OCD mediating the familial or genetic vulnerability for OCD.

Poster 104

CONFLICT DETECTION AND DEFENSIVE MOTIVATION: THE N2 AND ERN PREDICT STARTLE EYE-BLINK REFLEX

Michael Inzlicht1, & Greg Hajcak2 1University of Toronto, 2Stony Brook University

Descriptors: N2, error related potential, startle eye-blink reflex

Both the N2 and error-related negativity (ERN) are negative deflections in the event-related potential that are generated in the anterior cingulate cortex (ACC), a brain

region involved in a form of attention that serves to regulate both cognitive and emotional processing. Although the ACC has clear cognitive and affective components, early theories used to explain what the N2 and ERN represent have relied on computational models that have not taken affect and motivation into account. Recently, however, studies have linked the ERN with motivation and individual differences in anxiety, although empirical support for a link between the N2 and motivation has been absent. To fill this void, the current research explored the relationship between the N2 and defensive motivation, as measured by the startle eye-blink response. Twenty-five participants completed the Go/No-Go reaction time task, while we assessed both the N2 and ERN. The defensive startle reflex was elicited by a 50 ms white noise burst on a number of Go and No-Go trials. As predicted, results indicated that overall startle magnitude (on both Go and No-Go trials) was significantly correlated with N2 and ERN amplitudes. The larger these waves (more negative), the larger the defensive startle reflex; thus, individual differences in conflict monitoring predict defensive responding. Unexpectedly, startle magnitude was larger for Go than No-Go trials. This finding may be due to a motor priming effect on Go trials that potentiates motor reflexes, an effect that may overshadow startle differences related to conflict.

Poster 105

ANTISOCIAL PERSONALITY TRAITS AND FEEDBACK PROCESSING - AN ERP STUDY

Daniela Pfabigan, Johanna Alexopoulos, Uta Sailer, & Herbert Bauer University of Vienna

Descriptors: feedback related negativity, antisocial personality traits, EEG People with an antisocial personality disorder are described to have different error processing mechanisms than healthy controls, as measured with electroencephalography (EEG). In our present study we investigated whether or not antisocial personality traits influence the so called 'Feedback Related Negativity' (FRN), a negative deflection over frontocentral electrode sites after the presentation of unfavourable feedback. Twenty subjects (ten women, ten men) encountered unfavorable feedback in a probabilistic gambling task while 64-channel-EEG was recorded. Prior to this, participants were administered a personality questionnaire (PSSI), including the sub-scale 'self-determined personality and antisocial personality disorder.' The FRN amplitude was compared for 'antisocial' and 'non-antisocial' subjects with a peak-to-peak analysis at midline electrode sites. A significant between-subject effect of the PSSI 'antisocial' sub-scale was found. After receiving negative feedback the FRN amplitude was most prominent in 'antisocial' subjects. These results indicate that subjects with more 'antisocial' personality traits place higher emphasis on feedback outcomes that indicate a monetary loss than 'non-antisocial' ones do. These findings will be discussed referring to a comparable experiment with emotional faces serving as feedback stimuli (20 subjects, all women). Further results will be presented. The relation between personality traits and processing of decision outcomes are discussed to highlight psychopathological effects on feedback processing.

Poster 106

VISUAL ATTENTION AND NEUROTOXICANT STATUS IN 3-MONTH-OLD INFANTS

Nicki L. Aubuchon-Endsley, David G. Thomas, Tay S. Kennedy, Afework Bezibah, Barbara Stoecker, Stephanie L. Grant, Tabitha Valtr, & Melissa Oliver Oklahoma State University

Descriptors: attention, nutrition, infant

Developmental attention research is important given the construct's association with sensory and perceptual development and later skill/ability attainment. In particular, infants' visual attention has been linked with cognitive development and used to inform assessment of cognitive interventions. A well-known paradigm used to assess this is the heart rate-defined phases of attention, in which infant gaze behavior and changes in heart rate are assessed simultaneously. A recent addition to the developmental attention literature is the investigation of relations between these variables and early nutritional status. However, studies within the extant literature tend to focus on single indicators of nutritional status and mainly iron deficiency. Therefore, the following study investigated the relations between neurotoxicants (lead and cadmium) and 3-month old infant's orientation to facial stimuli, sustained attention, and attention termination. Results demonstrated that there was a statistically significant relation between maternal blood cadmium concentration and the infants' attention termination (r 5 .47, p 5 .003). However, maternal blood lead concentration was not significantly related to the attention phases. Although not statistically significant, relations between anthropometric indicators of nutrition and attention phase variables were in the expected directions. This study provides evidence of the relation between early infant attention and maternal neurotoxicant status. The significance, implications, and limitations of the study are discussed in greater detail.

SEQUENTIAL VERSUS SIMULTANEOUS STIMULUS ACKNOWLEDGMENT AND COUNTERMEASURE RESPONSES IN P300-BASED DETECTION OF DECEPTION

Alexander W. Sokolovsky, Jessica Rothenberg, John Meixner, & J. Peter Rosenfeld Northwestern University

Descriptors: deception, P300, CTP

A P300-based experiment is described which is a modification of the Complex Task Protocol (CTP) paradigm (Rosenfeld et al., 2008). A participant first sees either a rare probe or a frequent irrelevant and must respond with the same button to each stimulus; a P300 identifies stimulus recognition. The subject must then (after 1 - 2 s) identify a target or a non-target stimulus with one of two button presses. Three groups of participants were tested, a simple guilty (SG) group and two countermeasure (CM) groups. Our manipulation consisted of explicitly telling one of the two CM groups to respond with the button press and the CM 'simultaneously' (lumpers) while the other CM group did the CMs separated from the button press (splitters) as in '08. The probe-irrelevant differences were significant in all three group with detection rates of 11/12 (SG), 10/12 (CM-split), and 11/13 (CM-lump). Attempted CM use, diagnosed with reaction time (RT), detected CM use in the splitters but not the lumpers. In fact, when we compared reaction times of probes and countered irrelevants in the splitting group versus the lumping group, not only were reaction times to countered irrelevant stimuli in the lumping group significantly smaller than in the splitting group, t(23) 5 5.51, p < .05).

Poster 108

SUBLIMINAL PROCESSING OF FACIAL EXPRESSION AND THE EFFECT OF FACE ROTATION

Eligiusz Wronka, & Wioleta Walentowska Jagiellonian University

Descriptors: attention, emotional expression, ERP

There is growing evidence that facial emotional expressions can be detected and may trigger selective brain responses even when subjects are not consciously aware that such a stimulus was presented. To investigate how the brain processes emotional expression in the absence of conscious perception, we recorded ERPs in response to subliminally (16 ms) presented faces and non-face objects in a task in which participants had to identify whether the abstract masking stimulus was symmetrical or asymmetrical. We found that the amplitude of the N170 was bigger when recorded in trials when faces were presented when compared to responses elicited by a no-face object. Moreover, significant amplitude differences in this component were observed as a consequence of face rotation whereas no such differentiation was obtained for non-face objects. These findings clearly show that faces are processed differently than other objects even in the absence of conscious awareness. Additionally, we compared brain responses to fearful and neutral faces. The negative shift specific for the fearful faces was recorded over occipital and occipito-temporal locations starting 240 ms after stimulus onset (Early Posterior Negativity, EPN). However, this effect was observed only when faces were presented in their usual up-right position but not when faces were rotated. Our results demonstrate that involuntary differentiation of facial expression could be determined by the structural analysis of the face configuration.

Poster 109

ATTENTIONAL BIAS TOWARD EMOTIONAL FACES AND THE EFFECT OF HEMISPHERIC ASYMMETRY

Eligiusz Wronka, Dariusz Asanowicz, & Wioleta Walentowska Jagiellonian University

Descriptors: attention, emotional expression, n2pc

Previous studies show that emotional expressions can rapidly capture attention. Our study investigated the temporal course of attentional biases for negative and positive facial expressions. ERPs were recorded while participants were exposed to pairs of faces in a dot-probe task. We found that attentional orienting to angry faces emerged very early (170-320 ms poststimulus, N2pc). This effect was not obtained for happy faces. However, when we separately analyzed brain responses measured for the left and right-sided exposition of emotional faces, we found that later phase of the N2pc (220 - 320 ms) depends on the location of emotional expression. Comparable interaction effects were noticed for both positive and negative expressions. Similar effects of the visual field were also obtained for the Sustained Posterior Contralateral Negativity (SPCN, 320-500 ms). These findings are consistent with results from recent studies that show a similar temporal onset of attentional shift toward threat-related faces and slower emergence of attentional allocation toward positive expression. However, the results we obtained suggest that attentional shift triggered by facial emotion could be additionally modulated by functional asymmetry of the brain. This finding is consistent with models suggesting right hemisphere dominance for processing of faces and facial expressions.

ATTENTIONAL MODULATION OF FACIAL EMOTION PROCESSING

Eligiusz Wronka, & Wioleta Walentowska Jagiellonian University

Descriptors: attention, emotional expression, N170

Recent studies demonstrated that processing of facial emotional expression can be effectively modulated by attention. Our previous findings suggest that emotional expression effects could be observed at short latencies (N170) when the task demanded classification of facial expression but not when the task was to recognize gender of the faces. In the current study we record ERPs in response to pictures of faces presented in two different tasks. In a first task participants were instructed to compare expression of the two successively presented faces, while in a second task they had to evaluate if two pictures showed the same person or not. The amplitude of the face specific N170 was bigger when measured in response to emotional faces in comparison to neutral faces. In contrast to our previous study we observed this effect irrespective of the task. However, strength of this effect was related to amount of attentional resources available to process expression of the faces. We found also that emotional expression influences brain activity as early as 240 ms after stimulus onset (Early Posterior Negativity EPN). Moreover, this effect was comparable in both tasks. However, again this effect seems to be determined by attentional resources available to process facial expressions.

Poster 111

QUESTIONING THE VALIDITY OF FRACTAL MEASURES OF SHORT-TERM HEART RATE VARIABILITY: EVIDENCE FROM AUTONOMIC BLOCKADE AND PACED BREATHING EXPERIMENTS

Pandelis Perakakis1,2, Gustavo Reyes del Paso3, Jose Luis Mata1, Luis Carlos Delgado1, & Jaime Vila1 1University of Granada, 2University of Boston, 3University of Jaeen

Descriptors: fractal analysis, heart rate variability

Fractal scaling patterns in fluctuating signals are common in biology and are frequently associated with self-organized complex systems. We present results from two experiments on human subjects showing that fractal measures of heart rate variability (HRV) are sensitive to trend-like oscillations originating from specific control mechanisms such as respiratory sinus arrhythmia and baroreflex. In the first experiment, paced breathing at different frequencies (0.1, 0.2 Hz) was shown to significantly alter (t 5 11.59, p < 0.001) the alpha 1 scaling exponent of short-term HRV obtained by Detrended Fluctuation Analysis (DFA). In the second experiment atropine administration significantly increased the alpha 1 exponent (F 5 19.55, p < 0.05). We compare these results with those obtained by simulated signals. Our interpretation raises serious methodological and conceptual concerns regarding the application offractal measures to short-term HRV.

Poster 113

MEDIAL PFC THETA POWER SCALES WITH DEGREE OF NEGATIVE FEEDBACK PREDICTION ERROR

James F. Cavanagh1, Michael J. Frank2, Theresa J. Klein1, & John J.B. Allen1 1University of Arizona, 2Brown University

Descriptors: FRN, prediction error, action monitoring

Investigations into action monitoring have consistently detailed a fronto-central voltage deflection in the ERP following the presentation of negative feedback, sometimes termed the Feedback Related Negativity (FRN). This ERP component is thought to reflect the evaluative processes of an action monitoring system following error feedback. Varying accounts postulate that: 1) the FRN should scale with the degree of negative prediction error, 2) the FRN reflects a binary distinction between good/bad outcomes, and 3) amplitude modulation in the FRN is predictive of post-error behavioral adaptation. To test these different and sometimes conflicting accounts, we investigated EEG activity during a probabilistic reinforcement learning task. Performance data from this task were fit to abstract computational models (Q-learning) which estimate action values and prediction errors, providing a quantification of the degree to which events are worse than expected. Single trial mid-frontal theta power following error feedback (arguably the basis of the FRN) scaled with the degree of negative prediction error, as did mid-frontal / right lateral-frontal phase synchrony. Both of these power and synchrony metrics scaled with the degree of immediate post-error reaction time slowing. These findings indicate that an action monitoring - cognitive control network previously associated with motor error commission is similarly active following error feedback. Moreover, activity in this system is sensitive to the degree that events are ''worse than expected.''

INTER-REGIONAL NEURONAL OSCILLATORY SYNCHRONY UNDERLIES COGNITIVE CONTROL

Michael X. Cohen University of Amsterdam

Descriptors: cognitive control, oscillation, functional connectivity In our day-to-day life, we must constantly monitor our actions, and flexibly adapt our behavior according to rules that we are told or learn through feedback. These abilities are supported by the ''cognitive control network,'' a circuit of anatomically and functionally linked brain regions. Typically in cognitive neuroscience, researchers attempt to identify specific brain regions that are responsible for specific functions; here, we explore the hypothesis that spatially disparate regions form the functionally unified cognitive control network via synchronous oscillatory activity. EEG is particularly useful for investigating this hypothesis because it measures synchronous and rhythmic phase changes in excitability of neural networks (oscillations). I will provide an overview of convergent findings from several different experiments, comprising healthy individuals as well as various patient groups, that support this hypothesis. I will also outline open questions and future directions. Briefly, changes in inter-regional oscillatory synchrony wax and wane with corresponding fluctuations in cognitive control activation. Further, the strength of synchrony predicts subsequent performance adjustments. Together, these findings have implications for our understanding of the functional architecture and dynamics of cognitive control. Because fluctuations in synchrony may occur in absence of changes in overall activity, these findings also demonstrate that the ''functional localization'' approach to cognitive neuroscience provides a limited view of brain functional dynamics.

Poster 115

USING N400 TO ASSESS STEREOTYPES INCONGRUITIES WITH THE USE OF EXEMPLARS

Laura Zambrano-Vazquez, Stephen L. Crites, Katherine R. White, & Yvette M. Guereca University of Texas at El Paso

Descriptors: N400, stereotypes, exemplars

A recent study revealed the potential use of the N400 component as an effective and versatile tool to study stereotypes. The present study extends on this research by using exemplars, examples of individual men and women, as primes. Participants were primed with either a male or female exemplar followed gender stereotypical word (target) that was either congruent with gender stereotypes (e.g., Women: Nurturing) or incongruent (e.g., Women: Aggressive) with the preceding picture; their task was to indicate whether the stimuli matched or did not match. Both response times and ERPs were recorded during performance of the task. It was hypothesized that stereotype incongruent picture/word pairs were associated with more negative N400 amplitudes and slower response times, relative to congruent word pairs. The results supported both hypotheses, indicating that they might be reflecting the processes that occur in daily life interaction with individual men and women. The implications of this study are discussed.

Poster 116

THE EFFECT OF TEMPORAL PRECISION AND PROBABILITY ON THE RESPONSE TO THREAT OF SHOCK: A FEAR-POTENTIATED STARTLE STUDY

Rebecca Gloria, Jason J. Jaber, Timothy B. Baker, & John J. Curtin University of Wisconsin, Madison

Descriptors: fear, anxiety, startle

Research using FPS to examine the emotional response to threat suggests that shock predictability can be adjusted to distinguish between fear and anxiety. This study was designed to examine the effect of temporal precision and probability on shock predictability to determine whether manipulation of these stimulus characteristics will produce potentiation in the acoustic startle response. Participants completed two fear conditioning tasks that each included predictable and unpredictable pairings of visual cue presentations with electric shock. In Task 1 temporal precision of predictability of shock was manipulated by varying the duration of the visual cues preceding shock, such that predictable shock conditions included a single due duration (4.5 s) and unpredictable shock conditions included multiple cue durations (4.5 s, 19.5 s, 49.5 s and 79.5 s). Task 2 involved the manipulation of predictability in three conditions of shock probability that represented predictable (100%), unpredictable (20%) and no shock recovery (0%) blocks. A significant increase in startle potent-iation was elicited during both tasks in the predictable and unpredictable shock conditions suggesting that both temporal precision and probability are stimulus characteristics that can be used to parse affective changes associated with psychopa-thology. Results from samples of marijuana withdrawn and alcohol intoxicated individuals will be discussed.

RESTING CARDIAC VAGAL CONTROL AND QUALITY OF PARTNER RELATIONSHIP IN WOMEN NEWLY DIAGNOSED WITH BREAST CANCER

Anna Povzner, John J.B. Allen, Roisin O'Donnell, Amanda E. Brody, & Karen L. Weihs University of Arizona

Descriptors: cardiac vagal control, RSA, partner relationships

Cardiac vagal control as measured by respiratory sinus arrhythmia (RSA) is associated with a variety of indices of health and mental health. Whereas lower resting RSA characterizes a variety of chronic illnesses, higher resting RSA is associated with better affective regulation, social engagement, and coping with life stressors. To date, little is known about the association between RSA and partner relationship quality. The present study examined whether resting RSA was related to self-reported partner relationship quality in a sample of 39 women in committed partner relationships who were diagnosed with stage 0, I, II, or III breast cancer within the prior seven weeks, all of whom were free of medications that would affect cardiac function. At the oncology clinic visit, 10 minutes of resting electrocardiographic (ECG) data were recorded: the first 5 minutes from each subject alone, and the second 5 minutes holding the companion's hand, if the companion was present, otherwise both segments were recorded from the subject alone. Subjects completed questionnaires on the quality of their committed partner relationships. Although there was no significant effect of the hand-holding manipulation, higher RSA during both recording periods predicted greater relationship satisfaction as measured by the Dyadic Adjustment Scale (DAS) and more positive partner interactions on the Social Relationships Inventory (SRI). These data suggest that higher resting RSA is indeed associated with higher partner relationship quality in couples who are coping with a significant stressor.

Poster 118

CARDIAC VAGAL CONTROL AND DEPRESSION: THE MODERATING EFFECT OF SEX

Jie Pu1, Lingdan Wu2, & John J.B. Allen1 1University of Arizona, 2Southwest University

Descriptors: cardiac vagal control, depression, gender difference

Research on the relationship between cardiac vagal control (CVC) and depression has produced mixed findings, perhaps due to confounding factors such as medication use, poor physical health, and other comorbid psychiatric disorders that often accompany depression. To examine the relationship of CVC to depression, minimizing the influence of these confounding factors, the current study investigated a large (n 5 215) medically-healthy and medication-free sample of young adults (age 18-30) selected to span the full range of depression from clinical severity to symptom absence. Sex differences were specifically examined as sex has been reported as a possible moderator of the CVC-depression relationship. EKG data were collected during four lab visits. Each lab visit comprised two 8-minute rest periods. Respiratory sinus arrhythmia (RSA, an indicator of CVC) extracted from each 1-minute resting session was averaged across eight 1-minute sessions of each resting period and across two resting periods to yield an estimate of CV C at each of the four visits. Participants also completed the Beck Depression Inventory-II (BDI-II) at each lab visit. Results from a mixed-linear model revealed a significant interaction between sex and BDI-II in predicting resting RSA, whereby women with greater depression severity exhibited lower RSA, and men with greater depression severity showed higher RSA compared to their low-depressed counterparts. These results suggest the need to consider participant sex in the future study of the CVC-depression relationship.

Poster 119

INTERACTION BETWEEN 5HT1A RECEPTOR ALLELES, PSWQ & FRONTAL EEG ASYMMETRY

Andrew W. Bismark1, Jennifer L. Stewart1, James A. Coan2, & John J.B. Allen1 1University of Arizona, 2University of Virginia

Descriptors: serotonin, eeg asymmetry, worry

Anxiety and depression are commonly comorbid psychopathologies and are often treated using similar methods. Given serotonin's dominant role in pharmacological treatment of psychopathology, it is thought to be an important neuro-modulator of mood and arousal. It has also been hypothesized that serotonergic risk alleles in the 5HT1 a receptor gene may be associated with risk for psychopathology when faced with life stressors. The current study examined the relationship between serotonin 5HT1a alleles, depressive history, worry (as measured by PSWQ) and their interactive effects on resting frontal electrical brain asymmetry. The sample consisted of 226 (31 % male) Caucasian individuals with (n 5 110) and without (n 5 116) a history of depression. EEG was assessed from 64 scalp sites on four days (two 8-min periods each day). Although, the main effect of genotype on asymmetry across frontal regions indicated that the risk genotype was associated with greater relative right frontal activity, a significant interaction between PSWQ and 5HT1a genotype emerged. Pairwise comparisons indicated the 5HT1a risk genotype was associated with greater relative right frontal activity more strongly among those with low worry

compared to high worry (significant at channel pairs F7/8, F3/4 and F1/2 with a trend at F5/6). These results indicate the importance of evaluating genetic contributions to psy-chophysiological risk metrics, but also that this relationship is moderated by the complexity of comorbid phenotypic worry.

Poster 120

PATTERNS OF STATE AND TRAIT REGIONAL BRAIN ACTIVITY IN DEPRESSION SUPPORT THE CAPABILITY MODEL OF EEG ASYMMETRY

Jennifer L. Stewart1, James A. Coan2, Andrew W. Bismark1, David N. Towers3, & John J.B. Allen1

1University of Arizona, 2University of Virginia, 3University of Illinois, Urbana-

Champaign

Descriptors: EEG, depression, emotion

Resting frontal electroencephalographic (EEG) asymmetry is a promising marker of risk for major depressive disorder (MDD) and propensities to engage in less approach-than withdrawal-motivated behaviors across situations. The capability model of individual differences in EEG asymmetry (Coan, Allen, & McKnight, 2006) suggests, however, that brain activity during emotional challenge will provide a stronger index of the capacity for depressed individuals to engage in approach and withdrawal responses when emotion regulation may be needed. Frontal EEG asymmetry during rest and emotional challenge of approach (anger, happiness) and withdrawal (fear, sadness) was assessed on 4 occasions in 210 individuals age 18-33 (34% male) with (n 5 93) and without (n 5 117) a diagnosis of lifetime MDD (MDD+ and MDD —). Although results for men were not entirely consistent, findings for women were very clear: MDD + women exhibited greater relative right frontal activity (lower right frontal alpha power) than MDD — women across conditions. Importantly, EEG asymmetry during the emotional challenge task was a more powerful indicator of lifetime MDD status than resting asymmetry in women, evidence in support of the capability model. Additionally, MDD + women displayed lower bilateral alpha power during the emotional challenge conditions and higher bilateral alpha power during the rest condition than MDD — women, indicating that different mechanisms may underlie patterns of state and trait asymmetry as a function of lifetime MDD status in women.

Poster 121

SHOULD IT MATTER WHEN WE RECORD? TIME OF YEAR AND TIME OF DAY AS FACTORS INFLUENCING FRONTAL EEG ASYMMETRY

Jamie R. Velo1, Jennifer L. Stewart1, Brant P. Hasler1, David N. Towers2, & John J.B. Allen1 1University of Arizona, 2University of Illinois, Urbana-Champaign

Descriptors: EEG, seasonality

Resting frontal encephalographic asymmetry is a relatively stable individual difference that identifies trait aspects of risk for psychopathology such as major depression. Superimposed on stable trait variance are occasion-specific fluctuations that, to date, have been relatively poorly characterized. A recent study (Peterson & Harmon-Jones, 2008) found that time of year and time of day interacted to predict differences in resting frontal asymmetry, with participants assessed on fall mornings having more relative right frontal activity versus those assessed on spring mornings. In a sample of 111 non-depressed individuals, a time-of -year by time-of-day interaction emerged, although the direction differs from that of Peterson & Harmon-Jones, with participants assessed on fall mornings having more relative left frontal activity than those assessed on spring mornings. To determine if the effects were due to seasonal variations such as photo-period or possibly driven by seasonal psychosocial stressors inherent in a student sample, season was replaced by a dimensional scale of length of the photoperiod; results were largely consistent with those based on fall/spring coding. Morning sessions run in periods of less light show more relative left frontal activity than other session times. Time awake appears to be an important moderating variable for the interaction of photo-period and session time. Results of this study highlight the need to monitor or control seemingly extraneous factors that influence metrics assumed to be trait indices of motivational/affective propensities.

Poster 122

CORTICAL SOURCES OF INFANT VISUAL PREFERENCES

Greg D. Reynolds1, Mary L. Courage2, & John E. Richards3 1University of Tennessee, 2Memorial University, 3University of South Carolina

Descriptors: attention, ERP, infants

Measures of preferential-looking have been at the forefront of behavioral research on infant cognitive development, while event-related potential (ERP) studies have been commonly used by researchers interested in electrophysiological correlates of infant cognition. The goal of this study was to identify the cortical sources of infant visual preferences. The cortical sources of the ERP components associated with stimulus-type

effects and visual preference behavior were localized with equivalent current dipole (ECD) analysis. Forty-seven infants were tested at 4.5, 6, or 7.5 months of age. Paired-comparison trials were embedded within the modified-oddball ERP procedure. The location of cortical sources was estimated with ECD analysis (see Reynolds & Richards, 2005). The cortical source models for the ECD analysis used ''finite-element model'' (FEM) mapping of the electrical conductivity of the head to calculate the forward model. The cortical sources for the 4.5-month-olds were scattered across the mediallateral aspects of the basal prefrontal cortex well into the lateral aspects (Brodmann area 34). There was an increasing trend with increased age for infants to show a larger proportion of active cortical areas along the midline. The best fitting areas in common between the brief stimulus and paired-comparison procedures were in the inferior pre-frontal regions (e.g., BA 11, 25, 34). This common activation combined with visual preference effects found across behavioral and ERP tasks indicates that these areas of the brain are involved in infant visual preferences.

Poster 123

DIFFERENT AGES, DIFFERENT STAGES: A NEURODEVELOPMENTAL AGE-BASED DATABASE OF NORMAL BRAIN DEVELOPMENT FOR MRI

Carmen Sanchez, Alexandra Basilakos, & John E. Richards University of South Carolina

Descriptors: neurodevelopmental, MRI, database

Healthy children and adolescents demonstrate remarkable variability in regional brain measures with MRI (Durston et al., 2001). Using MRIs obtained from the Brain Development Cooperative Group's MRI database, this investigation explored the utility of developing brain templates based on age increments of 6 months. The main goal of the work was to create a database of age-normed MRI volumes and stereotaxic atlases for use with MRI, fMRI, EEG and ERP psychophysiological source analysis, and age-based MRI use. Participants included 860 children and adolescents ranging from 4.5 years to 19.0 years and were divided into age groups by 6 month increments. Anatomical MRIs were done that produced T1-weighted, T2-weighted volumes, and brain and material-segmented (gray matter, white matter, CSF) files for each participant. Each MRI volume was standardized to the appropriate age norm, and the individual MRIs were registered (''warped'') to the age norm average, and then a final average was made. This average was used to develop average T1-Weighted, T2-Weighted, normed MRI volumes in six-month increments from 4.5 to 19 yrs. This database can be used with MRI programs (FSL; SPM; VBM; ANTS) for doing age-based normed MRI and fMRI work. Several characteristics of MRI ''pipeline'' automatic analysis were examined with the database.

Poster 124

SHIFTS IN HEMISPHERIC CONTRIBUTIONS TO LANGUAGE COMPREHENSION WITH AGE

Edward W. Wlotko1, Kara D. Federmeier1, & Marta Kutas2 1University of Illinois, Urbana-Champaign, 2University of California, San Diego

Descriptors: aging, hemispheric asymmetry, sentential context

Although verbal knowledge remains relatively stable across the lifespan, there are age-related changes in online language comprehension, particularly message-level processing. In several studies, we have used event-related brain potentials (ERPs) to examine the nature of age-related change in these processes by varying the fit of sentence-final words with their sentence frames. Consistent with prior work, older adults elicited patterns similar to those for right-hemisphere-biased processing (based on visual field studies) in younger adults. These patterns are marked by reduced sensitivity to the fit between a word and its context when sentential constraint is weak. Thus, only with a strong base of contextual support do older adults, like the right hemisphere of younger adults, seem to benefit from sentential context. Overall, our results implicate a changing balance of hemispheric contributions to comprehension over the lifespan, with the left hemisphere bias toward efficient and predictive use of context information declining with advancing age.

Poster 125

HEMISPHERIC DIFFERENCES IN WORD CLASS EXPECTANCY—AN EVENT RELATED POTENTIAL STUDY

Chia-lin Lee, & Kara D. Federmeier University of Illinois, Urbana-Champaign

Descriptors: hemispheric differences, syntactic processing, nouns and verbs The current study used the split-visual field design to investigate each cerebral hemisphere's sensitivity for syntactic information and word class distinction. Function words (to/the) were used to create word class (verb/noun) expectancy of the upcoming word. After the centrally presented syntactic cue, nouns and verbs with no or little word class ambiguity (e.g., 'the sofa'/'to observe') were randomly presented to either visual field (VF), matching or mismatching the word class expectancy. Participants were asked to make a grammaticality judgment on the phrases. ERP responses to correctly judged

content words were compared across matching and mismatching conditions. The results showed that, compared with matched words, mismatched words elicited larger negativities (500 - 800 ms) and enhanced P600s (900 -1100 ms) after both VF presentations. However, the P600 mismatch effect after the LVF presentation is less robust and appears to be mainly elicited by mismatched verbs (e.g. 'the carve'). Taken together, the findings suggest that both hemispheres are sensitive to word class and can make use of syntactic information from function words. However, the left hemisphere seems more likely to engage in control processes associated with syntactic revision, while the right hemisphere may rely more on lexical information.

Poster 126

CONSCIOUS ERROR DETECTION: DIFFERENTIAL AUTONOMIC RESPONSES AND EVENT-RELATED BRAIN POTENTIALS

Jan R. Wessel, Claudia Danielmeier, & Markus Ullsperger Max Planck Institute for Neurological Research

Descriptors: error awareness, performance monitoring, ANS

The differences between erroneous actions that are consciously perceived as errors and those that go unnoticed have recently become a prevalent issue in the field of performance monitoring. In electroencephalography studies, ''error awareness'' has been suggested to influence the error positivity (Pe) ofthe response-locked event-related brain potential (ERP), a positive voltage deflection prominent approximately 300 ms after error commission. In the autonomic nervous system, erroneous actions in general have been related to subsequent heart-rate deceleration. In this study, ECG (heart rate) and pupillometry were recorded during two versions of an antisaccade task to measure autonomic arousal separately for perceived and unperceived errors. Additionally, the error-related negativity (ERN) and the Pe were investigated in relation to conscious error detection. Our results indicate that only aware errors do in fact provoke a heart-rate deceleration. The pupillometry results parallel the findings of heart-rate deceleration after an error, yielding a more prominent pupil-dilation after an erroneous saccade. This effect, however, is not modulated by error awareness, showing that in this physiological domain unaware errors do evoke autonomic arousal. In addition, we connect these indices of autonomic arousal to the differential effects of conscious error perception on the scalp ERPs by means of single-trial EEG.

Poster 127

ELECTROPHYSIOLOGICAL CORRELATES OF SPATIAL PROCESSING

Travis E. Baker, & Clay B. Holroyd University of Victoria

Descriptors: spatial processing, N170, parahippocampus

In a previous study, we identified an ERP component sensitive to the spatial location of reward-related stimuli in a virtual maze. The latency of this component, which we termed the ''Topographical'' N170 (NT170), occurred about 5-10 ms earlier for rewards following right turns versus left turns in the maze. We suggested that the NT170 was elicited when presentation of the reward-related stimuli in the maze alleys reset the phase ofan ongoing theta rhythm generated in the parahippocampal cortex (PPC), and that the timing of the resetting occurred slightly earlier for objects encountered on the subject's right side compared with the left side. In the present study we ran a series of three experiments to investigate this hypothesis further. All three experiments replicated the basic latency effect. In addition, in Experiment 1, the effect was not reproduced when subjects engaged in a guessing task that was formally equivalent to the T-maze task but that did not involve its spatial aspect. In Experiment 2, we observed the strongest latency effect in participants who used a ''place strategy'' to navigate a complex virtual maze and who were later able to reproduce the maze from memory. In Experiment 3, dipole source localization analysis indicated that the NT170 was best described by mirror dipoles located in the region ofPPC, and further, that this activity was characterized by power in the theta frequency range. Taken together, these data indicate that the NT170 is elicited by a spatially-dependent process mediated by the PPC that induces phase resetting of theta activity.

Poster 128

DECOMPOSITION ANALYSIS OF THE ELECTRODERMAL ACTIVITY (EDA) WITH SHORT INTERSTIMULUS INTERVALS, USING THE EXAMPLE OF CLASSICAL AVERSIVE CONDITIONING OF TACTILE STIMULI

Anne-Kathrin Brascher1, Dieter Kleinbohl1, Jorg Trojan1, Susanne Becker1, Francisco Munoz2, Jose Manuel Reales2, Soledad Ballesteros2, Rupert Holzl2 1Universit£lt Mannheim, 2Universidad Nacional de Educacion a Distancia

Two surface patterns of different roughness served as CS+ (rough) and CS- (smooth) in a differential classical conditioning paradigm. These patterns were moved across the

tip of the right digit by a custom-made, computer-controlled device. Healthy participants (N 5 19) received sequences of such stimuli (duration 550 ms; typical ISI 2650 ms). The rough CS+ was coupled with an aversive heat stimulus presented to the left thenar, serving as an UCS; the smooth CS- was presented uncoupled. In the course of the experiment, subjective ratings of perceived roughness and pleasantness were recorded. The CS+ was rated more negative after conditioning than before. To check the success of the conditioning procedure, electrodermal activity was measured and analyzed in relation to the stimulus onset by a decomposition method. Responses on the different stimulus categories were compared before conditioning, after conditioning and after an extinction phase. Because of the short interstimulus intervals in the experiment, a classical EDA analysis would have been hard to realize, whereas the decomposition analysis is a well suited possibility for short stimulations with overlaid EDA responses.

Poster 129

SENSORY AFFECTIVE GATING - A NEW DESIGN, AN OLD PHENOMENON, EXAMINED BY WAY OF MAGNETOENCEPHALOGRAPHY

Tzvetan Popov, Todor Jordanov, Thomas Elbert, & Brigitte Rockstroh University of Konstanz

Descriptors: affective gating, MEG, M50

The present study explored sensory gating for affective stimuli in the visual modality. The original double-click paradigm was changed into a double-affective-flash paradigm. Seventeen subjects (7 male) attended to 300 pairs of identical pictures (high arousing pleasant, high arousing unpleasant and low arousing neutral), presented for 100 ms with 500 ms SOA, while the magnetoencephalogram was recorded. Gating, defined as ratio of the event related field responses at 50 - 70 ms latency (ERF to the second divided by ERF to the first stimulus), was analyzed for each picture category. Ratios were significantly smaller for pleasant and unpleasant relative to neutral pictures, but did not differ between pleasant and unpleasant stimuli. Source analysis indicated affective sensory gating origin in the limbic system. Results indicate sensory gating for visual affective stimuli, suggesting an affective sensory filter system in the brain, which guides and determines human behavior.

Poster 130

A SMALL GAP AND ITS LARGE CONSEQUENCES IN AUTOMATIC OBJECT REPRESENTATION IN AUDITION

Annekathrin Weise1, Walter Ritter2, & Erich Schroger1 1University of Leipzig, 2Rockland Psychiatric Center

Descriptors: automatic, sound, representation

Previous research showed that the automatic representation only exists for short tones. Concerning long lasting tones information occurring beyond ~300 ms is not (or just to a minor degree) automatically represented. However, a recent finding revealed that a brief gap segmenting long tones re-gained the automatic sound representation. By utilizing the mismatch negativity (MMN), a brain wave elicited by auditory deviance, the present study determined whether this gap results in one meta-object consisting of two related sound parts or in two independent objects. As the MMN to the second of two successive deviances in a sound is known to be reduced, a deviance before and after the gap should result in an MMN decrease when the sound is organized as meta-object. Our finding of two full-amplitude MMNs (before and after the gap) suggests that the gap segmented the acoustic input in two (with respect to the MMN-system) independent objects.

Poster 131

THETA OSCILLATIONS AS A MARKER OF COGNITIVE CONFLICT

Roland Nigbur, & Birgit Sturmer Humboldt University, Berlin

Descriptors: conflict, adaptation, oscillations

Cognitive conflict resolution processes in the brain and behavioral adjustments following them have drawn much attention to the question whether the brain treats conflicts within a unitary conflict monitoring system or whether different mechanisms contribute to conflict adaptation processes. The present study aimed at investigating whether an increase in theta power (4-7 Hz) is observed during different types of conflict (as reported during error commission or in the Stroop task). In a within-subject design with 24 participants we used four different typical conflict paradigms (Eriksen flanker task, Simon task, Go-NoGo-task and mixed Simon-Go-NoGo-design). Theta power was increased significantly in incompatible compared to compatible Go trials whereas NoGo theta power depended on whether typical two-choice interference tasks were used or a mixed three-choice Simon Go-NoGo paradigm was applied. Response conflict was measured in terms of wrong-hand activation in the lateralized readiness potential, which was reduced following incompatible Go trials in the two-choice Simon task and as well in the mixed paradigm. In contrast, neither response conflict in the flanker task nor NoGo conflicts in the mixed task led to reduced wrong-hand activation in the upcoming

trial. We conclude that enhanced theta power indicates increased cognitive control demands across different conflict paradigms. Recruiting such cognitive resources, however, does not reduce upcoming response conflict in every case.

Poster 132

IS THE PROCESSING OF AFFECTIVE PROSODY INFLUENCED BY SPATIAL ATTENTION? AN ERP STUDY

Julia Gadeke, & Brigitte Roder University of Hamburg

Descriptors: emotion, attention, ERP

It is still a controversy whether the processing of emotional stimuli depends on attention. Most research in this area has been conducted with visual stimuli. Thus, the goal of the present study was to test whether the processing of spatial affective prosody is modulated by the locus of spatial attention. Two-syllable pseudo-words spoken by two female voices in different emotional prosodies (neutral, happy, threatening, fearful) were presented at two spatial positions (left or right). Participants attended to one position and one voice only in order to detect infrequent deviant stimuli of the attended channels (named targets, p 5 .05). Emotional prosody was task-irrelevant. The EEG was recorded throughout the experiment in order to assess processing differences for task-irrelevant stimuli as a function of spatial attention and emotional valence of the stimuli. First, the well known enhanced negative ERPs to spatially-attended compared to spatially-unattended stimuli were replicated. ERPs to vocal stimuli differed as a function of emotional prosody both when spatially attended to and when spatially unattended to, although the effect of emotional prosody was not identical under both spatial attention conditions. Processing of emotional prosody, therefore, seems to take place outside the focus of spatial attention.

Poster 133

THE INFLUENCE OF PRIOR BELIEFS ON THE VISUAL BRAIN: EVIDENCE FROM EVENT-RELATED BRAIN POTENTIALS

Jasmin Kizilirmak1, Lars Behrmann1, Karl Wessel1,2, & Bruno Kopp1,2 1University of Technology Braunschweig, 2Braunschweig Hospital

Descriptors: shape-from-shading, visual search, light-from-above prior The nature of visual perception is still a matter of debate. Two contrasting theoretical approaches to visual perception are predominant: one consists of variants on the Helm-holtzian constructivist-inferential approach (e.g., Gregory 1993; Rock 1983; 1997); the other, of the ecological-direct approach (Gibson 1979). In direct theory, perception does not involve computations of any sort, whereas inferential theories of perception assume that prior beliefs influence visual perception. One of the best-known examples of a prior is the assumption that light is coming from above (Kersten et al., 2004). This assumption is particularly useful to disambiguate convex from concave shapes from shading information (Ramachandran, 1988; 2008). Spatial orientation of the shading gradient (vertical, horizontal), direction of the assumed light source (from above, from below / from left, from right) and set size (1, 2, 4 items) were manipulated in our multiple-target visual search study (Thornton & Gilden, 2007). As revealed by RTs, visual search was more efficient when stimuli were vertically shaded than when they were horizontally shaded. P3b amplitudes revealed that visual search of vertically shaded stimuli was less attention demanding than horizontal shading, particularly when the source ofthe assumed light was above of and left from the stimuli (Sun & Perona, 1998). These ERP results are the first EEG-based data to provide empirical evidence in favor of inferential theories of perception. Future studies will examine the replicability and the generality of our conclusion.

Poster 134

THE BRAINS OF PROBLEMATIC ONLINE GAME USERS SEEK STRONGER SENSATION: AN EVENT RELATED POTENTIAL STUDY ON PROBLEMATIC ONLINE GAME USERS

Wooyeol Shin, Junghyun Hahm, Joohan Kim, & Hae-Jeong Park Yonsei University

Descriptors: N2, problematic online game use, go/no-go

As online games have grown in popularity, many studies have focused on the essential features of these online games. The state of knowledge regarding online game using generally consists of case studies or phenomenological descriptions of excessive game playing, whereas neural investigations of the underlying mechanism of the users are missing. The authors assessed the event-related potentials of online game users during a Go/No-Go task. We attempted to investigate the N2 component of online game users who were assessed by the Problematic Online Game Use scale. Sensation seeking is considered to be a biological trait of excessive online game users associated with a need for novel experience. We considered that the No-go trials might function as novel experience during the task. The N2 component, which is generated by the no-go stimuli might be a marker of a specific neural trait of problematic online game users. As a result, the levels of problematic online game use reflected individual differences in the functioning of a neural mechanism related to activation against novel stimuli. The problematic online game user group and the control

group differed in their neural control, not their behavioral performance. The N2 amplitudes in the anterior cingulate cortex region produced by the problematic online game use group were significantly greater than those produced by the control group. Higher Problematic Online Game Use scores, thus, reflected stronger neural sensitivity to rare stimuli. We contend that greater N2 amplitudes might reveal the specific trait, sensation seeking, of problematic online game users.

Poster 135

EFFECTS OF ATTENTION ON BINOCULAR RIVALRY

Sandra Veser1, Robert P. O'Shea2, Erich Schroger1, & Urte Roeber1 'University of Leipzig, 2Southern Cross University

Descriptors: binocular rivalry, attention

Binocular rivalry causes perceptual awareness to fluctuate between two dissimilar monocular images. We investigated what happens when attention is completely withdrawn from binocular rivalry. We presented one grating to one eye and another to the other eye. The gratings could either be the same orientation, fusion conditions, or different orientations, rivalry conditions. Our events were transitions from fusion to fusion, rivalry to rivalry, fusion to rivalry and rivalry to fusion. We had two tasks. In one, observers had to report changes in perceived orientation, focusing their attention on the gratings. In the other, observers had to report changes in a fixation cross, taking attention away from the gratings. In both tasks we measured event-related potentials to the onset of either fusion or rivalry. We found evidence that rivalry does not only take place when rivalry stimulation was task-relevant but also when it was ignored supporting the notion that rivalry processing does not depend on attention. However, a larger N1-component for all transitions when attention is taken away from the gratings as compared to the same transitions when attention is on the grating indicates that the gratings were processed differently in the two tasks. This difference was especially large with rivalry to rivalry and rivalry to fusion transitions. We presume that the processing of the transition is more adapted when attention is on the gratings than when attention is withdrawn from the gratings. This is possibly due to an increase of perceptual alternations with attention.

Poster 136

EEG CORRELATES OF MEMORY MATCHING IN THE VISUAL WORKING MEMORY

Elisa M. Holz1, & Paul Sauseng2 1University of Salzburg, 2University Hospital Hamburg-Eppendorf

Descriptors: working memory

During recognition processes of visual working memory it can be necessary to match incoming sensory information with retained memory contents. This study aimed to investigate the underlying electrophysiological correlates of memory matching process based on EEG oscillatory phase synchronization analysis. Twenty-three healthy subjects completed a delayed match to sample task in which items stored in visual-spatial short-term memory had to be compared with match or non-match probe items. The results show that this matching process of top-down memory representation and bottom-up visual information is reflected by transient phase-synchronization over par-ieto-occipital regions between theta (4 - 8 Hz) and high gamma (50 - 70 Hz) oscillations 150-200 ms after probe presentation. Furthermore, non-matching of information demands higher cognitive resources for maintaining and manipulating memory representations with new object information as reflected in large-scale theta and gamma phase synchronization.

Poster 137

ORIGINAL MEANING OF FACIAL EXPRESSION MODULATES EVALUATION OF OUTCOME

Shun Itagaki, & Kazuo Hiraki The University of Tokyo

Descriptors: facial expression, feedback-related negativity (frn), evaluation of outcome When we see someone else's face, we naturally understand their emotional states, as we understand that negative events are related to angry faces, and positive events are related to smiling faces. This ability is developed by the typical experiences after our births. In this study, we focused on the evaluation of outcome in terms of the congruency between facial stimuli contained the meaning related to actual outcomes and not related to actual outcomes. Two experiments were conducted to investigate this issue based on the feedback-related negativity (FRN). The FRN is an ERP component which reflects whether the outcome is good or bad. ERPs were recorded during the alternative gambling task, and we associated face stimuli with Gain/Loss outcome. In experiment 1, we associated smile/angry face with Gain/Loss (congruent) and Loss/Gain (incongruent). The result showed that the FRN was elicited by the Loss feedback in both conditions. In addition, the FRN in congruent condition was elicited faster than incongruent condition. This result suggests that the association between expression and actual result affects the evaluation with a temporary dimension. In experiment 2, we associated female/male face with Gain/Loss and Loss/Gain as a control. The result showed that the FRN was elicited by ''Loss'' but also that there was no difference of the FRN between two

conditions in terms of latency. These results suggest that the congruency between the original meaning of a facial expression and actual outcome modulates the evaluation process. We conclude that socially acquired meaning offacial expressions have effects on evaluation.

Poster 138

EXPERIMENTAL ERP EFFECTS DO NOT COINCIDE WITH THE LARGEST AMPLITUDES OF COMPONENTS IN A VISUAL SEARCH TASK

Florian Strelzyk, Katja Bertsch, Thomas Emmerling, Anne Siebenbrock, & Ewald Naumann University of Trier

Descriptors: data exploration, effect .size, components

There are many established analysis approaches that use average amplitudes to statistically secure experimental effects in research involving event-related potentials (ERPs). The spatiotemporal attributes of these average amplitudes are, however, to a large degree dependent on criteria that are set by individual researchers. Using an innovative effect-size based exploration technique, we explored ERP data of a visual search paradigm and obtained an objective criteria that more precisely defines interesting spatial and temporal areas for the average amplitudes. In addition, our results suggest that the largest experimental effects must not coincide with the relative largest amplitudes of a given ERP component. For example, a P2 component had its largest amplitude at parietal recording sites, while the P2 effect was largest at frontal recording sites. These kinds of findings suggest that effect-size based data exploration can hold additional information when making decisions about the spatiotemporal properties of average amplitudes.

Poster 139

THE NEURAL RESPONSES TO FEEDBACK INFORMATION PRODUCED BY SELF-GENERATED OR OTHER-GENERATED DECISION MAKING: AN ERPS STUDY

Atsuhito Toyomaki, Yui Takahashi, & Tasukasa Koyama Hokkaido University

Descriptors: schizophrenia, feedback related negativity, sence of agency INTRODUCTION: Schizophrenia can involve a delusion of control that is an abnormal sensation of being controlled. In this delusion, one experiences one's feelings, impulses, thoughts, or actions as not one's own, but as being imposed upon him or her by some external force. The purpose of this study was to investigate the neural response to feedback information produced by self-generated or other-generated decision making. METHODS: Eleven schizophrenia patients and 11 normal subjects participated in present study. They performed gambling task. In the self-decision condition, participant himself had to choose to press a button for one of two options. In the other-decision condition, other person sitting next to the participant chose one oftwo options and later the participant was instructed to press the button according to decision made by other person. We measured event-related brain potentials to feedback stimulus and examined differences of neural responses in the self-decision condition and the other-decision condition. RESULTS: In normal subjects, the neural response to feedback stimulus was obviously different for the normal subjects across the self-decision and other-decision conditions compared to those of schizophrenia patients. The positive slow wave was larger in self-decision condition than in other-decision condition. On the other hand amplitude ofpositive slow wave in self-decision condition in schizophrenia patients was reduced significantly compared to normal subjects. DISCUSSION: The results demonstrated that schizophrenic patients show reduced neural response to feedback information produced by self-generated action.

Poster 140

THE RELATIONSHIP BETWEEN LOW-FREQUENCY BRAIN OSCILLATIONS AND RESPONSE VARIABILITY IN ADHD: A TWIN STUDY

Charlotte R. Tye, Jonna Kuntsi, Philip Asherson, Patrick Bolton, & Grainne

McLoughlin Institute of Psychiatry, King's College London

Descriptors: default-mode network, twin study

Response variability is a clear characteristic of ADHD, and several studies suggest it best discriminates ADHD cases from healthy controls in comparison to other performance measures. Increased variability in ADHD may arise from the inability to appropriately modulate very low-frequency oscillations that are observed when the brain is at rest or in 'default-mode'. Previous research suggests the role of'default-mode interference' in attentional lapses, which may lead to increased response variability, through the intrusion of low-frequency oscillations during cognitive activity. Using a high-density electrode cap, goal-directed activity was recorded using EEG during the completion of an Eriksen arrow flanker task. Fast-Fourier Transform (FFT) analysis

extracted a specific EEG frequency band, 'slow-3' (.06-.2 Hz), identified in previous studies to be stable and consistent with fMRI findings in terms of electrode location. Data was collected on 11 subjects as part of a larger sample of 66 twin pairs with high and low scores of ADHD. Phenotypic analysis suggests that there is a possible relationship between absolute power of low-frequency oscillations and both reaction-time variability (RTV; r 5 .50) and errors (r 5 .61), and that greater associations are observed on incongruent trials (r 5 .61; Error r 5 .74). These preliminary findings suggest the involvement of the default-mode in performance on cognitive tasks and response conflict processing. Ongoing investigation aims to examine the familial relationships between electrophysiological correlates and ADHD in a larger twin sample.

Poster 141

THE NEURAL MECHANISM OF LONG-TERM PERCEPTUAL LEARNING ON THE TEXTURE DISCRIMINATION TASK: AN ERP STUDY

Xiaoli Ma, Bin Yang, & Yan Song Beijing Normal University

Descriptors: neural mechanism, visual perceptual learning, ERP

It is well known that training on a task improves the performance possibly as consequence of neural changes that evolve over a period of several hours or several days. The position- and orientation-specific learning effect in the texture discrimination task (TDT) indicated that such learning occurred at early stages of visual processing, such as primary visual cortex (V1), which has been demonstrated by previous fMRI and ERP studies. But recent studies suggested that the higher-level brain areas might be involved in the TDT learning. In the present study, we recorded the high resolution electroencephalography from the whole-scalp sensor array to investigate the neural mechanism of the long-term perceptual learning on the TDT. Fifteen subjects were trained on the TDT in the upper visual field for six days and 128-channel EEG was recorded before each training session. Behavioral performance was improved and then saturated across the training sessions and maintained at a constant level fourteen days after training. The event-related potential results showed that the amplitude of C1, known to reflect V1 activity, was not significantly different across the training sessions. However, the amplitude of the frontal P2 component, from about 160 ms to 350 ms post-stimulus, decreased steadily and considerably with the training. Interestingly, this positive wave became negative fourteen days later. These findings indicated that the higher-level brain areas might be involved in perceptual learning and made even greater contribution to the learning.

Poster 142

THE REGULATION OF EMOTIONS IN ALEXITHYMIA: AN ERP ANALYSIS

Sarah A. Walker, Alexandre Schaefer, & Daryl B. O'Connor University of Leeds

Descriptors: emotion, alexithymia, event-related potentials

The reduced ability to regulate, identify and communicate feelings or emotions is primarily seen as the deficit named as alexithymia. Many studies have examined this individual difference trait, to try and understand this impairment in more detail, with the majority of researchers concluding that although participants with alexithymia are able to perceive emotional information, they are unable to process such information effectively. To specifically analyse the effects of such deficits on electro-cortical responses, 30 individuals who scored low, and 21 individuals who scored high on the Toronto Alex-ithymia Scale, were asked to interpret emotional images using a series of regulation tasks (suppress, reappraise and attend), whilst their brain potentials were simultaneously recorded. Overall, negative images were found to elicit larger late positive potentials (LPPs) as compared to neutral images in left parietal regions starting from 300 ms post-stimulus onset, and becoming more prominent after 500 ms. Although there was no main effect of regulation task, or a regulation task by image type interaction, there was a moderation effect dependent on alexithymia. That is, reappraisal was found to exert higher LPPs when viewing negative as compared to neutral images in high alexithymia only. This may indicate that reappraisal can cause an increase in cognitive effort when trying to evaluate emotional stimuli in those who find it difficult to process their emotions.

Poster 143

SERIAL ORDER AND ITEM MEMORY IN MONO- AND BILINGUALS

Kathrin Klingebiel1, Steve Majerus2, & Brendan Weekes1 1University of Sussex, 2University of Liege

Descriptors: serial order memory, item memory, bilingualism

Our aim was to investigate serial order and item memory in mono- and bilingual language processing. Hypotheses were that 1) memory for serial order would activate specific brain regions and therefore can be seen as an independent part of short term memory and 2) bilinguals rely more on serial memory as language consists of phonological sequences and language specific grammatical word order. Serial order and item

memory were compared using data from behavioral and EEG methods. Fifty participants (25 monolingual, 25 bilingual) were tested and bilingual language proficiency was assessed using a battery of tests. Behavioral responses and EEG was recorded from a 128 electrode EEG net continuously sampled at AD rate 1000 Hz/channel. Inter-electrode impedance was maintained below 50kOhm. EEG and EOG were amplified offline using a.05-30Hz band-pass filter. Trials with EOG artifacts exceeding the range of + 150 mVwere excluded, and the remaining trials were baseline corrected, average re-referenced and averaged for each condition separately across participants. We identified independent ERP components associated with serial order and item memory and showed significant differences between mono- and bilingual speakers. Our data support previous findings that memory for serial order is an important predictor of language processing.

Poster 144

OPERANT CONDITIONING OF ALPHA PATTERNS IN HUMAN EEG USING AFFECTIVE REINFORCING STIMULATION

Alexander Yu Zhigalov, & Alexander Ya Kaplan M. V. Lomonosov Moscow State University

Descriptors: operant conditioning, eeg alpha patterns, neurofeedback It is known that a person can voluntary manage their own EEG rhythms using contour neurofeedback. However, this management can not form a basis for operative interaction with an environment; interaction with an external world should be automated to reduce conscious cognitive load. Earlier, we showed that it was possible to exert unconscious control of computer monitor color by means of mutual reinforcement of EEG rhythms and RGB values (Kaplan, 2005). This means that EEG can be used as a tool for the selection of an emotionally positive external environment. In the present study, we examined whether the brain can manage events having negative emotionality by means of EEG. Each EEG alpha wave or groups of waves switched on intermittent light stimulation if they exceeded a certain threshold level. This light stimulation switched on a warning sound stimulus when the subject had avoided a negative reinforcement (a very unpleasant sound or skin electric stimulation). The subjects did not know that they could cancel negative stimulation by means of EEG. It was shown that after only four 8-min sessions in one day, more than 60% of examinees learned to change EEG in response to the warning stimulus to escape negative stimulation. Results suggest that there is an opportunity for operative manipulation of external objects by means of EEG.

Poster 145

APPLICATION OF THE P300 IN THE EVALUATION OF THE COGNITIVES FUNCTIONS OF PATIENT WITH ENDOGENOUS MONOPLAR DEPRESSION

Tania Acosta1, Consuelo Acosta2, & Sergio Veloz1 1Hospital Juan B. Zayas, 2Polic. 30 de Noviembre

Descriptors: P300, endogenous monopolar depression

Objective: To use the P300 event-related potential (ERP) to evaluate cognitive functions involved in Endogenous Depression. Methods: Eighteen patients diagnosed with Endogenous Depression (age range 30 to 66 years) were studied, and results were compared with matched healthy controls. Results: P300 obtains significant continuation of the latencies of all the components of this Potential, with decrease of the values means of interpeak interval width for the N200-P300 complex. The duration and interpeak interval width for the N200-P300 complex and P300-N3 complex did not differ between patients and controls. Conclusion: These results suggest that during the DEM a retard exists in the speed of the cognitive processing of the information and a decrease in the intensity of the attentives processes, being conserved the sincronia among the different generators of this potential. Significance: The registration of the P300 is useful to evaluate the cognitive functions in in those with DEM and it contributes elements of interest in the physiopatological interpretation of these dysfunctions.

Poster 146

DOES THE LATERALIZED READINESS POTENTIAL REFLECT IMPAIRED RESPONSE SELECTION IN SCHIZOPHRENIA?

David Moellers1, Bendedikt Reuter1, Lisa V. Kloft1, Juergen Gallinat2, & Norbert Kathmann1 1Humboldt University, Berlin, 2Charite - Berlin

Descriptors: lateralizedreadiness potential, n2pc, schizophrenia

Slowed reaction time has been consistently documented in research on schizophrenia. Here we follow the hypothesis that the slowing reflects a generalized deficit in response selection, including the activation of simple manual responses. Recent findings of increased onset latencies of the lateralized readiness potential (LRP) in schizophrenia patients might indicate a slowing of response selection processes but could also be due to delayed allocation of attention to imperative stimuli. In the present study with 20 schizophrenia patients and 20 matched healthy control subjects, we use a Simon-type spatial

compatibility task to simultaneously measure onset latencies of the LRP and the N2pc of the event-related potential waveform - an electrophysiological correlate of the focusing of attention. Preliminary data suggest that this methodology is suitable to dissociate impaired response selection from normal attention allocation processes in schizophrenia.

Poster 147

THE ROLE OF AFFECT REGULATION AS A RISK FACTOR FOR FUTURE ABUSE POTENTIAL

Cory A. Burghy, Daren C. Jackson, Narina Nunez, & Walt D. Scott Univeristy of Wyoming

Descriptors: emotion regulation, physical abuse, EEG

The ability to regulate affect and behavior imbues an individual with myriad ways to interact and cope with their environment throughout life. The effects of dysregulated affect are not only limited to the experience of the individual, but may spill over into the lives of family members, friends, and strangers. Of particular import, the potential for child abuse is also heightened as symptoms of psychopathology and parent discord increase. Within the maltreatment literature, researchers have sketched an image of the at-risk parent as someone who is distressed, has poor problem-solving or coping skills, and hyper-reactive. However, few studies have incorporated psychophysiological data to explore neurophys-ical mechanisms which may confer risk for perpetrating abuse. The current study will explore relations among the ability to effortfully modulate affect and risk for perpetrating physical abuse. Forty-five unselected undergraduates filled-out a questionnaire measuring abuse potential and completed a voluntary emotion regulation task where they were instructed to change their emotional responses to unpleasant pictures while ERP and EEG data were collected using a 128-channel geodesic sensor net. We hypothesize that those individuals who evidence higher abuse potential will have more trouble effectively suppressing unpleasant affect and may show electrophysical changes suggesting difficulties with affect regulation. Analyses are ongoing and source localization and ERP techniques will be used to interrogate task-related activation across the dlPFC, mPFC, and ACC.

Poster 148

INCENTIVES INFLUENCE ERROR DETECTION BUT NOT POSTERROR REMEDIAL ACTION FOLLOWING SLEEP DEPRIVATION

Shulan Hsieh1, Tzu-Hsien Li2, & Ling-Ling Tsai2 1Institute of Allied Health Sciences, National Cheng Kung University, 2National Chung Cheng University

Descriptors: error-related negativity (ern), sleep deprivation, post-error remedial actions The present study examined whether one night of total sleep deprivation would deteriorate error monitoring, including error detection and post-error remedial actions, and further examined whether the deterioration in sleep deprivation conditions, if found, would be counteracted by proving monetary reward. All participants performed a letter version of the flanker task on two mornings, one following a normal sleep night, and one following a sleep deprivation night, with a 1-week interval between and with a counterbalanced sequence of the two sleep conditions. Participants were divided into two groups, with one group (12 participants) receiving monetary reward depending on response correctness, and one group (12 participants) receiving no reward for their performance. The results showed that sleep deprivation was associated with deficits not only in error detection processing, as reflected on reduced error-related negativity, but also in post-error remedial actions. The effect of reward was shown to be able to counteract deficit in error detection processing, such that the amplitude of ERN could be maintained at the same level following sleep deprivation as that following normal sleep, however the effect of reward was unable to alleviate deficit in post-error remedial actions following sleep deprivation. The amplitude of Pe was demonstrated to be correlated to the efficacy of post-error remedial actions, such that the Pe amplitude was found to be reduced following sleep deprivation and could not be modulated by the presence of reward as shown in post-error remedial actions.

Poster 149

SINGLE TRIAL EEG AMPLITUDE PREDICTS SUBSEQUENT CHANGES IN HEART RATE WITHIN INDIVIDUALS - THE CARDIO ELECTROENCEPHALOGRAPHIC COVARIANCE TRACE

Erik M. Müller, Barbara Ahrens, Gerhard Stemmler, Maria Zangl, & Jan Wacker University of Marburg

Descriptors: P300, heart period, anxiety

The presentation of feedback stimuli evokes ERP components such as the feedback related negativity (FRN) or the P300 and also induces changes in heart period (HP). Because HP modulations, FRN and P300 have all been linked to frontocentral brain structures, they may be generated in overlapping regions or may even be functionally coupled. To investigate the relationship between EEG and HP, single trial EEG magnitude in varying time windows was correlated with HP changes across trials within individuals. The results can be visualized as cardio-electroencephalographic covariance traces (CECTs), which plot the height of intraindividual EEG-HP correlations as

a function of time window lag for both EEG and HP. In the present study participants (N 5 31) performed a gambling task while EEG and ECG were recorded. CECTs revealed that frontocentral EEG magnitude in the P300 window (200 - 400 ms post feedback) predicted feedback-related HP changes 2-5 s later. This effect was robust across individuals (p < .00001) and remained stable when controlling for potential influences of habituation and respiration. In addition CECT amplitudes in the time window showing maximal HP-correlations were associated with self-reported trait anxiety for negative, but not for positive, feedback. Results are discussed with regard to (a) an evaluation of the CECTmethodology, (b) temporal dimensioning ofcentrally triggered modulations of autonomous activity, and (c) recent models relating anxiety to neurovisceral connectivity.

Poster 150

EFFECTS OF SURPRISE AND ENTROPY ON BEHAVIOR AND EVENT-RELATED EEG IN THE ERIKSEN FLANKER TASK

Hilde T. Juvodden1, Heike Eichele1, Markus Ullsperger2, & Tom Eichele1 1University of Bergen, 2Max Planck Institute for Neurological Research

Descriptors: cognitive control, surprise, entropy

Recently fMRI and EEG signals that precede performance errors have been described. In order to further characterize this activity we investigate conditions where performance is parametrically modulated in order to test if and how error-preceding activity relates to external manipulations. Here, we report on results from an Eriksen flanker task where ratio of compatible to incompatible trials was modulated in five levels (9/1, 7/3, 5/5, 3/7, 1/9). EEG data were collected from 22 participants (13f, age 21.5 yrs) from 64 channels. The data were filtered, segmented, trials with paroxysmal artefacts were rejected, and independent component analysis (ICA) was used to remove stereotyped artefacts. EEG epochs were then wavelet denoised. The data from each channel and time point were predicted with a multiple linear regression model as a function of compatibility, estimates of the information theoretical measures surprise and entropy, as well as predictors coding for error trials, and response side. Behaviorally, error rate and reaction time to incompatible trials increased as these became more surprising/less frequent, and error-preceding trials showed decreased entropy and reaction times. In the stimulus-locked EEG data, compatibility, surprise, and entropy predicted central negativities in the N2-range with separable peaks from 280 - 350 ms post-stimulus. The results highlight the sensitivity of performance and event-related EEG to modulations of stimulus probability and information, which represent one source of error-preceding (mal —) adaptation of behavior and brain activity.

Poster 151

THE IMPACT OF WORKING MEMORY LOAD ON EEG MEASURES OF MENTAL EFFORT AND MOTIVATION DISPOSITION

Katie C. Ewing, & Stephen H. Fairclough Liverpool John Moores University

Descriptors: EEG, mental effort

Mental effort may be conceived in terms of computation (energy mobilization for cognitive tasks) or motivation disposition (decision to invest or withdraw task effort). The current study measured EEG oscillations in order to capture computational and motivational aspects of mental effort. Working memory load was manipulated using a verbal version of the N-back task using 6 different load levels, ranging from 1-back (easy) to 6-back (extremely hard). 18 participants completed the task after a pre-trial period of training. Performance and EEG activity was measured during task completion and subjective levels of motivation and workload were reported by participants. Results are given for performance and subjective data, EEG theta power, alpha suppression and hemispheric asymmetry. The results showed omnibus effects for load on anterior and parietal alpha suppression. No effect for load was found on theta power at midline frontal electrode sites, however load effects were found on theta power at anterior frontal sites. In this study hemispheric asymmetry metrics were calculated using conventional (7.5-13 Hz) and individualized alpha bands. Hemispheric asymmetry scores showed greater relative left activation at frontal-central and parietal sites for low and high load levels compared to baseline, hypothesized to reflect expectancy and approach motivation respectively. No effect was found for the highest load compared to baseline, thought to indicate reduced approach motivation due to overload. Results are discussed in relation to mental effort and motivation disposition.

Poster 152

IN THE EAR OF THE BEHOLDER: NEURAL CORRELATES OF ADAPTATION TO VOICE GENDER

Romi Zaske1, Stefan R. Schweinberger1, Jurgen M. Kaufmann1, & Hideki Kawahara2 1Friedrich Schiller University of Jena, 2Wakayama University

Descriptors: voice perception, auditory adaptation, N1/P2

While high-level adaptation to faces has been extensively investigated, research on behavioral and neural correlates of auditory adaptation to paralinguistic social information in voices has been neglected. Here we replicate novel findings that adaptation to voice gender causes systematic contrastive aftereffects such that repeated exposure to

female voice adaptors causes a subsequent test voice to be perceived as more male (and vice versa), even minutes after adaptation (Schweinberger et al., 2008). In addition, we recorded event-related potentials (ERPs) to test voices morphed along a gender continuum. A systematic attenuation in fronto-central N1-P2 amplitudes was seen whenever a test voice was preceded by gender-congruent voice adaptors. Additionally, similar amplitude attenuations were seen in a late parietal positive component (P3, 300-700 ms). These findings suggest that contrastive coding ofvoice gender takes place within the first few hundred milliseconds from voice onset, and is implemented by neurons in auditory association areas that are specialized for detecting male and female voice quality.

Poster 153

DISENTANGLING VALENCE AND AROUSAL EFFECTS DURING EMOTION WORD PROCESSING

Francesca M.M. Citron, Brendan S. Weekes, & Evelyn C. Ferstl University of Sussex

Descriptors: arousal, emotional valence, erps

Emotional content affects early processing of words. Scott et al. (2009) manipulated word valence and frequency in a lexical decision task (LDT) in an ERP study. They found P1 was greater for frequent positive and neutral words than frequent negative words and a reversed interaction at N1 with an early Posterior Negativity that was greater for valenced than neutral words. However, emotional arousal of stimuli was not manipulated. The aim of this study was to disentangle the effects of both valence and arousal. 28 English native speakers performed a LDT while EEG was recorded. 150 words (Citron et al., in press) were presented: 50 positive, 50 negative, and 50 neutral. Half of the valenced words were high (HA) and half low (LA) in arousal. EEG was recorded using a 128-channel Net (EGI, Eugene, Oregon). Impedance was kept below 50 k?. Sampling rate was 250 Hz. EEG was band-pass filtered between 0.3 and 40 Hz and segmented from 100 ms before to 1300 ms after stimulus onset. Segments were baseline corrected and re-referenced to the mastoids. Reaction times (RTs) showed main effects of valence and arousal and an interaction between arousal and valence.

Poster 154

THE EFFECT OF MOTIVATION IN BCI PERFORMANCE

Sonja C. Kleih1, Sebastian Halder1, Adrian Furdea1, Boris Kotchoubey1, & Andrea Kubler2

1Institute for Medical Psychology and Behavioural Neurobiology, University of Tiibingen,2University of Wurzburg

Descriptors: BCI, motivation, ALS

People with amyotrophic lateral sclerosis (ALS) lose their motor activity and so their ability to talk in the course of their disease. Brain-Computer Interfaces (BCIs) provide an alternative communication channel because they rely on brain signals and are muscle independent. However, individuals differ in their ability to use a BCI. To investigate the relevance ofpsychological influencing variables such as motivation in patients with ALS this study examined the relation between motivation and the ability to learn using a BCI and the P300 amplitude measured within a BCI controlled by event-related potentials (ERP). Motivation was manipulated with a 20 Euro gift certificate for an internet store. In the first run twelve ALS patients spelled a 14 character sentence without receiving a reward. In the second run they were promised a gift certificate for trying particularly hard to spell the sentence correctly. Motivation was assessed with a BCI-adapted questionnaire and a visual analogue scale. BCI performance was defined as the overall percentage of correctly selected characters (correct response rate 5 CRR). Three patients were not able to finish the session and were excluded from analysis. Average CRR across all runs and patients was 93%; four patients had a CRR of 100%. The gift certificate did not affect motivation but BCI performance. We found a trend for CRR being higher after motivation (96%) than before motivation (89%, Z 5 — 1.84, p 5 .07). The results indicate that motivation may explain some of the variance in BCI performance and should be monitored in BCI settings.

Poster 155

SEX DIFFERENCES IN MENTAL ROTATION: HEMISPHERIC LATERALIZATION EFFECTS

Julia Pellkofer, & Martin Heil Heinrich-Heine-University Duesseldorf

Descriptors: EEG/ERP

Mental rotation can be investigated in paradigms, in which a parity judgment decision is required after mentally rotating an object. A larger angular disparity between a rotated and an upright version of a stimuli goes along with longer RTs and more negative ERPs. This is called the mental rotation effect (MRE). RT data usually reveal that men outperform women. This effect might be traced back to the hemispheric lateralization account, i.e. women prefer an analytic way of mentally rotating - involving more likely the left hemisphere -, while men use a rather holistic strategy - involving more likely

the right hemisphere. The recent study investigated the effects of sex on the MRE. In a two-alternative forced choice task two-dimensional polygons were used as stimuli. Two polygons were presented side by side on the screen with an angular disparity of 30, 90 or 150 degrees in a clockwise or counterclockwise direction. Participants (N 5 51) had to perform a parity judgment decision after they had mentally rotated the stimuli. RT data and ERPs from 32 electrode locations were recorded. RTs were significantly faster for males than for females. ERP analyses revealed a parietal distribution of the MRE as a function of angular disparity. Women showed the MRE as a function of angular disparity in the P300 time frame at left-parietal electrode position P7, while men showed the same effect at the right parieto-temporal electrode position TP10. These lateralization effects are in line with the hemispheric lateralization accounting for sex differences during mental rotation.

Poster 156

MOVEMENT-RELATED CORTICAL POTENTIALS AND PERCEPTION OF EFFORT DURING EXERCISE

Helma M. de Morree, Samuele M. Marcora, & Christoph Klein Bangor University

Descriptors: effort, movement-related cortical potentials, exercise It has been speculated that increases in movement-related cortical potentials (MRCPs) with increasing workload and muscle weakness are related to effort. However, MRCPs have never been measured together with ratings of perceived effort and most studies have tested finger or hand movements. This study tested the feasibility of investigating the neurophysiology of perceived effort by recording MRCPs during exercise with larger muscle mass. Perceived effort was manipulated by varying the load (0, 2, and 4 kg) around the ankle during blocks of 50 dynamic leg extensions. Extension and flexion phases were indicated by 2 beeps (1 s apart); lifts were separated by 4 s rest. In task 2, perception of effort was increased over time by repeating the 2 kg lift 150 times. EEG was recorded from 64 channels with a DC amplifier (BrainProducts, UK) at 2500 Hz with a DC-1000 Hz band-pass filter. The electromyogram (EMG) was recorded from the thigh (vastus lateralis). Participants rated their perceived effort (RPE) on a CR-10 scale (Borg, 1998) after every 10 trials. After an independent component analysis (ICA) to reduce eye movement, eye blink and skin potential artifacts, EEG was time locked to the EMG onset and average amplitudes of early Bereitschaftspotential (early BP;

_ 1500--650 ms), late BP (_ 650-0 ms) and motor potential (0-1000 ms) were

calculated. Preliminary data suggest that it is feasible to measure MRCPs during exercise with a large muscle mass and that changes in MRCPs are associated with changes in perception of effort induced by increasing load and time on task.

Poster 157

NEUROPHYSIOLOGICAL SUBSTRATES OF BEHAVIORAL FLEXIBILITY: AN ERP STUDY

Liesel-Ann C. Meusel1, Marc D. Lewis2, Connie A. Lamm3, & Isabela Granic4 1McMaster University, 2University ofToronto, 3Hunter College, The City University of New York, 4Hospital for Sick Children

Descriptors: emotion regulation, EEG/ERP

Normal development relies on the ability to effectively regulate emotions, and children lacking these skills often develop serious behavioral and interpersonal problems. Emotion regulation skills are acquired within the context of parent-child interactions, where emotional flexibility (i.e., the capacity to move across emotional states according to the contextual demands of the interaction), may reflect emerging emotion regulation capacities. Using a sample of children clinically referred for aggressive behavior problems, we examined the association between flexibility in parent-child interactions during a problem-solving discussion, and amplitude of the N2 — an ERP component linked with self-regulation. Dyadic interactions were measured using state space grid analysis, a graphical tool based on dynamic systems principles that quantifies behavioral interactions based on movement across a field of behavioral states. Dense-array EEG data were collected during an emotional Go-Nogo task, and N2 amplitudes were measured 200 -400 ms post-stimulus. Results showed that children with lower flexibility scores showed significantly smaller N2 amplitudes and significantly higher scores on clinical measures of emotional problems, such as depression. These results may reflect decreased recruitment of frontal control systems necessary to regulate negative emotions. Furthermore, these findings suggest that children with the most serious behavior problems may have the poorest emotion regulation capacities.

Poster 158

UNDETECTED ERROR COMMISSION AFTER TASK-SWITCHING

Koki Ikeda, & Toshikazu Hasegawa The University of Tokyo

Descriptors: task switching, ERN

Causes of behavioral error can be classified into three types; internal noise, external interference (e.g. Stroop task), and goal setting. The last type of error may slip through

the supervisory top-down control, because it is generated from the ''top'' end of the system. Behavioral studies have suggested that the error rate increase after task-switching might be generated in this way (Altmann & Gray, 2009; Ikeda & Hasegawa, 2009). This study provides neural evidence for this hypothesis, utilizing the response-locked ERN, an ERP component of error generation. In the randomized-runs task-switching procedure paradigm, the ERN amplitude was significantly attenuated after task-switching compared with task-repetition, suggesting that error was not efficiently detected by the error (or conflict) monitoring system in the brain. Implications for the cognitive models of task-switching and cognitive control will be discussed.

Poster 159

EXAMINING THE NEURAL SUBSTRATES OF THE AFFECTIVE PRIMING EFFECT

David R. Herring, Stephen L. Crites, Jennifer H. Taylor, Guadalupe Corral, Katherine R. White, Nazy Heydarian, Laura Zambrano-Vazquez, & Yvette Guereca University of Texas at El Paso

Descriptors: affective priming, erps, LPP

Studies focusing on semantic/associative priming find that when primes are presented that are congruent with the target (e.g., GRAPE: JELLY), reaction times are quicker compared to when primes are incongruent (e.g., SHOE: JELLY) with the target. Also, the N400 peak amplitude of the ERP is more negative when pairs are incongruent than congruent (Kutas & Federmeier, 2000). Collectively, these findings suggest spreading activation as a mechanism involved. The affective (or evaluative) priming literature has established similar behavioral findings, yet the electrocortical signals involved with these effects remain unclear. Twenty-six participants were exposed to affectively congruent (unpleasant-unpleasant, pleasant-pleasant) and affectively incongruent (unpleasant-pleasant, pleasant-unpleasant) picture pairs via the International Affective Picture System (IAPS) in an affective sequential priming paradigm. Participants assessed the target valence and indicated whether it was pleasant or unpleasant while electroencephalo-graphic data were recorded. The mean peak amplitudes of the N400 for congruent (_ 2.61 mV) and incongruent (_ 2.57 mV) conditions were not significantly different. These data, however, revealed a significant effect of congruence (p 5 .001)fora late positive potential (LPP), such that affectively incongruent pictures pairs elicited a larger (more positive) LPP peak amplitude (M 5 6.04 mV) than congruent picture pairs (M 5 5.25 mV). The current study may add insight into the process models for the affective priming effect.

Poster 160

DETECTION AND COMPENSATION OF RESPONSE SELECTION DIFFICULTIES: SIMON VERSUS FLANKER CONGRUENCY EFFECTS

Karen L. Mansfield1, Geert J.M. Van Boxtel1, & Maurits W. Van der Molen2 1Tilburg University, 2University of Amsterdam

Descriptors: N2, simon, flanker

Behavioral stimulus-response congruency effects are similar for irrelevant stimulus locations (Simon effect), and noise stimuli (Flanker effect). In Event Related Potentials (ERPs), Simon effects at N2 are often response-locked, but visual asymmetry evokes large deflections in stimulus-locked Lateralized ERPs (L-ERPs). Flanker effects are as early as stimulus-locked N2, despite little asymmetry in L-ERPs. This dissociation suggests that Flanker effects are incurred during stimulus processing, but Simon effects during response selection. We employed behavioral and ERP measures to make a direct comparison between Simon and Flanker effects, using arrow stimuli in neutral, congruent, and incongruent conditions. Performance results revealed the expected similarity in congruency patterns for Simon and Flanker effects, with slightly larger effects for incongruent noise than for incongruent locations. Both incongruent noise and locations delayed P3, but it was incongruent locations and not noise that enhanced the stimulus-locked N2. This appeared to reflect incorrect-side activation found in stimulus-locked L-ERPs for incongruent locations, but not for incongruent noise. The combined results for incongruent Simon stimuli, with larger asymmetries in L-ERPs, an enhanced stimulus-locked N2, but smaller performance deficits, suggests that N2 not only reflects detection of incongruent stimulus locations, but also serves a function in reducing resulting response selection difficulties. N2 appears less involved in compensating for incongruent Flanker stimuli.

Poster 161

DOES MMN AMPLITUDE VARY WITH DEVIANT PROBABILITY? NEGATIVE FINDINGS USING PATTERNED AUDITORY STIMULI

Lauren D. Sculthorpe, & Kenneth B. Campbell University of Ottawa

Descriptors: mismatch negativity, auditory, sensory memory

The mismatch negativity (MMN) is an ERP that signals the detection of change in the auditory modality. It is classically obtained in the oddball paradigm, in which

a train of identical standard stimuli is interrupted at rare and unpredictable times by a deviant stimulus with some changed feature, often tonal frequency. The MMN is thought to reflect the outcome ofa comparison between an incoming deviant stimulus and the memory representation of the standard, and its amplitude is thought to vary directly with the strength of the memory for the standard. This relationship was established in part by studies showing a negative correlation between MMN amplitude and deviant stimulus probability. An alternative interpretation for this probability effect, however, is that it results from differential refractoriness in the afferent neuronal populations responding to the standard and deviant frequencies of the frequency oddball paradigm. The current study examined the effect ofprobability on the MMN using a standard pattern in which two pure tones alternated (A-B-A-B-A-B-). Deviants were physically identical to the standards, but violated the rule of alternation (A-B-A-B-B-B-). In different conditions, this repetition deviant was presented at a rare (p 5 .02), low (p 5 .04), moderate (p 5 0.08), or high (p 5 0.16) probability. Contrary to the results of standard oddball paradigms, probability had no effect on the amplitude of the MMN (F < 1). These results call into question whether the amplitude of the MMN should be used to assess the integrity of auditory sensory memory.

Poster 162

ALPHA ACTIVITY ERD IN THE VISUAL SEARCH TASK

Natalia S. Yermachenko1, Alexander A. Yermachenko2, & Alexander V. Latanov1 1Moscow State University, 2Modern University of Humanities

Descriptors: eye tracking, EEG, ERD

Nowadays eye movements (EM) are usually recorded by the video eye tracking (ET) technology. It is widely used for EM pattern analyses during complex image scanning but usually not with simultaneous EEG recording. EEG dynamics is traditionally considered to indicate processes related to visual task performance. By EEG and ET synchronization we marked out the short EEG epochs concurrent with the moment of finding the RS and analyzed ERD dynamics. We studied the alpha band ERD induced by finding a nonverbal relevant stimulus (RS) among about fifty nonverbal irrelevant ones in a visual search task paradigm. Subjects were instructed to find the RS and fixate gaze on it for a couple of seconds. After each test trial the subjects were asked to fixate on the four RS that were exposed and angular points of rectangle (control session). The gaze fixation on RS was verified by ET. The finding of RS in test trials induced the ERD 2-2.5 times greater and longer than in control trials for all leads. ERD was better exposed in frontal leads in test trials, and in occipital leads in control trials. We suppose that mostly bottom-up attentional processes were involved in control task, as occipital ERD was expressed better. The visual search task performance additionally involves the top-down attentional process that is proved by better expressed ERD in all leads, especially in frontal leads. We suppose that ERD features and spatial distribution to indicate the different attentional processes' contributions to different task performances.

Poster 163

INTERACTIONS BETWEEN LANGUAGE AND ATTENTION SYSTEMS: EARLY AUTOMATIC LEXICAL ACCESS?

Yury Shtyrov1, Teija Kujala2, & Friedemann Pulvermuller1 1MRC Cognition and Brain Sciences Unit, University of Cambridge, 2Cognitive Brain Research Unit, University of Helsinki

Descriptors: early language time course, attention, memory circuits, EEG, ERP, MMN, N400

An ongoing debate is whether, and to what extent, access to cortical representations is automatic or dependent on attentional processes. To address this, we modulated the level of attention on auditory input, and recorded ERPs elicited by syllables completing acoustically matched words and pseudowords. Under non-attend conditions, the word-elicited response (peaking at ~ 120 ms) was larger than that to pseudowords, confirming early activation of lexical memory traces. However, when attention was directed towards the auditory input, the word-pseudoword difference disappeared. Whereas responses to words seemed unchanged by attentional variation, early pseudoword response was significantly modulated by attention. Later on, attention modulated a positive deflection at ~230 ms and a second negativity at ~370 ms for all stimuli. The data indicate that the earliest stages of word processing are not affected by attentional demands and may thus be automatic, with attention effects on lexical processing accumulating after 150-200 ms. These findings may be explained by the robustness of pre-existing memory networks for words whose strong internal connections guarantee rapid full-scale activation irrespective of the attentional resources available. Conversely, the processing of pseudowords, which do not have such stimulus-specific cortical representations, appears to be strongly modulated by the availability of attentional resources, even at its earliest stages. Topography analysis and source reconstruction indicated that left perisylvian cortices mediate attention effects on memory trace activation.

PARALLEL RESPONSE ACTIVATION AND INHIBITION AS ASSESSED WITH THE LATERALIZED READINESS POTENTIAL (LRP)

Emily S. Kappenman, & Steven J. Luck University of California, Davis

Descriptors: LRP, response selection

The lateralized readiness potential (LRP) is an important tool in the study of response selection processing. Typical LRP paradigms use lateralized motor responses to isolate the LRP difference wave, which provides a measure of the difference in activation between a correct response and an incorrect response. Separately isolating the activation and inhibition of the correct and incorrect responses as they unfold parallel in time would greatly supplement our knowledge of response selection processing. We provide a detailed description of new methods that utilize approaches related to experiment design in order to separate activation and inhibition of correct and incorrect responses as they unfold over time. In Experiment 1, correct and incorrect response activation and inhibition are isolated through the use of a go/no-go task. These results are replicated in Experiment 2 with a two-alternative choice design that incorporates a bilateral eye blink response. Applications of this new method to the understanding of basic cognitive processes and cognitive dysfunction in schizophrenia will also be explored.

Poster 165

POST-ERROR AND ERROR-PRECEDING ERPS IN ADHD

Jan R. Wiersema Ghent University

Descriptors: ADHD, ERP, error monitoring

Introduction: Studies reporting reduced post-error slowing in children with ADHD have suggested impaired error monitoring in ADHD. Recently, event-related potential (ERP) studies have provided support for this hypothesis. A smaller Error positivity (Pe), indicative of diminished error awareness, is the most reported finding in ADHD although aberrant Error-related negativity (ERN; error detection) generation has also been noted (for an overview see Wiersema et al., 2009). In the current study, we examined whether in children with ADHD errors are foreshadowed in brain activity prior to errors. More specifically, a larger Error-preceding positivity (EPP; Hajcak et al., 2005) was expected in children with ADHD, indicative of enhanced disengagement of the performance monitoring system. Method: A flanker task was used. ERPs were compared between 19 children diagnosed with ADHD and 19 age- and IQ-matched typically developing children. Results: Children with ADHD showed normal ERNs but smaller Pe amplitudes. Children with ADHD also differed in brain activity on the trial directly preceding an error, mirrored in a larger EPP. Conclusions: The smaller Pe in children with ADHD indicates diminished error awareness. In addition, errors were foreshadowed in children with ADHD on the trial directly preceding an error, suggestive of increased transient deficiencies in functioning of the monitor system prior to actual execution of an error.

Poster 166

FULLY SIMULTANEOUS ACQUISITION OF SLOW CORTICAL POTENTIAL CHANGES AND FUNCTIONAL MRI AT 3 TESLA

Florian P.S. Fischmeister1,3, Veronika Schopf2, Christian Windischberger2, Ewald Moser2, & Herbert Bauer3 1MR Center University of Vienna, 2Medical University of Vienna, 3University of Vienna

Descriptors: concurrent eeg/fmri, slow cortical potentials

Simultaneous acquisition of EEG and fMRI data causes severe artifacts in EEG recordings. In the case of SCPs, representing changes in the frequency range below.5 Hz, existing artifact reduction methods fail since they modify the DC level. Here we show an approach that allows adequate artifact compensation for SCP experiments based on refined EEG methodology enabling for simultaneous SCP and fMRI data acquisition. A slowly rotating propeller was presented 40 times for 8 s with a 7 s black screen ISI. In order to verify the EEG setup and methodology, this paradigm was performed three times, outside and inside of the scanner, with and without simultaneous fMRI acquisition. EEG was recorded using an MR compatible EEG amplifier (NeuroConn, Germany). Imaging and pulse artifacts were corrected on-line using an adaptive template matching algorithm. Single trial signals were low-pass filtered and averaged using a 500 ms baseline. Images were acquired on a 3 Tesla Trio system (Siemens, Germany). Activity in occipital areas was perfectly visible in all SCP recording runs. Clear negative SCPs were easily depicted with slightly smaller amplitudes within the scanner and during the fMRI acquisition. fMRI results showed activation in the middle occipital gyrus. We have shown that simultaneous acquisition of SCP and fMRI data results in comparable SCP time courses and topography. Since SCP changes and the BOLD signal show high positive correlations, our approach allows to simultaneously investigate endogenous fluctuations of cortical excitability within functional systems.

AGE EFFECTS ON EVENT-RELATED POTENTIAL AND CARDIOVASCULAR ACTIVITY IN A WORKING MEMORY TASK

Sergei A. Schapkin, & Gabriele Freude Federal Institute for Occupational Safety and Health

Descriptors: aging, ERP, memory

Age-related impairments of working memory (WM) may cause problems in older employees who are occupied with complex work. Older employees were hypothesized to engage in controlled processing associated with frontal brain regions to prevent performance decline when they have to cope with WM load; in turn, enhanced frontal activity can negatively affect cardiovascular reactions to WM load. 21 younger (28 + 3 years) and 21 older (54 + 3 years) employees had to perform visual 0-back and 2-back tasks. EEG, ECG, and beat-to-beat blood pressure were registered. In the 2-back task older employees responded slower and less accurately than younger employees, while no age effects in the 0-back task were observed. Target P3 of the event-related potential (ERP) was progressively reduced from parietal to frontal sites in the younger group, while more evenly distributed P3 upon the scalp in the older group was found. Older employees showed a prolonged P3 latency and an enhanced level of cardiovascular activity throughout conditions as compared with younger employees. Lower re-sponsivity of baroreflex, heart rate, and heart rate variability to task demands and a delayed cardiovascular recovery was found in older relative to younger employees. Results suggest that increased WM load in older employees can impair target categorization and lead to compensatory involvement of frontal lobes to enhance controlled processing and mental effort. In turn, the increase in frontal activity may induce maladaptive functioning of cardiovascular system potentially due to age-related reduction in vagal tone.

Poster 168

ERP MARKER OF EMOTION REGULATION: AN INDIVIDUAL DIFFERENCE STUDY

Connie Lamm, & Tracy Dennis Hunter College, The City University of New York

Descriptors: emotion regulation, n2 activation, individual differences Learning to regulate our emotions is one of the most important skills we learn. One strategy frequently employed is suppression. Individual differences in the use of suppression as an emotion regulation strategy have been linked with poor cognitive performance potentially due to increased cognitive load. In the present study, we examined this possibility by testing whether individual differences in suppression were related to a neural measure of efficiency in conflict monitoring. The N2 is an ERP found 200 to 400 ms after stimulus onset. It is enhanced to high vs. low conflict stimuli. The N2 difference score (incongruent - congruent) is thought to reflect efficient recruitment of cognitive control to monitor conflict. That is, larger difference scores indicate cognitive efficiency in that more resources are being devoted to monitoring high versus low conflict. The N2 was measured for 52 undergraduate students using a flanker task. Participants were classified as low suppressors (LS) or high suppressors (HS) based on a mean split. Accuracy and reaction time analyses revealed no group differences. Analysis of the N2 difference scores revealed a main effect of group, F(1,48) 5 6.96, p 5 .01, with the LS group showing greater difference scores. Thus, as predicted, the LS group is showing greater efficiency by reducing cognitive load for low conflict trials. The HS group may instead encumber a greater cognitive load across both low and high conflict contexts, although this did not compromise performance. Implications for long-term use ofsup-pression in daily life are discussed.

Poster 169

DIPOLE PARAMETER ESTIMATION OF M50 AUDITORY EVOKED FIELDS APPLIED TO THE STUDY OF TRAINING-INDUCED NEUROPLASTICITY IN SCHIZOPHRENIA

Todor Iordanov, Tzvetan Popov, Christian Wienbruch, Thomas Elbert, & Brigitte Rockstroh University of Konstanz

Descriptors: MEG, asymmetry, schizophrenia

In a first step three different methods for dipole localization of M50 auditory sources evoked by the double click paradigm were compared in order to differentiate between 12 schizophrenic patients (1 female) and 10 controls (1 female). Dependent variables were sensory gating ratios (dipole moment ofthe magnetic counterpart ofclick two divided by click one) and hemispheric asymmetry (left vs. right hemispheric dipole location). MEG was measured using a 148 channels magnetometer system. Dipoles were fitted using (1) a spherical head model with 34 MEG channels over the left and right temporal lobe, respectively, (2) a spherical head model with 68 MEG channels over both temporal lobes, (3) a boundary element model (BEM) based on an averaged magnetic resonance imaging (MRI) dataset (using 68 MEG channels). Differentiation between patients and controls for both gating ratios and anterior-posterior asymmetry was most precise when dipole moments were calculated with the BEM model. Thus, in a second step, the BEM method

was used to investigate changes across 4 weeks, during which patients completed a cognitive training program. In patients, gating ratios were decreased after training but no changes in the asymmetry were noticed. Stability of measures was confirmed in controls.

Poster 170

OXYTOCIN AN CORTICAL ACTIVITY: THE INFLUENCE OF INTRANASAL OXYTOCIN ON EEG ALPHA FREQUENCY

Nicolas Hardung, Markus Quirin, Miguel Kazeen, Anja Fiedler, & Julius Kuhl University of Osnabrück

Descriptors: oxytocin, needs, motivation

Background: Oxytocin facilitates social cognition and interpersonal behavior but little is known about the neural underpinnings of oxytocin effects. The present study investigates direct effects of intranasal oxytocin on electroencephalographic (EEG) alpha frequency as a measure of reduced resting cortical activity. Methods: In a double-blind study, twenty-four healthy male students were randomly assigned to receive 24 IU oxytocin intranasally or placebo. Resting EEG based on the 10-20 system was measured immediately before and 50 minutes after oxytocin application, for 8 minutes each. Results: Oxytocin led to significant increases of activity (alpha reductions) in the right frontal and right parietal cortex. The findings are in line with evidence on the involvement of the right prefrontal and right parietal cortex in social cognition and empathy and thus suggest that activity in these areas may mediate the effects of oxytocin on social cognition and prosocial behavior found in previous research. Additionally, oxytocin led to significant increases of bilateral activity over the occipital cortex. Conclusions: The results are discussed with respect to a right-hemisphere bias in prosocial and affiliative functions and with respect to their relevance for neuropharmacological treatment of psychiatric disorders.

Poster 171

DISTINGUISHING THE RELATIONS BETWEEN SELF-EFFICACY, PERSONALITY, AND INDICES OF ACTION MONITORING

Jason R. Themanson1, Peter J. Rosen1, Michael J. Cunningham1, Aaron B. Ball1, Brandon M. Clark1, Matthew B. Pontifex2, Charles H. Hillman2, & Edward McAuley2 1Illinois Wesleyan University, 2University of Illinois, Urbana-Champaign

Descriptors: error-related negativity, self-efficacy, action monitoring Previous research indicates that both self-efficacy (i.e., beliefs in one's capability to successfully complete a course of action) and personality are related to the amplitude of the error-related negativity (ERN) as well as behavioral indices of action monitoring. However, given the known relationships between self-efficacy (SE) and multiple personality traits, it is unclear whether these associations with action monitoring are unique or part of a larger common construct. To assess this issue, we examined the relationships between SE, a five-factor personality model, and behavioral and neural indices ofaction monitoring for 59 young adults during the completion of a flanker task. Results indicated higher levels of SE and Intellect/Openness were independently associated with larger ERN amplitude. Further, larger ERN amplitude was associated with higher posterror accuracy, even after controlling for overall response accuracy as well as the relationships post-error accuracy had with IQ and Emotional Stability. These findings suggest that SE and personality provide unique and discriminating insights into the factors underlying the function of the ERN and action monitoring system, and are not simply examples of redundancy evidenced from a common core factor. Further, although individual difference variables may be able to account for some variation in posterror behavior, the cognitive processes relating the ERN and corrective behavioral adjustments are distinct from these characteristics and traits.

Poster 172

PERCEPTUAL CUES MODULATE RESPONSE CUE EFFECTS ON FRONTAL N200 AMPLITUDE AND RESPONSE ACTIVATION

Thorsten Albrecht, & Uwe Mattler University of Gottingen

Descriptors: combined expectancies, perceptual conflict, response activation When participants use cues to prepare for a likely stimulus or a likely response, reaction times are facilitated by valid cues but prolonged by invalid cues. When two cues independently give information regarding two dimensions of the forthcoming task, cueing effects regarding one dimension can be reduced when the cue regarding the other dimension is invalid. According to the Adjusted Expectancy Model, cues affect different processing levels and a mechanism is presumed which is sensitive to the validity of cues for early level processing and leads to an online adjustment of cueing effects at late levels ofprocessing. Therefore, response activation and response conflict should be modulated by perceptual cues. Here we used two-level stimuli in a speeded two-choice reaction time task. Participants reported the target stimulus, which could occur either at the global or local level of the two-level stimulus. Prior to each target stimulus two cues announced the likely level of the target stimulus (global vs. local) and the likely response (left vs. right). Electrophysiological measures confirmed the model. The effect of response cues

on the lateralized readiness potentials (LRP) was modulated by the validity of stimuluslevel cues. The N200 amplitude was used to measure conflict. N200 amplitudes were similarly increased in trials with any one invalid cue compared to trials with two valid cues. Findings suggest measures of N200 amplitudes reflect stimulus and response related conflict.

Poster 173

STRUCTURING THE INTER-INDIVIDUAL VARIATION IN WAKING EEG FOR DISCRIMINATION BETWEEN THE OBJECTIVE MARKERS OF SLEEP DEBT AND SLEEP PRESSURE

Arcady A. Putilov, Olga G. Donskaya, Evgeniy G. Verevkin, & Mark B. Shtark Research Institute for Molecular Biology and Biophysics

Descriptors: sleep deprivation, sleepiness, waking eeg

Modern society is characterized by the steadily increasing demand for wakefulness at all hours of the day. The psychophysiological research can offer the instruments enabling the quantitative differentiation of people with such advantageous traits as little need for sleep, decreased sleepiness associated with sleep loss, and rapid adaptation to the alternations of the work-rest schedule. Our aim was to assess, inter-individually, the association of the waking EEG structure with the response of sleep-wake regulation to sleep loss. Resting EEG was recorded 9 times at 3-hour intervals with eyes closed and eyes open in the course of sustained wakefulness of 130 healthy subjects. The ipsatized power densities were calculated from the log-transformed absolute powers averaged across 10 frequency ranges (from slow delta to slow gamma). These spectra were further reduced by performing the principal component analysis that yielded the subjects' scores on the largest principal components (PCs). It was found that any EEG spectrum can be represented by only three scores on the PCs with eigenvalues greater than 1. The PCs remained virtually invariant in terms of the order of their extraction and loading patterns which signify EEG amplifying (1st), EEG slowing (2nd), and EEG smoothing (3rd). In the course of wakefulness, the 1st PC score showed a link with sleep deprivation (i.e., the self-reported sleep restriction in the morning preceding the experiment), while the 2nd PC score was associated with sleep pressure (i.e., the perception of increased sleepiness caused by sleep deprivation).

Poster 174

EARLY CORTICAL RESPONSES CORRELATE WITH SUBSEQUENT VISUAL EXPLORATION

Hiroshi Nittono, & Junko Ishiguro Hiroshima University

Descriptors: anterior n2, novelty, viewing duration

Exploring novel objects is a common tendency of human beings and animals. In a free viewing task in which participants were asked to view novel drawings as long as they wished, a larger anterior negativity (N2) of the event-related potential (ERP) peaking around 250 ms was elicited by the longer-viewed drawings than by the shorter-viewed drawings (Nittono, et al., 2007). This finding suggests that the anterior N2 is sensitive to stimulus unfamiliarity or difficulty in encoding and that its elicitation triggers further recognition processes. However, because the drawings used in the previous study varied greatly in brightness and complexity, such physical differences may explain the observed ERP differences. In the present study, a modified replication experiment was conducted by using black-and-white polygons with 24 sides. The polygons were identical in size and were similar to those used in past visual exploration experiments. Sixteen university students viewed 80 novel polygons for as long as they wished. ERPs were recorded from 38 scalp electrodes and averaged separately for polygons that were viewed for longer or shorter than the median viewing time of each participant. As predicted, longer-viewed polygons (mean 3.4 s) elicited a larger anterior N2 than shorter-viewed polygons (mean 2.0 s). This result suggests that the anterior N2 elicited by visual objects is an endogenous ERP component that reflects psychological processes.

Poster 175

NEUROPLASTICITY-BASED TRAINING MAY NORMALISE AUDITORY GATING IN SCHIZOPHRENIA AND IMPROVE VERBAL PROCESSING

Tzvetan Popov1, Todor Jordanov1, Gregory A. Miller2, Thomas Elbert1, Michael M. Merzenich3, & Brigitte Rockstroh1 1University of Konstanz, 2University of Illinois, Urbana-Champaign, 3University of California, San Francisco

Descriptors: auditory gating, MEG, schizophrenia

An unusually large response ratio in the auditory paired-click task is a common finding for schizophrenia patients. In the present magnetoencephalographic (MEG) paired-click design, sensory gating ratio (SGR) served to study effects of computer-based cognitive exercises (CE, Posit Science, SF), which emphasizes auditory discrimination and verbal memory, with the aim of improving signal-to-noise ratio of auditory/verbal

processing in schizophrenia. Across 100 paired-click trials, M50 was scored as peak amplitude of the magnetic field 40 - 80 ms post S-onset; SGR were determined in source space (activity of two best-fitting equivalent current dipoles, one in each hemisphere). In an ongoing study, 21 patients (F20.0 ICD-10) exhibited higher SGR than 17 sex and age-matched healthy subjects, F(1, 39) 5 6.68, p < .01. SGR tended to decrease during the course of CE (20 sessions within 4 weeks) in 12 patients, F(2, 10) 5 7.43, p < .01; right hemisphere SGR declined from .57 to .39, p < .01; left hemisphere .58 to .44, p 5 .09. No such decrease was observed in a 9 patients accomplishing standard cognitive training F(2,7) 5 .36, p 5 .7 (Cogpack, Markersoftware). Performance in verbal memory improved only after CE (p < .01), though largely unrelated to SGR changes. Results indicate that MEG-based SGR assessment can track the course of successful auditory training and provide preliminary evidence that the auditory training tasks employed here provide a specific impact on sensory gating.

Poster 176

CHILDHOOD STRESS AND PSYCHIATRIC DISORDER MODIFIY REWARD PROCESSING

Astrid Steffen, Katharina Matz, Christine Naegele, & Brigitte Rockstroh University of Konstanz

Descriptors: reward processing, MEG, stress

Altered functioning of the reward system is assumed for individuals with mental disorders relative to normals, but also as a consequence of stressful experiences. Using a gambling design to produce reward processing, the present magnetoencephalographic (MEG) study examined brain activity during value appraisal and reward expectation in 22 patients with psychiatric diagnoses (MDD, schizophrenia, BPD, addiction) and 12 healthy subjects. The life-stress interview determined high childhood stress in 11 and low stress in 11 patients and the healthy subjects. During MEG-recording, subjects decided, whether or not to gamble for 10 or 50 c, which they could win with 10%, 50% or 90% chance, with value and chance being represented by visual cues. All subjects showed more posterior temporal activity to cues for higher value.

Poster 177

THE SPATIO-TEMPORAL PATTERN OF REWARD PROCESSING:

MAGNETOENCEPHALOGRAPHIC RESPONSES TO VALUE APPRAISAL AND REWARD PREDICTION IN A GAMBLING TASK

Astrid Steffen, Daniel Muller, Christian Wienbruch, & Brigitte Rockstroh University of Konstanz

Descriptors: reward prediction, MEG, decision making

Reward processing is frequently examined in decision-making designs, as they involve essential components like evaluation of value and reward prediction. The present study examined magnetoencephalographic (MEG) correlates of such components in 20 volunteers: subjects had to decide, whether or not to gamble for 10 or 50 c (Eurocent), which they could win with 10%, 50% or 90% chance. MEG responses to the visually presented value (10 or 50 c) and chance (10, 50 or 90%) stimuli, analyzed using Minimum Norm Estimates (MNE), distinguished value evaluation and reward prediction in time windows between 150 and 350 ms after stimulus onset in different brain areas: right-hemispheric temporo-parietal dipole activity 150-230 ms distinguished value evaluation (p < .01), whereas the chance prediction varied with right-hemispheric temporo-parietal dipole activity at 215-255 ms (p < .05), bilateral fronto-temporal dipole activity at 235-275 ms (p < .01) and frontal dipole activity at 250-350 ms (p < .05). Frontal activity was larger and decision time was longer on risky trials (decision to gamble at 50% chance). Activation of the same region by both cues (value and chance) suggests that reward processing comprises the interaction of preferred value and expectancy of outcome, while the course of activity suggests a consecutively activated neuronal network of reward processing, including posterior temporal to prefrontal regions.

Poster 178

FREQUENCY SPECIFIC EEG COHERENCE CHANGES RELATED TO DIFFERENT COMPONENTS OF WORKING MEMORY

Regina I. Machinskaya, Andrey V. Kurgansky, & Lubov S. Sokolova Institute of Developmental Physiology of the Russian Academy of Sciences

Descriptors: working memory, eeg coherence

Analysis of EEG coherence in theta, alpha and beta frequency bands was performed to investigate brain functional organization of verbal and visuo-spatial working memory (WM). WM task consisted of a warning signal (exclamation sign), a set of referent stimuli (RS) and a test stimulus (TS) with a random 4-4.5 s interval between RS and TS. Subjects pressed 'yes' or 'no' response key to indicate the presence/absence of the test stimulus in the referent set. Verbal (semantically unrelated words) and visuo-spatial (nonverbalized shapes) matching and nonmatching pairs of stimuli were shown in random order with equal probability. The EEG was recorded in 18 healthy 18-25-year-old adults at rest with eyes closed (background), during 2 s preceding the referent stimuli (nonspecific mobilization) and during 2 s preceding the test stimulus (information re-

tention in WM). Results showed different functional organization of regulatory and information-related components of WM. Nonspecific mobilization increased cross-hemispheric theta rhythm synchronization between the frontal and temporal zones, and local beta-specific links within those zones. Information retention strengthened modality independent alpha rhythm distant synchronization with foci in the right frontal, parietal and temporo-parietal zones accompanied by modal-specific local synchronization of beta oscillations: in speech zones of the left hemisphere synchronization was higher in the verbal task than in the visuo-spatial task, whereas in posterior zones of the right hemisphere the pattern was reversed.

Poster 179

ASSESSING LATENT FEATURES OF BRAIN DEVELOPMENT BY EEG PHOTIC DRIVING REACTIVITY

Vladimir V. Lazarev, Maria Alice Genofre, Adailton Pontes, & Leonardo C. deAzevedo Oswaldo Cruz Foundation

Descriptors: eeg photic driving, brain development, neurologic disorders The capacity of the EEG driving reactivity (DR) to the intermittent photic stimulation (IPS) to enhance the manifestation of latent EEG oscillators can provide an additional tool for assessment ofnormal brain development and its pathological alterations. In the present work, the DR to 11 fixed IPS frequencies (3 - 24 Hz) was studied in 70 normal subjects and 99 neurologic patients, aged 5-18 years. In the occipital visual areas where the DR was most pronounced, both children and adolescents showed strong responses to the theta IPS frequencies while spontaneous EEG spectra had increased theta values only in children. In this way, the DR revealed one additional stage of ''latent theta oscillators'' in the brain development not apparent in the resting state. In general, the driving amplitude in the delta and theta bands negatively correlated with the age. The occurrence of the driving peaks in the spectra of the 12 non-visual areas and EEG coherence among these leads at the IPS frequencies positively correlated with the age indicating a gradual generalization of the DR with the brain maturation. In 85 patients with partial epilepsy, the number of driving peaks in the spectra of non-visual areas and coherence at the IPS frequencies were reduced showing a likely delay in brain maturation as well as the effect of the antiepileptic drugs. Fourteen ''high functioning'' autistic boys showed reduced spectral characteristics of DR in the right hemisphere and higher coherence in the left hemisphere, particularly at the alpha and beta IPS frequencies, not apparent in the resting state.

Poster 180

THE ILLUSION OF MISALIGNMENT IN THE POGGENDORFF FIGURE IS MODELED BY AN EARLY VISUAL PROCESSING AND COGNITIVE MECHANISMS

Irina Shoshina1, Leonid Medvedev2, Ella Olada3, & Ekaterina Fedorova2 1Siberian Federal University, 2Krasnoyarsk State Pedagogical University, 3Free University of Berlin

Descriptors: illusion, erps

Features of the geometrical figures causing the Poggendorff illusion in the Jastrow modification were investigated. We recorded event-related potentials of 13 right-handed females in a visual classification task. We used a set of different stimuli, all of them were composed of five identical elements. Figures differed from each other only by angle of inclination of lateral segments. The control figure had an inclination angle of lateral segments .164 radians and did not cause the Poggendorff illusion. These stimuli allow us to differentiate the processing of collinear elements (stimulus features) and illusory figures (perceptual properties). There was registered a visual component in response to visual stimulus, whereas in response to the presentation of another collinear stimulus that does not cause distortion - N100. The occurrence of this component in parietal, temporal and occipital areas of the cortex is probably evidence that the illusion of displacement of the collinear pieces relative to each other arises during the information processing in the ventral pathways. The visual N170, registered in response to visual stimulus, was significantly smaller than the same in response to another collinear stimulus in the symmetric parietal, occipital and right temporal areas. This indicates that perceptual processing beyond the analysis of the stimulus' physical properties can be shown by the N170 amplitude. Besides, during the illusory perception, the visual P300 had smaller amplitude, than during the presentation of a stimulus perceived without distortion.

Poster 181

EXPLORING THE ELECTROPHYSIOLOGICAL CORRELATES OF EMOTION-ENHANCED RECOLLECTION

Alexandre Schaefer, Claire L. Pottage, & Karrie Alexander University of Leeds

Descriptors: EEG/ERP, emotion, memory

Why are memories for events such as the 9/11 terrorist attacks or private emotional memories so vividly remembered? These are instances of the phenomenon of emotion-

enhanced recollection (EER), i.e. the fact that emotional memories are more vivid and detailed than neutral memories. We report a study that used event-related potentials (ERP) to investigate the formation of memory traces leading to the EER phenomenon at both encoding and retrieval stages. Participants had to watch emotional and neutral pictures in an incidental encoding task. One week later, they performed a recognition test followed by a ''Remember-Know'' task (Gardiner and Java, 1993). For encoding-related activity, ERPs recorded during the encoding task were sorted according to subsequent memory performance in the recognition test performed one week later. Results revealed an early frontal (100-400 ms) and a late posterior (post-800) positivity specific to emotional items that were richly recollected (''Remember'' items) one week later. For retrieval-related activity, ''Old-New'' effects were measured contrasting ERPs to items judged as ''Remember'' and ERPs to items judged as ''know'' with ERPs to correctly rejected items during the recognition test. Old-New effects (between 300 and 800 ms) were enhanced for emotional items that were richly recollected mainly in fronto-central sites. In addition, an early (P200) Old-new effect was observed specifically for emotional ''Remember'' items. Results will be discussed in relation with current developments in the field of human memory.

Poster 182

EVOKED AND INDUCED EVENT-RELATED EEG OSCILLATIONS IN HIGH-PERFORMING YOUNG AND ELDERLY INDIVIDUALS DURING A COGNITIVE FLEXIBILITY TASK

Bruno Kopp1,2, Christine Uhlmann2, Lars Behrmann1,2, Jiirgen Howe2, & Karl

Wessel1-2

1Braunschweig Hospital, 2University of Technology Braunschweig Descriptors: eeg oscillations, brain aging, cognitive flexibility

We conducted a study of normal brain aging that was based upon the quantitative analysis of event-related EEG biosignals. Forty participants (24 young, mean age 22 years; 16 elderly, mean age 70 years) took part in a task that was designed to challenge cognitive flexibility. Elderly participants had slower RTs than young participants, whereas error rates did not differ between the two age groups. The analysis of evoked and induced event-related EEG oscillations rested on Morlet wavelet transformations in the theta-, alpha- und beta-frequency bands. The analysis of the evoked event-related EEG oscillations revealed more pronounced fronto-parietal theta activity during response selection in the elderly compared to the young participants. We also observed a crossover interaction with regard to the induced EEG oscillations. Specifically, young participants showed more pronounced event-related alpha-desynchronization at occipito-parietal electrodes during stimulus recognition, whereas elderly participants showed evidence of more pronounced event-related beta-desynchronization at central electrodes during response preparation. These data are discussed against the background of thalamo-cortical mechanisms of the genesis of EEG rhythms. Specifically, process-induced facilitation of posterior thalamo-cortical processing (stimulus recognition) and of anterior basal ganglia-thalamo-cortical processing (response preparation) seem to be age-dependent. Future studies will examine the role of dopamine in these EEG phenomena that are related to the aging of the brain.

Poster 183

AUTOMATIC PROCESSING OF FEATURE- VS. OBJECT-RELATED DEVIANCES IN THE VISUAL MODALITY

Dagmar Müller1, Istvaan Winkler2, & Erich Schroger1 institute for Psychology I, University of Leipzig, 2Institute for Psychology, Hungarian Academy of Sciences

Descriptors: visual change detection, vmmn, visual objects

Task-irrelevant visual stimuli deviating from some feature-based regularity established by the preceding stimulus sequence elicit the visual mismatch negativity (vMMN). In this study we compared the processing of a simple feature-related and a more complex object-related visual deviance to test the power of the automatic visual change detection mechanism. Each test-display contained 8 colored discs evenly distributed around the fixation point. In the color-deviance condition, usually all discs were equally colored (p 5 .9, standard) but occasionally 2 neighboring discs were deviant colored (p 5 .1, deviance). In the object-deviance conditions, the 8 discs formed 4 objects by use of the gestalt principle of common region. Each object-display contained 6 blue-colored and 2 neighboring red-colored discs which either belonged to the same or to different objects. Standards and deviances were exclusively defined on the basis of color-object-assignments. Participants were instructed to detect slight changes of the continuously presented fixation cross and to ignore the serial presentation of test-displays. In the color-deviance condition, the comparison of ERPs elicited by deviances and physically identical standards yielded a vMMN peaking in the 200-260 ms latency range. However, in the object-deviance conditions, we observed (if at all) considerably reduced vMMN amplitudes. Our results suggest that the automatic visual change detection system has difficulties to deal with complex object-related deviances and thus, seems to be more limited than its auditory counterpart.

INVESTIGATING ALTERATIONS IN THE ERROR-RELATED NEGATIVITY AND POST-ERROR BEHAVIORAL IMPROVEMENTS ACROSS TIME

Jason R. Themanson1, Peter J. Rosen1, Aaron B. Ball1, Michael J. Cunningham1, Brandon M. Clark1, Matthew B. Pontifex2, Charles H. Hillman2, & Edward McAuley2 1Illinois Wesleyan University, 2University of Illinois, Urbana-Champaign

Descriptors: error-related negativity, cognitive control, post-error behavior Both the error-related negativity (ERN) and the increased implementation of cognitive control following error commission (e.g., post-error response accuracy) have been shown to be sensitive to self-efficacy (SE; one's beliefs in their ability to successfully perform a task). However, no investigations have manipulated SE to determine if altering participants' task-related beliefs influences action monitoring processes. To examine this topic, 56 healthy young adults completed two sessions of a flanker task, both under accuracy instructions, and were exposed to either false positive, false negative, or no performance feedback after the first session to alter their task SE. Results indicated a significant effect of the feedback manipulation on SE, but no significant influences on the ERN, post-error accuracy, or changes in either measure. However, a relationship was evident between changes in ERN amplitude and post-error accuracy across task sessions, with more negative ERN amplitude changes associated with greater improvements in post-error accuracy. No other variables, including age, sex, IQ, five-factor personality, or SE were significantly associated with changes in post-error accuracy across sessions. These results indicate that the relationship between ERN amplitude and post-error accuracy remains intact despite manipulations intended to alter both action monitoring metrics through SE, and the relationship is not directly dependent upon any individual difference variables previously associated with action monitoring in normal or non-symptomatic populations.

Poster 185

SINGLE-TRIAL ANALYSIS EXPLAINS REDUCTION OF P300 AMPLITUDE IN CIRRHOTIC PATIENTS

Sami Schiff, Costanza D'Avanzo, Giorgia Cona, Giovanni Sparacino, Patrizia Bisiacchi, & Piero Amodio University of Padova

Descriptors: single-trialp300

Average-based P300 amplitude reduction is a common feature in dementia and in others psychiatric illness. P300 amplitude reduction was previously assessed also in cirrhotic patients. The phenomenon may depend, in cirrhotic patients, by an amplitude reduction of each single-trial P300 response, or by an increased variability. An increased variability was previously described in cirrhotic patients in reaction time distribution. EEG was recorded during the execution of a visual choice reaction time task in 13 cirrhotic patients with minimal hepatic encephalopathy (MHE 5 spectral EEG and/or TMT alteration), 10 cirrhotic patients without MHE, 10 healthy control subjects matched for age and educational level, and in 9 young normal subjects. Single-trial P300 amplitude and latency, together with their standard deviation, were derived using a non-parametric Bayesian estimation method which employs mild assumptions on the smoothness of the unknown single-trial P300 response. Repeated-measures ANOVA replicated the average-based P300 amplitude reduction previously observed in cirrhotic patients compared to age-matched and young controls F(3, 48) 5 4.9; p < .05.

Poster 186

PARALLEL PREPARATION OF HAND AND FOOT: INFERENCES FROM THE LATERALIZED READINESS POTENTIAL

Hartmut Leuthold1, & Ines Jentzsch2 University of Glasgow, 2University of St. Andrews

Descriptors: lateralized readiness potential, response precuing, motor preparation Recently we proposed the foreperiod lateralized readiness potential (fLRP) to sensitively reflect advance specification of movement parameters at an effector-specific level of the brain. Here we exploit this characteristic to test in a response precuing paradigm whether different effectors are simultaneously prepared in advance although they are unknown before the imperative signal. Participants were asked to perform left versus right hand responses and left versus right foot responses after the imperative signal. The precue (S1) provided either no, partial (side, effector), ambiguous (e.g., left hand and right foot), or full (right hand) information about the forthcoming response. After a foreperiod of 1,400 ms, the imperative signal (S2) indicated the required response. EEG was continuously recorded and mean fLRP amplitude during a 200-ms interval immediately preceding S2 was analysed. Critically, the parallel preparation view predicts a strong fLRP with ambiguous side-effector information. In contrast to this prediction, we observed a reliable fLRP only with full precue information but not with ambiguous precue information. In contrast to our previous reports of parallel hand preparation with partial direction precues (e.g., extension movement) and ambiguous precues (e.g., left-hand extension and right-hand flexion), the present results indicate that participants do

not simultaneously prepare different effectors at an effector-specific level of motor preparation. We speculate that limitations in higher-level motor memory are responsible for these effects.

Poster 187

CHANGE EVENT RELATED NEGATIVITY FOR DEVIANTS IN VISUAL SEARCH

Elke B. Lange1, Olga V. Sysoeva2, Alexander B. Sorokin3,4, & Tom A. Campbell4 1Cognitive Brain Research Unit, University of Helsinki, 2Institute of Higher Nervous Activity and Neurophysiology of the Russian Academy of Sciences, 3Mental Health Research Center of the Russian Academy of Sciences, 4Helsinki Collegium for Advanced Studies

Descriptors: change-related negativity, deviant distraction, visual search Consistently, visual search for a unique shape is slowed by a singleton distractor object that differs in color from all other objects in the search array. This reaction time (RT) effect is classically interpreted as the automatic recruitment of attention by the distractor. Here we show a different form of distraction that is mediated by changing one feature of the distractor: A deviant-colored singleton slowed RTs more than a standard-colored distractor singleton. This color deviance effect indicates that the standard color was: i) extracted, and ii) stored in memory. This memory serves to enhance subsequent selectivity so as to prioritize the processing of information. This slowing of search by color deviance was accompanied by four spatiotemporally distinct memory-based processes of visual change detection: early posterior positivity, followed by change-related negativity - CERN (120-160 ms), and two late frontal negativities (310-350 and 360-400 ms). Crucially, a significant correlation revealed that higher CERN amplitudes indexed larger color deviance effects in RTs, in accoradnce with the perspective that this distraction effect is connected to early sensory-memory processes that are indexed by CERN to color deviance.

Poster 188

MATERIAL-SPECIFIC ELECTROPHYSIOLOGICAL CORRELATES OF RECOLLECTION

Giulia Galli, & Leun J. Otten Institute of Cognitive Neuroscience, University College London

Descriptors: ERP, memory, recollection

Event-related potential (ERP) studies have shown specific electrophysiological signatures of recollection using verbal material. In contrast, studies with objects and faces have yielded dissimilar results. This suggests that the ERP correlates of recognition memory are material-specific. To verify this hypothesis, ERP responses to objects, words and faces were directly compared using a source memory task. At study, visual stimuli were paired with auditorily-presented names of locations. At test, only visual stimuli were presented, and for old items subjects were asked to retrieve the location. Stimuli belonging to different materials were presented in separate study-test lists ("blocked design'', Experiment 1) or intermixed across trials ("intermixed design'', Experiment 2). Performance was better for objects compared to words, and for words compared to faces, and overall in the intermixed compared to the blocked experiment. Recollection effects had a more frontal scalp distribution for objects and faces compared to words. This effect was more evident in the blocked experiment. These findings show that ERP recollection effects for pictorial material differ from those typically found with words. Moreover, material specificity interacts with the kind of design. The different cognitive mechanisms involved in different designs do not only affect behavioral performance, but also the ERP correlates of recognition memory.

Poster 189

PROCESSING OF FACIAL EMOTION IN PATIENTS WITH MAJOR DEPRESSION: ERP CORRELATES OF A NEGATIVE BIAS

Andrea Figura1, Katja Werheid1, Norbert Kathmann1, Philipp Klein2, & Isabella Heuser2 1Humboldt University, Berlin, 2Charite - Berlin

Descriptors: ERP, depression, attention

Rationale: Mood-congruent information processing in terms of a 'negative bias' is a well-established phenomenon in major depression. Yet, it is unclear whether the negative bias is characterized by hyperattention toward negative information or hypoattention toward positive information. Method: Event-related brain potentials (ERPs) were recorded inpatients with major depression (n 5 19) and healthy controls (n 5 20) while participants judged the emotional valence of faces with positive, negative, and neutral facial expressions. Group differences in emotional processing were examined by analyzing emotion-sensitive ERP components and valence judgments. Results: Analysis of behavioral data revealed negatively biased valence judgments in patients, which were significantly correlated to current mood and severity of depression. ERP analysis revealed the expected pattern ofenhanced LPP amplitudes to positive and negative faces in the control group, but attenuated LPP amplitudes for positive faces in the depressed

group. Conclusion: Negatively biased emotion processing in depression was confirmed both by behavioral and electrophysiological results. Attenuated LPP amplitudes to positive faces are interpreted as hypoattention toward suppressed processing ofpositive social signals and confirm the view that the pathological mechanism in major depression is an altered processing of mood incongruous information.

_CLUSTERED POSTER SESSION #1_

ROLE OF ATTENTION IN PROCESSING OF VISUAL STIMULI

Chairs: Michal Kuniecki1, & Piotr Jaskowski2, 1Jagiellonian University, 2University of Finance and Management

Descriptors: attention, vision, emotion

This group of posters summarizes current work being conducted in leading Polish psychophysiological laboratories on broadly defined aspects of visual attention. The posters bring together interdisciplinary research paradigms having one common denominator, which is visual attention. Jaroslaw Michalowski presents research on mechanisms of visual attention in subjects with spider phobia. His results suggest that effects ofincreased attention to phobia related pictures in spider phobics seem to be related to emotional relevance of the stimulus cues, rather than reflecting a fear-specific response. Michal Kuniecki, using oculography, shows how colour of emotional stimuli influences their attention capturing features. Piotr Jaskowski explores interactions between the prime and the mask on motor responses. His findings suggest that in certain circumstances a mask, traditionally thought to be neutral, can also exhibit attention capturing features. Finally, Mateusz Gola investigates attentional deficits in spatial attention in elderly and young subjects showing that the number and power of beta bursts are correlated with subjective level of difficulty.

Poster 190

TEMPORAL DYNAMICS OF THE BRAIN RESPONSE TO PHOBIA-RELEVANT AND STANDARD EMOTIONAL VISUAL STIMULI IN SPIDER-PHOBIC INDIVIDUALS

Jaroslaw M. Michalowski1, Christiane A. Melzig2, Almut I. Weike2, Jessica

Stockburger3, Herald T. Schupp3, & Alfons O. Hamm2 1University of Gdansk, 2University of Greifswald, 3University of Konstanz

Dense sensor event-related brain potentials were measured in participants with spider phobia and non-fearful controls exposed to spider and standard emotional (pleasant, unpleasant, neutral) pictures. Spider phobia participants showed enlarged P1 amplitudes for all picture contents than controls, suggesting increased vigilance in this group. Furthermore, spider phobia participants responded with significantly larger early posterior negativity (EPN) and late positive potential (LPP) during the encoding ofphobia-relevant pictures, relative to non-fearful control participants. No group differences in the EPN and LPP were found for standard emotional materials indicating that these effects were specific to phobia-relevant material. However, within group comparisons of the spider phobia group revealed comparable EPN and LPP evoked by spider pictures and emotional (unpleasant and pleasant) picture contents. These results demonstrate a temporal shift in perceptual processing from unspecific vigilance (P1) to preferential responding (EPN and LPP) to phobia-relevant materials in the spider phobia group. However, at the level of early stimulus processing, these effects of increased attention seem to be related to emotional relevance of the stimulus cues rather than reflecting a fear-specific response.

Poster 191

ELEMENTS OF FORMAL CHARACTERISTIC OF EMOTIONAL VISUAL STIMULI DETERMINING THEIR ATTENTIONAL ADVANTAGE

Michal J. Kuniecki1, Szymon Wichary2, Szczepan Grzybowski1, & Piotr Jaskowski3 Jagiellonian University, 2Warsaw School of Social Psychology, 3University of Finance and Management

What makes a stimulus emotional? Is it color? According to some researchers, color has no role in determining emotional valence of a stimulus. However, others postulate that color is an important stimulus characteristic, determining its valence and arousal values. In order to shed light on this issue, we conducted two experiments using oculograph for eye-gaze tracing. Both experiments employed lateral presentation of stimuli, however the first one was conducted in free viewing while the second one in antisaccade paradigm. Part of the stimuli were transformed to eliminate physical differences (e.g. luminance) between them - pixels from an emotional picture were used in the neutral stimulus, and vice versa. Results clearly show that color is a significant factor in processing of emotional stimuli even at the very early stages of stimulus evaluation. In the first experiment we found that neutral stimuli with pixels from its emotional counterparts have higher probability of attracting attention than original neutral stimuli. Those results were generally confirmed in the second experiment, however they were affected by laterality.

ATTENTION CAN BE CAPTURED BY NEUTRAL MASKS

Piotr Jaskowski1, & Anna Przekoracka-Krawczyk2 1University of Finance and Management,2Adam Mickiewicz University

In subliminal priming, a backward masked prime can affect motor responses to a main stimulus displayed after the mask. It is commonly accepted that the mask renders the prime invisible and does not affect the motor response to the target. However, there is a growing body of evidence suggesting that a mask containing elements shared with the target (i.e. the target-like mask) can modulate the motor response to the target. Accordingly, the target-like mask is expected to capture participants' attention. We examined this hypothesis by using lateralized parietal potential (N2pc). Pairs of primes, followed by pairs of masks and pairs of main stimuli were presented. The two elements of each pair of primes, masks, and main stimuli appeared on the left and on the right of fixation point. One element of the main stimulus pair was the target. The participants' task was to indicate the side where a specific target (an arrow or diamond both formed from oblique lines) was shown in the main pair. In some trials, only masks were displayed and participants were asked to withdraw their responses (no-go trials). We showed that a target-like mask (i.e. formed from randomly distributed oblique lines) evoked N2pc in no-go trials suggesting that the mask attracted attention (N2pc) to the place where it appeared. Additionally, such a mask was shown to evoke lateralized readiness potential suggesting that the mask can affect motor preparation. This finding strongly indicates that the mask cannot be treated as a neutral stimulus but is processed and can modulate prime-induced motor preparation

Poster 193

BETA-BAND EEG ACTIVITY AS A NEURONAL CORRELATE OF ATTENTION - CHANGES RELATED WITH AGING

Mateusz K. Gola1, Jan Kaminski2, Aneta Brzezicka1, & Andrzej Wrobel2 1Warsaw School of Social Sciences and Humanities, 2Nencki Institute of Experimental Biology

Daily observation and plenty of psychological research on elderly people (>65 y.o.) have shown attentional deficits compared to young people (18 - 30 y.o.). In our human research, we compared the image of beta-band activity of young and elderly subjects who were involved in visual and auditory spatial differentiation experimental tasks. Experimental procedure was relevant to the one used previously in our animal research. The task was to observe whether the first target stimulus appears in the left or right channel. Modality of stimuli was signaled by the cue. Beta burst EEG activity was identified in all subjects. Data analysis showed that the number and power of bursts and frequencies correlates with subjective level of task difficulty. Decrease of the number and power of beta bursts in visual cortex significantly correlates with behavioral response errors. In the case of elderly people, two different beta activity patterns have been observed: Local increase of number and power of beta bursts in visual and frontal cortex (characteristic for high performance level subgroup) and general increase of number and power of beta activity in visual, sensorimotor, and frontal cortex (characteristic for low performance level subgroup). Decrease of the number and power of beta bursts in visual cortex significantly correlates with behavioral response errors in high performance level subgroup. Correlation between this patterns and behavioral results suggests also a connection with speed-accuracy effort.

_POSTER SESSION III_

Poster 1

RIGHT VENTROLATERAL PREFRONTAL CORTICAL ACTIVITY IS INCREASED DURING REWARD ANTICIPATION IN EUTHYMIC BIPOLAR ADULTS

Robin Nusslock, Jorge R. Almeida, Erika E. Forbes, Amelia Versace, Edmund J. LaBarbara, Crystal Klein, & Mary L. Phillips Western Psychiatric Institute and Clinic

Descriptors: fmri, bipolar disorder, reward responsivity

Psychosocial and electrophysiological research indicate that bipolar individuals display a hyperresponsivity to reward relevant stimuli. Reward relevant life events have been demonstrated to trigger bipolar episodes, and bipolar individuals display excessive approach motivation in response to reward relevant events, as indexed by electroencephalography (EEG). The current study extends this research by examining reward-related brain function in euthymic bipolar adults and healthy controls. Participants were 15 euthymic bipolar adults and 15 individuals with no lifetime history of psychiatric disorder who underwent functional MRI scanning while engaged in a number-guessing task with monetary reward. Euthymic bipolar adults and controls were classified based on structured diagnostic interviews. Data were collected using a 3T Siemens Trio scanner. Analyses, conducted in SPM5, addressed group differences in BOLD response during reward anticipation. Preliminary findings indicated that during

reward anticipation, bipolar individuals displayed increased ventrolateral prefrontal cortical (VLPFC) activity relative to control individuals (t 5 3.86, p < .05).

Poster 2

EXPENDING COGNITIVE EFFORT LEADS TO EMOTIONAL DYSREGULATION

Dylan D. Wagner, & Todd F. Heatherton Dartmouth College

Descriptors: emotion, regulation, amygdala

Failure to appropriately regulate one's emotions is a hallmark of many clinical psychiatric disorders. Evidence from brain imaging research has focused on an amygdala -prefrontal circuit that appears to be critical for successful emotion regulation and is often impaired in mood disorders such as PTSD and depression. Findings from research on self-regulation have repeatedly demonstrated that engaging in effortful emotion regulation tasks impairs attempts at self-regulation in cognitive and social domains. In the present study, we tested whether engaging in effortful self-regulation in a demanding attention-control task would disrupt the prefrontal - amygdala circuit, leading to dys-regulation of amygdala response to negatively valenced stimuli. Participants viewed two blocks of valenced images during functional magnetic resonance imaging (fMRI). Task blocks were separated by a depletion task which required participants to engage in effortful attention control. Prior to the depletion task activity in the amygdala when viewing negatively valenced images was inversely correlated with a region of ventral PFC associated with emotion regulation. Cognitive depletion disrupted the prefrontal -amygdala circuit leading to a positive response in both amygdala and ventral PFC following depletion. These findings suggest that prefrontal regulation of amygdala response draws from a limited resource which can be depleted by acts of self-regulation.

Poster 3

MISMATCH NEGATIVITY TO CHANGE IN AZIMUTHAL POSITION OF LOW-FREQUENCY NOISE BURSTS IN FREE FIELD: SUGGESTION FOR AN OVER-REPRESENTATION OF LATERAL SOUND SOURCES COMPARED TO SOUND SOURCES IN FRONT

Nicole Richter, Erich Schroger, & Rudolf Rubsamen University of Leipzig

Descriptors: mismatch negativity, sound localization

According to the 'duplex theory' sound localization in humans is based on the processing of interaural time differences (ITDs) at low frequencies. Frontal sound sources separated by only 1-2 degrees can be differentiated, while the minimal separation threshold increases for lateral sound sources. This is caused by the fact that already small azimuthal changes in front of the head cause noticeable changes in inter-ear differences, while in the periphery larger spatial separations are required to achieve comparable changes in inter-ear differences. Here, we investigated the cortical representation of azimuth by measuring the location mismatch negativity (MMN). The first experiment employed a passive oddball paradigm by presenting deviant/standard (D/S) pairs with different azimuthal positions, but constant ITD separation. The second experiment used an active oddball paradigm in which the stimulation design was mainly retained, but the subjects had to detect the occasional deviant positions. In both experiments the frontal (S/D) positions elicited smaller MMNs than respective (S/D) positions located more laterally. In the second experiment the inter-hemispheric comparison of the MMNs revealed a prominent right-hemispheric activation, while the sound source discrimination performance was not affected by the azimuth of(S/D) positions. Thus, present MMNs suggest a cortical over-representation of lateral compared to frontal sound source positions. Further, pronounced right-hemispheric MMNs suggest an engagement of right cortical networks during active sound source discrimination.

Poster 4

AUDITORY ATTENTION: EFFECTS OF TEMPORAL AND SPATIAL EXPECTATION

Johanna Rimmele1,2, Hajnal Jolsvai2, & Elyse Sussman2 'University of Leipzig, 2Albert Einstein College of Medicine

Descriptors: audition, attention, ERP

A naturalistic behavioral task was used to investigate mechanisms of spatial and temporal attention in audition. Attention was directed to a specific moment in time, respective to a specific location. Expectations were set up implicitly, using the information inherent in the movement of a sound. There were four conditions of expectation: temporal plus spatial expectation; temporal expectation only; spatial expectation only; and no expectation. Event related brain potentials were recorded while participants performed a go/no-go task, set up by anticipation of the reappearance of a target tone through a white noise band. Results showed that 1) temporal and spatial expectations independently enhanced target detection at both early indexed by N1) and late (indexed by N2) processing stages; 2) later task-related processing (indexed by P3) was modulated only by both spatial and temporal expectations together; 3) temporal expectation alone speeded reaction time and increased response accuracy compared to the other conditions. Thus, the results indicate an important role for temporal attention in audition. There appear to be distinct mechanisms of

spatial and temporal attention, which act independently on early processing stages. However, late synergistic effects demonstrate that these mechanisms are not completely independent, but interact according to task characteristics. Our results are consistent with the view from vision research that spatial and temporal attentional control is based on the activity of partly overlapping, and partly functionally specialized neural networks.

Poster 5

THE DIFFERENTIAL ROLE OF MODALITY-SPECIFIC WORKING MEMORY TRAINING IN LEARNING CHINESE AS A SECOND LANGUAGE

Julia A. Schneiders1, Christoph Krick2, & Axel Mecklinger1 1Saarland University, 2Saarland University Hospital

Descriptors: fmrt, working memory, training

Logographic Chinese differs from alphabetic German in aspects of phonology and orthography, which results in differences in brain networks involved in reading Chinese characters and alphabetic words. Whereas previous research has shown a systematic relationship between phonological working memory capacity and second language proficiency for alphabetic languages, for Chinese as a second language visuo-spatial working memory should be a better predictor of second language proficiency due to the greater visual complexity of Chinese characters. In our working memory training study we investigated the differential impact of visuo-spatial and auditory working memory training (n-back training paradigm) while Germans learned Chinese as a second language. Additionally, training induced modulations in language-related and working memory related brain networks using functional magnetic resonance imaging (fMRI) were examined. Behavioral data show that especially the training of visuo-spatial working memory leads to larger transfer effects in orthographic proficiency as compared to auditory working memory training and no working memory training. Furthermore, brain imaging data showing training and transfer effects in language-related brain areas are reported. Our results suggest that, consistent with our predictions, the training of visuo-spatial working memory leads to higher proficiency when Germans learn logographic Chinese as a second language.

Poster 6

EFFECTS OF TEMPORALLY UNPREDICTABLE CONTEXTS ON AMBIGUOUS FACIAL EXPRESSIONS OF EMOTION

Caroline Davis, Maital Neta, & Paul J. Whalen Dartmouth College

Descriptors: facial expressions

While some facial expressions predict clearly positive or negative environmental events, others (e.g., surprise) can predict both positive and negative events. This ambiguity in the predictive value of surprised faces makes their interpretation susceptible to contextual manipulation. The human amygdala is particularly responsive to facial expressions with ambiguous predictive value. Specifically, while amygdala responses to clearly negative expressions habituate rapidly with repeated presentations, responses to ambiguous expressions are sustained over time. The amygdala is also sensitive to subtle contextual manipulations of ambiguous stimuli, such as temporal unpredictability, which can prime anxiety-like behaviors. This suggests that unpredictable contexts might induce viewers to interpret surprised faces negatively. Here, we used facial EMG and fMRI to examine implicit valence interpretations of surprised faces presented in temporally predictable and unpredictable sequences. Predictable surprised faces elicited corrugator responses similar to clearly positive (happy) expressions. In contrast, unpredictable surprised faces elicited corrugator responses similar to clearly negative (angry) expressions. Amygdala response to predictable surprised faces was of moderate amplitude and sustained over time. However, response to unpredictable surprised faces was enhanced compared to predictable faces, but this response habituated over time. We conclude that the amygdala mediates biased valence interpretations of surprised faces based upon temporal predictability.

Poster 7

EXTINCTION OF CONDITIONED FEAR RESPONSES TO MASKED STIMULI

Armita Golkar, Rasmus Berggren, Tina Lonsdorf, Andreas Olsson, & Arne Ohman Karolinska Institute

Descriptors: pavlovian fear conditioning, awareness, fear potentiated startle Research on human fear conditioning suggests that conditioned fear responses are independent of awareness of the conditioned stimulus (CS). In contrast, fear extinction, involving prefrontal mechanisms, may be more dependent on cognitive awareness. We examined conditioned fear to masked and unmasked extinction trials using the fear potentiated startle reflex and shock expectancy ratings as our primary measures. During acquisition, subjects watched four different pictures of fearful faces. Two faces (CS+) were paired with a mild electric shock (US) and two were never paired with a shock (CS — ). In the subsequent extinction phase, awareness of one CS+ and one CS — was prevented by backward masking while the other CSs were presented unmasked. Following extinction, participants received three unsignaled presentations of the US followed by a reinstatement test including only unmasked CSs. Acquisition resulted in a differentially potentiated startle response to the CS+ vs. CS —, paralleled by differential shock expectancy ratings. During extinction, a significant startle

CS+/CS _ differentiation was seen to both the masked and the unmasked CSs with no difference between the masked and the unmasked CS+, even though expectancy ratings were higher for the unmasked CS+ . This relationship between startle and expectancy differentiation was reversed during reinstatement with larger expectancy to the formerly masked vs. unmasked CS+. These results suggest that awareness was not necessary for extinction of conditioned fear responses, but that masking resulted in less expectancy extinction.

Poster 8

OSCILLATORY BRAIN ACTIVITY IN THE TIME-FREQUENCY DOMAIN ASSOCIATED TO CHANGE BLINDNESS AND CHANGE DETECTION AWARENESS

Alvaro Darriba1, Paula Pazo-Alvarez1, Almudena Capilla2, & Elena Amenedo1 1University of Santiago de Compostela, 2University of Glasgow

Descriptors: change blindness, ERSP

In spite of the evolutionary importance of successful change detection, observers often fail to detect substantial changes to visual objects and scenes when these happen across saccades, blinks, flickers, blank screens, movie cuts and other interruptions. This phenomenon is known as change blindness. Using EEG data obtained in a one-shot change detection paradigm, we performed time - frequency analysis to reveal the changes in oscillatory neural activity in the theta and alpha bands of the spectrum. Participants saw two brief and successive visual displays, each with four sinusoidal gratings, and reported whether or not one of the gratings changed its orientation between the first and second displays. Analyses were performed on epochs including the pre-change and post-change stimuli as well as the blank interval between them. Spectral modulations were computed by the event-related spectral perturbation index. Relative to change blindness, change detection was associated with a distinct pattern of power changes at several processing stages, including some during the presentation of the first display, that is, before the occurrence of a change. Power modulations after the second display also showed differences associated to correct change detection in the analyzed bands. These results suggest that differences in the oscillatory activity related to change detection do not only depend on the processing of the change itself, but also on the activity while encoding the visual scene even before the change happens.

Poster 9

RELATING VISUAL WORKING MEMORY CAPACITY AND ATTENTIONAL CONTROL IN THE SCHIZOPHRENIA-SPECTRUM

Veronica B. Perez1, Judy M. Ford1, Daniel H. Mathalon1, & Edward K. Vogel2 1University of California, San Francisco, 2University of Oregon

Descriptors: schizophrenia, working memory, attention

Numerous studies have found deficits in visual working memory (VWM) in schizophrenia patients (SZ) in comparison to healthy controls (HC). Gold et al (2003) found that SZ have reduced VWM capacity, particularly when presented with larger set size arrays. Moreover, in HC, memory capacity strongly predicts selective attention ability (Vogel et al, 2005). Here, behavioral and electroencephalographic data were recorded while 19 schizotypal (SPD) and 23 HC performed a battery of attention and VWM tasks. We examined whether the predictive relationship between VWM capacity and selective attention is preserved within SPD. Contralateral delay activity (CDA), a highly sensitive index of VWM capacity (Vogel et al, 2004), was used to pinpoint each individual's capacity limit. The CDA is a large negative-going component that occurs during the maintenance stage of a VWM task, and is primarily observed over temporoparietal electrode sites about 275 ms after stimulus onset. SPD exhibited lower memory capacity than HC, especially at super-capacity arrays. Despite differences in memory capacity, selective attention remained intact and the relationship between capacity and attention was preserved. Examining the association between cognitive domains allows for the investigation into mechanisms that underlie known cognitive deficits within schizophrenia. Since memory capacity has been shown to be predictive of later cognitive performance (e.g., Kane et al, 2004), understanding VWM deficits may help unveil the mechanisms related to discrepant cognitive achievement between HC and SPD populations.

Poster 10

THE CONTRIBUTION OF AFFECTIVE STYLE TO THE SUCCESSFUL DOWNREGULATION OF PAIN: A PSYCHOPHYSIOLOGICAL AND NEUROIMAGING INVESTIGATION

Regina C. Lapate1, Tim V. Salomons1, Hyejeen Lee1, Carien M. van Reekum2, Larry L. Greischar1, & Richard J. Davidson1 1University of Wisconsin, Madison, 2University of Reading

Descriptors: affective style, EMG, pain regulation

Pain is a nonlinear phenomenon with a strong affective signature. Stable individual differences in emotion regulation are known as affective style, a framework hereby adopted to assess individual differences in pain regulation. We compared responses recorded from the same sample across two different paradigms spaced ~ 3 yrs apart. In study #1, participants underwent a voluntary emotion regulation task where they were instructed to either maintain [M] or suppress [S] their responses to negative pictures.

Corrugator supercilii power (COR) provided a metric of regulatory success. Affective style was hence indexed by the [M-S] difference in COR. In study #2, participants were trained to either [M] or [S] their responses to painful heat. BOLD fMRI and pain unpleasantness ratings were acquired. Pain regulation success was calculated as the [M-S] difference in pain ratings. Neural correlates of successful pain regulation were computed by correlating across participants [M-S] pain ratings with [S-M] BOLD parameter estimates. The contribution of affective style to pain regulation was assessed by regressing [M-S] COR within brain areas associated with the successful regulation of pain. Pain unpleasantness was attenuated during [S], t(17) 5 8.27, p < .01. As predicted, affective style was associated with successful regulation of pain, r 5 .64, p < .01. Maladaptive affective style and poor regulation were associated with increased engagement of sub-callosal cortex during suppression, z 5 2.9, p < .01, an area known to be implicated in chronic emotion dysregulation, such as in depression.

Poster 11

PROPRANOLOL BLOCKS THE NEURAL SIGNATURE OF UNPLEASANT MEMORIES: A SPATIOTEMPORAL EEG ANALYSIS

Mathias Weymar, Andreas Low, Christiane Modess, Georg Engel, Matthias Grundling, Astrid Petersmann, Werner Siegmund, & Alfons O. Hamm University of Greifswald

Descriptors: EEG/ERP, emotional memory, propranolol

Evidence from both animal and human research suggests that the formation of emotional memories is triggered by the beta-adrenergic system. In the present EEG (256 channel) study we investigated whether pre-encoding administration of beta-adrenergic antagonist propranolol modulates electrocortical brain potentials (ERPs) to emotional pictures during memory retrieval. 46 male participants incidentally encoded IAPS pictures varying in emotional content after pre-encoding administration of either propranolol (80 mg) or placebo and recognition memory was tested one week later. During retrieval, a widespread old/new effect was obtained over mid-frontal (300-500 ms) and parieto-central sites (500 - 800 ms), indicating more positive ERP waveforms for correctly memorized old pictures relative to correctly categorized new pictures. The centro-parietal old/ new effect was more pronounced for emotional pictures than neutral pictures, indexing the explicit recollection of the material. Systemic administration of propranolol selectively blocked this neural signature- during the retrieval ofunpleasant, but not pleasant pictures. Source analyses using sLORETA showed that activity in the parietal cortex during retrieval of unpleasant pictures was reduced in the betablocker group relative to placebo, but not for pleasant pictures. Taken together, these data suggest that the beta-adrenergic antagonist propranolol selectively reduces the neural signature of the memory trace for unpleasant events in the parietal cortex.

Poster 12

BOLD-RESPONSES TO REPEATED STIMULUS EXPOSURE IN ANIMAL PHOBIA

Julia Wendt, Luise E. Schmidt, Almut I. Weike, & Alfons O. Hamm University of Greifswald

Descriptors: animal phobia, fear response, habituation

Fear is an aversive emotional state elicited by threatening cues that activate the organism's defense system. In people with specific phobias this defense system seems to be overre-active causing marked fear responses if confronted with the phobic stimulus which are recognized as both excessive and unreasonable. One central aim of exposure therapy in animal phobia is the habituation of phobic fear. However, the mechanisms of the fear reduction gained with exposure therapy, particularly the interaction of brain regions initiating the defensive mobilization (insula, amygdala) and those regions modulating this initiation (prefrontal cortex) remain unresolved. Therefore, the current study investigates BOLD-responses during repeated presentations of phobia-relevant and neutral stimuli in snake/spider phobic participants (n 5 9) and non-phobic controls (n 5 11). Preliminary data analyses indicate that phobic participants show an initial potentiation of insula BOLD-responses during viewing phobia-relevant compared to neutral stimuli, which is diminished with repeated picture presentation. Additionally, phobic participants show an increase of BOLD activity bilaterally in the middle frontal gyrus throughout repeated presentations ofphobia-relevant pictures. These results indicate that the neural structures that regulate the fear response may need active inhibition exerted by prefrontal brain regions to gain substantial fear reduction.

Poster 13

WHY DO SOME PATIENTS ESCAPE WHILE OTHERS DON'T?

AUTONOMIC AROUSAL BUT NOT SUBJECTIVE REPORTS PREDICTS ESCAPING BEHAVIOUR DURING A BEHAVIORAL AVOIDANCE TEST IN HIGH ANXIOUS PANIC PATIENTS WITH AGORAPHOBIA

Jan Richter, Christiane A. Melzig, & Alfons O. Hamm University of Greifswald

Descriptors: panic disorder and agoraphobia, behavioral avoidance test, autonomic arousal In a multi-centre psychotherapy study 270 panic disorder patients with agoraphobia

(PDA) were, after an anticipation period, instructed to remain in a small, dark and locked chamber for as long as possible (max 10 minutes). Anxious activation was indexed by 1) subjective reports of anxiety and panic symptoms, 2) skin conductance level, heart rate and startle response magnitudes, and 3) the duration of stay in the chamber. Overall, escape frequency from the chamber increased with greater reported anxiety. However, a high proportion of patients completed the full exposure period despite intense anxiety. These 48 high anxious non-escapers were compared to 64 escapers. While the groups did not differ in reported anxiety or number and intensity of reported panic symptoms, different response patterns in autonomic arousal were observed. Escapers showed a stronger heart rate acceleration at the beginning of the exposure as compared to the end of anticipation. Furthermore, the escapers showed a lack of habituation of heart rate and skin conductance level. Heart rate acceleration was negatively correlated with duration ofexposure in the escaper group. Interestingly, no group differences were observed in sensitization and habituation of startle response magnitudes during exposure. Taken together, the data indicate that autonomic response patterns predict escaping behavior in high anxious PDA patients while subjective reports and startle response magnitudes did not. Theoretical implications are discussed.

Poster 14

THE HIDDEN COSTS OF ANXIETY ON COGNITIVE PERFORMANCE: IMPLICATIONS FOR ATTENTIONAL CONTROL THEORY

Tahereh L. Ansari, & Nazanin Derakshan Birkbeck, University of London

Descriptors: anxiety, attention, ERP

Evidence shows that anxiety impairs cognitive performance via its adverse effects on attentional control (Derakshan & Eysenck, 2009). In the antisaccade task, the working memory functions most affected by anxiety are the inhibition and shifting functions (Derakshan et al., 2009; Ansari et al., 2008). According to Attentional Control Theory (Eysenck et al. 2007), high anxious individuals (HA) invest more resources to overcome the effects of anxiety; and so anxiety is thought to be associated with hidden costs. Using ERPs we tested this prediction in a modified version of the mixed antisaccade task that manipulated the time between offset of instructional cue and the peripheral target (0 or 400 ms CTI) to which the antisaccade was made. HA compared with low-anxious (LA) individuals made more errors and had longer antisaccade latencies at 0 CTI, but both groups showed comparable performance at 400 ms CTI. ERPs to cue indicated that while both groups showed the expected N1/N2 patterns, the LA showed greater activity in anterior, central frontal, and temporal sites. However, ERPs in the CTI period showed that the HA had greater positivity than the LA in the parietal, temporal, and occipital sites indicative of larger P3 activity. Our findings indicate that anxiety impairs the recruitment of frontal areas necessary for attentional control. As a result the HA exert greater compensatory effort to maintain comparable performance levels to the LA. Implications of these findings are discussed with reference to recent models of anxiety and attentional control (Bishop, 2009).

Poster 15

THE EFFECTS OF NATURALISTIC STRESS AND SEROTONIN TRANSPORTER (5-HTT) GENOTYPE ON REWARD RESPONSIVENESS: IMPLICATIONS FOR DEPRESSION

Yuliya S. Nikolova, Ryan Bogdan, & Diego A. Pizzagalli Harvard University

Descriptors: depression, stress, serotonin transporter

Individuals carrying the short (S) allele of the serotonin transporter gene (5-HTTLPR) are more prone to depression under stress, than long (L) allele homozygotes. Stress-induced hedonic deficits may be a mechanism underlying the association between stress and depression. However, no human study has investigated whether stress-induced anhedonia may be influenced by 5-HTTLPR genotype. We hypothesized that exposure to a naturalistic stressor (school examinations) would disrupt reward learning, a key component of hedonic capacity, and that this effect would be more pronounced in S allele carriers, than L/L homozygotes. To assess reward learning, we administered a probabilistic reward task to 90 high school students over 2 study sessions in the 6-month period preceding their school-leaving examinations. For each participant, the two sessions were subsequently designated as the Stress and Control conditions, based on a self-report measure of exam stress. Within each session, participants reporting high exam stress had impaired reward learning, relative to participants reporting low exam stress. Additionally, a Genotype x Stress interaction emerged, such that S allele carriers had reduced reward learning in the Stress relative to the Control condition, whereas the inverse pattern was observed in L/L homozygotes. Our results indicate that naturalistic stress produces hedonic deficits, the susceptibility to which is modulated by 5-HTTLPR genotype. These findings identify anhedonia as a promising mechanism linking 5-HTTLPR genotype and stress to depression.

IS THE BDNF MET-ALLELE A PROTECTIVE FACTOR FOR THE 5-HTTLPR S-ALLELE ASSOCIATED REDUCTION OF GREY MATTER VOLUME?

Denise Doerfel1, Annett Werner2, Ruediger von Kummer2, & Anke Karl3 1Dresden University of Technology, 2Dresden University of Technology, University Hospital, 3University of Southampton

Descriptors: structural mri, voxel based morphometry, gene interaction Both Brain Derived Neurotrophic Factor (BDNF) and the serotonin transporter polymorphism (5-HTTLPR) have been discussed in the regulation of memory and the etiology of depression and anxiety. Studies using the common BDNF Val66Met polymorphism indicate that Met carriers show poorer hippocampal-dependent memory, lower hippocampal and amygdala volume, whereas the Val allele could be the risk allele in depression. Carriers of the 5-HTTLPR s allele show increased anxiety, an elevated risk of depression, and also decreased gray matter volume of amygdala and hippocampus. However, a recent study showed that the BDNF Met allele, which is predicted to have reduced reactivity to serotonin signaling, protects against s allele-associated decrease of the amygdala volume. In our study, we assessed the interactions of BDNF Val66Met with 5-HTTLPR genotype and their influences on brain morphology of 45 young healthy subjects using Voxel Based Morphometry. We found a significant interaction of the two genotypes indicating that the BDNF Met allele not only protects against 5-HTTLPR s allele reduction of amygdala and hippocampal volume but leads to greater volume in s allele carriers.

Poster 17

EEG DYNAMICS UNDERLYING THE P1 AND N170 FACE EFFECT

James Desjardins, & Sidney J. Segalowitz Brock University

Descriptors: N170, ICA, faces

The N170 ERP produces a reliably increased negative deflection to faces relative to other images at occipito-temporal locations centered around 170 ms poststimulus onset. The N170 is more generally associated with high-level, integrative visual processing. The earlier P1 ERP component measured as a positive peak around 100 ms post stimulus onset at occipital scalp sites is predominantly associated with low-level visual processing and has been less reliably documented as displaying a face-specific amplitude increase. In a dataset containing a robust P1 as well as an N170 increase at the scalp for faces compared to objects, an independent component clustering analysis revealed four component clusters accounting for the scalp variance of the ERP difference envelope during the P1 and N170 time periods. While three of the clusters having occipito-temporal scalp projections accounted for the greatest variance in the ERP difference envelope during the N170 latency (130 to 200 ms), the fourth cluster with an occipital projection accounted for the greatest variance in ERP difference envelope during the P1 duration (80 to 130 ms). While other methods have revealed independence of the P1 and N170, ICA applied to the train of single trials maintains the dynamics of the ongoing EEG processes underlying the averaged scalp ERPs. Single trial characteristics and individual differences related to the complex P1 and N170 face-effects are discussed.

Poster 18

SMOKING CUE REACTIVITY AS A LABORATORY MODEL OF SHORT-TERM TOBACCO ABSTINENCE

Jeffrey M. Engelmann, & Bruce N. Cuthbert University of Minnesota

Descriptors: tobacco, abstinence, emotion

Emotional responses to smoking-related cues are thought to contribute to relapse in quit-smoking programs, and it is important to develop new measures of responses to these stimuli. Nonsmokers (n 5 23) and smokers (n 5 42) participated in an affective picture viewing task, during which half the smokers were 24 h into a 48 h abstinence period and the remainder were nonabstinent. Eyeblink startle reflex, EEG, and peripheral measures were recorded while participants viewed a series of emotional pictures (15 each from 4 content categories: tobacco, pleasant, neutral, unpleasant) for 6 s each, ordered randomly with respect to content. Corrugator and Orbicularis EMG, P300 to the startle probe, and the late positive potential to picture onset at Pz all followed their familiar patterns of affective modulation across pleasant, neutral, and unpleasant pictures in both smokers and nonsmokers. Corrugator responses to tobacco pictures were smaller in nonabstinent smokers than in nonsmokers or abstinent smokers (p < .05). Startle probe P3 suppression to tobacco pictures was greater in smokers than in non-smokers (p < .01). There were no differences in responses to tobacco pictures between the groups using the other physiological measures. These results suggest that certain responses (corrugator and startle probe P3) may be promising measures of tobacco cue-reactivity, with relevance to studies regarding the role of physiological mechanisms in the efficacy of smoking-cessation treatments.

SADNESS AND REWARD SENSITIVITY: TRAIT AND STATE MOOD VARIABLES IMPACT THE MAGNITUDE OF THE FEEDBACK NEGATIVITY

Dan Foti, & Greg Hajcak Stony Brook University

Descriptors: ERP, FN, depression

The feedback negativity (FN) is a negative deflection in the ERP that is larger following feedback that indicates outcomes are worse than expected. Building upon behavioral and biological evidence demonstrating that depression is associated with abnormal reward processing, a recent study found that the enhancement of the FN to non-rewards relative to rewards was inversely related to depressive symptoms. In two studies, we sought to further examine the relationship between the FN and constructs relevant to depression. In the first study, individuals from an unselected sample were randomly assigned to either a sad or neutral mood induction; following the induction, ERPs were recorded during a gambling task in which participants could win or lose money on each trial. The enhancement of the FN to non-rewards relative to rewards was reduced among individuals who reported a more unpleasant mood following the induction, even after taking into account current levels of depressive symptoms. In the second study, the FN was recorded from never-depressed individuals who either reported parental history of depression or not. Following a negative mood induction, the magnitude of the FN in response to monetary losses was significantly reduced in individuals at risk for depression. Taken together, the results of these two studies indicate that the propensity to experience sadness moderates electrocortical measures of reward processing. The FN, therefore, may be useful in detecting both state and trait abnormalities in reward sensitivity relevant to the prediction of depressive symptoms.

Poster 20

ADVANCE MOVEMENT PREPARATION IN HEMIPARETIC PATIENTS: ELECTROPHYSIOLOGICAL INDICE

Philip Dean, Ellen Seiss, & Annette Sterr University of Surrey

Descriptors: motor preparation, hemiparesis, CNV

Movement preparation in patients with left hand hemiparesis (n 5 26) was investigated using a response priming paradigm, and in addition compared to age-matched controls (n 5 26). In this experiment, trials with valid, neutral and no response cues were presented 1300 ms before the imperative stimulus. Behavioral results showed validity effects for the control and the patient group's affected and unaffected hand. In addition, patients responded slower with both the affected and the unaffected hand compared to the control group. Analysis of CNV amplitude within the patient group revealed validity effects over the contralateral left hemisphere for the unaffected hand. Interestingly, similar validity effects where found for both hemispheres for the affected hand. This additional usage of the ipsilateral left hemisphere might reflect a greater effort required for movement preparation. A comparison between conditions of patient and control groups showed reduced CNV amplitude over central and centro-parietal right hemisphere for validly prepared trials of the unaffected hand compared to the control group's right hand. This might suggest a reduced usage of the lesioned ipsilateral cortex side possibly reflecting reduced innervation after the acute phase of the stroke. The competition for resources in the left hemisphere between the affected and unaffected hand and the reduced usage of the right ipsilateral hemisphere for the unaffected hand might explain why patients are generally slower than controls in the task.

Poster 21

AN ELECTROPHYSIOLOGICAL INVESTIGATION OF GLUCOSE ADMINISTRATION EFFECTS ON SENSORIMOTOR PROCESSING IN A MODIFIED ERIKSEN FLANKER TASK

Christopher Hope, Ellen Seiss, Philip Dean, & Annette Sterr University of Surrey

Descriptors: glucose, LRP, flanker task

Behavioural studies suggest that elevated blood glucose concentrations accelerate response times in complex tasks (Owens and Benton, 2004, Neuropsychobiology). With the present study we aimed to explore the mechanisms subserving elevated blood glucose effects (7 mmol/litre versus fasting levels of 5 mmol/litre) by studying EEG-derived indices of sensorimotor processing. More specifically, the Eriksen flanker task was used to examine glucose-dependent modulations of the P300, the stimulus lateralized readiness potentials (LRPs), and response-locked LRP, to see whether enhanced blood glucose levels affect stimulus evaluation, response planning, and response selection respectively. 10 participants took part in a within-participant double-blind 2-session experiment where either glucose (25 g) or placebo drinks were administered. Initial data suggests slower reaction times, higher error rates and delayed stimulus-locked LRP onset in incongruent compared to congruent and neutral trials. With placebo admin-

istration, error rates were increased for the non-dominant hand but not the dominant hand; no effects were found for the EEG parameters. This suggests that hyperglycaemia does not affect senorimotor processing in the flanker task. However, the placebo-related increase in error rates together with the findings of(Donohoe and Benton, 2000) support the proposition that beneficial effects of increased blood glucose levels on cognition might only occur when cognitive demands are high.

Poster 22

THE INFLUENCE OF COLOR ON THE PERCEPTION OF BRIEFLY PRESENTED EMOTIONAL SCENES

Maurizio Codispoti, Vera Ferrari, & Andrea De Cesarei University of Bologna

Descriptors: emotion, categorization, perception

Event-related potential studies have consistently found that emotionally arousing (pleasant and unpleasant) pictures elicit a larger late positive potential (LPP) than neutral pictures. This effect has been obtained when participants view color pictures, and recent studies have demonstrated that these emotional cues affect the LPP even when scenes are flashed for an extremely brief duration (25 ms). However, less is known regarding the influence of color on the affective modulation of ERPs. Particularly, when pictures are briefly presented, color could help with scene segmentation, and/or color could act as a cue for scene meaning via its association with scene-relevant concepts (e.g., red for mutilated bodies). To clarify the influence of color on affective picture perception, we compared LPPs to color versus black-and-white pictures, which were presented for very brief (25 ms) versus long (6 sec) exposure durations. Electroencephalogram was recorded with a 256 dense sensor array. Results indicated that removing color information had no effect on the affective modulation of the LPP, regardless of exposure duration. Both color and black-and-white pictures showed an identical affective modulation of the LPP, suggesting that this effect reflects the categorization of significant events. Moreover, these data seem to indicate that the categorization of very briefly presented emotional scenes does not critically rely on color information.

Poster 23

INDEXING EXTERNALIZING PSYCHOPATHOLOGY AS A MULTIVARIATE PHYSIOLOGICAL PHENOTYPE

Lindsay D. Nelson, Christopher J. Patrick, & Edward M. Bernat University of Minnesota

Descriptors: externalizing psychopathology, event-related potentials, impulsivity Externalizing (EXT) is a broad dimension that appears to underlie risk for a number of disorders involving deficient impulse control, such as attention deficit/hyperactivity disorder, substance abuse and dependence, and antisocial personality disorder. Prior work has documented deficits in event-related brain potential (ERP) responses in individuals prone to EXT. Specifically, high externalizers show reduced amplitudes in the error-related negativity (Hall et al., 2007), target P300, and feedback P300 (Bernat, et al., 2009a, 2009b). The present study (N 5 88) evaluated relations among these three brain response measures in order to examine their coherence as indicators of EXT. The three measures correlated with one another such that each loaded appreciably on a common factor when subjected to a factor analysis. A further factor analysis of the three ERP measures together with self-report EXT scores likewise yielded a single factor on which all four variables loaded strongly—despite the fact that one measure (EXT) was based on self-report. Furthermore, the creation of a physiologically-based composite variable using the three ERP measures yielded a variable that both predicted self-report indices of externalizing and accounted for externalizing-related variance in other common ERP indicators of externalizing. These findings indicate that the EXT construct can be indexed as a composite (multivariate) physiological variable (phenotype) and suggest that these ERP measures may share something that reflects a common neurobiological substrate of EXT.

Poster 24

ALCOHOL PLACEBO SELECTIVELY INCREASES THE FEEDBACK-RELATED NEGATIVITY IN A GAMBLING TASK

Lindsay D. Nelson1, Edward M. Bernat1, Alan R. Lang2, & Christopher J. Patrick1 1University of Minnesota, 2Florida State University

Descriptors: alcohol, placebo, feedback-related negativity

Alcohol intoxication is known to affect event-related potential (ERP) responses such as the P300 (Marinkovicetal., 2001), an ERP response to stimuli, and the error-related negativity (ERN), an ERP response to behavioral errors thought to reflect online action monitoring (Ridderinkhof et al., 2002). The present study evaluated the effects of alcohol consumption on two feedback-locked brain potentials in a gambling task: the feedback-related negativity (FRN), a measure thought to reflect a similar neural process as the ERN, and the feedback P300. Time-frequency analysis was used to isolate these overlapping components, yielding theta-FRN and delta-P300. Participants were assigned to one of three conditions: alcohol (mean BAC 5 .089%), placebo beverage, or no beverage. Similar to prior work on ERN and P300, both theta-FRN and delta-P300 were reduced in amplitude for the alcohol

relative to either control condition. However, interesting differences between the control conditions emerged. Specifically, the placebo group showed increased theta-FRN response to loss feedback relative to the no beverage group. Thus, the placebo condition was associated with the opposite effect relative to alcohol intoxication - enhanced initial processing of the loss stimuli relative to the no beverage condition. In addition to demonstrating the effects of alcohol consumption on the FRN, these findings support the idea of an overcompensation induced by the placebo administration and demonstrate how these two experimental control conditions differentially impact feedback ERPs.

Poster 25

FRONTO-STRIATO-LIMBIC HYPERACTIVATION IN OBSESSIVE-COMPULSIVE DISORDER DURING INDIVIDUALLY TAILORED SYMPTOM PROVOCATION

Daniela Simon, Christian Kaufmann, Kathrin Muesch, Eva Kischkel, & Norbert Kathmann Humboldt University, Berlin

Descriptors: anxiety, obsessive-compulsive disorder, fmri

Anxiety disorders have been linked to a pathologically hyperactivated cortico-amygdalar circuitry. To date, inconsistent findings regarding the amygdala's role in the pathophysiology of obsessive-compulsive disorder (OCD) have been provided, probably due to methodological variability across studies. Fourteen medication-free OCD patients and 14 healthy controls underwent a symptom provocation paradigm using individually tailored OCD-relevant, generally aversive and neutral stimuli presented for brief and long time periods during functional magnetic resonance imaging (fMRI). Relative to controls, patients showed increased activation in fronto-striatal brain areas that have consistently been linked to OCD when facing OCD-relevant contrasted with neutral stimuli. Brief stimulus exposure additionally revealed the recruitment of limbic and paralimbic areas, such as the amygdala, the anterior cingulate cortex (ACC) and the insula. Whereas amygdala engagement did also occur to equally arousing aversive control stimuli, hyperactivation of frontal brain regions was specific to OCD-relevant stimuli. Our results demonstrate a hyperactivity of the fronto-striatal circuit and connected limbic and paralimbic areas during individually tailored symptom provocation in a multisymptomatic sample of OCD patients. Amygdala hyperactivation in OCD patients reflected general emotional hyperarousal. The hyperactivation of frontal areas known to be engaged in emotion regulation points towards a sustained endeavor to suppress exaggerated emotional responses to symptom-related triggers.

Poster 26

REDUCTION OF PATHOLOGICAL INHIBITION OF CORTICAL REACTIVITY TO AVERSIVE STIMULI IN VISUAL SENSORY AREAS IN PTSD THROUGH EXPOSURE THERAPY

Hannah Adenauer1, Claudia Catani2, Julian Keil1, Hannah Aichinger1, Martina Ruf1, & Frank Neuner2 1University of Konstanz, 2University of Bielefeld

Descriptors: change of neural networks, exposure therapy, PTSD Posttraumatic Stress Disorder (PTSD) is associated with an altered processing of aversive or trauma-related stimuli. It remains unclear whether these functional abnormalities can be changed by psychotherapy. The present randomized controlled treatment trial examined whether exposure therapy causes alterations of affective picture processing in patients with severe and chronic PTSD. 32 (14 women; mean age: 33.3; SD 5 9.9) survivors of organized violence diagnosed with PTSD were randomly assigned to either 10 sessions of exposure treatment (Narrative Exposure Therapy, NET) or a waiting-list condition. Prior to and 4 month after the therapy, patients underwent an extensive clinical interview as well as an MEG examination employing a visual steady-state design to measure cortical correlates of affective picture processing. Minimum norm source localization was carried out to estimate the distribution of sources of the evoked neuromagnetic activity in the brain. PTSD symptom severity score declined significantly in the NET group, whereas symptoms persisted in the waiting-list condition (Time x Treatment interaction F(1, 17) 5 35; p < .05.

Poster 27

METHYLPHENIDATE MODULATES SENSORIMOTOR INTEGRATION AS REFLECTED BY NEUROELECTRIC OSCILLATIONS IN A GO/NOGO TASK

Yordan Hodzhev1, Juliana Yordanova1, Martin Diruf2, Oliver Kratz2, Vasil Kolev1,

& Hartmut Heinrich2,3 1Institute of Neurobiology, Bulgarian Academy of Sciences, 2University of Erlangen, 3Heckscher Hospital

Descriptors: methylphenidate, sensory and motor systems, sensorimotor integration Methylphenidate (MPH) is a psychostimulant drug acting mainly on the dopaminergic and noradrenergic systems. It is widely used in the treatment of attention-deficit/hyper-activity disorder (ADHD). Behavioral and pschophysiological studies have shown that MPH affects executive functions at the level of both sensory and motor systems. Thus

suggested effects of MPH on sensorimotor integration can be assessed by means of event-related neuroelectric oscillations (Yordanova et al, 2004). Fourteen healthy subjects (8 male, aged 20 - 40 years) performed a visual Go/NoGo task (S1-S2 paradigm). MPH (20 mg) or placebo were administered using a randomized, double-blind, cross-over design. Event-related electroencephalographic (EEG) activity after S2 was recorded. Time-frequency decomposition (wavelet analysis) was applied to evaluate power dynamics in delta, theta, slow and fast alpha, and beta frequency bands. At the performance level, faster reaction times and a trend towards less impulsivity errors under MPH vs. placebo were observed. MPH effects on EEG were specific for Go-trials at parietal locations. MPH enhanced slow alpha total power (8.29-9.68 Hz), fast alpha total power (10.32 -14.45 Hz) within the first 300 ms post-stimulus associated with motor production. It might be proposed that a single dose of 20 mg MPH modulates early visual information processing related with motor response generation in healthy adults.

Poster 28

GENDER-SPECIFIC DEVELOPMENT OF AUDITORY INFORMATION PROCESSING IN CHILDREN: TIME-FREQUENCY ANALYSIS

Plamenka Nanova, Vasil Kolev, Laura Lyamova, & Juliana Yordanova Institute of Neurobiology, Bulgarian Academy of Sciences

Descriptors: time-frequency erp components, gender, children

Developmental changes in auditory processing mechanisms depend on gender in children as reflected by earlier and larger N1, P2, N2, and P3 ERP components in 7-10 year old girls than boys. The aim of the present study was to provide evidence for the neuro-physiologic sources of these gender differences. Three neurophysiologic sources that could account for the gender effects on auditory ERP components were explored: (a) background power, (b) stability of synchronization of oscillatory neuroelectric networks, and (c) shifts of task-specific slow waves. Thirty six healthy children were divided into two age groups (7-8 and 9-10 years-old), pairwise matched for age. Auditory ERPs were recorded in a passive listening condition, a simple reaction task and a serial learning reaction task. Single-sweep ERPs were analyzed in the delta (.5-4 Hz), theta (4-7 Hz), slow (8-10 Hz), and fast (10-14 Hz) alpha frequency bands. It was found that delta and slow alpha phase-locking increased with development only in girls, whereas theta phase-locking was overall stronger in girls than boys. Parietal delta magnitude reflecting task-specific shifts in slow waves increased with development only in girls. The results demonstrate that gender differences in auditory ERPs basically originate from a stronger functional synchronization of oscillatory responses subserving stimulus processing. It is concluded that the functional maturation of oscillatory auditory networks, whose synchronization progressively increase with age, is more accelerated in girls than in boys.

Poster29

EVENT-RELATED POTENTIALS TO SCHEMATIC SPIDERS AND FLOWERS IN A CHANGE DETECTION TASK

Nathalie Peira, Joakim Norberg, & Stefan Wiens Stockholm University

Descriptors: change detection, fear, ERP

Feared stimuli have been found to draw attention in many experimental tasks. The present study used ERPs to investigate whether feared stimuli are processed differently than non-feared stimuli in a change detection task. Spider fearful (n 5 14) and non-fearful (n 5 16) participants detected schematic spiders and flowers controlled for low-level features appearing in black and white backgrounds. Because a stimulus appearing in a background gives rise to a motion signal that makes it easy to detect, we removed the motion signal by introducing a blank interval before the change. Overall, participants detected 41.7% of the targets on trials with a blank. As a manipulation check, 25% of the trials contained no blank and had a very high detection rate (98.2%). Detected changes were associated with a more positive peak (P3) at central sites at 450 to 510 ms (p < .001). The groups did not differ in detection performance (d'; p > 0.30). However, fearful participants tended to show a more positive P3 to detected spiders than flowers whereas non-fearful did not; groups did not differ for undetected pictures (picture type x fear group x response; p 5 .13). This suggests that schematic representations of feared stimuli may be processed differently than non-feared stimuli only if they are detected.

Poster 30

DISSOCIATION OF PSYCHOLOGICAL AND CARDIOVASCULAR CAFFEINE EFFECTS IN HIGH AND LOW ANXIETY SENSITIVE CAFFEINE USERS

Jan P. Stender1, Christiane A. Melzig1, Christiane Modess1 Terry Blumenthal2, & Alfons O. Hamm1 1University of Greifswald, 2Wake Forest University

Descriptors: anxiety sensitivity, caffeine, heart rate

The theory of anxiety sensitivity proposes an increased sensitivity to somatic arousal sensations in high anxiety sensitive persons. To elucidate the relationship between phys-

iological responding, expectations and subjective feelings of somatic arousal the present study investigated effects of caffeine on subjective (mental activation, feeling of heart racing or pounding) and cardiovascular parameters (heart rate, HRV) in 21 high and 19 low anxiety sensitive caffeine users in an expectation controlled substance administration design (coffee vs. lemon soda crossed with 4 mg/kg caffeine or no caffeine). Thirty minutes after the intake of caffeine subjective mental activation and perceived heart racing increased in all participants. As expected, these effects were more pronounced in high anxiety sensitive participants. In contrast to the subjective perception of somatic processes, heart rate showed a pronounced decrease after caffeine intake in low anxiety sensitive caffeine users. Interestingly, this caffeine dependent modulation was not found in high anxiety sensitive persons. Contrary to some existing research we did not find effects of expectation (Coffee vs. Soda) on either subjective feeling or cardiovascular responding. Results will be discussed regarding the relevance of anxiety sensitivity as a possible moderating factor of subjective and physiological caffeine effects.

Poster 31

THE INFLUENCE OF EMOTION ON RESPIRATORY-RELATED EVOKED POTENTIALS

Andreas von Leupoldt1, Andrea Vovk2, Margaret M. Bradley2, Andreas Keil2, Peter J. Lang2, & Paul W. Davenport2 1University of Hamburg, 2University of Florida

Descriptors: emotion, ERP, respiration

Psychological factors such as emotion can influence the perception of respiratory sensations, but the neural mechanisms underlying this modulation are unknown. We therefore examined the impact of viewing pleasant, neutral, and unpleasant affective picture series on the respiratory-related evoked potential (RREP) elicited by short in-spiratory occlusions in healthy volunteers. We observed reduced P3 amplitudes of the RREP for inspiratory occlusions presented during viewing pleasant or unpleasant series, when compared to those presented during the neutral series. Earlier RREP components, such as Nf, P1, N1, and P2, showed no difference between emotional conditions. The present findings suggest that emotion impacts the perception of respiratory sensations by reducing the attentional resources available for processing afferent respiratory sensory signals.

Poster 32

THE IMPACT OF EMOTION ON THE PERCEPTION OF DYSPNEA IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE

Andreas von Leupoldt1, Karin Taube2, Maren Henkhus1, Helgo Magnussen3, & Bernhard Dahme1 1University of Hamburg, 2Atem-Reha Hamburg, 3Pulmonary Research Institute at Hospital Grosshansdorf

Descriptors: emotion, perception, respiration

Dyspnea (breathlessness) is the impairing cardinal symptom of chronic obstructive pulmonary disease (COPD). Emotions can profoundly impact the perception of dyspnea, however, little is known about this relationship in patients with COPD. The present study examined the impact of viewing pleasant versus unpleasant affective picture series on perceived dyspnea during two cycle ergometer exercise tests (CEET) in 30 patients with COPD. Whereas cardiopulmonary measures indicated comparable levels of exercise intensity during both CEETs, parallel viewing of unpleasant affective pictures resulted in increased dyspnea ratings compared to parallel viewing of pleasant affective pictures. Additional regression analyses demonstrated that increases in the affective unpleasantness of dyspnea, but not in the sensory intensity of dyspnea, during CEETs were predictive of greater dyspnea during activities of everyday life and reduced health-related quality of life. The present findings suggest that a negative emotional state is associated with increased levels of perceived dyspnea in patients with COPD, which underscores the importance of targeting the emotion-dyspnea-relationship in this patient group.

Poster 33

DOWN REGULATION OF INSULAR CORTEX ACTIVITY DURING DYSPNEA AND PAIN IN ASTHMA

Andreas von Leupoldt1, Tobias Sommer2, Falk Eippert2, Sarah Kegat1, Hans J. Baumann2, Hans Klose2, Bernhard Dahme1, & Christian Buechel2 1University of Hamburg, 2University Medical Center Hamburg-Eppendorf

Descriptors: pain, perception, respiration

Dyspnea (breathlessness) is an impairing symptom of asthma, but the brain mechanisms underlying the perception of dyspnea in these patients are unknown. The present fMRI-study examined whether patients with asthma show different brain responses during perceived dyspnea than healthy controls. These responses were compared with brain activations during perceived pain to examine possible neural generalization processes to another unpleasant bodily sensation. While positioned in a 3 Tesla scanner, 14 asthma patients and 14 healthy controls repeatedly received conditions of mild and severe

resistive load induced dyspnea and mild and severe heat pain. The sensory intensity of dyspnea and pain was rated similar by patients and controls, whereas affective unpleasantness ratings for both sensations were reduced in patients. This was mirrored by reduced activity in the insular cortex, but increased activity in the periaqueductal grey (PAG) in asthma patients during dyspnea and pain. Connectivity analyses demonstrated that the asthma-specific down regulation of the insular cortex during dyspnea and pain was moderated by increased PAG activation. The findings show a down regulation of insular cortex activity by the antinociceptive PAG in patients with asthma during perceived dyspnea, but also pain. This could represent an asthma-specific brain habituation mechanism to decrease the perceived affective unpleasantness of dyspnea, which generalizes to other unpleasant bodily sensations such as pain which are processed by common brain areas.

Poster 34

DECLINE OF THE VISUAL ERP DURING THINKING

Akihiro Yagi1, Atsushi Noritake2, Shinpei Nagae1, & Tomomi Shikata1 1Kwansei Gakuin University, 2Kansai Medical University

Descriptors: ERP, eye movement, thinking

When a person is given a question; e.g., mental calculation or imaging, she/he shifts the gaze to another position with vacant eyes. While a person thinking about something, visual function would be declining. We can obtain a EFRP (Eye Fixation Related Potential) with averaging EEGs at terminations of saccadic eye movements. EFRP varies with visual perception and attention. In this experiment, we measured EFRP during thinking, while each participant faced stripe pattern. Ten participants faced to a stripe pattern varied with sinusoid luminance level. They were assigned three tasks: 1) mental calculation task, 2) image task, and 3) eye movement task. For task one, each participant was given orally 30 questions of mental calculation and asked to solve the question. For task two, 10 image tasks (e.g., Give names of the world inheritance) were assigned. For task three, the participant was asked to move eyes on the stripe pattern. Eye movements and EEGs (Oz, Pz, Cz) were recorded on a hard disk. When a participant started to think about a question, an involuntary saccadic eye movement (saccade) occurred. EEGs associated with terminations of saccades were averaged to obtain EFRP. The early positive component with latency of about 80 ms of EFRP appeared from all participants in the eye movement task. The amplitudes of the component in two thinking tasks were significantly smaller than the amplitude in the eye movement task. Some subjects showed alpha waves after eyes shifted. Results showed that visual function declined while a person was thinking about something.

Poster 35

POTENTIATION OF THE ACOUSTIC STARTLE REFLEX DURING IMAGERY OF SELF-ESTEEM VIOLATING SCENES IN PATIENTS WITH BORDERLINE PERSONALITY DISORDER

Anke Limberg1, Sven Barnow2, Harald J. Freyberger1, & Alfons O. Hamm1 1University of Greifswald, 2University of Heidelberg

Descriptors: startle reflex, script-driven imagery, borderline personality disorder According to Linehan's biosocial theory, Borderline Personality Disorder (BPD) is primarily a disorder of the emotion regulation system. BPD patients show stronger reactions to emotional evocative cues, especially for affective stimuli like violation of self-esteem or abandonment. In the current study, psychophysiological responses in a script-driven imagery paradigm were assessed to test the reactivity of BPD patients to disorder-related cues compared to standard emotional stimuli. In 35 unmedicated patients with BPD and 35 healthy controls startle responses and autonomic measures were recorded while the subjects were first reading and then imagining personalized and standardized unpleasant, neutral and pleasant scripts. The standardized unpleasant category included disorder-specific scripts about self-esteem violation and abandonment as well as standard unpleasant scripts describing diverse threat scenarios. Compared to healthy controls, patients with BPD rated all scripts as more unpleasant and arousing. Furthermore, in comparison to neutral scripts, BPD patients displayed a pronounced startle potentiation during imagery ofdisorder-specific scripts but not during imagery of standard threat. This effect was not observed in the control group. These data confirm a specific emotional vulnerability of patients with BPD.

Poster 36

NATURAL IMAGE STATISTICS AND BRAIN POTENTIALS

Andreas Low, Mathias Weymar, & Alfons O. Hamm University of Greifswald

Descriptors: EEG/ERP, natural image statistics

Event-related potentials (ERPs) are reliably modulated by semantic and emotional properties of pictorial stimuli. On the other hand, function of the visual system is strongly connected to physical image properties (e.g. contrast, spatial frequency). Here, we studied the influence of statistical properties of natural images on event-related potentials. 20 participants passively viewed a large number (n 5 1024) of photographs,

while the electroencephalogram was recorded from 256 sensors. Stimuli were divided into quartiles according to various statistical image parameters (e.g. brightness, contrast, spatial frequency) and for each quartile an ERP was created. Initial analysis of the data reveal that late components (> 300 ms) are not related to the examined physical parameters. However, during early time windows (< 300 ms) brain potentials were modulated by physical features. Enhanced negativity (starting around 150 ms after picture onset) over posterior sensors was found for images of lower complexity (estimated by JPEG compressibility) relative to images of higher complexity. Moreover, the P1 component was enhanced for images with higher brightness values compared to darker images. Results indicate that physical image features are reflected in early ERP components and therefore need be controlled in ERP studies of emotion and cognition using natural images.

Poster 37

ANTICIPATION OF INTEROCEPTIVE THREAT - AN FMRI STUDY

Katharina Holtz, Christiane A. Melzig, Julia Wendt, Martin Lotze, & Alfons O. Hamm University of Greifswald

Descriptors: anticipatory anxiety, interoceptive threat, anxiety sensitivity Although the anticipation of interoceptive threat is of specific relevance for etiological models of panic, it has rarely been investigated applying imaging technology. Therefore, the current study was designed to evaluate a novel paradigm suitable for the fMRI environment using a symptom provocation procedure to establish an interoceptive threat. As a sample analogue to panic patients concerning their high fear of inter-oceptive arousal sensations, 15 subjects high and 14 subjects low in anxiety sensitivity were trained in an anticipation of and exposure to a repeated hyperventilation task outside the scanner. In a second session, the participants expecting repetitions of this procedure, were exposed to short periods (18 sec) of either anticipation of hyperventilation or normoventilation (each condition indicated by a different colored slide) while BOLD-responses were recorded. During anticipation of hyperventilation all participants showed increased activation of a neural network consisting of the insula, anterior cingulate cortex, and orbitofrontal cortex. Highly anxiety sensitive persons showed an increased activation ofthis network during both conditions, possibly indicating a greater sensitivity to the experimental context in this group. This novel paradigm proved its usefulness for the fMRI environment and will be discussed with regard to future implementations in studying interoceptive threat.

Poster 38

USING REAPPRAISAL OR RESPONSE MODULATION TO INCREASE AND DECREASE EMOTIONAL RESPONSES: AN FMRI STUDY

Elisa C.K. Steinfurth, Julia Wendt, & Alfons O. Hamm University of Greifswald

Descriptors: emotion regulation strategies, reappraisal and response modulation, amygdala

People differ in their preferred regulation strategies to modulate emotional responses. Among the most commonly used emotion regulation strategies are reappraisal and response modulation. Thus, in the current study comparing these strategies, participants were instructed to regulate their emotional responses induced by pleasant and unpleasant pictures either by varying their interpretation of the picture content (reappraisal) or by varying their elicited tension and expression (response modulation) while BOLD responses were recorded. Region-of-Interest analyses revealed that independent of the applied regulation strategy, orbitofrontal cortex (OFC) activity was increased both during enhancing and reducing the emotional response. As expected, activity of the amygdala generally increased when instructed to enhance the emotional response and decreased when instructed to reduce the emotional response. However, response modulation appeared to be effective to enhance amygdala activity but rather ineffective in decreasing emotional responses elicited by unpleasant pictures. These results confirm the involvement of the OFC in emotion regulation. Furthermore, the findings support the hypothesis that suppression of negative emotion-expressive behavior does not alter the negative emotional significance as indicated by amygdala activity.

Poster 39

GESTATIONAL AGE PREDICTS NEONATAL STARTLE EYE BLINK

Harriet J. Huggenberger1, Susanne E. Suter1, Terry Blumenthal2,

& Hartmut Schachinger3 1University of Basel, 2Wake Forest University, 3University of Trier

Descriptors: startle eye blink, gestational age, heart rate

The human startle eye blink response to abrupt and intense acoustic, visual, or tactile stimulation does not depend on voluntary control, can be activated during sleep, and is already present immediately after birth. Startle is based on activation of a brainstem circuit that may not be fully matured in neonates, indicating that gestational age may play a role in neonatal startle. Thus, the present study examined the effect ofgestational age on the startle eye blink and heart rate in full-term newborns. Sixty- five healthy full-

term infants were tested 72-96 hours after birth. Acoustic broadband white noise stimuli of 50 ms duration and instantaneous rise and fall times were delivered unilaterally with inter-stimulus intervals of 15 s. During the procedure infants remained in a quiet sleep stage. Startle eye blink responses were investigated by surface EMG of the orbicularis oculi muscle. EMG response magnitudes were log transformed and averaged per subject. ECG (lead II) signals were assessed and beat-to-beat heart rate was calculated offline. Mean duration of gestation of the neonates was 40 (SD 5 1.3; range 37 to42)weeks. Startle eye blink response magnitude was positively correlated (r 5 0.317; p 5 .010) with gestational age, but heart rate responses were not. These results show enhanced acoustic startle reactions in full-term neonates with higher gestational age, suggesting that maturation effects of brainstem structures may play a role in neonatal startle.

Poster 40

ERROR-RELATED NEGATIVITY AND FEEDBACK-RELATED NEGATIVITY IN OBSESSIVE-COMPULSIVE UNDERGRADUATES

Emily M. Stanley, & Robert F. Simons University of Delaware

Descriptors: anxiety, ERN, FRN

The Error Related Negativity (ERN) is larger in highly anxious individuals than it is in normal controls (Hajcak, McDonald & Simons, 2003). Much less is known about the Feedback Related Negativity (FRN) and anxiety. The ERN and FRN share a common source in the anterior cingulate cortex (ACC; Luu et al., 2003). This, together with the functional similarity that errors and feedback may serve in performance monitoring, might suggest that both the ERN and FRN would be increased in anxious individuals. On the other hand, a recent study by Foti and Hajcak (2009) reported a negative relationship between the FRN and negative affect suggesting that the relationship between the ERN, FRN and anxiety may not be straight forward. In the present study, we examined this relationship by measuring the ERN and FRN in an undergraduate population with high and low levels of self-reported Obsessive-Compulsive behaviors. We measured the ERN as the difference between error and correct trials during a flankers task and the FRN as the difference between lose and win trials during a mock gambling task. Our results indicated that the ERN is larger but the FRN is smaller in the high-compared to low- OC group. Furthermore, these relationships were evident even within the group of high-anxious subjects; as OC symptom scores increased, the ERN grew larger and the FRN grew smaller. These results suggest that the ERN and FRN are functionally distinct ERP components and that the role played by the ACC in trait anxiety (and negative affect in general) is more complex than once assumed.

Poster 41

DISSOCIABLE ROLES FOR EMPATHY AND SYMPATHY IN WILLINGNESS TO SHARE: AN FMRI STUDY

K. Richard Ridderinkhof1, Johannes Fahrenfort1, Ben Pelloux2, & Frans Van Winden2 1University of Amsterdam, 2University of Amsterdam, Centre for Research in Experimental Economics and Political Decision-Making

Descriptors: social neuroscience, neuroeconomics, empathy

Willingness to share monetary benefits has been argued to relate to empathy. Empathy involves activation in neural networks, most prominently the anterior insula (AI) and anterior cingulate cortex (ACC). Sympathy, or caring about the interests of others based on positive interactions with those others, involves activation in neural networks, most prominently the superior temporal sulcus (STS) and posterior cingulate cortex (PCC). Here we show that willingness to share monetary benefits increases after positive interaction in a public goods game, and that this increased willingness to share is predicted by activation of the STS and PCC. Activation of the AI and ACC did not predict willingness to share, not even for people scoring high on empathy scales. These patterns suggest dissociable roles for empathy and sympathy in one's willingness to share monetary benefits with others.

Poster 42

THE N400 AS A SPECIFIC INDEX OF THE SAUSSUREAN ARBITRARINESS POINT IN WORD RECOGNITION

Aniela I. Franca1, Miriam Lemle1, Aline R. Gesualdi2, Mauricio Cagy3, & Antonio C. Infantosi1 1Federal University of Rio de Janeiro, 2Federal Centers of Technological Education (CEFET ), 3Fluninense Federal University

Descriptors: neurophysiology of language, word decomposition, N400 This is a priming study of Brazilian Portuguese words, matched for frequency and size, assessed by reaction times (RTs) and event-related brain potentials (ERPs) extracted from 36 college students. The test had 360 prime-target pairs, 120 of which were experimental: 60 pairs made up the Phonological Group (PG), sharing similar onsets (tarántula-tartaruga 'tarantula'-'turtle'); and 60 pairs made up the Morphological Group (MG): (globo-globalizar 'globe'-'globalize'). Both PG and MG were further

divided into 3 subgroups of increasing linear lengths: PG1, PG2, PG3 / MG1, MG2, MG3. In PG, the Saussurean Arbitrariness Point (SAP), i.e. the crucial point where form is mapped to meaning, is at the end of words. Contrastingly, in MG, SAP is internal. In ''globalizar'' SAP is at globo where the first categorizing morpheme merges with the root. The layers beyond globo (glob_al, glob_al_izar) are not interpreted arbitrarily. In PG, a target as tartaruga is similar in linear size to globalizar, but different internally because SAP lies at the end. The hypothesis was that if the N400 were an index of SAP, then tartaruga should yield a longer-latency N400 than globalizar because SAP is at the end of PG words but not in MG words. The results were that in PG, the longer the target, the longer RTand the longer-latency N400 were found. Nevertheless, in MG, difference in linear size yielded similar N400 latencies. These findings point to the significant conclusion that while RTs relate to the whole word, N400 ERPs seem to index SAP.

Poster 43

PUTTING SYNTACTIC TABS ON SEMANTIC RELATEDNESS: AN ERP STUDY OF BRAZILIAN PORTUGUESE WORDS

Juliana N. Gomes1, Aniela I. Franca1, Mauricio Cagy2, & Antonio C. Infantosi1 1Federal University of Rio de Janeiro, 2Fluminense Federal University

Descriptors: semantic decomposition, syntax ofsemantics, ERP How much closer is BANANA to peel than BANANA to fall or PEEL to banana? This is a masked priming ERP experiment, with 4 series of word pairs and 1 series of word/ non-word pairs to gauge levels of semantic relatedness. It engaged 40 college students, native speakers of Portuguese in a lexical decision task. Under standard Connectionist assumptions, semantic relatedness bears on the frequency that two words appear in the same discourse. Challenging this view, we tested the hypothesis that it bears on syntax: when specific semantic aspects of the target are involved in the definition of prime (PEEL-banana), speakers automatically insert the nouns into a structure. This way there is proper connection between the words: BANANA with peel (Series 1). Conversely, if target does not define prime, as in BANANA-fall (Series 2), then more structure might be needed: (BANANA with peel: PEEL to fall). If this is true, then BANANA-peel should yield a faster reaction time (RT) and a shorter latency ERP than BANANA-fall. Still iftarget were completely unrelated to prime, (BANANA-computer - Series 3), connection should be idiosyncratic and slower on average across subjects. Results revealed that targets in Series 1 yielded the fastest RTs and shortest latency ERPs. Moreover, since directionality would only matter to a syntactic account, Series 1 was tested in reverse (PEEL-banana - Series 4), and it resulted in slower RTs and ERP latencies than those in Series 1. These findings point to an underlying structure that spontaneously pops up to connect words: the syntax of semantics.

Poster 44

CARDINALITY AND SYNTAX: A BEHAVIORAL AND AN ERP STUDY OF TWO INTERACTING COMPUTATIONS

Aniela I. Franca1, Miriam Lemle1, Mauricio Cagy2, & Antonio C Infantosi1 1Federal University of Rio de Janeiro, 2Fluminense Federal University

Descriptors: pragmatics, number cognition, ERP

A stirring investigation in linguistics examines the interface between syntax and number cognitions. A speculation is that the capacity to count springs from the language capacity to merge recursively. Numbers naturally define a range of values that go from a lower bound to a higher bound. If there are 4 chairs in a room, it is fair to say that there is at least 1 chair in the room (lower bound), or that there are 3 or the most 4 chairs (higher bound). But, while adults settle for the highest possible value, children seem to accept all intermediate ones. This study compares two experiments about the pragmatics of numbers: a behavioral study with children and an ERP study with adults. Volunteers were presented a figure, for instance, a saw nursing 4 piglets. Then they heard a sentence: The saw is nursing 3 piglets. Their task was to decide if the sentence matched the picture. The behavioral results confirmed literature findings that children from 4 age groups (3,4,5 and 6) accept lower bound numbers. The ERP results from adults disclosed 3 waves of interest: at 400, 600 and 700 ms. Both pragmatically congruous and incongruous sentences were related with an overlapping N400. The component at 600 ms peaked higher and slower when the sentence was pragmatically incongruous. Finally, the findings in relation to the third wave showed a statistically meaningful difference in amplitude between stimuli that depicted the exact value and those that did not. This result can be explained if we propose a cardinality congruence-checking at the end of the computation of the verb.

Poster 45

UNILATERAL HAND CONTRACTIONS AND RESPONSES TO CYBERBALL: THE ROLE OF ASYMMETRICAL FRONTAL CORTICAL ACTIVITY IN HOW WE REACT TO OSTRACISM

Carly K. Peterson, Kim Hawkins, & Eddie Harmon-Jones Texas A&M University

Descriptors: frontal asymmetry, approach motivation, social rejection Previous research has shown that greater relative left frontal cortical activity is associated with approach-related responses to social rejection. To extend and more firmly

establish the causal link between frontal asymmetry and these responses, the present research examined the effect of unilateral hand contractions on physiological and emotional responses to ostracism during a Cyberball game. As predicted, right-hand compared to left-hand contractions caused greater relative left frontal cortical activity during the contraction period as well as during ostracism. Right-hand contractions also caused greater self-reported anger but decreased sadness and distress in response to social rejection. Across all participants, relative left frontal cortical activity during ostracism related to greater self-reported anger and decreased perception of inclusion during the game. Greater relative EMG activity in the right arm related to increased left frontal cortical activity during the contractions and Cyberball game. Taken together, results provide further evidence for the role of left frontal cortical activity in approach-oriented responses to social rejection. Furthermore, this study gives additional support for manipulating frontal cortical activity via unilateral hand contractions, which allows for better experimental designs in this area of research.

Poster 46

MOTIVATIONAL BODY POSTURES LEAN TOWARD LEFT FRONTAL BRAIN ACTIVITY

Tom F. Price, Carly K. Peterson, & Eddie Harmon-Jones Texas A&M University

Descriptors: motivation

The current study examined the effect of different motivational body postures on relative left frontal cortical activity, which has been associated with approach motivational processes. Three body postures were manipulated to create three levels of approach motivation. Relative to an upright sitting position, leaning forward with arms extended was predicted to increase approach motivation and relative left frontal activity, whereas reclining backward was predicted to decrease approach motivation and relative left frontal activity. In each body posture, to ensure that participants were in a positive affective state, participants contracted their facial muscles to form a smile. Results indicated that the leaning forward condition caused greater left frontal cortical activation as compared to the upright and reclining backward conditions. This is the first study to demonstrate that leaning forward is associated with increased left frontal cortical activity and it suggests that this body position evokes approach motivation. The results add further support to the theory that certain psychological states may be grounded or embodied. Future research will examine the effects of these body postures on cognitive processes related to a goal-directed focus.

Poster 47

PSYCHOPHYSIOLOGICAL EVIDENCE FOR VIOLENT VIDEO GAMES IMPAIRING COGNITIVE CONTROL

Christopher R. Engelhardt, J. Scott Saults, Eddie A. Vasquez, Bryson E. King, & Bruce D. Bartholow University of Missouri, Columbia

Descriptors: violent video games, cognitive control, ERP

We tested the effect of violent video games on cognitive control. Previous research suggests a causal link between violent video games and aggression, but the underlying mechanisms remain unclear. One possibility is that violent video game play produces temporary decrements in executive control, leading to difficulty in regulating aggressive responses. Here, ERPs were recorded from 50 undergraduates who were randomly assigned to play a nonviolent or violent video game for 20 min prior to completing a go/ no-go spatial Stroop task and an impulsive aggression task. Task order was manipulated between subjects. We hypothesized that violent game play would lead to decreased N2 (conflict monitoring) and negative slow wave (NSW; control implementation) amplitude during the spatial Stroop task. Results showed that the N2 on incompatible ''go'' trials was larger for nonviolent than for violent game participants, but only for subjects who completed the Stroop task before the aggression task. A similar pattern occurred on ''no-go'' (i.e., inhibition) trials. Additionally, the NSW was larger among nonviolent compared to violent game participants, but only for those who completed the aggression task first. These findings, particularly the task order effects, support the hypothesis that violent game exposure produces short-term deficits in conflict-related cognitive control processes, which largely disappear after an intervening aggression-related task.

Poster 48

THE NEURAL SOURCES OF THE FACE-SENSITIVE N170 EVENT-RELATED POTENTIAL

Esther Alonso-Prieto1, Stephanie Caharel1, Laurence Dicrot1,

Ernesto Palmero-Soler1,2, & Bruno Rossion1 1Catholic University of Leuven, 2Advanced Neuro Technology

Descriptors: faces, N170, brain generators

Face perception is subtended by a distributed network of areas in the human brain, as evidenced by fMRI. A subset of these areas presents a selective response to faces

compared to other object categories. ERP studies offace perception have identified the first reliable face-preferential response at the onset of the N170. However, the relationship between the cortical face network identified in fMRI and the N170 remains unclear. We recorded ERPs (128-channels system) in 15 subjects presented with four kinds of stimuli used in an independent fMRI experiment (50 subjects): pictures of faces and cars, with phase-scrambled versions. Neural generators were determined using the inverse method swLORETA which exhibits a small localization error even in the presence of noise and deep sources. Results were mapped in a 3D regular grid of points that covered the head volume which was co-registered with the electrodes on an MRI from a single individual (Colin27). Relevant sources were determined by imposing an activation threshold corresponding to 60% of the highest activation during the N170. For faces-scrambled faces, there was a strong right hemispheric dominance, with major contributions of the posterior STS and lateral fusiform gyrus, which were activated the most in the independent fMRI experiment. There was also a strong contribution of the bilateral parahippocampal gyrus, an area that is deactivated in fMRI for faces, but no contribution of the amygdala (a closed electrical field). Perceiving pictures of cars (vs. scrambled cars) activated the posterior fusiform gyrus bilaterally.

Poster 49

RECOGNIZING AN INDIVIDUAL FACE: 3D SHAPE CONTRIBUTES EARLIER THAN 2D SURFACE REFLECTANCE INFORMATION

Stephanie Caharel1, Fang Jiang1, Volker Blanz2, & Bruno Rossion1 1Catholic University of Leuven, 2University of Siegen

Descriptors: N170, face recognition, erp adaptation

A human face is recognized efficiently by means of two main sources of information: three-dimensional (3D) shape and two-dimensional (2D) surface reflectance (texture) (O'Toole et al., 1999). Here we used event-related potentials (ERPs) in a face adaptation paradigm (Jacques, d'Arripe & Rossion, 2007) to examine the time-course of processing for these two types of information. With a 3D morphable model (Blanz & Vetter, 1999), we generated pairs of stimuli that were either identical, varied in 3D shape only, in 2D surface reflectance only, or in both. Sixteen participants discriminated individual faces in these 4 types of pairs, in which a first (adapting) face was followed shortly by a second (test) face. Observers were as accurate and fast for discriminating individual faces based on either 3D shape or 2D surface reflectance, but were faster when both sources of information were present. The face-sensitive N170 component (~ 160 ms following the test face) increased relative to repetition of the same face for changes in 3D shape, but not for changes in 2D reflectance, especially in the right occipitotemporal cortex. At about 250 ms, both kinds of information contributed equally, and the largest difference in amplitude compared to the repetition of the same face was found when both 3D shape and 2D reflectance were combined, in line with observers' behavior. These observations indicate that evidence to recognize individual faces accumulate faster in the right hemisphere human visual cortex from diagnostic 3D shape information than from 2D surface reflectance information.

Poster 50

ELECTROPHYSIOLOGICAL EVIDENCE OF ATTENTIONAL BIAS FOR ALCOHOL CUES IN SOCIAL DRINKERS DIFFERING IN ALCOHOL SENSITIVITY

Eunsam Shin, Sarah A. Lust, Erika A. Henry, & Bruce D. Bartholow University of Missouri, Columbia

Descriptors: attentional bias, alcohol sensitivity, motivational incentive Research indicates that a low sensitivity (LS) to the acute effects of alcohol is a risk factor for alcoholism. We examined whether LS individuals would differ from high sensitivity (HS) individuals in initial attentional orienting to alcohol cues and in maintaining this initial orienting. Event-related potentials were recorded while LS and HS participants, recruited based on a self-report measure assessing alcohol consumption experiences, performed a modified dot-probe task in which pictures of one alcoholic and one nonalcoholic beverage were presented in each hemifield, followed by a target replacing either alcohol cue locations (AT) or nonalcohol cue locations (NAT). Participants responded to the color of the target (blue or green) using one of two keys. Results showed: (a) in response times the LS participants showed a larger difference between the ATand NAT conditions than HS participants; (b) the posterior P1 (an index of attentional orienting to a particular location), peaking about 150 ms, was larger for the AT trials than for the NAT trials among LS participants, whereas HS participants showed the opposite pattern; (c) ipsilateral invalid negativity (IIN), reflecting attentional reorienting and occurring about 200 - 300 ms, was similar for both conditions in the HS participants. Yet, the IIN was less negative for the AT trials than for the NAT trials in the LS participants. These results suggest that both groups exhibit attentional biases, LS toward alcohol cues and HS against alcohol cues, but only LS individuals maintained their biases at a later processing stage.

5-HTTLPR, TPH2-703G/T AND THE NEURAL BASIS OF EMOTION REGULATION

Andrea Hermann1, Katharina Tabbert1, Yvonne Kiipper2, Anja Schmitz3, Dieter Vaitl1, Jurgen Hennig2, & Rudolf Stark1 1Bender Institute of Neuroimaging, University of Giessen, 2University of Giessen, 3Section on Developmental Genetic Epidemiology, National Institutes of Mental Health

Descriptors: emotion regulation, genetic imaging, serotonin

Previous studies have shown that serotonin-related gene variations are associated with different brain responses to emotional stimuli, in regions such as the amygdala and prefrontal cortex. The goal of this study was to investigate the influence of variations in the serotonin transporter (5-HTTLPR) and the tryptophan hydroxylase-2 (TPH2-703G/T) genes on the neural correlates of negative emotion regulation by reappraisal. Four groups, defined by absence versus presence ofthe short (S) allele ofthe 5-HTTLPR and T variant of the TPH2-703G/T polymorphism (S+T+, S+T — , S — T+,S — T — ), participated in a functional magnetic resonance imaging study. They were instructed to either look at blocks of aversive or neutral pictures, or to down-regulate their emotions elicited by aversive pictures. Early results show that carriers of the S and T alleles are characterized by stronger subjective emotional responses towards aversive compared to neutral pictures. During effortful down-regulation of emotion, diminished activity in regulation-related prefrontal cortex areas was observed for these individuals. These results indicate that serotonin-related gene variations are not only associated with emotional experience, but also with effortful emotion regulation processes.

Poster 52

UGH! DISGUST CONDITIONING AND THE INFLUENCE OF INDIVIDUAL DIFFERENCES

Tim Klucken, Jan Schweckendiek, Dieter Vaitl, & Rudolf Stark Bender Institute of Neuroimaging, University of Giessen

Descriptors: classical conditioning, disgust, insula

Disgust is associated with various anxiety disorders and provokes physiological, behavioral, and neural responses. However, only few studies have been conducted to investigate conditioned responses (CRs) of aversive learning with disgust stimuli. These studies report robust CRs when using disgust pictures as unconditioned stimuli. Yet, to date, no study has examined brain activations during disgust conditioning. The present study investigated SCRs, changes in subjective ratings, and brain activity when conditioning with disgusting pictures. In a differential conditioning paradigm, one picture frame (CS+ ) was filled out with disgust pictures, while a second picture frame (CS — ) predicted the absence of disgusting pictures. Simultaneously, we assessed SCRs and neural responses, yet subjective ratings and contingency awareness were assessed after the conditioning procedure. Each subject also filled out personality questionnaires (e.g. disgust sensitivity). We found increased activity in the occipital cortex, lateral orbito-frontal cortex, thalamus, and strong bilateral insula activations in the contrast CS+ > CS — . Conditioned SCRs were obtained in contingency aware subjects only. We also found individual differences to have an influence on CRs. In sum, disgust pictures can be used as unconditioned stimuli to investigate aversive learning. Further, the strong bilateral insula activation underlines its important role for aversive learning, which might be especially important for disgust conditioning.

Poster 53

TESTING BASIC ASSUMPTIONS OF THE CONCEALED INFORMATION TEST

Vanessa Thompson, Sarah Stevens, & Stephen D. Benning Vanderbilt University

Descriptors: concealed information test, P3, lie detection

The Concealed Information Test, or CIT, has been tested extensively as a method of physiologically detecting deception. This paradigm is based on the finding that the P3 ERP is larger when elicited by meaningful or familiar information than by meaningless or unfamiliar information. The vast majority of studies that test the validity of the CIT have used "mock crimes'' as the method for introducing information to participants. Our study tested whether the simple act of reading about events could also elicit larger P3 amplitude for familiar versus unfamiliar information. In this study, participants were asked to read two different stories, one about a crime and one about a normal school day. Participants were then asked to respond to a series of multiple-choice questions regarding each story. We found a significant difference in P3 amplitude for familiar details in the story versus unfamiliar details that were not included in either story. However, we did not find a main effect of story type, nor did we find an interaction between story type and detail familiarity. Therefore, P3 amplitude was larger for familiar details, irrespective of story type (crime versus normal day). These findings suggest that the CIT is a viable form of lie detection, whether it would be used for crime-related or everyday events, though the CIT could also be spoiled by reading elaborate reports of crime scenes.

Poster 54

THE INFLUENCE OF TRAIT ABSORPTION ON EMOTIONAL PICTURE AND ACOUSTIC STARTLE PROCESSING: EVIDENCE FROM ERPS

Melville M. Malone, & Stephen D. Benning Vanderbilt University

Descriptors: personality, P3, absorption

The current study explored the influence of trait levels of Absorption on processing of emotional foreground and distracting background stimuli. EEG was recorded while undergraduate participants watched pleasant, neutral, and aversive pictures, and acoustic startle probes were presented during the picture viewing period. P3 waveforms time-locked to the picture onset as well as to the startle probe onset were examined. Consistent with prior research, larger P3s were obtained at the onset of emotional vs. neutral pictures, and smaller P3s were obtained to the startle probe during emotional vs. neutral pictures. Parietal P3 amplitude at picture onset was negatively correlated with frontal P3 amplitude to the later startle probe, indicating a transfer of emotional differentiation of the pictures from parietal to frontal regions over the course of picture processing. Additionally, we found that Absorption scores were correlated with the emotion vs. neutral differentiation of the parietal P3 to pictures and of the frontal P3 to startle probes. Absorption was also negatively correlated with parietal P3 magnitude to the startle probe, irrespective of picture valence, indicating that those high in Absorption have fewer processing resources to devote to a second stimulus while their attention is absorbed by a previous, concurrent stimulus. Thus, Absorption may facilitate focusing on initial salient information, thereby inhibiting processing of subsequent incoming information.

Poster 55

REDUCED APPETITIVE POSTAURICULAR REFLEX POTENTIATION IN DEPRESSED UNDERGRADUATES

Stephen D. Benning Vanderbilt University

Descriptors: postauricular, startle, depression

In prior studies, severely depressed patients have exhibited blunted overall modulation of the startle blink reflex by emotion, though this pattern has not been observed for less depressed patients or undergraduates. The postauricular reflex may be a more sensitive measure of blunted appetitive processing in depression than the startle blink, given that the postauricular reflex appears to be a relatively sensitive measure of appetitive processing. In a sample of 83 undergraduates (mean Zung depression score 5 34.2, SD 5 7.06), potentiation of the postauricular reflex to pleasant vs. neutral pictures was negatively related to self-reported depression scores. This negative relationship was particularly evident for the anhedonic features of depression and for postauricular reflexes during nurturant vs. neutral scenes. In contrast, there were no significant correlations between any form of emotional startle blink reflex modulation and depression scores. These findings indicate that blunted appetitive potentiation of the postauricular reflex may be a psychophysiological marker of even low levels of anhedonia in depression.

Poster 56

MENTAL COACHING DURING FLIGHT TRAINING OF MILITARY STUDENT PILOTS: EFFECTS ON SUBJECTIVE STRESS PERCEPTION, FLIGHT PERFORMANCE AND CORTISOL LEVELS

Nathalie Pattyn1,2, Sharon Arcay2, & Raymond Cluydts1 'Vrije University Brussel, 2Royal Military Academy

Descriptors: stress, coaching

Military flight training is known to be a very demanding curriculum, and a high coping ability has been repeatedly named by instructors and former students as one of the key factors for success. Recently, the Royal Military Academy has introduced a coaching module, comprising relaxation techniques and bio-feedback, aiming at teaching student-pilots adequate coping techniques, to allow them to manage their stress reactions and improve their performance in-flight. The present study aimed to investigate whether an individualized coaching technique, based on similar principles, would improve their stress management and flight performance. Twenty-two student pilots participated in the 6-month study, where they were assessed once a month. They were divided in two groups, the intervention and the control group, which were matched according to baseline Trait Anxiety scores and flight performance. The intervention group received an individualized coaching for the duration of the study, with mandatory visits to the coach every two weeks, and free access if they felt the need for more. The control group was subjected to normal sport sessions. Measurements, performed once a month, included saliva samples to determine cortisol levels, taken every two hours, the Spielberger State Anxiety Inventory and the Profile of Mood States. Results show higher cortisol levels and higher scores for the control group, despite these results not reaching significance, probably due to the high amount of missing data from the attrition rate. Feedback from students showed they deemed the coaching very useful.

Poster 57

MONITORING AN ANTARCTIC SUMMER EXPEDITION: HOW CONSTANT ILLUMINATION AND PHYSICAL ACTIVITY AFFECT MOOD, COGNITIVE PERFORMANCE AND SLEEP-WAKE REGULATION

Nathalie Pattyn1,2, Elke De Valck1, Aisha Cortoos1, Sandra Pirrera1, Xavier Neyt2, & Raymond Cluydts1 1Vrije University Brussel, 2Royal Military Academy

Descriptors: circadian rhythms, antarctica, sleep-wake regulation The present investigation was conducted during two Antarctic summer expeditions. This study aimed at investigating how well the subjective complaints of participants were related to objective measures of sleep quality. Second, we hypothesized that participants with more intense physical activity would increase their sleep pressure, and therefore suffer less from the possible circadian disruption due to the constant daylight conditions. Eight subjects were investigated in the first expedition. Actigraphy data were collected for 48 hrs every ten days. Sleep efficiency (sleep time/lying down time) as well as a sleep fractionation were computed, and related to the magnitude of active energy expenditure. 23 subjects participated during the second campaign. Data included 24 hours of acti-graphy, one night polysomnography, morning and evening Profile of Mood States and Karolinska Sleepiness Scale, morning Psychomotor Vigilance Test. Morning and evening saliva samples to determine melatonin levels. First-year data showed poor sleep efficiency and high sleep fractionation, in concordance with participants' subjective evaluations. Furthermore, there was a strong correlation between sleep efficiency and active energy expenditure (Pearson's r 5 0,63; p 5 .015), as well as a strong relationship between active energy expenditure and sleep fractionation. Second year data are still being analyzed, preliminary results showing a deficit in deep sleep and a similar relationship between physical activity and sleep efficiency.

Poster 58

IMPACT OF AGE ON BASAL ACTIVITY OF SALIVARY ALPHA-AMYLASE

Jana Strahler1, Antje Tietze1, Clemens Kirschbaum1, & Nicolas Rohleder2 1Dresden University of Technology, 2Brandeis University

Descriptors: salivary alpha-amylase, cortisol, aging

Recent studies revealed a pronounced diurnal rhythm of salivary alpha-amylase (sAA) characterized by a strong decrease after awakening and steadily increasing values during the day with peaks in the late afternoon in adults and children, but no data on older adults is available, and no direct comparisons between different age groups across the lifespan have been made. To determine salivary alpha-amylase and cortisol basal rhythms, five saliva samples were collected immediately after awakening, 30 minutes after awakening, 11am, 3pm, and 8pm. Controlling for Body Mass Index and awakening time, results showed a pronounced rhythm of sAA as well as cortisol in all age groups. However, older men lack the typical decrease of sAA in the morning and showed the lowest cortisol awakening response. Furthermore, older adults showed a much higher total output of sAA and a group by sex effect indicated a total cortisol output especially pronounced in older men. No associations between sAA and cortisol variables were found, and analyses revealed age and awakening time as the strongest predictors of daily amylase and cortisol. The present findings showed higher salivary alpha-amylase output in older adults, indicating higher sympathetic activity, and implying a possible mechanism for increased susceptibility to cardiovascular events. Furthermore, higher cortisol levels in older men may indicate, for example, an increased risk for metabolic diseases. Our findings in older adults are of particular interest for the increasingly important research area of stress, hormones, and aging.

Poster 59

CENTRAL PAIN PROCESSING AFTER REPETITIVE INTRAMUSCULAR PROTON/PROSTAGLANDIN E2 INJECTIONS IN FIBROMYALGIA SYNDROME AND HEALTHY CONTROLS

Mariela Rance1, Martin Diers1, Marcus T. Schley2, Pinar Yilmaz1, Martin Schmelz2,

& Herta Flor1

1Central Institute of Mental Health, 2University of Heidelberg

Descriptors: pain, prostaglandin, fibromyalgia

While the etiology of fibromyalgia syndrome (FMS) remains unclear, it is assumed that both peripheral and central components are involved. It was shown that the release of prostaglandins (PG) in muscle in response to tissue damage is defective in chronic muscle pain. To shed light on the connection between PGE2 release, tenderness, and hype-ralgesia we repetitively injected FMS patients and healthy control subjects (HC) with PGE2 in phosphate-buffered isotonic solution in the left extensor carpi radialis brevis muscle. During the injections functional magnetic resonance imaging measurements were conducted and continuous pain ratings were recorded. Continuous pain ratings revealed higher instantaneous pain in HC and higher sustained pain in FMS. Injection

of PGE2 led to activation of the anterior and medial cingulate cortices, contralateral primary sensory cortex, bilateral insula and thalamus, left basal ganglia, left orbito-frontal cortex and the cerebellum in FMS patients. In HC activations were found only in the anterior, medial, and posterior cingulate cortices, and the primary somatosensory cortex. The contrast between the groups revealed significantly more activation for FMS patients in the left insula. In both groups similar concentrations of hypotonic saline and PGE2 solutions led to a more pronounced perception of pain and more wide spread activation in pain-related brain areas in FMS especially in the left insula despite a delayed perceived pain reaction to PGE2. As PG sensitizes sensory neurons to pain it might be a peripheral contributing factor in FMS.

Poster 60

THE P300- BRAIN-COMPUTER INTERFACE BROWSER: A MUSCLE-INDEPENDENT SURFING TOOL FOR PARALYZED PEOPLE

Carolin Ruf1, Emily Mugler1, Sebastian Halder1, Michael Bensch2, & Andrea Kübler3

1Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, 2Wilhelm-Schickard-Institute for Computer Science, University of Tübingen, 3University of Würzburg

Descriptors: brain-computer interface, P300, amyotrophic lateral sclerosis EEG-based-brain-computer interfaces (BCIs) can be used by paralyzed people for communication. To increase the general usefulness of BCI systems applications for particular activities are needed. The presented study evaluated the efficacy of a BCI application for surfing the web. A matrix paradigm based on the event-related potential P300 was used to control the BCI web browser. Ten healthy subjects and three paralyzed patients diagnosed with amyotrophic lateral sclerosis (ALS) performed web surfing tasks in several sessions. All participants were asked to evaluate the BCI browser after use. The healthy subjects achieved an average accuracy of 90% and an information transfer rate (ITR) of 16.5 bits/minute when controlling the web browser. The ALS patients used the browser with an average accuracy of72% and an ITR of7 bits/minute. The patients indicated that they would use the BCI browser in everyday life and would participate in more BCI web browser sessions. The results confirmed a decreased ITR in people with neurological disease as compared to healthy controls. A lower P300 amplitude and a longer latency in the ALS patients may account for this difference. This aspect has to be taken into account when designing BCI protocols for patients. Nevertheless, accuracy in patients was still high enough to control the browser reliably.

Poster 61

AFFERENT FEEDBACK INFLUENCES FOR AN ON-LINE BCI FOR STROKE REHABILITATION

Ander Ramos1, Ernesto S. Soares1, Manuel Agostini2, Doris Broetz1, Boris Benkner1, Massimilliano Rea1, Sebastian Halder1, Andrea Caria1, Surjo Soekader3, & Niels Birbaumer1

1University of Tübingen, 2University of Freiburg, 3University Hospital Tübingen

Descriptors: neurofeedback, stroke, learning

The last decade yielded the development of brain-computer-interfaces (BCI) that use neurophysiological signals to control external devices or computers, delivering sensory afferent patterns of activity in response to experimentally controllable CNS events with time delays in the order of tens of milliseconds. Based on the importance of the relative timing of synaptic events in the induction of long lasting changes in neuronal function, BCI- based rehabilitation techniques for patients with motor functionality in such conditions as Stroke, ALS and spinal chord injury constitutes a promising technique. Four sub-cortical chronic stroke patients displaying severe hemi-paresis with loss of finger control were submitted to a 16-session BCI-training regime. Having identified the EEG correlates of the Attempt to Move (AM) the affected hand, an online EEG adaptive classifier controlling a robotic device attached to the affected arm generated specific Sensory Feedback (SF) patterns. The effects over instantaneous and long term neuro-physiological and behavioral measures of, and caused by, BCI training using distinct 1) sign of AM-SF contingency (Positive Vs. Negative) and 2) degrees of AM-SF anatomical correspondence (SF being either Proximal or Distal, contrasting with constant Distal AM) were evaluated. These results will be most instructive for future developments of BCI systems that include using natural afferent sensory information as feedback.

Poster 62

THE ROLE OF TOP-DOWN TASK SET FOR ATTENTIONAL CAPTURE IN VISUAL SEARCH

Monika Kiss, & Martin Eimer Birkbeck, University of London

Descriptors: attentional capture, top-down control, n2pc

Studies investigating attentional capture by task-irrelevant singletons in visual search have often used the two-singleton paradigm where a shape target singleton can be accompanied by a more salient color singleton distractor. Previous behavioral and ERP experiments have found evidence that attention is captured by these task-irrelevant

singletons, suggesting that capture is triggered by bottom-up salience rather than top-down task set. However, in most of these studies, the identity of target and distractor singletons changed unpredictably across trials, which may have attenuated the impact of top-down task sets. We investigated this hypothesis by employing the N2pc component as a marker of attentional capture in the two-singleton paradigm, and contrasting blocks where target and distractor identity either remained constant or varied unpredictably. Results demonstrate that attentional capture by task-irrelevant singletons is strongly modulated by top-down task set.

Poster 63

THE INTEGRATION OF PERCEPTUAL AND WORKING MEMORY REPRESENTATIONS: EVIDENCE FROM LATERALIZED ERP COMPONENTS

Silvia Dalvit, & Martin Eimer Birkbeck, University of London

Descriptors: n2pc-spcn, relationship attention - working memory

Previous behavioural work has demonstrated that working memory and perceptual representations can be integrated to guide visual discrimination performance (Brockmole et al., 2002). We used ERP measures to investigate such image-percept integration processes and to compare them to percept-percept integration. In a temporal integration task, participants were asked to combine information from two successively presented visual displays which were separated by a variable interval (0-900 ms). Both displays contained lateralized semicircles, whose orientation varied pseudo-randomly. The task was to detect whether the combination of the two successive semicircles presented at the same location resulted in a complete circle. Detection performance was good when the two displays followed each other immediately and also when the interstimulus interval was 300 ms or longer, demonstrating the effectiveness of percept-percept and image-percept integration, respectively. Posterior contralateral ERP components were elicited in both conditions, suggesting that both types of integration are based on retinotopically organized representations. However, they emerged later and were more sustained for image-percept integration. In a follow-up experiment, we studied the role of spatial correspondence between images and percepts, and the impact of working memory load on image-percept integration.

Poster 64

CARDIAC AUTONOMIC FUNCTION AND RESPONSE CONTROL DEFICITS IN OLDER ADULTS

Lesley J. Capuana, Jane Dywan, William J. Tays, & Sidney J. Segalowitz Brock University

Descriptors: aging, cardiac autonomic function, attentional control The anterior cingulate cortex (ACC) is involved in the control of attention as well as the modulation of autonomic activity. Despite the observation that both processes decline with age, they are very rarely studied together, so it is not known whether an age-related reduction in the ability to control sympathetic arousal would be implicated in the attent-ional control problems experienced by older adults. To examine this, we recorded event-related potentials (ERPs) and cardiac activity while older and younger adults completed a Go-NoGo task that involved withholding a response when probe trials matched the information being held in working memory. We varied working memory load to include 2, 4, or 6 items, and expected that autonomic regulation would become increasingly important for older adults at higher load, when fewer attentional resources were available. We found that a higher memory load resulted in an increased error rate and a reduction in error-related ERP amplitude (ERN & Pe). ERP amplitude did not relate to errors rate, but higher rate pressure product (RPP), an index of sympathetic predominance, was associated with increased NoGo error, especially for NoGo trials that unexpectedly repeated, and only for older adults. Results suggest that a decline in the autonomic control of sympathetic activity is linked to response control problems in older adults, and generally support Thayer's model of neurovisceral integration in that age-related change in ACC must be considered with respect to both its cognitive and regulatory functions.

Poster 65

N170 IS SENSITIVE TO SEVERAL FACTORS IMPORTANT FOR DIFFERENTIATING INDIVIDUAL FACES

Xin Zheng, Mark D. Vida, Catherine J. Mondloch, & Sidney J. Segalowitz Brock University

Descriptors: N170, faces, eye colour

Using event-related potentials, we investigated whether the face-sensitive N170 component varied with dimensions previously shown to influence adults' face similarity judgments. Nishimura et al. (in press) collected similarity ratings for 36 female faces with identical hair. A 4-5 dimensional face-space solution accounted for adults' judgments. We measured several facial characteristics to describe these dimensions. Although influenced by multiple face characteristics, each dimension had one dominant feature: (X) eye colour, (Y) face width: height of bottom face half, (Z) eye size, and (W) height of top face half: height of

bottom face half. In the current study we presented 9 male faces among the 36 female faces; participants pressed a button when they detected a male face. We measured N170 amplitude to see if it varied with each of these dimensions and its associated facial feature for female faces only. The right N170 amplitude had a linear relationship with eye color (p < .01), and a curvilinear relationship with face width (p < .01), but no relationship with the other features (p > .1). The left N170 amplitude had a linear relationship with both height of top face half: height of bottom face half (p < .05) and eye size (p < .05), but not with the other features. Thus, the N170 relates to the factors important for differentiating individual faces, and our results suggest that the scalp-recorded N170 component can be affected by a variety of factors and is likely produced by multiple neural sources.

Poster 66

ERP CORRELATES OF EMOTIONAL FACE PROCESSING IN PSYCHOPATHY

Meghan J. Weissflog1, Sidney J. Segalowitz1, Gillian E.S. Munro2, & Jane Dywan1 1Brock University, 2MIND Research Network

Descriptors: psychopathy, ERP, emotional faces

One proposed aspect of the affective deficiency in psychopathy is a deficit in the processing of emotional facial expressions. To date, research in this area has produced inconsistent documentation of these deficits. We recorded event-related potentials (ERPs) in a sample of incarcerated psychopathic offenders and a nonoffender control sample during an emotional flanker task containing fearful and angry facial expressions. From these data the N170 ERP component, commonly associated with face processing, and the P2 and N2/P3 were examined. Although we observed no significant difference in the average amplitudes of the N170 and P2 components between groups, there was a trend indicating a difference between groups in the descending arm of the P200. Similarly, the N2/P3 component (average voltage between 300 and 400 ms) differentiated groups in the ascending arm of the P300 component with a slower ascent in the psychopaths, F(1, 23) 5 15.5, p 5 .001. These data are compatible with psychopaths showing intact structural processing of emotional faces despite their poor performance in identifying facial fear expression in this task, with the poorer perceptual processing emanating after 300 ms.

Poster 67

PROCESSING REWARD MAGNITUDE AND VALENCE: DISSOCIATIONS AND INDIVIDUAL DIFFERENCES IN THE FRN AND P300

Angela Dzyundzyak, Diane L. Santesso, & Sidney J. Segalowitz Brock University

Descriptors: gambling, FRN, P300

Yeung & Sanfey (2004; Y&S) reported that, in a gambling paradigm, valence (winning versus losing) and magnitude (large versus small wager) are dissociable in the human electrophysiological response, namely, the feedback related negativity (FRN) and the P300 components, respectively. Our goal was to further examine this dissociation as well as evaluate the role ofindividual differences in the processing ofthis feedback. A modified version of the Y&S gambling paradigm was used to evaluate these relationships. The separation between valence and magnitude at the scalp was found but not as simply as suggested by Y&S: (1) The P300 component at Cz was sensitive only to the wager magnitude (replicating Y&S), while at Fz the P300 differentiated between wins and losses. Fitting the P300 to dipole sources using BESA, we found symmetric dipoles in dorsal ACC, one pointing toward Fz and active only in loss conditions and the other pointing to Cz and active for both wins and losses. (2) The FRN at Cz differentiated valence and magnitude with complication due to the P300 effects, with best fit dipoles in the rostral portion of the ACC. Additionally, it was found that personality factors predisposing to or against gambling are related to both FRN and P300 amplitudes and furthermore to the activation levels in ACC and medial PFC regions as derived by LORETA current source density. Thus, while magnitude and valence are dissociable in the brain, this independence is not simply in terms of the ERP component and can be influenced by personality.

Poster 68

DOES TARGET LETTER POSITION AFFECT ERP AMPLITUDES AND CLASSIFICATION ACCURACY IN THE P300 BASED BCI? IMPLICATIONS OF A PRINCIPAL COMPONENT ANALYSIS

Siri-Maria Kamp, Ty Brumback, Yael Arbel, & Emanuel Donchin University of South Florida

Descriptors: brain computer interface, P300

The P300 Brain Computer Interface (BCI) presents a user with a matrix of options for communication. The user focuses attention on the desired character, the rows and columns of the matrix are randomly highlighted and, by detecting which row and column flash elicit a P300, the BCI identifies the target character. Some users report having difficulty attending to characters in particular areas of the matrix. Therefore, using principal component analysis (PCA) on the event-related potentials (ERPs) from six participants, we investigated whether the position of the target character in the matrix, such as the row and column it is located in, influences amplitudes of elicited

ERPs. The PCA revealed a P300 factor and an earlier frontal positivity whose amplitudes strongly differed between target and non-target flashes. The factor scores of both factors were compared as a function of target position in the matrix. Two significant effects were found: for the column flashes the P300 was smallest when the target character was located in the top rows compared to the bottom rows, while for the row flashes the frontal factor was smallest when the target was located in the bottom rows. We conducted a similar analysis on the scores computed by a stepwise discriminant analysis, which is the classification method currently used online by our BCI system. Thereby, we investigated whether the results from the PCA may translate into differences in classification accuracy as a function of matrix letter position. Implications for the optimal matrix organization and BCI performance are discussed.

Poster 69

IDENTIFYING THE FUNCTIONAL ROLE OF THE INTERFERENCE-ELICITED MEDIAL FRONTAL NEGATIVITY

William J. Tays, Jane Dywan, & Sidney J. Segalowitz Brock University

Descriptors: interference effects, medial frontal negativity, N450

Using event-related potentials (ERPs) to examine neural responses to cognitive interference (CI) has consistently revealed a medial frontal negativity (MFN) 450 ms following interference eliciting stimuli. However, it is unclear whether the MFN reflects CI detection or CI resolution. Our goal was to probe the nature of the processes that give rise to this MFN by manipulating cognitive load, thus limiting available executive resources. We elicited CI by using a modified Sternberg task that involved the strategic repetition of recent probes. Cognitive load was manipulated by using 2, 4, & 6 items in the memory set. We hypothesized that CI effects would increase with greater cognitive load. If the MFN reflects CI detection, its amplitude should increase as load (and thus CI) increases. Alternatively, if the MFN reflects CI resolution, its amplitude should decrease as load increases and executive resources become limited. Behavioural data supported a clear pattern of increased CI; errors to lures increased linearly with load. ERP data were surprising in that two CI-related negativities were observed. At low load (maximal resources available) a RIGHT-frontal negativity occurred, while at high load (minimal resources available) an earlier, LEFT-frontal negativity was apparent. We suggest that the typically observed MFN is actually a composite oftwo functionally distinct responses: An early left-lateralized response reflecting interference detection, and a later, right-laterali-zed response reflecting the application of executive resources for interference resolution.

Poster 70

FRONTAL EEG ASYMMETRY IN HIGHLY AGGRESSIVE 5-6 YEAR

OLD GIRLS

Michelle K. Jetha1,2, Sidney J. Segalowitz2, & Lisa Gatzke-Kopp1 Pennsylvania State University, 2Brock University

Descriptors: externalizing, eeg asymmetry, girls

Greater relative left frontal activity has been associated with approach-related emotion (e.g., happiness and anger) and behaviour, whereas greater relative right frontal activity has been associated with withdrawal-related emotion (e.g., fear and sadness) and behavior. We investigated whether highly aggressive 5 and 6-year-old girls would differ from controls on frontal EEG activity. We measured frontal and parietal EEG alpha asymmetry in 30 girls (18 identified as high on aggression and 12 controls) during baseline and during the presentation of three emotion-evoking film clips (fear, happy, and anger). There was a significant condition x hemisphere x group interaction (p 5 .001). Decomposing this effect, we found that girls identified as high on aggression showed significantly different patterns of frontal asymmetry both in baseline (p 5 .002) and anger conditions (p < .05) compared to controls in that they showed greater amounts of left frontal activation in both conditions. No such differences in asymmetries were found in parietal regions or for fear and happy conditions. This is the first investigation of electrophys-iological asymmetry in highly aggressive girls in this age group. The findings suggest dysfunction in approach motivation and affect regulation in those identified as high on aggression. Early patterns of physical aggression in children often remain stable and are indicative of risk for on-going behavioral problems over the lifespan. These findings have possible implications for the identification of children at risk for externalizing disorders.

Poster 71

I AM POSITIVE I AM GOING TO BE CORRECT: CORRECT RESPONSES ARE FORESHADOWED BY INCREASED POSITIVITY IN A LOW INTERFERENCE TASK

Hiroaki Masaki1, Timothy I. Murphy2, Keita Kamijo3, & Katuo Yamazaki1 1Waseda University, 2Brock University, Japan Society for the Promotion of Science

Descriptors: response monitoring, EEG/ERP

Research has suggested that errors are foreshadowed by a positive deflection of the response-locked event-related potential in the trials immediately preceding an erroneous response. However, these studies all employed tasks that had an element of stimulus-response interference in these error-preceding trials. The present study adopted an al-

ternating-response task to essentially eliminate stimulus-response interference on the trials prior to any errors. In the present study, participants responded to the pointing direction of an arrowhead (up or down). The arrowhead direction alternated for the majority of trials (95%); however, periodically this pattern was broken by presenting two consecutive arrows pointing in the same direction. We referred to these as lure trials. We examined the lure-1 trial by comparing the matched-reaction-time correct-preceding and error-preceding ERPs. Contrary to previous research, we found no evidence that a positive EEG deflection foreshadows errors. In fact, analyses of ERPs on the three consecutive lure-preceding trials showed that both stimulus-locked and EMG-locked positive deflections were larger on the correct-preceding trials than on the error-preceding trials. The post-response negativity was comparable between the correct-preceding and error-preceding trials. These results suggest that in a reduced conflict task, the positive deflection immediately following responses seems to foreshadow correct performance and not errors.

Poster 72

THE EFFECT OF SLEEPINESS ON REWARD-RELATED ELECTROPHYSIOLOGICAL ACTIVITY DURING A GAMBLING TASK

Timothy I. Murphy, Diane L. Santesso, Dirk B.H. Homan, Warren Tilbrook, & Cassandra Lowe Brock University

Descriptors: sleep deprivation, EEG/ERP, risk assessment

Sleep deprivation can adversely affect an individual's decision-making ability while gambling by elevating the expectation of gains and minimizing losses. Sleepiness has also been shown to have deleterious effects on prefrontal cortex functioning and performance monitoring. The goal of the present study was to examine the effects of sleepiness on reward processing using a gambling task similar to blackjack in young adults. Twenty participants completed the task when alert and after 20 hours of sleep deprivation. We examined the feedback-related negativity (FRN) as an index of anterior cingulate cortex (ACC) reward processing and examined low resolution electromagnetic tomography (LORETA) during monetary win and loss feedback. Consistent with previous studies, loss feedback elicited larger (more negative) FRNs and slightly greater ACC activity (BA 24) compared with win feedback. Although win and loss FRNs did not differ under conditions of alertness and sleepiness, LORETA analyses revealed that losses were associated with greater activity in the ACC during the alert session compared to the sleepy session. Only slight differences were evident for winning across the alert and sleepy conditions. This indicates that individuals may devote less attention to losses while sleepy. These findings may have implications for individuals who gamble for extended periods or very late at night.

Poster 73

VAGAL REACTIVITY TO STRESS IN SEXUALLY REVICTIMIZED WOMEN

Michelle A. Patriquin, Angela Scarpa, & Kristy E. Benoit Virginia Polytechnic Institute and State University

Descriptors: vagal augmentation, sexual revictimization

Research suggests that vagal augmentation, or an increase in parasympathetic activation, indicates heightened attention and the ability to detect environmental change. Vagal augmentation may provide an individual with the physiological (e.g., storing energy) and psychological (e.g., attention) capabilities to face environmental challenge [stress]. One hundred and fifteen female undergraduates (aged 18-22) were administered a modified Stroop task to assess for physiological differences to an environmental stressor. The following groups were established: revictimization (n 5 30), child sexual abuse (n 5 24), adult sexual victimization (n 5 35), and no sexual victimization (n 5 26). The modified Stroop presented three word blocks: neutral (e.g., apple), general threat (e.g., death), and sexual (e.g., rape). Vagal reactivity was quantified as the mean Stroop minus mean baseline difference score in high frequency (HF) power percent heart rate variability (HRV). Re-victimized women showed a significant increase in HF HRV (M 5 11.39, SD 5 74.19) compared to child sexual abuse [M 5 _ 11.42, SD 5 10.74; F(1, 112) 5 1.80, p < .05] andatrendcomparedtonovictimization[M 5 _ 9.83, SD 5 23.16;F(1,112) 5 1.80,p 5 .06]. Victimized adults showed HF HRV decrease (M 5 _ 5.70, SD 5 22.49). These results indicate vagal augmentation in only sexually revictimized women to an environmental stressor. Revictimized women may have developed an adaptive physiological response that allows for necessary engagement to and assessment ofenvironmental challenge.

Poster 74

ERROR-RELATED BRAIN ACTIVITY IN INDIVIDUALS WITH MAJOR DEPRESSIVE DISORDER

Doreen M. Olvet, & Greg Hajcak Stony Brook University

Descriptors: major depressive disorder (mdd), error-related negativity, symptom severity Recently, event-related potentials (ERPs) have been used to elucidate neural indices of response monitoring: the error-related negativity (ERN) and the correct-response negativity (CRN) are ERPs that present as a negative deflection approximately 50 ms fol-

lowing an erroneous and correct response, respectively. Some studies have reported an increased ERN in individuals with major depressive disorder (MDD), but others have failed to find such differences when assessing individuals with severe MDD. The purpose of this study is to investigate the ERN in individuals with MDD; more specifically, we sought to examine the relationship between the ERN and depression severity. In the current study, individuals with MDD (DEP; n 5 22) and healthy controls (HC; n 5 22) performed an arrow version of the flanker task. Although the results show that these groups did not differ on the ERN/CRN overall, depression severity appeared to moderate the ERN/CRN in the DEP group. When the DEP group was divided using a median split on self-reported symptom severity, the high severity group (n 5 10) had a smaller difference between the ERN and the CRN than the low severity group (n 5 9). This study suggests a non-linear relationship between depressive symptom severity and the ERN, such that individuals with mild to moderate MDD have an increased ERN and individuals with severe MDD have a decreased ERN relative to healthy controls.

Poster 75

SPATIAL ATTENTION AND ANXIETY MODERATE THE LATE POSITIVE POTENTIAL

Annmarie MacNamara, & Greg Hajcak Stony Brook University

Descriptors: LPP, spatial attention, anxiety

Recent fMRI work suggests that amygdala activity is increased by aversive stimuli, even when presented in spatially unattended locations. Other neuroimaging work indicates that individual differences in anxiety - associated with heightened attention towards threat - may influence the degree to which unattended aversive stimuli capture attention and activate the amygdala. The present study examined whether the LPP elicited by aversive IAPS is modulated by spatial attention and state anxiety. On each trial, four pictures were simultaneously presented for 250 ms: above, below, and to the left and right of fixation. Participants had to indicate whether two of the pictures on each trial were the same or different; a cue presented before each trial indicated whether this decision should be based on the horizontal or vertical pictures. Results indicated that the LPP was larger for aversive pictures, but only when presented in spatially attended locations. Trials in which aversive pictures were presented in spatially unattended locations were associated with increased reaction times and a greater number of errors. Finally, participants who reported higher state anxiety had larger LPPs to aversive pictures presented in spatially attended locations. These data suggest a role for both spatial attention and individual differences in anxiety in the extent to which aversive pictures elicit increased electrocortical measures of perception and attention.

Poster 76

FEAR GENERALIZATION AS A FUNCTION OF BDNF AND 5-HTTLPR POLYMORPHISMS

Jonathan P. Dunning1, Claude Castille1, Doreen M. Olvet1, Eli Hatchwell2, & Greg Hajcak1 1Stony Brook University, 2Stony Brook University Hospital

Descriptors: startle, fear conditioning, genetics

Recent studies have demonstrated that genetic variation in both the brain-derived neu-rotrophic factor (BDNF) and serotonin transporter (5-HTTLPR) polymorphism relate to abnormal startle responses in fear conditioning paradigms. In the present study, we simultaneously investigated the effect of both BDNF and 5-HTTLPR genotypes in a fear generalization paradigm. Participants were shocked following a CS+ and were also presented with stimuli that ranged in similarity to the CS+ (20, 40, or 60% smaller or larger than the CS+). Carrying the risky short allele of the 5-HTTLPR gene was uncorrelated with carrying the risky Met allele of the BDNF gene. Individuals who carried both non-risky alleles (n 5 17) exhibited potentiated startle only to the CS+. Relative to this group, carriers of either risky allele (n 5 30) showed potentiated startle to CS + 20% and CS + 40% stimuli, and a decrease in startle response to theCS+ itself. Thus, carrying either risky allele was associated with increased generalization offear-potentiated startle. Finally, individuals who carried both risky alleles (n 5 9) also showed generalization of potentiated startle to CS + 20% and CS + 40% stimuli, but exhibited a further reduction in startle to the CS+. Collectively, these data suggest that variation in the 5-HTTLPR and BDNF genotypes have independent and additive effects related to abnormal fear conditioning.

Poster 77

OLD-NEW ERP EFFECT DURING EXPLICIT AND IMPLICIT RECOGNITION OF AFFECTIVE PICTURES

Vera Ferrari1, Margaret M. Bradley1, Marie Karlsson1, Maurizio Codispoti2, & Peter J. Lang1 1University of Florida, 2University of Bologna

Descriptors: emotion, memory, erps

A larger late centro-parietal positivity in the ERP waveform is typically found for stimuli (both words and pictures) that are correctly recognized as previously encountered in the

study (''old''), compared to new stimuli. Effects of hedonic content on the old-new difference have been mixed. In the current study, we investigated the ERP old-new effect both when an explicit recognition decision was required in the memory phase, and when it was not. In the encoding phase, the hedonic content of picture stimuli, as well as the number (1 or more) and type of repetition (massed vs. distributed), was varied. After a short retention interval, old pictures were presented combined with new pictures: one group made explicit old-new decisions for each picture (explicit recognition task), whereas a second group simply looked at the pictures (implicit recognition task). Results showed a larger late (400-600 ms) centro-parietal positivity for emotional pictures that were old, compared to new, in both the explicit and the implicit memory tasks. Neutral pictures, on the other hand, only prompted an old-new difference in the context of the explicit recognition task. Moreover, the number and type of repetitions only affected the magnitude of the old-new effect in the explicit recognition task. Taken together, the data suggest that affective pictures are retrieved regardless of task, whereas neutral pictures rely on explicit memory retrieval. Repetition appears to primarily facilitate explicit memory decisions.

Poster 78

UNDERSTANDING INTRA-INDIVIDUAL VARIABILITY IN AUTONOMIC AND ERP MEASURES

Sarah L. Karalunas, Lisa Gatzke-Kopp, & Cynthia L. Huang-Pollock Pennsylvania State University

Descriptors: intra-individual variability, psychophysiology

High rates of behavioral intra-individual reaction time variability (IRV) have been documented in Attention Deficit Hyperactivity Disorder; however, little is known about the developmental trajectory ofIRV in typically-developing children. Further, variability appears to be affected by task contexts, with reduced variability in reward conditions. Although some etiological theories of ADHD suggest that IRV is a manifestation of underlying physiological dysregulation in reward processing, it remains unclear whether these contextual effects are reflected at a physiological level. The aim of the current study was to quantify normative physiological variability and its relationship to task performance, as a critical first step to understanding pathological physiological and behavioral variability. To-date, 34 typically-developing children ages 9-16 completed a go/no-go task with reward and punishment blocks while autonomic and high-density EEG data were collected. As expected, pre-ejection period (PEP) was significantly smaller in the reward as compared to the punishment blocks (t 5 2.14, p 5 .05). However, PEP responses were more variable in reward conditions (t 5 3.52, p < .05)

Poster 79

PROFILING WITHIN-GROUP HETEROGENEITY USING PSYCHOPHYSIOLOGICAL MARKERS

Kathleen M. Gates, Lisa M. Gatzke-Kopp, & Nilam Ram Pennsylvania State University

Descriptors: statistical methods, parasympathetic, sympathetic

Individuals are complex dynamic systems, the component parts of which interact with one another in complex ways over time. Physiological mechanisms, in particular para-sympathetic and sympathetic influence on heart rate, change reciprocally, coactively, and/or independently (Bernston, Quigley, & Lozano, 2007). Such complexity necessitates analytical models that consider how these measures cohere across time. Using variants of P-technique factor analysis, which has been used previously to examine cardiovascular activity (Friedman & Santucci, 2003), we examined the response coherence profiles of typically developing children during a series of reward based behavioral tasks for sympathetic (cardiac pre-ejection period, left ventricular ejection time, cardiac output) and parasympathetic (respiratory sinus arrhythmia) measures, as well as heart rate. Multiple response coherence profiles were identified, with some children characterized by highly coordinated one-factor structures, and others by more complex three-factor structures. This heterogeneity in functional cohesion highlights the diversity of pathways for normative development, and illustrates that findings from group-level analysis may not apply to individuals. We will also apply this analysis to a comparison sample of children with ADHD to examine how this technique can be used to identify heterogeneity of neurobiological pathways to common behavioral outcomes. Whereas current approaches pool measures across time to explain variance in the outcome variable, there is added benefit to looking individuals across time.

Poster 80

INDEXING COGNITIVE CONTROL PROCESSES IN A STROOP TASK USING TIME-FREQUENCY DECOMPOSITION OF EVENT-RELATED

POTENTIALS

Lacy A. Olson1, Lindsay Nelson2, Edward Bernat1, & Christopher J. Patrick1 1Florida State University, 2University of Minnesota

Descriptors: cognitive control processes, event-related potentials, time-frequency analysis The Stroop task requires cognitive control, or monitoring and adjusting attentional resources and actions according to task demands. The current study (N 5 130)

measured brain event-related potentials (ERP) during a 'task-switching' Stroop task in which a pre-stimulus cue instructed participants to either read or name the color of the upcoming target word. Consistent with the idea that color-naming trials require more cognitive control (cf. MacDonald et al., 2000), the cue-locked ERP revealed enhanced preparatory slow-wave activation for color versus word cues. Concurrently, time-frequency (TF) analyses revealed reduced alpha power for 'color' versus 'word' cues just prior to target onset, indicating enhanced alertness preceding more difficult (color-naming) cues. Consistent with prior research, the target-locked ERP showed a significant effect for congruent (color-word match) versus incongruent (color-word mismatch) trials between 300-800 ms after target onset. TF analyses of the target ERP data revealed distinct theta (3 - 7 Hz) and delta (0-3 Hz) components contributing to the congruency effect. Theta was stronger for incongruent trials (particularly during color-naming), consistent with the idea that theta indexes cognitive effort and conflict monitoring. In contrast, delta was stronger for congruent trials across word-reading and color-naming trials. These findings demonstrate the utility of time-frequency analysis for identifying separable processes underlying brain potential responses in cognitive processing contexts.

Poster 81

APPRAISALS AND SKIN CONDUCTANCE IN RESPONSE TO FOUR EMOTIONAL EXPRESSIONS ACROSS PHYSIOGNOMIC CATEGORIES

Augusta D. Gaspar, & Francisco G. Esteves Instituto Superior de Ciencias do Trabalho e da Empresa (ISCTE)

Descriptors: facial expression, physiognomy, skin conductance

We investigated appraisal and skin conductance responses (SCRs) to facial expressions of four emotions: Anger, Happiness, Fear and Surprise. Whereas Anger and Happiness have been previously shown to be efficiently decoded from facial expressions, other emotions fall behind with substantial misinterpretations. Because appraisals and emotional reactions can be affected by familiarity with a target, we tested photos of the four emotions across five physiognomic categories: human child, human adult, chimpanzee, bonobo and gorilla. Skin conductance response, verbal evaluation (valence and arousal) and identification of emotional content were scored. All photos displayed the exact same action configuration. Forty adult subjects were tested. We expected SCRs to discriminate emotions, and, due to experience, more efficient recognition of the emotional expressions on human faces than non-human faces. Furthermore, anger and happiness were expected to get higher correct recognition and receive higher scores of appraised arousal. Although there were SC reactions to all emotions and physiognomic categories, SCRs were not discriminative among emotions or physiognomies. Correct identifications were significantly higher for the human adult faces and Anger, and appraised arousal discriminated between emotions, being highest for anger and lowest for happiness. Results indicated better conscious discrimination of emotional expressions displayed by human faces and better recognition of anger expressions, but no correspondeing differentiation at a more implicit level was observed.

Poster 82

CARDIOVASCULAR ACTIVITY AND PROCESS OF CHANGE IN NICOTINE WITHDRAWAL

Sasha D. Jaquez1, Jared P. Dempsey1, Ashley N. Junghans1, Kasey R. Claborn1, Jason Kaplan1, William Lechner1, & Lee M. Cohen2 1Oklahoma State University, 2Texas Tech University

Descriptors: blood pressure, nicotine withdrawal

The connection between nicotine dependence and blood pressure has been well established. For example, subsequent to smoking, and when one is in nicotine withdrawal, an increase in blood pressure is observed. Cardiovascular activity is also known to increase during numerous emotional states, such as anxiety and depression. Given the robust emotional reaction that is known to occur during the state of withdrawal, the current exploratory analysis was conducted to examine how factors associated with the decision to quit smoking may be associated with blood pressure. The Process of Change (POC) measure and cardiovascular activity were examined among 23 nicotine dependent individuals. Results indicated numerous significant correlations among POC subscales. For example, the belief in one's ability to quit smoking (POC-Self Liberation) was associated with higher blood pressure (MAP; R [23] 5 .57, p < .01), as was greater acknowledgement of nicotine problems, R(23) 5 .43, p < .05. Further, increased levels of ''triggers'' for nicotine use were associated with higher rates of heartbeat (POC-Stimulus Control; R(23]) 5 .44, p < .05). This does not appear to be purely an association with level ofnicotine dependence, as none of the POC subscales were associated with nicotine dependence severity, or carbon monoxide breath test levels. Rather, this association with cardiovascular activity seems more likely to be associated with the psychological components in the decision to quit smoking, as numerous factors including depression and alcohol use were also associated with POC.

THE DEFAULT NETWORK: NOT SO DEFAULT

Brian A. Gordon1, Carrie Brumback2, Gabriele Gratton1, & Monica Fabiani1 University of Illinois, Urbana-Champaign, 2University of California, Irvine

Descriptors: default network, working memory

Early studies using Positron Emission Tomography (PET) and functional magnetic resonance imaging (fMRI) noted areas that not only showed an increase, but also a decrease with tasks. These clusters came to be loosely referred to as "the default network'' (Shul-man et al., 1997). This network has at different times been linked to mind wandering (Mason et al., 2007) and mental self-projection (Buckner and Carroll, 2007). It has been suggested that overly engaging this network is associated with metabolic damage and cognitive impairment later in life (Buckner et al., 2005). Although this phenomenon has received large amounts of scientific interest, much remains unknown. The relationship between default network activation and task performance has not been systematically investigated. To perform well on a behavioral task, it stands to reason that resources must shift away from the default network. Additionally, the homogeneity of the network itself remains to be discovered. In the current study a Sternberg memory task was varied in difficulty in a blocked fashion. The modulation of the default network by working memory load was examined across several regions of interest. A number of distinct patterns emerged. In several locations (STG, MTG, lateral occipital complex) deactivation of the default remained stable across low set sizes, but dramatically increased at high loads. Other areas (precuneous, lingual gyrus, and temporal occipital) showed an increase in deactivation starting even at low loads that continued into high memory demands.

Poster 84

NEURAL SUBSTRATES OF AMBIGUITY RESOLUTION: INDIVIDUAL DIFFERENCES IN RESPONSE TO SURPRISED FACIAL EXPRESSIONS

Maital Neta, M. Justin Kim, Catherine J. Norris, & Paul J. Whalen Dartmouth College

Descriptors: individual differences, positivity-negativity bias, ambiguity In previous research, we found that activity in the corrugator supercilii muscle region in response to surprised facial expressions reflected individual differences in positivity-negativity bias, rather than valence ratings on a given trial. Moreover, neuroimaging studies have shown that negative versus positive interpretations of surprised faces are correlated with distinct inverse reactivity patterns between the amygdala and a region of the ventral anterior cingulate cortex. This lends support to the notion that surprised faces are a useful tool for examining individual differences in positivity-negativity bias. Here, we sought to dissociate neural activity to a facial expression of ambiguous valence (i.e., surprise) when contrasted with expressions of clear valence at both ends of the valence continuum (e.g., happy, angry). We found greater activity in dorsal anterior cingulate cortex as well as frontal operculum to surprise when compared to angry and happy faces, consistent with previous data showing that these regions play a role in conflict monitoring and ambiguity resolution, respectively. When we compared subjects who interpreted surprise positively vs. negatively, we observed activation in a region of ventrolateral pre-frontal cortex in response to surprise vs. angry and happy faces. Responses in this region, previously implicated in regulatory processes, were functionally coupled with parahip-pocampal cortex and posterior cingulate in the presence of ambiguity (i.e., surprised faces).

Poster 85

MOVEMENT CORRECTION IN OPTICAL DATA; COMPARISON BETWEEN FEATURE BASED AND PRINCIPAL COMPONENT BASED APPROACH

Nils Schneider-Garces, Ed Maclin, Gabriele Gratton, & Monica Fabiani University of Illinois, Urbana-Champaign

Descriptors: optical imaging, movement correction, NIRS

Optical imaging can be used to record hemodynamic (near-infrared spectroscopy; NIRS) and neuronal signals (event related optical signals; EROS) from the brain. Movement artifacts, arising from variations in the interfaces between sources and detectors and the scalp, can pose problems, especially for the measures of light intensity used to derive hemodynamic (NIRS) signals. Although movement artifacts can be greatly reduced by good interface design and recording procedures, in large data sets they will inevitably occur. We have developed an algorithm for detecting and either correcting or rejecting data segments affected by movement artifacts. Abrupt changes in the data, likely due to movement, are detected and replaced with interpolated data. As the data are averaged, channels whose range within a given trial after correction exceeds a specified value are discarded. The number of accepted trials is accumulated separately for each channel. We investigated the utility of this program in a large dataset (10 blocks of 4 minutes with 1024 channels, in 46 subjects). We compared main effects in the NIRS data across subsamples of ''clean'' and "noisy" subjects before and after artifact cleaning and found the algorithm to improve the consistency of results between the ''clean'' and ''noisy'' groups. Furthermore we compared the achieved improvement in consistency of our feature based approach with improvements gained by a principal

component based approach. We found that our correction algorithm produced significantly greater improvement without introducing detectable artifacts.

Poster 86

EEG-DERIVED BIOMARKERS FOR DAYTIME SLEEPINESS IN PATIENTS WITH CHRONIC STROKE

Katherine Herron, Derk-Jan Dijk, Philip Dean, Ellen Seiss, & Annette Sterr University of Surrey

Descriptors: sleep, EEG, stroke

Stroke patients with motor deficits often report daytime sleepiness. While slowing of the EEG during wakefulness has been shown after stroke, it is unknown if and how this is linked to their perception of sleepiness. Using waking EEG and a motor task (associated with mild sleepiness), we examined: 1) differences in the frequency composition and lateralisation of the EEG between stroke patients and controls, and 2) the relationship between the EEG and subjective sleepiness ratings. EEG and Karolinska Sleepiness Scale (KSS) data were collected from 15 right hemispheric stroke patients and 15 matched controls before and after a motor priming task. Frequency analysis was performed on C3 and C4 channels. Prior to the task, the stroke group revealed increased power density below 10 Hz compared to controls for both hemispheres, with more pronounced effects within the lesioned hemisphere. The motor task significantly increased KSS scores in both groups. Increased beta and alpha activity was observed after the task in the control group. The stroke group showed post task increases in beta activity for the non-affected hemisphere and bilateral increases in alpha and theta activity. An association between KSS and the EEG was observed post task in the stroke patients within the theta and alpha bands. Therefore, slowing of the EEG is related to perception of daytime sleepiness in stroke patients. This effect may not have been observed in the controls due to the way in which the motor task manipulates sleepiness within each group, as it is more challenging for those with motor deficits.

Poster 87

FUZZY PICTURE PROCESSING: EFFECTS OF SIZE REDUCTION AND BLURRING ON EMOTIONAL REACTIONS

Andrea De Cesarei, & Maurizio Codispoti University of Bologna

Descriptors: emotion, engagement, perception

Emotional engagement varies not only as a function of stimulus content, but also depends on stimulus imminence. Consistent with this, in the picture-viewing context it has been demonstrated that the affective modulation of skin conductance changes increases linearly with picture size, suggesting that stimulus imminence affects action preparation. However, stimuli which lie in the distance appear not only smaller, but also less detailed compared to closer objects. To disentangle the effects ofsize reduction from the detail loss associated with picture degradation, emotional and neutral images which were either reduced in size or low-pass filtered were presented. Affective modulations ofstartle reflex, skin conductance and heart rate were assessed, together with subjective ratings of valence and arousal. Loss in picture detail, achieved either by blurring or by size reduction, was associated with less pronounced affective modulation of skin conductance. Moreover, skin conductance change in response to mutilated bodies compared to neutral stimuli was more reduced when viewing small than blurred pictures, indicating that the visual angle may modulate sympathetic activation in response to the most arousing and unpleasant contents. On the other hand, emotional modulation of the startle reflex was not affected by either manipulation. The present results suggest that, as long as picture content can be identified, emotional cues engage the appetitive and defensive motivational circuits regardless of image resolution whereas action preparation varies with stimulus imminence.

Poster 88

MAKING SENSE OF HEMISPHERIC DIFFERENCES IN MEANING APPREHENSION

Padmapriya Kandhadai, & Kara D. Federmeier University of Illinois, Urbana-Champaign

Descriptors: erps, semantic processing, cerebral hemispheres

This work examined semantic processing in the cerebral hemispheres by combining the visual-half field (VF) technique with event-related brain potentials (ERPs). Associative strength and, in turn, predictability was manipulated between purely associated prime-target pairs, which shared minimal or no semantic features in common. Overall, in both hemispheres, ERPs to lateralized targets revealed significant N400 facilitation for associated pairs relative to unrelated pairs. This N400 facilitation was greater for strongly associated than weakly associated pairs in both VFs, suggesting broad similarity in sensitivity to associative strength across the two hemispheres. However, under passive task conditions, weakly associated pairs that possessed a strong reverse association from target to prime elicited enhanced late positive complex activity in the left hemisphere (LH), suggesting that the LH naturally employed controlled processes to reorder non-canonical meaning relations. The right hemisphere was also able to recruit such strategic

processes with more explicit task support. Further, consistent with findings seen in sentence processing studies, the present study revealed a LH benefit for processing moderately predictable (associated) pairs, suggesting that the LH seems better able to use top-down mechanisms to prepare for upcoming words, especially in contexts that afford only moderate predictions. In sum, these results suggest that the hemispheres differ in how they recruit top-down semantic mechanisms to mold largely similar semantic representation and activation over time.

Poster 89

INTERACTING EFFECTS OF LEXICAL VARIABLES ON LANGUAGE-SENSITIVE ERPS AT THE SINGLE-ITEM LEVEL

Sarah Laszlo1, Pablo Anaya1, & Kara D. Federmeier1 1University of Illinois, Urbana-Champaign

Descriptors: lexical variables, language processing, EEG/ERP

Effects of lexical variables on ERPs are typically measured on waveforms aggregated over many items and subjects. This approach allows for factorial analysis of the effects of single variables on single components, but cannot detail the interacting effects of lexical variables on single items. We collected EEG from 120 participants who viewed 300 orthographic items (75 each words, acronyms, pseudowords, and illegal strings), which varied systematically in length, orthographic neighborhood size (N), and frequency (words and acronyms only.) With this large number of participants, we were able to compute stable ERPs representing responses to single items (e.g., representing only the response to the word ''DOG.'') We find that a linear combination of length, N, and frequency explains an amount of variance in N4 amplitude similar to that explained by the same variables in naming latency tasks. Notably, we find that the relationship between N and N4 amplitude is stronger than that between frequency and N4 amplitude, despite the emphasis in the literature on the latter. Frequency instead exerts a smaller effect on the N4, and additionally affects the latency of the Frequency Sensitive Negativity (FSN), and the amplitude of the P2. Our results suggest that while the high level perceptual processing represented by the P2 and FSN is most strongly affected by frequency, the lexical semantic processing indexed by the N4 is more sensitive to N. More generally, our results demonstrate the feasibility of examining effects of lexical variables on ERPs at a single-item level.

Poster 90

ON THE FUNCTIONAL NATURE OF THE N400: THE LEXICAL INTERFERENCE CREATED BY NEIGHBOR FREQUENCY EFFECTS

Nicola Molinaro1, Markus Conrad2, Manuel Carreiras3, & Horacio Barber1 1University of La Laguna, 2Free University of Berlin, 3Basque Center on Cognition, Brain and Language

Descriptors: N400, sentence comprehension, lexical interference

Electrical scalp recordings have revealed the brain's sensitivity, around 400 ms after the presentation of a stimulus word, to both the lexical properties of that word and its contextual fit with a previous context. This negative deflection (N400) has been suggested to reflect either the lexical processing of the target word or a post-lexical process for integrating a meaning into a context. To contribute further evidence to this debate, in the present study we directly tapped into the lexical recognition mechanism for a target word. The electrophysiological effects due to the lexical interference exerted by orthograph-ically similar lexical units (orthographic neighbors) were monitored during a sentence comprehension study: Critical words could have neighbors of higher frequency or not, and they could follow either a highly constraining or a low constraining semantic context. Only the low constraining context words with neighbors of higher frequency elicited a larger N400 effect compared to words without higher frequency neighbors. In the high constraining contexts, the largely suppressed N400 - compared to the low constraining context - showed no effect of neighbor frequency. These results suggest that the N400 is the ERP manifestation of the lexical recognition mechanism. It is possible that in sentence context the higher predictability of a word leads to a top-down pre-activation of the lexical unit. This pre-activation facilitates the lexical selection mechanism since it cancels out the neighbor interference evident in the low-constraining sentence context.

Poster 91

ERP PARAFOVEAL-ON-FOVEAL EFFECTS DURING SENTENCE READING

Horacio A. Barber1, Nuria Dofiamayor2, Marta Kutas3, & Thomas Miinte2 1University of La Laguna, 2Otto von Guericke University, 3University of California, San Diego

Descriptors: parafovea, reading, visual hemifields

During reading, words perceived parafoveally can facilitate their subsequent processing when they are fixated. The impact of parafoveal information on the processing of the word currently fixated is more controversial. Here, we provide electrophysiological evidence for fast integration of parafoveal and foveal information during sentence reading. Seventeen volunteers read 360 German sentences presented word-by-word at

fixation. Each of these words (n) was flanked 2 degrees bilaterally by two different words: the next word in the sentence (n+1) to its right, and the previous word in the sentence (n-1) to its left. On 2/3 of the trials, one of the flankers (half the time on the right side and half on the left), sentence medially, was replaced by a word that was seman-tically incongruous with the overall sentence context. Event-related brain potentials (ERPs) time-locked to the onset of the critical triads showed N400 differences as a function of flanker congruity: Triads with incongruent flankers elicited larger N400s than triads with congruent flankers. The congruity effect for right-sided flankers was larger over right-parietal sites, whereas those for left-sided flankers had a more anterior scalp distribution. These results show that parafoveal information is integrated with the incremental sentence representation very quickly during reading, and that the processing of a word at fixation can be influenced by adjacent words.

Poster 92

ERP EFFECTS OF CODE SWITCHES IN LATE SECOND LANGUAGE LEARNERS WHEN READING

Maartje van der Meij1, Manuel Carreiras2, & Horacio A. Barber1 1University of La Laguna, Spain, 2Basque Center on Cognition, Brain and Language

Descriptors: bilingualism, code-switching, ERP

Event Related potentials were used to investigate the processing of code switches during sentence reading in second language learners. Participants were Spanish speakers classified in two groups depending on their English proficiency (high and low). Sentences were presented in English and half of them contained in the midst of the sentence an adjective in Spanish. Both groups showed an early negativity between 200 and 300 ms after word onset in response to code switches, which was localized at the left occipital-temporal electrodes. Also starting at 200 ms, a long lasting prefrontal positivity distinguished code switches from no code switches. In addition, code switching generated an enhanced negativity in the N400 time window. This negativity had a typical N400 distribution for the low proficient and a more frontal distribution for the high proficient. The effect was followed by a late positive component (LPC) with a maximum at the frontal sites for the low proficient and showing a right posterior distribution for the high proficient. This pattern of results could reflect the time-course of code switching processing: an initial detection of the switch attending to orthographic regularities (Left Occipital N250), followed by lexical integration efforts (N400) and reanalysis processes (LPC). The differences in topography suggest that high and low proficient bilinguals may use different strategies for integration and reanalysis. Finally, the common frontal effect could be associated with the executive control system monitoring the change from one language to another.

Poster 93

THE EFFECT OF FREQUENCY CHANGE DETECTION IN THE AUDITORY BRAINSTEM AND MIDDLE LATENCY RESPONSES

Lavinia Slabu, Sabine Grimm, Jordi Costa-Faidella, & Carles Escera University of Barcelona

Descriptors: novelty detection, middle-latency potentials, auditory brainstem potentials Humans are able to detect unexpected new events in the auditory environment. The neural correlates of change detection are commonly studied through the oddball paradigm that elicit a negative potential approximately 100 - 300 ms after the stimulus onset called mismatch negativity (MMN) response. Besides the temporal and possible frontal and parietal contribution to MMN generation, few animal studies reported a MMN like-response in the non-primary thalamus and inferior colliculus. The goal of the preliminary study is to investigate the effect of auditory frequency deviance detection in humans, in the time range of the auditory brainstem (ABR) and middle latency (MLR) responses. Broadband noise bandpass-filtered from 500 to 3000 Hz in steps of 500 Hz was delivered to the right ear. Left ear was masked with white noise. Three blocked conditions were presented: an oddball block with a deviant probability of p 5 .2; a reverse oddball block; and a control block in which stimuli of five different frequency bands were presented randomly, each with a probability of p 5 .2. The responses were recorded from 10 participants at Cz using right ear lobe as the reference. Our results indicate the absence of significant differences in the ABR. In the MLR time range differences were obtained for the Pa peak amplitude at about 31 ms for deviants compared to standards, t(9) 5 2.40, p < .04, and controls, t(9) 5 3.14, p < .01, for the 500-1000 Hz frequency range. This might reflect a probability-sensitive index, clearly preceding MMN, even though not at the level of the auditory brainstem.

Poster 94

ULTRAFAST NOVELTY DETECTION IN THE HUMAN AUDITORY SYSTEM

Sabine Grimm, Lavinia Slabu, Jordi Costa-Faidella, & Carles Escera University of Barcelona

Descriptors: novelty detection, middle-latency potentials, auditory processing

The rapid detection of changes in the acoustic environment is a crucial function of the

auditory system allowing for prompt adaptive behavior to potentially relevant novel

events. Change detection is usually related to the elicitation of the mismatch negativity (MMN) - a component of the scalp potential evoked 100 - 250 ms after the onset of a rare stimulus. On the single-unit level, specific responses to new stimuli can already be seen at earlier latencies in so-called novelty neurons even in subcortical structures, suggesting that novelty detection is a pervasive property of the auditory system, expanding from low to high levels along the auditory hierarchy. In the present experiment we test this hypothesis by measuring long-latency (LAEP) and middle-latency auditory evoked potentials (MAEP) to frequency deviants in two ranges (800 Hz, 3730 Hz) in an oddball paradigm. Deviants were compared to physically identical stimuli presented frequently in a reversed oddball block (standard) and in a block intermixing randomly five equally rare tones of different frequencies (control). Latencies and amplitudes of the components P0, Na, Pa, Nb, and MMN were analysed. In addition to a clear MMN component, deviants elicited already in the time range of MAEP a distinct response. Particularly, the Nb component peaking at about 40 ms was enhanced for deviants compared to standards and controls in both frequency ranges. This response indexes an early process of novelty detection preceding the higher-order detection index MMN and supports the idea of a multistage model of novelty detection.

Poster 95

NEURAL AND BEHAVIORAL EFFECTS OF TRYPTOPHAN DEPLETION ON EMOTIVE FACIAL PROCESSING IN DEPRESSION-PRONE INDIVIDUALS

Natalia Jaworska1,2, Andrea Thompson3, Dhrasti K. Shah2,3, Judy McIntosh1, Crystal M. Villeneuve2,3, Derek J. Fisher2,3, & Verner J. Knott1,2,3 1University of Ottawa, 2Institute of Mental Health Research, 3Carleton University

Descriptors: tryptophan depletion, facial expressions, erps

Major depressive disorder (MDD) has been linked with disturbed processing of affective stimuli. Altered 5-HT system functioning has been implicated in both the etiology of MDD and in affective processing. This study assessed the effects of acute tryptophan depletion (TD), which transiently lowers CNS 5-HT, on neural responses to emotive facial expressions in individuals with a family history (FH+) of MDD. Within a randomized, double-blind and placebo-controlled design, event-related potentials (ERPs) were acquired in 20 FH+ individuals during a facial recognition task involving the presentation of facial expressions (sad, joy and surprise at 20% (neutral), 50%, & 100% intensities); participants were required to respond to expressions of surprise. Subjective ratings revealed increased depression, tension and confusion scores, and decreased calmness and contentedness with TD. Early positive (P1 and P2) and the face-specific N170 ERP components were differentially altered by emotional intensity and valance. The N170 was not modulated by TD, but was enhanced by expressions of happiness. Sad facial expressions enhanced P2 amplitude, regardless of region, while this effect was regionally-dependent on P1 amplitude. TD was associated with increased P1 and P2 amplitudes to sad expressions. Additionally, TD prolonged P2 latency to sad (100% intensity) expressions. As such, transiently lowered 5-HT levels altered brain activity in a manner suggestive of more sustained processing of sad expressions and impaired processing of positive ones in individuals susceptible to MDD development.

Poster 96

STARTLE BLINK DEFICITS IN PSYCHOPATHY ARE UNIQUELY ASSOCIATED WITH INTERPERSONAL-AFFECTIVE TRAITS

Uma Vaidyanathan, Edward M. Bernat, Jason R. Hall, & Christopher J. Patrick University of Minnesota

Descriptors: psychopathy, fear-potentiated startle, low fear

Previous research has shown that psychopaths, relative to non-psychopaths, exhibit reduced startle blink potentiation during viewing of aversive stimuli. Available data have suggested that this deviation is related more to scores on Factor 1 (i.e., interpersonal-affective features) of the Psychopathy Checklist - Revised (PCL-R) than Factor 2 (i.e., impulsive antisociality). The goal of the current study was to evaluate this idea in a sample of incarcerated offenders (N 5 108) spanning a broad range of PCL-R scores, allowing assessment of the startle blink response with continuous PCL-R scores rather than discrete participant subgroups. To accomplish this, we recorded blink responses to startle probes administered while subjects viewed pleasant, neutral and unpleasant pictures drawn from the standardized IAPS database. Pleasant contents were further divided into erotic and nurturant scenes, while unpleasant contents were categorized into threat (e.g., spiders, snakes, guns pointed at the subject, etc.) and ''victim'' scenes (i.e., pictures of vicarious attack). Results indicated that higher overall scores on the PCL-R were associated with reduced startle responses for unpleasant but not pleasant pictures. Additionally, this effect was most marked for threat pictures. Further analyses confirmed that this reduced startle potentiation was selectively related to PCL-R Factor 1 rather than Factor 2. This pattern of results provides strong evidence for the idea that low fear is a key emotional deficit underlying psychopathy.

USING TIME-FREQUENCY ANALYSIS TO DISENTANGLE PROCESSES IN A CUED GO/NO-GO TASK

Vaughn R. Steele, Edward M. Bernat, William L. Schoeppner, & Christopher J. Patrick University of Minnesota

Descriptors: cognitive control, ERP, time-frequency analysis

Response inhibition tasks (e.g., go/no-go) have been used to develop cognitive control theories. In the current study, a compound cue preceding a go/no-go target (75% go, 25% no-go) allowed for manipulation of preparatory and contextual effects on cognitive control by introducing several manipulations. These included: a tentative or certain directional cue that modulated anticipation of a left/right hand response, a gain or loss cue that indicated a gain or loss frame (i.e., correct responses result in a gain or avoid a loss), and a monetary cue (zero or ten cents) that indicated whether there was money at stake for the current trial. Event-related potentials (ERPs) were recorded using this cued go/no-go task (undergraduate students; N 5 62). P2, N2, and P300 ERP components were measured to target stimuli, as well as a CNV prior to the targets. Results indicated that cue manipulations significantly modulated each time-domain measure. Time-frequency (TF) analysis, conducted to assess potential overlap in processes among these components, parsed target responses into distinctive theta (3 -9 Hz) and delta (< 3 Hz) TF components. Results indicated that all three target-locked time-domain components were characterized by a mixture of theta and delta activity. Further, time-domain effects were more parsimoniously described using the TF measures. Overall, findings from this study suggest that conventional time-domain measures represent a mixture of relevant neuro-cognitive processes more succinctly indexed by theta and delta frequency components delineated by the TF approach.

Poster 98

REDUCED P300 AMPLITUDE IN CRIMINAL PSYCHOPATHY IS RELATED TO EXTERNALIZING TENDENCIES: EVIDENCE FROM A SIMULATED GAMBLING TASK

Noah C. Venables, Justin L. Jobelius, Lindsay D. Nelson, Edward M. Bernat, & Christopher J. Patrick University of Minnesota

Descriptors: externalizing, P300, time-frequency

P300 amplitude reductions have been consistently related to impulse dysregulation problems (externalizing) in community samples using oddball tasks. Recently, similar reductions in P300 were demonstrated to feedback stimuli in a simulated gambling task through use of time-frequency (Bernat et al., submitted). This was in contrast to the feedback-related negativity (FRN) response to the same stimuli, which showed no such reduction. The current study investigated whether reduced P300 amplitude to feedback stimuli in this gambling task would be observed as a function of higher externalizing tendencies, as indexed by Hare's PCL-R, in a sample of prisoners. Findings indicated that P300 reductions were related to higher PCL-R total scores, indicating that psychopathy predicted P300 in the expected (negative) direction. Importantly, the impulsive behavioral deviance factor (F2) was related to reduced P300 whereas the affective-interpersonal factor was not. This further supports the idea that P300 reductions are related to elevated impulse dysregulation across a broad range of individual variation. Interestingly, we found a positive association between the FRN response and F2 which was independent of the P300 reduction. This suggests that processes indexed by the FRN (exogenous monitoring) are operating intact for individuals across levels of impulse dysregulation, although appears to be increased within an incarcerated sample. Together, these findings support the idea that parallel neurobiological deviations may underlie externalizing tendencies across diverse samples.

Poster 99

PSYCHOPATHS SHOW DEFICITS IN SUBCONSCIOUS PROCESSING OF FEAR FACES

Robert W. Shannon, Noah Venables, Justin Jobelius, Edward Bernat, Sheng He, & Christopher Patrick University of Minnesota

Descriptors: psychopathy, ERP

Previous studies have reported that psychopaths have difficulty in recognizing sad or fearful faces, as compared to non-psychopaths (Blair et al. 2001, 2004; Stevens et al. 2001; Dolan & Fullam, 2006). It is unclear whether these deficits are due to difficulties in the explicit recognition of emotion or rather, a more fundamental deficit in the processing of emotional information. In the current study ofa sample ofincarcerated male offenders, we investigated this question by using a binocular rivalry paradigm in which we presented images of neutral and fearful faces with or without interocular suppression noise, while we recorded event-related potentials. We compared the amplitude of the N170 component, which has been linked to facial recognition, between psychopaths and nonpsychopaths. Preliminary results show that for the visible condition psychopaths did not show any differences between fear and neutral faces while nonpsychopaths showed greater reactivity

to fear faces; for the invisible condition psychopaths showed little evidence of an N170 response to either neutral or fearful faces while nonpsychopaths had similar N170 responses to fearful and neutral faces. Results support the view that psychopathy can involve deficits in facial affect recognition, and suggested deficits in the recognition of fearful faces may be rooted in a fundamental deficit in automatic facial information processing.

Poster 100

RESPONSE INHIBITION AND ERROR DETECTION RELATE TO IMPULSIVENESS

Wen-Pin Chang1, William J. Gavin2, & Patricia L. Davies2 1University of Indianapolis, 2Colorado State University

Descriptors: response inhibition, error detection, impulsiveness

Impulsiveness has been linked to premature responses in reaction time tasks, such as the Eriksen flanker task or the go/nogo task. Premature responses may reflect a failure to properly inhibit prepotent responses or a lack of error monitoring. In the present study, 29 healthy adults were examined. Impulsiveness was determined by the Conners Adult ADHD Rating Scale in order to divide the participants into a low impulsiveness (LI) group(n 5 14, age 5 24.46 7 3.94) and a high impulsiveness (HI) group (n 5 15,age 5 23.10 7 2.98). Electroencephalogram (EEG) was recorded while participants performed both visual letter flanker and go/nogo tasks. Four event-related potential (ERP) components were examined, i.e., error-related negativity (ERN) and error positivity (Pe) from the flanker task, nogo-N2 and nogo-P3 from the go/nogo task. As expected, the results revealed that the HI group had a significantly enhanced nogo-N2 amplitude (M 5 8.14 7 5.48 mV) compared to the LI group (M 5 3.21 7 3.44 mV)with t(27) 5 2.884, p 5 .004. The HI group exhibited a larger ERN amplitude (M 5 10.27 7 5.35 mV) compared to the LI group (M 5 6.81 7 5.35 mV), t(27) 5 1.742, p 5 .047. No differences were found between the two groups in either Pe or nogo-P3 amplitudes. Our results suggest that healthy adults with a high impulsiveness tendency exert more effort in response inhibition (nogo-N2) and exhibit a larger error detection (ERN) response. Such effort may be necessary to sustain optimal task performance in daily life activities compared to adults with less impulsiveness.

Poster 101

CHANGING PERCEPTUAL LOAD IN VISUAL FLANKER TASKS AFFECTS ERN AMPLITUDE

William J. Gavin, & Patricia L. Davies Colorado State University

Descriptors: ERN, perception, development

A diversity of visual stimuli each varying in demands on perceptual and cognitive processing has been used in studies oferror-related negativity (ERN) employing flanker tasks. To investigate the effects oftask demands on ERN amplitude, we manipulated the level of perceptual load in three paradigms by differing the number of arrow symbols (1, 3 or 5) used. All 3 ERN paradigms were administered in a single session with the order of presentation counterbalanced across participants, 23 adults (18 -23 years) and 13 children (9-10 years). Each paradigm consisted of 480 trials with a short break after each block of 240 trials. Increasing the perceptual load was successful in producing increased processing demand. Significant increases in the mean number of errors and mean reaction times (RT) were found across both groups as perceptual load increased. Children made significantly more errors and had significantly longer RTs than adults. Significant interactions indicated that changes in task demands affected errors and RT more dramatically for children than for adults. ERN peak-to-peak amplitude significantly decreased for both children and adults as perceptual load increased. For 3 and 5 symbol paradigms, children had significantly smaller ERN amplitudes than the adults. However, the effects of perceptual loading and maturation on ERN amplitude were no longer significant when the number of segments (i.e. errors) is utilized as a covariate to control for possible attenuation of the ERN amplitude due to increased noise (e.g., latency jitter) introduced via segment averaging.

Poster 102

RELIABILITY OF ERN IN ADULTS PERFORMING A VISUAL FLANKER TASK

William J. Gavin, & Patricia L. Davies Colorado State University

Descriptors: ERN, reliability, signal processing

Impairment in performance monitoring may result in problems in everyday functioning. A reliable measure of underlying brain processing related to performance monitoring may be helpful in studying clinical populations. The error-related negativity (ERN) has been associated with performance monitoring. The purpose of this study was to examine the reliability of the ERN in a visual flanker task. In the present study, 21 healthy young adults (Mean age 5 23.5, SD 5 2.5; 10 males) completed a visual flanker task in each of two sessions, one week apart. The ERN peak-to-peak amplitude for session 1 (M 5 11.6, SD 5 5.4) was not significantly different from the ERN amplitude for session 2 (M 5 13.2, SD

5 5.0), F(1, 20) 5 3 .2, p 5 .087. The reliability of the ERN amplitude between sessions was significant and very high (Cronbach's Alpha 5 .84; Pearson's r 5 .72; ICC 5 .72)

Poster 103

RELIABILITY OF ERN IN CHILDREN PERFORMING A VISUAL FLANKER TASK

Patricia L. Davies, & William J. Gavin Colorado State University

Descriptors: ERN, reliability, development

This study examined the test-retest reliability of the ERN in children. Fifty-three children ages 8 to 13 years (Mean age 5 10.3, SD 5 1.5, Males 5 23) completed a visual flanker paradigm in each of two sessions one week apart. No significant difference was found between the ERN peak-to-peak amplitude for session 1 (Mean 5 7.5, SD 5 4.0) and session 2 (M 5 8.1, SD 5 4.7). Moderate reliability in ERN amplitude was found (Cronbach's Alpha 5 .54; ICC 5 .37, p 5 .003). The reliability was examined after adjusting for trial-to-trial latency variability using an adaptive Woody filter to improve signal-to-noise ratios. The mean ERN amplitudes increased for session 1 (M 5 13.6, SD 5 7.8) and session 2 (M 5 14.6, SD 5 7.1) but difference between sessions was not significant. After adjusting for latency variability minor improvements in reliability was found (Cronbach's Alpha 5 .58; ICC 5 .40, p 5 .001). To illustrate developmental differences, the 20 youngest children (< 9.6 years) revealed no reliability between session 1 and 2 (Cronbach's Alpha 5 _ .01; ICC 5 _ .003, p 5 .51). For these children the latency adjustment had a large impact on reliability (Cronbach's Alpha 5 .56; ICC 5 .39, p 5 .04). For the 33 older children, the reliability between session 1 and 2 was stronger (Cronbach's Alpha 5 .66; ICC 5 .49, p 5 .002) though the adjustment for the latency variability had a similar reliability levels as the younger children. The results suggest the reliability of ERN amplitude is moderate for children between 8 and 12 years of age and that reliability improves with age.

Poster 104

THIS IS YOUR BRAIN ON ADS: ADOLESCENTS' RESPONSES TO ANTI-DRUG TELEVISION ADVERTISEMENTS

Daniel J. Goldman1, Brittany R.L. Duff2, Michelle A. Roth1, Julia K. Langer1, & Bruce N. Cuthbert1 1University of Minnesota, 2University of Illinois

Descriptors: anti-drug messages, facial emg, skin conductance

While large sums are spent annually on anti-drug advertisements, little is known about what makes them effective. The present study is part of a series designed to evaluate the combined use of psychophysiological/neuroimaging measures and attitude/emotional ratings in evaluating ad effectiveness. The goals of this study were (1) to compare physiological responses to ads previously rated as effective vs. ineffective, and (2) to examine effects of continuously rating vs merely watching an ad. Twenty anti-drug ads - 10 strong and 10 weak in rated effectiveness - were selected based on adolescents' ratings of over 100 ads in a prior study. Facial EMG and skin conductance were recorded while adolescents (N 5 46) aged 15-19 viewed each ad twice, once while making continuous ratings of arousal and once while simply watching. Skin conductance levels (SCL) during the first run were greater than the second run and also declined over time during each ad, p's < .0001. However, SCL increased during the first 12'' while rating, whether the first or second run. In contrast, corrugator and orbicularis EMG increased significantly across the course of film clips; corrugator EMG also showed stronger increases during Rating than Watching, p < .04. No systematic effects were observed for zygomatic EMG. Some moderate effects of Strong vs. Weak ads were observed, but the effects ofmaking continuous ratings appeared to have a stronger effect overall across the various measures. The results suggest that the physiological effects of making ratings must be accounted for in evaluating ad effectiveness.

Poster 105

PUT IT IN CONTEXT: THE INTERACTION OF AFFECTIVE ODDBALLS WITH EMOTIONAL CONTEXT

Daniel J. Goldman, Julia K. Langer, Scott J. Burwell, & Bruce N. Cuthbert University of Minnesota

Descriptors: affective oddball, emotional context, P300

The late positive potential (LPP) ERP component varies with valence and arousal in rapid (1/sec) presentation of emotional pictures. Further, we have demonstrated systematic LPP effects in the mood-like context of sustained, rapid presentation of emotional pictures of a single affective valence. Other work using oddball paradigms shows a potent-iation of the P3 ERP component in response to visual affective oddballs; however, standard stimuli are almost always non-affective, thus failing to model an emotional context in which the target affective stimuli are processed. The present study employs a contextual affective oddball paradigm in which both standards and oddballs are IAPS images. Participants (N 5 50) viewed six blocks, each with one ''standard'' emotional valence (pleasant, neutral, unpleasant) randomly interspersed with oddballs of a different

valence at a ratio of 4:1. At Pz, peak P3 amplitude to oddballs was significantly larger than to standards in every block, p's < .02. In each block with pleasant or unpleasant oddballs, the mean LPPs to oddballs significantly differed from standards (p's < .05), but in blocks with neutral oddballs, the LPPs to oddballs did not differ from standards. Analyses across blocks demonstrate the effects of context; P3 amplitudes for standards of the same valence significantly differed as a function of oddball valence, p's < .03, while only pleasant oddballs differed as a function of standard valence, p < .01. The valences of the affective context and of the target stimuli interact to alter the processing of both stimulus types.

Poster 106

EEG ASYMMETRY PATTERNS IN INDIVIDUALS WITH HIGH AND LOW TRAIT ANXIETY

Antonia Kaczkurkin, Bruce N. Cuthbert, & William G. Iacono University of Minnesota

Descriptors: asymmetry, anxiety

Resting frontal brain asymmetry is a correlate of individual differences in affective and motivational tendencies. Relatively greater left frontal activity is proposed to be associated with approach-motivated behaviors while greater right frontal activity is hypothesized to index withdrawal-motivated behaviors. However, the sparse research on asymmetry in anxious populations has been inconsistent with some researchers finding frontal asymmetry in anxious groups while others do not. Such inconsistencies lead Heller et al. (1997) to propose that anxiety is actually comprised of two distinct processes: anxious apprehension and anxious arousal. Heller et al. found that individuals characterized by anxious apprehension showed greater activity in the left hemisphere. The current study sought to replicate and extend the findings of Heller et al. (1997). In this study, a sample of individuals with high or low anxiety was selected based on their responses to the State-Trait Anxiety Inventory. A mixed-model ANOVA revealed a significant group by region effect for the anterior and posterior areas. Greater relative left parietal and occipital activity at rest was associated with the high anxious group. One hypothesis for the current findings is that anxious participants are engaged in more subvocal, verbal thoughts during the task. The utility of subdividing the alpha frequency range (8-13 Hz) into lower alpha (8-10 Hz) and upper alpha (11-13 Hz) will also be discussed.

Poster 107

DO WE CARE ABOUT THE POWERLESS THIRD? AN EEG STUDY ABOUT SOCIAL INTERACTION IN ECONOMIC DECISION MAKING

Johanna Alexopoulos, Daniela Pfabigan, Florian P. S. Fischmeister, & Herbert Bauer University of Vienna

Descriptors: three person ultimatum game, EEG, fairness

We were interested whether or not the presence of a third (passive) player influences the processing of different offers in the ultimatum game. Therefore we recorded event-related potentials (ERP) simultaneously while subjects were playing the three-person ultimatum game; one person in the role of the dummy, the other one in the role of the responder. Nineteen pairs of subjects of the same sex had been tested. Both players were seated in the same room, while DC-EEG was recorded from 61 scalp electrodes. Behavioral data are in line with previous experiments. Unfair offers are rejected significantly more often than fair ones, in particular those where both players received an unfair share. As expected, reaction times differed significantly between the different types of offers. Allocations where the dummy received a very unfair share and the responder himself a fair one took longest. Peak-to-peak analysis at frontal electrode sites revealed a significant difference between fair and unfair offers for the responder 250 ms after the presentation of the offer. Latency and scalp distribution suggest the presence of a Feedback Related Negativity. On this note data indicate that the responder cares least about the share for the dummy. Furthermore, it will be of special interest to investigate brain areas involved in processing of unfair compared to fair offers, and whether or not these are the same in regard to the dummies share.

Poster 108

AUTONOMIC REACTIVITY AS MARKER OF INDIVIDUAL ATTITUDE TO A VIOLENT EVENT: ROLE OF PSYCHOTICISM IN APPRAISAL PROCESSES

Nadezhda E. Lysenko, & Dmitry M. Davydov Moscow Research Center of Narcology

Descriptors: baroreflex, personality trait, information processing

The Eysenkian psychoticism scale is highly utilized in psychological practice to evaluate predisposition to antisocial behavior. A decreased ability for empathy was proposed in subjects with high psychoticism, which would determine low mental rumination coupled with low autonomic load related to processing of affective stimuli with violent content. Sixty-four healthy subjects (35 women) were recruited from the Moscow community by advertisement. The study was composed of three experimental sessions with audio presentation of three short texts with different violent contents. The subjects were evaluated for psychoticism. Heart rate before and as a response to Valsalva maneuver was measured at rest and during recovery after each text listening. Results indicated that subjects

with high scores of psychoticism showed no or low change in reactivity of heart rate to Valsalva maneuver after violent text presentations compared to the rest period, while low scores of psychoticism were associated with enhanced heart rate reactivity during recovery periods. This reactivity was also related to level of violence in the content of the texts. These differences in autonomic reactivity are proposed to reflect personality trait-and text content-dependent variations in level of engagement in processing of information and were associated with individual levels of mental rumination that persisted after exposure to affective texts. Thus the autonomic process traced by Valsalva maneuver appeared to be a physiological component of cognitive activity evoked by violence or violent behavior perception.

Poster 109

BAROREFLEX LOOP COMPONENTS, BLOOD PRESSURE DIPPING, AND DAILY MOOD

Dmitry M. Davydov1, & David Shapiro2 1Moscow Research Center of Narcology, 2University of California, Los Angeles

Descriptors: baroreflex, blood pressure, mood

Previous research in clinical samples suggests that mechanisms related to the baroreflex are associated with blood pressure (BP) level and mood and that mood as a component of subjective well-being may be mediated by blood pressure changes. The objective of this study was to examine these relationships in 213 healthy women and men. Evaluation of baroreflex activity under resting conditions in the laboratory was followed by two days of 24-hour ambulatory blood pressure recording and diary ratings of mood (stressed, happy, alert, angry, sad, tired, anxious, and sleepy). Variations of 24-hour blood pressure (wake/ sleep SBP difference) mediated the effects of baroreceptor activation on daytime positive moods (happy and alert): greater baroreflex-related SBP up slope - > greater SBP dipping - > higher daily positive mood. Baroreceptor inhibition predicted daytime negative moods (sleepy and anxious): i) greater baroreflex-related SBP down slope -> lower daily sleepy mood; ii) greater baroreflex-related slope of heart rate increases -> higher daily anxious mood. Evaluation of the baroreflex components can provide significant information about mood variations, which may have applications in the prediction of risk and resilience factors related to mood disturbance in healthy people.

Poster 110

POSTURAL BLOOD PRESSURE, MOOD REGULATION, AND LIFE STRESS

Dmitry M. Davydov1, & Karen Ritchie2 1Moscow Research Center of Narcology, 2French National Institute for Health and Medical Research (INSERM)

Descriptors: blood pressure, mood, stressful event

Several studies have shown individual variations in the blood pressure (BP) difference between postures after stabilization. This variation has been attributed to individual differences in physiological mechanisms protecting brain and body homeostasis. Mood level was proposed to be one of markers of this homeostasis. This study examined 672 individuals for BP in standing and supine positions at inclusion in the year following at least one stressful life event, e.g., bereavement. Positive and negative mood changes from inclusion to the 4-year follow-up were examined by scores retrieved from the CES-D depression scale. The relationship between posture-related BP differences and mood was evaluated after adjusting for socio-demographic and clinical variables (e.g., sex, age, body mass index, major depressive episodes and their number during lifetime). For subjects in whom BP was higher in the standing position compared to supine a significant increase was observed in positive mood from inclusion to the follow-up. Subjects with lower BP in the standing position compared to supine demonstrated a higher depressive mood level averaged across time points, had a major depressive episode in the past, or used psychotropic drugs. Individual variations in the postural BP difference were not dependent on hypertension status, use of antihypertensive drugs, sex, age, or body mass index. BP postural differences may be associated with biological mechanisms that promote positive mood and provide protection against depressive mood during life and after significant life stress.

Poster 111

ERROR PROCESSING, TASK DIFFICULTY AND MOTIVATION IN SCHIZOPHRENIA: AN EVENT-RELATED FMRI STUDY USING A SPEEDED FLANKER-TASK

Alexander M. Nitsch, Johannes Hewig, Thomas Hiller, Wolfgang H.R. Miltner, & Thomas Straube Institute of Psychology, Friedrich Schiller University of Jena

Descriptors: error monitoring, schizophrenia, cognitive control

The rostral cingulate Zone (RZC) is currently associated with processes of error monitoring, effort and error probability. Earlier studies showing activation differences in this area between patients and healthy control subjects had the shortcoming of usually large behavioral differences in the error rates of the two groups. In the present study functional magnetic imaging (fMRI) was applied in a modified Eriksen Flanker-Task with adaptive

time pressure in order to achieve a comparable number of errors for patients suffering from Schizophrenia and healthy control subjects. Behavioral data supports the assumption of a robust interference effect. Increased activation for error minus correct trials and for incompatible minus compatible trials was found in RCZ. The 12 patients showed decreased activation in cognitive control regions compared to the 12 matched healthy control subjects with comparable behavioral parameters. The results will be discussed referring to the role of task difficulty and the putative motivational deficit of schizophrenic patients.

Poster 112

DETECTING RECOGNITION OF FAMILIARITY IN FACES USING SCR IN A PATIENT WITH MINIMALLY CONSCIOUS STATE (MCS)

Maria L. Bringas1, Margarita M. Baez-Martin1, Elizabeth Fernandez1, & Iliana Quiñones2

international Center for Neurological Rehabilitation, 2Cuban Neuroscience Center

Descriptors: skin conductance response, face familiarity, covert recognition Autonomic variables can be useful to evaluate cognitive functions in cases were verbal and nonverbal communications is impaired. In this study we examined the reactivity of the autonomic nervous system using skin conductance response (SCR) to familiar and unfamiliar faces in a traumatic brain injury patient who transited from a vegetative state to a minimally conscious state. An Autogenics AT64 Portable SCR unit coupled to a neurometric system was employed to record SCR (microSiemens) in synchronism with the onset of faces at the screen. Each stimulus was presented for 5 sec and the next was delayed until the SCR recording returned to baseline. The familiar faces included 15 pictures of people with a close relationship with the patient categorized using a familiarity scale. A subset of 11 unfamiliar faces (same distribution of gender and age of the familiar faces) was employed. The average response of all the epochs corresponding to the two experimental conditions showed a marked negativity to the familiar faces with bigger amplitude 6 sec after the stimuli. The SCR structure was different in the two conditions but the recovery time after familiar faces was longer and habituation was not founded. ERPs in a similar paradigm showed no significant difference between familiar and unfamiliar faces. Conclusion: in MCS, where physical and verbal answers are restricted and voluntary actions almost inexistent, the preserved SCR provided insight into mental activity related to the perception and processing of recognition of familiar faces even in the absence of observable behavior.

Poster 113

DIRECTED ATTENTION TO AUDITORY, TACTILE OR VISUAL STIMULI ACTIVATES MODALITY-SPECIFIC SENSORY CORTICES AND A COMMON FRONTO-PARIETAL NETWORK IN THE ABSENCE OF STIMULATION

Robert Langner1, Thilo Kellermann1, Frank Boers2, Walter Sturm1, Klaus Willmes1, & Simon B. Eickhoff2 1RWTH Aachen University, 2Julich Research Center

Descriptors: attention, modality, fmri

We studied the neural correlates of directing attention to the modality of task-relevant stimuli, using event-related fMRI to measure brain activity in 24 healthy participants during a simple reaction-time task. A visual cue indicated the modality of the upcoming target stimulus, which could be either a white square, a 1000-Hz tone, or a vibrotactile stimulation at the ring finger. To detect brain areas that mediate top-down attention to stimulus modality, we only analyzed trials without target stimuli (33%) to avoid confounds from bottom-up processes. Auditory vs. tactile or visual attention yielded stronger activity in superior temporal cortices. Analogously, tactile vs. auditory or visual attention yielded stronger activity in anterior parietal areas. Visual vs. auditory or tactile attention produced stronger activity in superior lateral and inferior medial occipital areas. A conjunction analysis across all three conditions revealed a bilateral network comprising posterior parietal, dorsal premotor, supplementary motor and lateral occipital areas as well as unilateral activity in the right anterior insula, temporo-parietal junction, and middle frontal gyrus and in the left basal ganglia. These results corroborate the notion of specific expectancy-related activity in early and late sensory cortices across modalities and modality-independent activity in a bilateral motor-preparation network. The preparatory activity in sensory areas may reflect a top-down bias to facilitate processing ofstimuli in the expected modality, which originates from a fronto-parietal network.

Poster 114

EFFECT OF WILLINGNESS ON DECEPTIVE AND HONEST RESPONSES IN A TWO-STIMULUS PARADIGM: AN ERP STUDY

Wu Hai-Yan, Fu Genyue, & Hu Xiaoqing Zhejiang Normal University

Descriptors: deception, P300, n2b

The current research employed the two-stimulus paradigm to investigate the effect of willingness in truthful and deceptive responses. In the two-stimulus paradigm, subjects

are instructed to determine to make deceptive or honest response to the firstly presented word by oneself and should make a opposite response to the second word. If a subject determined to be deceptive in response to the first presented word (self-determined deception), then the subject should respond to the second word truthfully (forced truth). Event-related potentials were recorded while participants were performing a deceptive and honest-task to memorized and new words. Results showed that the reaction times were faster to old words than to new words, truthful responses were faster than deceptive responses. Concerning ERP results, the P300 elicited by old words were larger than new words, yet truthful and deceptive responses could not be distinguished. On the other hand, the cognitive conflict-related N270 component was more negative-going in the forced lying versus self-determined responses. Moreover, there was a strong interaction (willingness and response type): deceptive response elicited more negative N270 compared to truthful response in the self-determined situation. This difference disappeared during forced responses. The dipole analysis revealed that self-determined lies elicited stronger activation in the anterior cingulate cortex than did forced lies. Results suggested that self-determined lies involved more cognitive control and emotional response than did forced lies.

Poster 115

THE EFFECTS OF EARLY DEPRIVATION ON THE PSYCHOPHYSIOLOGY OF AFFECTIVE PROCESSING DURING ADOLESCENCE

Karina Quevedo1, Anna Johnson2, Michelle Loman2, Theresa Lafavor2, & Megan

Gunnar2

1Western Psychiatric Institute and Clinic, 2University of Minnesota

Descriptors: adolescence, early adversity, emotion processing

Disturbances in early caregiving (i.e. maternal deprivation due to institutionalization) will affect the affective circuitry that is later challenged by neurodevelopmental change during adolescence. Sample: Adolescents (M age 5 12.9, SD 5 .7): Control condition: born/raised in Minnesota (n 5 52); Early Adopted condition: adopted 8 months from orphanages (n 5 37). Participants viewed 75 pictures (IAPS: pleasant, neutral and aversive) while listening to auditory probes. The startle response and the post-auricular reflex (PAR) were collected as measures of defensive and reward processing respectively. All groups showed heightened startle to aversive pictures and heightened PAR to pleasant pictures. Early deprivation affected overall average magnitude of the startle response, F(2, 97) 5 9.76, p < .05. Control < overall PAR magnitude than Early Adopted and Post-Institutionalized adolescents. Early adversity has a non-linear association with affective processing. Moderate early challenges lowers physiological sensitivity to aversive context, (lower startle), while both highly protective and highly adverse contexts result in higher sensitivity (Boyce & Ellis Biological Sensitivity to Context Theory). However, results suggest that early adversity affects sensitivity to rewarding contexts in an opposite direction: moderate early adversity enhances reward sensitivity and both low- and high-early challenges lowers reward sensitivity.

Poster 116

INTERACTION EFFECTS BETWEEN LOCATION AND DIRECTION OF STIMULUS IN THREE STIMULUS-RESPONSE COMPATIBILITY TASKS

Jesus St Cespon, Santiago Galdo, & Fernando Diaz University of Santiago de Compostela

Descriptors: stimulus response compatibility, simon effect, LRP

RT to laterally presented stimuli are faster when the location of the response corresponds with the location of the stimulus than when it does not, even if the spatial location of the stimulus is not task-relevant (Simon effect). In the present study three stimulus-response compatibility (SRC) tasks with response to stimulus color (a red or a blue arrow) were utilized. In the first task two irrelevant stimulus dimensions were considered: location (left or right hemicampus) and direction (left or right) of the arrow, with the aim of determining the behavioral (RT) and psychophysio-logical (LRP) interference in the conditions in which one or two irrelevant dimensions were incompatible with the response to color. With the same aim another two tasks were utilized, each with one of the irrelevant dimensions. A behavioral interference effect was observed for the stimulus location in both tasks and for the direction in the simple task. The interference was located in the response selection phase (LRP) and was larger for the location than for the direction of the arrow, which is consistent with the higher capacity of the stimulus location to involve attentional resources. In the first task interference effect was not observed when the direction was incompatible; neither interaction effect was observed when both irrelevant dimensions were incompatible with the color response, probably due to an attentional masking of the direction provoked by the different speed that position and direction are processed.

Poster 117

EVENT-RELATED POTENTIALS IN A COLOR-WORD STROOP TASK: AGING EFFECTS

Montserrat Zurron, Fernando Diaz, Monica Lindin, & Santiago Galdo University of Santiago de Compostela

Descriptors: stroop task, ERP, aging

Reaction Time (RT) and Event-Related Potentials (ERPs) elicited by congruent and incongruent color-word stimuli of a Stroop task in which participants were required to judge the congruence/incongruence of the two dimensions of the stimuli, were recorded in two groups of participants: young adult and older adult group. The RT was longer to the incongruent than to the congruent stimuli (Stroop effect) in both groups. The older adult group showed longer RTs than the young adult group, but there was not Group x Condition interaction. N2 and P300 latencies were longer for the older adult group. P150 amplitude was larger and P300 amplitude was smaller for the older adult group. With regards to the Condition effect in each group, while the older adult group showed larger N2 amplitude to congruent than to incongruent stimuli, the young adult group showed larger P300 amplitude to congruent than to incongruent stimuli. The results would reflect that in spite of the slowing-down in the TR and in N2 and P300 latencies in the older age group, the temporal locus of the semantic conflict, which intervenes in generating the Stroop effect, may occur within the time interval between 300 and 450 ms for both groups, although it is related with different ERP components for each age group: with N2 in older adult group and with P300 in the young adult group

Poster 118

APPLIED TENSION AND BLOOD DONATION REACTIONS: THE ROLE OF ANXIETY

Crystal D. Holly, & Blaine Ditto McGill University

Descriptors: vasovagal reactions, anxiety

Applied Tension (AT) reduces dizziness and faintness in people with blood/injury phobias and patients undergoing invasive procedures. This study investigated psychophysiological mechanisms of AT. Healthy adults (N 5 132, 51 males) viewed a 30-min video of blood collection procedures and were randomly assigned to control (n 5 64) or AT condition. The AT group was shown a video on the AT isometric muscle tensing technique prior to the blood film, and practiced AT constantly. Continuous psychophysiological measures (Systolic/Diastolic BP, HR, EDA) were obtained. Participants completed the Spielberger Anxiety scale, the Blood Donation Reaction Inventory (BDRI), and the Medical Fears Survey - an indicator of fear of needles/injections/blood. A Sex x Condition x High/Low Medical Fears Blood/ Injection (MFI) GLM was conducted on the BDRI. A main effect of MFI was found.

Poster 119

VASOVAGAL SYNCOPE AND APPLIED TENSION IN THE BLOOD DONATION SETTING: THE ROLE OF ANXIETY

Crystal D. Holly, Lindsey Torbit, & Blaine Ditto McGill University

Descriptors: vasovagal syncope, anxiety, blood donation

For the most part, despite the blood loss inherent in blood donation, symptoms such as dizziness and fainting typically reflect classic stress-related vasovagal reactions. Research has increasingly implicated anxiety reduction as a mechanism of the effects of the muscle tensing technique Applied Tension (AT) on blood donation related symptoms. This study investigated the issue further by comparing groups asked to practice AT at different points in the blood donation process. Healthy inexperienced blood donors (N 5 136, fewer than 5 previous blood donations) were randomly assigned to groups asked to practice AT Pre-Donation, During Donation, Both (Pre/ During), or Neither (Control). Measures of heart rate, blood pressure, and several psychological variables were obtained before and after donation. Questionnaires included the Blood Donation Reactions Inventory (BDRI), a measure of vasovagal symptoms, and the Medical Fears Survey. A 2 (sex) x 4 (condition) x 2 (high/low blood draw fear) ANOVA of BDRI scores produced significant main effects of condition p 5 .042, sex, p 5 .030, and blood draw fear, p < .001. Most important, AT practiced pre-donation significantly reduced vasovagal symptoms as compared to no treatment controls. To investigate the physiological data, ANCOVAs of change scores, controlling for the effects of baseline values, were performed. The ANCOVA of heart rate revealed a significant Sex x Condition x Blood Draw Fear interaction, p 5 .048. The results suggest that that AT may function in part by reducing anxiety and maintaining cardiovascular activity.

Poster 120

MODIFICATION OF THREAT PROCESSING IN NON-ANXIOUS INDIVIDUALS: AN ERP STUDY

Jenna N. Goldstein1, Lauren K. White1, Ross E. Vanderwert1, Yair Bar-Haim2, & Nathan A. Fox1 1University of Maryland, College Park, 2Tel Aviv University

Descriptors: emotion, attention, ERP

An attentional bias toward threatening stimuli is thought to underlie the development and maintenance of anxiety. This bias can be induced in non-anxious individuals through training, using a modified dot-probe task. The aims of the current study were to examine changes in ERP components reflecting attention as a function of training, and to examine whether individual differences in ERP amplitude were related to stress vulnerability. The dot-probe paradigm consisted of simultaneously presenting neutral and angry facial expressions, followed by a probe located behind the angry (congruent trial) or neutral (incongruent trial) face. After a pre-assessment of attention bias to threat, the training group (n 5 17) received only congruent trials whereas the controls (n 5 17) received an equal number of congruent and incongruent trials. After training, participants completed an attention bias assessment and a stress task. Following training procedures, the training group significantly increased their attention bias to threat and showed increased emotional vulnerability to stress compared to controls. The training group showed an increase in P2 amplitude, a component associated with threat processing, whereas the control group showed a decrease in P2. Moreover, in the training group increased P2 amplitude was related to increased emotional vulnerability during the stressor. Thus, induction of attention bias to threat is associated with increased neural response to threatening facial expressions and the magnitude of such neural response is related to stress vulnerability.

Poster 121

ALPHA AMYLASE REACTIVITY TO WRITTEN EMOTIONAL DISCLOSURE

Andrea Konig, Wendy L. Kliewer, Alison M. Eonta, Stephanie R. Pitts, & Scott R.

Virginia Commonwealth University Descriptors: alpha amylase, trauma, writing

Writing about a personal traumatic event increases short-term anxiety and physiological response and produces long-term health benefits. In this study, college students wrote for 20 minutes on three occasions about a personal traumatic event (n 5 45) or a trivial topic (n 5 53). Alpha amylase was assessed in sessions one and three by saliva samples collected before writing and 0, 10, and 20 minutes after writing. Trauma writers, but not neutral writers, reported significant increases in unpleasantness after writing in sessions one and three. Trauma writers reported increases in arousal after writing in session one and marginal decreases in arousal from pre-to post-session three. Neutral writers showed no change in arousal after writing in session one, but showed a significant decrease in arousal after writing in session three. Among trauma writers, post-writing unpleasantness and arousal decreased from session one to session three, suggesting across-session habituation. Salivary alpha amylase reactivity was analyzed in a Writing Condition x Time ANCOVA controlling for gender, nicotine, caffeine, and time ofday. In session one trauma writers showed greater alpha amylase reactivity from pre- to post-writing than neutral writers. This was no longer the case by session three, suggesting habituation had occurred. Overall, alpha amylase reactivity mirrored self-reported emotional reactions to trauma writing. Trauma writing evoked alpha amylase reactivity, a sympathetic nervous system response, which is consistent with other findings of a physiological response to trauma writing.

Poster 122

EMOTIONAL REGULATION THROUGH FOCUSED ATTENTION: AN EVENT-RELATED POTENTIALS STUDY

Jonas K. Olofsson1, Gilles Pourtois2, & Stefan Wiens1 1Stockholm University, 2Ghent University

Descriptors: erps, emotional regulation, affect

Event-related potential (ERP) studies have revealed that cortical activity is affected by the emotional arousal value ofpicture stimuli from around 250 ms (i.e. larger amplitudes for high vs. low arousing pictures; the ''late positive potential'', LPP). In this experiment, we investigated whether emotional regulation would modulate the LPP in women and in men. Twenty-two participants (12 F, 10 M) were presented with positive pictures of high and low arousal value to elicit the LPP. The participants were instructed to appraise the emotional value of the pictures without making any overt response, and to gazeat a central fixation point. Pictures were presented for either 3000 ms or 350 ms in a mixed list, and were followed by a visual mask (300 ms). A pre-stimulus cue (3000 ms) indicated whether the picture stimulus had a short or long duration. We hypothesized

that short stimulation would elicit a larger LPP due to an increased attentional focus during early processing stages. The LPP was analyzed for the Cz electrode site at 250 -350 ms latency. Results show that in women, but not in men, short duration was associated with a larger LPP compared to the long duration (a three-way interaction effect of gender x picture duration x picture arousal; p = .013). The results indicate that in women, focused attention can amplify the cortical processing of affect on an event-related basis.

Poster 123

AFFECTIVE REACTIONS IN FINANCIAL DECISION-MAKING: THE CASE OF PROFESSIONAL TRADERS

Ottaviani Cristina, Borlimi Rosita, Nucifora Valeria, & Brighetti Gianni University of Bologna

Descriptors: decision-making, traders, somatic marker hypothesis A controversy in economics is whether financial markets are governed by rational or emotional forces, therefore it seems plausible to apply Damasio's Somatic Marker Hypothesis (SMH) in the field of finance. We tested the role of affective reactions in those individuals who are supposed to be the most rational decision makers in the population: financial traders. Forty-five traders and 45 bank clients underwent the Iowa Gambling Task (IGT ) while their skin conductance responses (SCRs) were recorded before and after each card selection. According to Damasio's hypothesis, each behavioral option becomes associated with an unaware anticipatory somatic response that either encourages or discourages a certain choice. Traders showed a higher sensitivity to punishment compared to controls as demonstrated by bigger anticipatory and punishment SCRs to disadvantageous choices (t 5 _ 3.47; p < .0001 and t 5 _ 5.77; p < .0001, respectively). Apparently, experienced traders learn to develop hyposensitivity to big gains but not to big losses. A multiple regression model was computed to predict the IGT score by anticipatory SCRs to disadvantageous decks and subject group as predictors. Both predictors were significant (R Square 5 .21) showing that being trader (b 5 _ .07; p 5 .0001) and having higher anticipatory SCRs to risky choices (b 5 _ .01; p 5 .04) were predictors for the best score at the test. Given the need to make rapid decisions, traders assert to follow their intuition; this insight can be the consequence of the progressive developement of an adaptive somatic response to risk.

Poster 124

THE IMPACT OF COLD PRESSOR STRESS ON VOICE PITCH (F0)

Debora E. Plein, Andre Schulz, Steffen Richter, & Hartmut Schachinger Institute of Psychobiology, University of Trier

Descriptors: acute stress, cold pressor, voice pitch

The voice is an important carrier of paralinguistic information. Listeners immediately draw conclusions about diverse speaker characteristics, especially about emotional state. It is assumed that stress raises the tension of the larynx muscles leading to a higher voice pitch (F0). But until now, there has been no unitary empirical evidence. This might be partially due to the application of non-validated tests and / or stress provocations, respectively. In this study, we investigate the influence of a validated stress test (cold pressor) on the voice pitch (mean F0) in 36 healthy subjects. The cold pressor stress test is a well-established and simple procedure with well-documented sympathetic activation and neuroendocrine responses. The heart rate was significantly higher (p 5 .03) during the cold pressor test procedure (86,53 + 16,11 bpm) than during a control condition with hand in warm water (79,52 + 11,77 bpm). The mean F0 was moderately raised (p 5 .03) while reading a standard text during the cold pressor test compared to the control condition. This result supports findings of a stress-induced acute rise of voice pitch.

Poster 125

CONFOUNDING INFLUENCES ON LONG-TERM ELECTRODERMAL RECORDING

Sigrun Doberenz, Sunyoung Kim, Eileen Wollburg, Nina I. Maslowski, & Walton T.

Stanford University & VA Palo Alto Health Care System Descriptors: ambulatory monitoring, skin conductance

Long-term electrodermal recording has rarely been reported in the literature. Theoretically such recording could contribute to our knowledge of emotions (especially anxiety) and stress in people with and without mental disorders. Investigators may have been discouraged by the possibility that long-term recordings in daily life might be subject to uncontrollable influences of electrode deterioration, ambient temperature, physical activity, and time of day. Measures may also vary with individual differences in age, gender, race, body mass index (BMI). We recorded skin conductance level (SCL), the number of non-specific fluctuations (NSFs), ambient temperature, and physical activity in 50 healthy control subjects for a 24-hour period. SCL was much higher and NSFs much more frequent during waking than during sleep. Electrode sensitivity declined 13% over 24 hours. Higher age was associated with lower mean SCL, and women had a higher mean SCL and number of NSFs. Higher ambient temperature was related to

more NSFs during the day. Neither race, nor BMI, nor physical activity affected our electrodermal measures. Eighteen participants repeated the monitoring after 8 weeks. They showed high within-subject correlations between days in SCL and in number of NSFs, both during waking and sleeping. In this subgroup, electrode sensitivity declined 24% during the second recording day. Thus, future long-term electrodermal studies should record temperature, and need to correct electrodermal measures for temperature effects and skin electrode deterioration.

Poster 126

IMPLICIT MEMORY AND AUTONOMIC REACTIVITY IN AN ADULT COMPLEX TRAUMA SAMPLE

Wendy M. D'Andrea1, & Nnamdi Pole2 1Trauma Center at JRI/Boston University, 2Smith College

Descriptors: trauma, implicit memory, RSA

Survivors of childhood abuse have complex presentations with respect to symptoms, physiology and cognition. Though child abuse occurs frequently within our society, few studies have examined psychophysiology and cognition in adult survivors of childhood abuse; instead, studies have focused on survivors of acute traumas, or on abused children. This study examines autonomic reactivity and implicit memory over the course of 16 weeks of therapy in women who have experienced childhood abuse. Participants participated in a word-stem completion task and standardized cue physiological challenge task before therapy and again after 16 weeks of treatment. Therapy occurred in a naturalistic setting and was not manualized. At pre-treatment, participants showed implicit memory biases towards anxiety- and trauma-related words, and against positive words. Participants also evidenced a pattern of elevated heart rate and respiratory sinus arrhythmia, and decreased skin conductance during the challenge task. Lower RSA and higher implicit memory for trauma words were related to increased symptoms of PTSD and interpersonal sensitivity. Following therapy, change in implicit memory and physiology was related to use of therapy techniques which focused on unconscious processes and early relationships, rather than on challenging beliefs. These data provide valuable insight into how severe trauma impacts cognition and physiology over a developmental trajectory.

Poster 127

CAN IMPLICIT MEASURES CONTRIBUTE TO THE PREDICTION OF AVOIDANCE BEHAVIOR AND PHYSIOLOGICAL FEAR RESPONSES TOWARDS SPIDERS?

Bram Van Bockstaele, Geert Crombez, Bruno Verschuere, Ernst H.W. Koster, & Jan de Houwer Ghent University

Descriptors: implicit measures, prediction study, fear/anxiety

Research with implicit measures has shown that anxiety is associated with a threat-related attentional bias and threat-related associations. However, there is ongoing debate to what extent these measures predict real life behavior. Our study was designed to investigate the predictive power ofa spider-flower IAT, a spider dot probe task, a spider interruption task and the Fear for Spiders Questionnaire (FSQ) on the approach of a real spider as well as on physiological responding (heart rate and skin conductance) during an anticipation phase, a picture viewing phase and a live spider viewing phase. The data of 36 participants show that explicitly measured spider anxiety strongly correlates with avoidance behavior, and with physiological responding in the picture viewing phase. Although we obtained meaningful associations between the implicit measures and the outcome measures, none improved the predictive power of the explicit measures. Our results indicate that explicit measures of fear are still the best predictor of future behavior, and cast doubt on the incremental predictive power of implicit measures.

Poster 128

EFFECTS OF BIOFEEDBACK ON SKIN CONDUCTANCE AND HEART RATE IN DEPERSONALIZATION DISORDER

Poppy L.A. Schoenberg, Mauricio Sierra-Siegert, & Anthony S. David Institute of Psychiatry, King's College London

Descriptors: biofeedback, SCL, HR, depersonalization disorder

Objectives: Based on previous psychophysiological research outlining hypoactive au-tonomic response in patients with depersonalization disorder, the objective was to ascertain whether increasing autonomic arousal would alleviate specific symptoms of emotional blunting, disembodiment and estrangement from self, in such patients using a biofeedback paradigm. Method: Thirty-two patients with a DSM-IV diagnosis of de-personalization disorder received 8 sessions of electrodermal biofeedback, concomitant to heart rate recording, over a 4 week period. Results: Unlike prior investigation of skin conductance response in people with depersonalization, patients showed significant elevated baseline skin conductance levels compared to healthy controls. Heart rate variability spectra showed significant increases in the low frequency bandwidth following Fast Fourier Transformation, reflecting increased vagal tone and relaxation, consistent with the reductions in sympathetic activity indexed by skin conductance level.

Contrary to our hypothesis, a decrease in autonomic arousal alleviated symptoms of depersonalization. Conclusions: Depersonalized patients were unable to increase physiological levels, suggesting the disorder reflects problems in autonomic arousal regulation, affecting appropriate emotional and physiological responsivity. As baseline skin conductance levels were significantly higher than healthy controls, a future therapeutic target would be to 'normalize' such levels in patients.

Poster 129

DEPRESSION AND BIASED ATTENTION: EVIDENCE FROM SKIN CONDUCTANCE RESPONSES

Catarina Silva1, Ana Ferreira1, Isabel Soares2, & Francisco Esteves1 1Lisbon University Institute, 2University of Minho

Descriptors: SCR, attention, emotion

The present study investigated psychophysiological differences in skin conductance responses (SCRs) for attention biases related to anxious and depressive symptomatology. Twenty-one undergraduate students (mean age 22.6 years), participated in a rapid serial visual presentation task (RSVP). Participants' depression and anxiety symptomatology were accessed with the Brief Symptom Inventory. Skin Conductance was continuously recorded during the RSVP task performance. Trials consisted of a stream of 15 images, in which participants had to search for one target (neutral image rotated 90° to the left or to the right). A critical distractor (emotionally negative, positive, or neutral), preceded the target either two or four items in the stream. The largest increase in conductance in a time window from 1 to 4 seconds after onset of the critical image was scored as the SCR elicited by the distractor stimulus. Trials with artifacts were excluded from analysis, while trials with no detectable response were scored as zero. Results showed increased SCRs for emotional critical distractors to be related with depressive but not with anxious symptomatology. Specifically, depressive symptomatology was significantly correlated with larger SCRs to emotional critical distractors, both with positive and negative valence. These findings are consistent with psychophysiological changes in SCR during emotional-information processing, and in line with recent work documenting an association between depression and biased attention.

Poster 130

EFFECTS OF EXPOSURE TO NATURAL SOUNDS AND ENVIRONMENTAL NOISE ON PHYSIOLOGICAL STRESS RECOVERY

Jesper J. Alvarsson, Mats E. Nilsson, & Stefan Wiens Stockholm University

Descriptors: stress recovery, positive sounds, SCL

Research suggests that physiological stress reactions may be reduced by visual impressions from natural environments as compared to urban or built-up environments. The present experiment tested whether similar effects may be found by auditory stimulation. Forty university students were tested in an experiment with four consecutive recovery sessions after stressful mental arithmetic tests. The independent variable was type of sound during recovery. The sound was either a natural sound environment (sounds from water and birdsong, at 50 dBA), or three types of noisy environments (traffic noises at 50 or 80 dBA or ambient background sound at 40 dBA). The main dependent variables were physiological recovery from stress, as measured by decrease in heart rate (HR) and skin conductance level (SCL) after the stressful arithmetic test. The main result was that SCL reduction was faster during the nature sounds than during the various noises. For HR, no systematic effects of experimental sounds were found. The result for SCL lends some support to the hypothesis that exposure to natural sounds facilitates physiological stress recovery.

Poster 131

CARDIAC SYMPATHETIC ACTIVITY IS NOT INFLUENCED BY DEPRESSION BUT BY ANTIDEPRESSANTS

Carmilla M.M. Licht1, Brenda W.J.H. Penninx1, & Eco J.C. de Geus2 1Vrije University - Amsterdam Medical Center, 2Vrije University - Amsterdam

Descriptors: pre-ejection period, depression, antidepressants

Increased sympathetic activity may play an important role in the increased risk of cardiovascular disease among depressed subjects. Recent research suggested that these detrimental effects of depression on sympathetic activity are attenuated by sympatho-lytic effects of antidepressants. To test this hypothesis, we compared the pre-ejection period (PEP) between depressive subjects using antidepressants, depressive subjects not using antidepressants, and non-depressed controls. Data were available from 194 control subjects and 581 subjects with a depression diagnosis of which 289 subjects used an antidepressant (mean age 43.6 years, 70% female) participating in a large cohort study: the Netherlands Study of Depression and Anxiety (NESDA). The PEP was measured during 1.5 hours of ambulatory recording of impedance cardiography. Analysis showed that the PEP of depressive subjects not taking antidepressants did not differ from the PEP in controls. Depressive subjects using tricyclic antidepressants (TCAs) and com-

bined noradrenergic/serotonergic antidepressants (NS-ADs) showed a significantly shorter PEP compared to controls (5.5 ms and 11.1 ms shorter with effect sizes of d 5 .311 and d 5 .627 respectively). In contrast, depressed subjects using selective serotonin re-uptake inhibitors (SSRIs) had a longer PEP than the controls. This study shows that depression itself is not associated with increased sympathetic activity in comparison to healthy controls, but that some antidepressants significantly increase sympathetic activity, whereas SSRIs seem to decrease sympathetic activity.

Poster 132

HABITUATION RATE AND ADHD SUBTYPE IN A LARGE SAMPLE OF PREADOLESCENT CHILDREN

Ian McLaughlin, Daniel Bedford, Scott Burwell, Micah Hammer, Dragana Vidovic, Casey S. Gilmore, Stephen M. Malone, & William G. Iacono University of Minnesota

Descriptors: ADHD, skin conductance, habituation

Childhood ADHD and decreased electrodermal responding (EDR) have both been associated with increased risk for antisocial behavior later in life and are both highly heritable. Evidence is mixed, however, on whether ADHD is associated with reduced EDR, and whether ADHD subtypes may play a role in moderating these relationships. The present study, therefore, examined the relationship between EDR and ADHD subtypes (ADHD-inattentive, ADHD-hyperactive, and ADHD-combined) during a habituation paradigm. Subjects were 403 male and 414 female twins (mean age 11.9 years; range, 10.9-13.0) from a large population based sample drawn from the Minnesota Center for Twin and Family Research Enrichment Sample, whose sampling method was designed to increase the number of subjects with externalizing disorders in both sexes, making it particularly useful for the present study. Subjects were separated into four groups: those with one of the 3 ADHD subtypes or those with no disorder (controls). Skin conductance responses (SCRs) were recorded as subjects focused their attention on a series of tones, occurring approximately once per minute, while watching a moderately engaging, closed-caption movie. ANOVA revealed a significant main effect of group, with the ADHD-combined group habituating fastest to the tones and control subjects habituating slowest - a significant difference by post-hoc tests. Preliminary analyses further suggest that comorbid disinhibitory disorders may moderate these results, suggesting that an underlying externalizing factor may help to explain the variation between groups.

Poster 133

DIFFERENTIATING ORIENTING AND DEFENSIVE RESPONSES TO CONCEALED INFORMATION: THE ROLE OF VERBALIZATION

Bruno Verschuere, Geert Crombez, Lieselot Smolders, & Armand De Clercq Ghent University

Descriptors: orienting reflex, deception, concealed information test Using physiological measures, concealed information can be validly assessed. Orienting theory has been proposed to account for concealed information testing. As orienting is characterized by heart rate deceleration, one would expect this type of heart rate response to concealed information. However, with some exceptions, an initial heart rate acceleration to concealed information is typically observed. In the present paper, we examine the role of verbalization to explain the mixed pattern of heart rate changes. Using a within-subjects design, 30 participants were asked to either remain silent or to give an overt verbal response (''yes''/''no'') to concealed autobiographical and control information. The results indicate that verbalization accounts for the initial heart rate acceleration. In line with the orienting theory, initial heart rate deceleration was observed when participants remained silent.

Poster 134

PALMAR AND PLANTAR SKIN CONDUCTANCE RESPONSES TO STIMULUS REPETITION AND STIMULUS CHANGE

Gerhard Vossel1, Matthias Gamer2, & Martina Florchinger1 Johannes Gutenberg-Universitat Mainz, 2Universitatsklinikum Hamburg-Eppendorf

Descriptors: palmar skin conductance, plantar skin conductance

Eccrine sweat glands that are intimately involved in the generation of skin conductance responses (SCRs) are primarily located at palmar and plantar surfaces. In psychophys-iological research, SCRs are usually recorded from palmar sites, while plantar recordings are only occasionally used in special circumstances. The present study was designed to systematically compare palmar and plantar SCRs to stimulus repetition and stimulus change. For that purpose, pictures of the International Affective Picture System (IAPS) were presented to male subjects (N 5 40), while SCRs were concurrently measured from palmar and plantar sites by two constant voltage systems (0.5 V). During the habituation phase one picture (low arousal, neutral valence) was presented 15 times. On subsequent trials, 3 picture sets (5 pictures each) were presented. Here, half of the subjects viewed high arousal pictures (neutral valence), while the other half viewed low arousal pictures (neutral valence). The main findings were: (a) plantar SCR-amplitudes were significantly smaller

than palmar amplitudes; (b) latencies of plantar SCR-amplitudes were longer than latencies of palmar amplitudes, while there were no differences in rise time between the two recording sites; (c) habituation of plantar SCR-amplitude was slower than habit-uation ofpalmar responses; (d) the effects ofchanges in arousal were more pronounced at plantar sites. These results are discussed with reference to a potential application of plantar measures as well as to the physiology of palmar and plantar sites.

Poster 135

CAN AUTONOMIC CARDIOVASCULAR REGULATION PROFIT FROM AEROBIC EXERCISE AND HEARTRATE-VARIABILITY-BIOFEEDBACK?

Lutz Mussgay, & Heinz Ruddel St.Franziska-Stift Bad Kreuznach

Descriptors: autonomic cardiovascular regulation, aerobic exercise, heart rate variability biofeedback

Deficient autonomic cardiovascular regulation (ACR) is a concomitant feature ofseveral severe illness states (i.e. depression, hypertension, anxiety and somatoform disorder). The question arises by what means these observed dysfunctions in ACR can be reduced. In our laboratory data of three experimental trials are available. Aerobic exercise was administered in somatoform and anxiety patients (study 1), heart ratevariability-biofeedback in hypertensive (study 2) and depressive patients (study 3). ACR was indexed by heart ratevariability (HRV) and baroreflex-sensitivity (BRS), established by spectral analysis. In 89 subjects of study 1 BRS-increase was correlated with the relative increase of exercise during the observation period. HRV was higher in the experimental group, reactivity was slightly diminished. In studies 2 (N 5 36)and3(N 5 45) hypertension and depression were only mildly changed. ACR, however, was positively affected, especially during the first phase of the intervention. Subsequently counter regulation took place. The findings show that a reduction of ACR dysfunction is possible, but that a high and possibly long-lasting dose of either exercise or biofeedback is necessary.

Poster 136

BODY SIGNALS INFLUENCE THE PERCEPTION OF TIME

Karin Meissner1, & Marc Wittmann2 1Ludwig-Maximilian University of Munich, 2University of California, San Diego

Descriptors: time perception, interoception, autonomic nervous system Although the perception of time is essential for everyday life decisions the basic question of how our sense of time is created is still unsolved. Craig (2009) recently proposed a direct link between the perception of time and visceral processes through temporal integration of bodily signals within the insula. In a fMRI study, Wittmann et al. (2008) found that posterior insula activation increased linearly during the encoding phase of a time estimation task, implicating insular involvement for the encoding of duration. We therefore investigated whether performance in a time estimation task would be linked to changes in visceral activity, and the ability of interoceptive awareness. Thirty-two healthy subjects underwent a heart beat perception task and repetitiously estimated time intervals of 8s, 14s, and 20s duration, while cardiac interbeat intervals (IBI) and skin conductance levels (SCL) were recorded. Results showed that time estimation accuracy was positively associated with heartbeat perception scores (r 5 .43, p 5 .015). Repeated-measures ANOVAs revealed that IBI increased, while SCL decreased from the beginning to the end of the encoding intervals (main effect of time: F 5 47.7).

Poster 137

POLYGRAPH INDUCED DISCLOSURE IS RELATED TO INTEROCEPTIVE AWARENESS

Ewout H. Meijer, Tom Smeets, & Glynis Bogaard Maastricht University

Descriptors: polygraph, lie detection, interoceptive awareness

Despite debates about its accuracy, the polygraph has been used for the detection of deception for decades. Among the reasons for its continued use is that it is effective in inducing confessions and disclosure, also referred to as the bogus pipeline effect. In this study, we looked at whether this bogus pipeline effect is related to interoceptive awareness. Interoceptive awareness refers to an individual's ability to perceive bodily signals and their changes, and has been shown a crucial determinant for the subjective experience of emotions and feelings. Importantly, there are differences in the accuracy by which individuals can perceive their own bodily signals, and individuals with more accurate perception of their bodily signals experience more intense emotions. We hypothesized that participants scoring high on interoceptive awareness would perceive the polygraph as more threatening, consequently showing increased disclosure. Forty participants performed a heart beat counting task to establish interoceptive awareness. Next, they executed a mock crime, after which they were subjected to a concealed information polygraph test (CIT). After the CIT, they were asked to write down an alibi, followed by an interrogation. Results showed that the alibis of the participants scoring high on interoceptive awareness contained more crime details that were asked during the

CIT than those of the participants scoring low on interoceptive awareness. This supports our hypothesis that polygraph induced disclosure is related to interoceptive awareness.

Poster 138

NEURAL MECHANISMS OF INTERMODAL SUSTAINED SELECTIVE ATTENTION WITH CONCURRENTLY PRESENTED AUDITORY AND VISUAL STIMULI IN THE HUMAN BRAIN

Katja Saupe, Erich Schrôger, S0ren K. Andersen, & Matthias M. Millier University ôf Leipzig

Descriptors: intermodal attention, SSVEP, ASSR

We investigated intermôdal attention effects ôn the auditory steady-state response (ASSR) and the steady-state visual evoked potential (SSVEP). Fôr this purpose, 40-Hz amplitude modulated tones and a stream ôf flickering (7.5 Hz) random letters were presented concurrently. By means ôf an auditory ôr visual target detection task, participants' attention was directed tô the respective modality fôr several seconds. Attention tô the auditory stream led tô a significant enhancement ôf the ASSR compared tô when the visual stream was attended. This attentional modulation was located mainly in the right superior temporal gyrus. Vice versa, attention tô the visual stream especially increased the second harmonic response ôf the SSVEP. This modulation was focused in the inferior occipital and lateral occipitotemporal gyrus ôf bôth hemispheres. Indications fôr supramôdal attentional modulations were found in the lateral occipitotemporal and the temporal gyrus, in the right inferior occipital gyrus and the left inferior frontal gyrus. To the best of our knowledge, this is the first demonstration of amplitude modulation ofthe ASSR and the SSVEP by intermodal sustained attention. Our results open a new avenue of research to understand the basic neural mechanisms of intermodal attention in the human brain.

Poster 139

BEHAVIORAL AND ELECTROPHYSIOLOGICAL ENDOPHENOTYPES OF THE COMT AND DRD2 GENE-GENE INTERACTION REVEAL HUMAN VARIABILITY IN DISTRACTION AND NOVELTY PROCESSING

Manuel Garcia-Garcia, Iria SanMiguel, Immaculada C. Clemente, & Carles Escera University of Barcelona

Descriptors: genetic endophenotypes, gamma band responses, dopamine A wide variability in human distraction by novel events during task performance is paralleled by differences in electrophysiological responses. An optimal range of DA activity at the prefrontal cortex (PFC) is needed for proper working memory (WM) functioning, and might be required for optimal processing of novel events, thus subserving such differences. Forty healthy volunteers were distributed into four groups combining polymorphisms of the genes for the Catechol-O-Methyltransferase (COMT) and the DA receptor D2 (DRD2). All participants performed an auditory-visual distraction paradigm in which task-irrelevant frequent standard and rare novel sounds were followed by a visual target. Behavioral performance and phase-synchronization (PS) of gamma-band responses (GBRs) centered at 35 and 40 Hz to novel and standard sounds were analyzed. Individuals within the optimal balance of COMT levels and DRD2 density (Met A1 — and Val A1 +) showed longer response times after novel than standard sounds (i.e., distraction; Sound X COMT X DRD2: F(1,29) 5 13.815, p 5 .001) and similar PS to novel and standard sounds, while participants displaying lowest or highest PFC DA activity failed to show distraction, but presented a stronger PS of GBRs to novel as compared to standard sounds (Sound X COMT X DRD2: 35 Hz: F(1,29) 5 5.10, p 5 .032; 40 Hz: F(1,29) 5 7.62, p 5 .039). GBRs might constitute an endophenotype of COMT display and DRD2 density for exogenous attentional functioning, and the combination ofbehavioral responses and the PS ofGBRs may provide a good marker of DA-related attentional dysfunctions.

Poster 140

TEMPORAL CUING ENHANCES THE AUDITORY N1

Alexa Lampar, & Kathrin Lange Heinrich-Heine-University of Duesseldorf

Descriptors: attention, ERP

Temporal selective attention enhances stimulus processing. Event related potential (ERP) studies using auditory stimuli and a temporal variation of the Hillyard-paradigm consistently reported increased amplitudes for attended compared to unattended stimuli in the early (perceptual) N1-component. By contrast, when visual stimuli and a temporal variation of the Posner-cuing-paradigm were applied, early components were not consistently affected. The goal of the present study was to investigate whether temporal selective attention can modulate the perceptual N1-component within an auditory cuing paradigm. In two experiments, two different symbolic cues predicted the onset of a target (white noise bursts; continuous or with a gap) after a 600 ms or a 1200 ms interval, either validly (attended) or invalidly (unattended). In the first experiment, a reaction was only required for validly cued gap-targets. In the second experiment, both valid and

invalid targets required a reaction (discrimination). We observed shorter reaction times for valid compared to invalid targets. Over fronto-central electrodes, amplitudes of the N1 were larger for valid compared to invalid stimuli, but only when the invalid stimuli did not require a reaction (i.e., in the first experiment). It may be concluded that temporal selective attention modulates early processing levels ifthe unattended stimuli can be completely ignored.

Poster 141

ASSESSING THE CONSTRUCT VALIDITY OF ATTENTIONAL MODIFICATION OF PREPULSE INHIBITION OF STARTLE AMONG CHILDREN WITH ATTENTION-DEFICIT/HYPERACTIVITY DISORDER

Jessica D. Rhodes, Rebecca L. Ashare, Keri Shiels, & Larry W. Hawk University at Buffalo, SUNY

Descriptors: attention, prepulse inhibition, startle

Though prepulse inhibition (PPI) ofstartle does not require active attention, the effect is enhanced during attended compared to ignored prepulses. While the construct validity of basic PPI has been the focus of many studies, less is known about the nature of attentional modification ofPPI (AM-PPI). We examined the relationships between AM-PPI and several relevant constructs in children with ADHD (N 5 36 for preliminary analyses; anticipate N 5 60), among whom AM-PPI appears impaired. Participants completed a tone discrimination task to assess AM-PPI of eyeblink startle, as well as measures ofvisual attention (CPT), inhibition (stop task), and working memory. Multiple informants reported on temperament (effortful control on the EAT-Q) and symptoms of inattention and hyperactivity/impulsivity (H/I). Behavioral performance on the AM-PPI task converged with the CPT (hits r 5 .54) and working memory span (r 5 .41). However, AM-PPI was only weakly related to behavioral performance on all tasks. Greater effortful control tended to predict greater AM-PPI (r 5 .30 child, but .22 parent). AM-PPI was marginally and inversely related to teacher-reported inattention symptoms (r 5 — .32; H/I r 5 — .27; parent rs 5 _ .12, — .17). These data provide initial evidence regarding the construct validity of attentional modification of PPI in children with ADHD. The lack of orderly relations to other lab measures was troubling. There was some evidence of convergent validity with temperament and symptom reports, though it depended upon reporter.

Poster 142

DIFFERENCES IN GRAY MATTER VOLUME ASSOCIATED WITH INSIGHT MEDITATION: A VOXEL-BASED MORPHOMETRY STUDY

Lucas D. Eggert1, Britta K. Holzel2, Markus R. Quirin1, Jens C. Pruessner3, & Sara W. Lazar2

1University of Osnabrueck, 2Massachusetts General Hospital, 3McGill Centre for Studies in Aging

Descriptors: meditation, voxel-based morphometry, attention

Meditation practice aims to improve attention and emotion regulation. Previous studies have identified altered brain morphology in brain regions crucial for these functions in groups ofexperienced meditators. It has also been suggested that meditation practice may slow age-related decline in gray matter. We re-analyzed an MRI data-set of 20 Insight meditators and 15 control participants that was previously analyzed for group differences in cortical thickness (Lazar et al., 2005, Neuroreport). Here we report differences in subcortical gray matter volume (GMV) using voxel-based morphometry in SPM5. A region of interest analysis confirmed higher GMV in meditators in the hippocampus and the putamen bilaterally, consistent with previous reports. A significant age by group interaction was found in these two regions: GMV declined with age as expected in the control group but not in the meditators. Exploratory whole brain analyses revealed significant differences in clusters comprised of the lentiform nucleus, the parahippocampal gryrus, the amygdala and the caudate nucleus. Our results replicate previous findings and further demonstrate that GMV in these regions differs between the groups with age, suggesting that meditation might prevent normal age-related decline. The putamen is strongly implicated in attention processing, while the limbic regions are crucial for emotional processing. Our results suggest that improvements in attention and emotion regulation ascribed to meditation training might be mediated by growth of these neural structures.

Poster 143

EFFECTS OF BIASED COMPETITION ON PARAFOVEALLY PRESENTED FLICKERING STIMULI

Christian Keitel, S0ren K. Andersen, & Matthias M. Muller University of Leipzig

Descriptors: spatial attention, biased competition, SSVEP

The steady-state visual evoked potential (SSVEP) is a continuous electrophysiological response driven by a flickering stimulus. It has the same temporal frequency as the driving stimulus. Its amplitude can be modulated by attention. To date, the interaction of SSVEPs elicited by simultaneously displayed stimuli and attention has not been

sufficiently investigated. This study employed two reference-SSVEPs driven by two equally lateralized stimuli (eccentricity: 2.5° from central fixation) with frequencies in (10.6 Hz) and above (14.2 Hz) the classical alpha band range. Subjects covertly attended to one of two endogenously cued locations where they had to detect brief changes in luminance. We measured the impact on both reference signals introduced by a third stimulus appearing in their immediate vicinity. As hypothesized, allocating attention to one of the stimuli enhanced its amplitude. Furthermore, the additional stimulus presentation led to a systematic decrease of the reference signal's amplitude in the respective conditions. These findings corresponded to the assumptions made by the biased competition model (Moran & Desimone, 1995). According to this approach, the reduction reflected the competition of close-by presented stimuli. Influences of an alpha supression could not account for our data since declining amplitudes were observed regardless of the reference signal's frequency. Surprisingly, the data also yielded evidence for a dissociation of sources of the fundamental component of the SSVEP and its first harmonic.

Poster 144

ARE FEATURE-SELECTIVE AND SPATIAL ATTENTION INDEPENDENT?

S0ren K. Andersen1, Steven A. Hillyard2, & Matthias M. Miiller1 University of Leipzig, 2University of California, San Diego

Descriptors: feature-selective attention, spatial attention, steady-state visual evoked potentials

In three studies we investigated three different possible interrelations of feature-selective and spatial attention. In all studies, we assessed the attentional deployment to multiple concurrently presented random dot stimuli differing in spatial location and/or color by recording steady-state visual evoked potentials (SSVEPs) elicited by these flickering stimuli together with behavioral data. Our results show that 1) features can be directly selected without mediation by spatial attention 2) feature-selective attention and spatial attention enhance stimulus representations independently and additively and 3) splitting feature-selective attention across different locations is not possible, i.e. features are selected across the entire visual field, even when this explicitly conflicts with task demands. Taken together, these results strongly suggest that feature-selective and spatial attention operate independently at early levels of visual processing.

Poster 145

EVENT-RELATED BRAIN POTENTIAL INDICES OF SELECTIVE LISTENING TO TIMBRE AND PITCH

Kimmo Alho1, Ville Villberg2, Sebastian Cederstrom1, Istvan Winkler3, Elyse S.

Sussman4, & Teemu Rinne1 1University of Helsinki, 2Kuopio University Hospital, 3Hungarian Academy of Sciences, 4Albert Einstein College of Medicine of Yeshiva University

Descriptors: attention, auditory, timbre

Event-related brain potentials (ERPs) were recorded from 62 scalp sites during selective listening to timbre and pitch. Ten healthy young adults listened to random tone sequences consisting of lower-pitched tones (131, 139 or 147 Hz; c, c# or d in musical scale, respectively) and higher-pitched tones (220, 233 or 247 Hz; a, a# or b, respectively), synthesized with the timbre of a piano or clarinet. Their task was to attend selectively to a designated timbre-pitch combination (i.e., low piano, high piano, low clarinet or high clarinet tones), to ignore the three other timbre-pitch combinations, and to respond with a button press to occasional shorter-duration target tones among the attended tones. ERPs to attended but non-target tones called T+ P+ tones (tones sharing the timbre and pitch with the target tones) were more negative than ERPs to T — P — tones (differing in timbre and pitch from the attended tones). Smaller attention-related negative differences (Nds) were observed for T+P — tones (sharing the timbre but not the pitch with the attended tones) and T-P+ tones (sharing the pitch but not the timbre with the attended tones). The Nd to T+ P — tones had a more frontal scalp distribution than the Nd to T-P+ tones suggesting a difference in cortical mechanisms involved in timbre and pitch selection. Moreover, the modeled sum ofthese two Nds was smaller than the Nd elicited by T+P+ tones, suggesting that in addition to timbre and pitch selection, the integration of timbre and pitch information contributed to the Nd to T+P+ tones with the attended timbre and pitch.

Poster 146

ELECTROENCEPHALOGRAPHIC MEASUREMENT OF MANUAL POINTING IN VISUALLY GUIDED COMPOUND SEARCH

Thomas Toellner1, Hermann Mueller2, Howard Poizner3, Scott Makeig3, & Klaus Gramann3

Ludwig-Maximilian University of Munich, 2Birkbeck College, University of London, 3University of California, San Diego

Descriptors: visual search, pointing, sequence effects

Visual Search for pop-out targets is speeded when the target-defining dimension (e.g., color, motion) as well as motor response (e.g., button press with the left, right

index finger) is repeated (relative to being changed) across consecutive trials. Recently, Tollner et al. (2008) observed an electro-cortical dissociation of both previous-trial effects: dimension changes were reflected in the PCN component, whereas response changes modulated LRP activations. In everyday life, however, we typically have specific intentions with regard to the objects we are looking for (e.g., pointing to, reaching, grasping the object), rather than making simple button presses. Thus, the present study was designed to approximate such situations by linking goal-directed pointing movements to a compound-search task: participants first had to find and identify a target object (defined by color or shape) before they could select the appropriate motor effector (defined by the orientation of the target) to point to the target location (using a touch screen). For the onset latencies of the pointing movements (i.e. reaction times), the behavioral as well as electrophysiological results were dependent on the motor effector as well as target-defining dimension of the previous trial, replicating previous findings. In addition, the same factors had a strong impact on the movement (times) of the manual pointing responses, affecting the timing and activation of the LRP. Accordingly, this pattern of effects demonstrates an influence of perceptual (dimension-based) processes even after response initiation.

Poster 147

EFFECT OF ATTENTION ON CORTICAL PROCESSING OF SOUND MOTION: AN EEG STUDY

Stephan Getzmann1, & Jens Kreitewolf2 1 Leibniz Research Centre for Working Environment and Human Factors, 2Ruhr-University Bochum

Descriptors: spatial hearing, auditory motion, attention

The onset of motion in an otherwise continuous sound elicits a prominent auditory evoked potential, the so-called motion onset response (MOR). Here, task-specific top-down influences of spatial attention on the MOR were tested. Twenty listeners were presented with free-field sound sequences consisting of a stationary part and a subsequent motion part, in which the sound moved in horizontal direction. In a psycho-physical two-alternative forced-choice task, the listeners judged either whether the motion trajectory coincided with the spatial positions of two subsequent test tones; alternatively, they assessed the pitch of the test tones. While the auditory evoked potentials to the onset of the stationary acoustic stimulation did not vary between conditions, especially the late portions of the MOR were significantly increased when the auditory motion was task-relevant. Electrical brain source localization revealed that this extra activation mainly resulted from contribution of bilateral precentral and middle frontal gyrus, left inferior and superior frontal gyrus as well as right cingulate gyrus, suggesting the involvement of additional cortical processes that subserve spatial attention, short-term memory, and sensorimotor action. The present results indicate that the MOR has a supra-modal, task-specific component and support the notion that sound motion processing is based on a complex interaction of stimulus-specific and higherorder cognitive processes.

Poster 148

THE EFFECT OF MUSIC TEMPO AND INTENSITY ON VISUAL SELECTIVE ATTENTION

Frances H. Martin, & Isobel C. Ludford University of Tasmania

Descriptors: visual attention, music tempo and intensity, ERP

The aim of this investigation was to examine the independent and combined effects of music tempo and intensity on visual selective attention to a driving based task. The presence of an auditory distracter is thought to increase the mental workload and reduce the amount of attentional resources available for a given task. Using a repeated measures design, 18 female non-musicians completed a driving based visual attention oddball task in five auditory conditions (fast tempo high intensity, fast tempo low intensity, slow tempo high intensity, slow tempo low intensity, and music absent control), and reaction time and accuracy to the targets were recorded. Amplitude and latency of event-related potential components, N2 and P3b, were also recorded and analyzed as measures of evaluation and resource allocation. In accordance with the hypothesized effect, fast tempo music decreased the amplitude of the visual P3b with a trend towards significance for larger P3b amplitude in the presence of low intensity music found. However, contrary to the hypothesized effect of intensity on N2 amplitude, the component increased with intensity. Significant latency differences were not observed for either component. The results suggest that the impact of distracting music on cognitive processes varies according to the tempo and intensity of the music such that fewer resources are available in the presence of loud, fast music.

MODULATING THE LEFT-HEMIFIELD BIAS IN RAPID SERIAL VISUAL PRESENTATION BY REPETITIVE TRANSCRANIAL MAGNETIC STIMULATION

Kamila Smigasiewicz1, Rolf Verleger1, Friderike Moller1, Michal Kuniecki2, Sergiu

Groppa3, & Hartwig R. Siebner4 1The University Lubeck, Jagiellonian University, 3Christian-Albrechts University of Kiel, 4Danish Research Centre for Magnetic Resonance, Hvidovre University Hospital

Descriptors: transcranial magnetic stimulation, rapid serial visual presentation, hemispheric asymmetry

In the two-stream RSVP task, left targets are better identified, possibly reflecting dominance of the right hemisphere. If so, rTMS to the right parietal cortex might boost left hemisphere performance for right hemifield targets, by weakening control of the right hemisphere over the left. Participants had to identify a red letter (T1) and a black digit (T2) occurring within two streams of black letters presented in the left and right hemi-field. Simultaneously with T1 presentation, five pulses of TMS, 55 ms apart, were applied, either at P4 or at P3 (right or left parietal cortex), either as potentially efficient stimulation or as sham stimulation. In Experiment 1, the left-hemifield advantage was smaller with rTMS applied at the right than at the left parietal cortex with rTMS. Although no such effect was obtained in the group with sham-rTMS, the mechanism of this influence was not clear. Therefore, in Experiment 2, performance with rTMS and sham-rTMS was compared within-subjects, either (between subjects) at the right or at the left hemisphere. rTMS had an effect only at the left hemisphere, deteriorating identification ofthe right-side targets. Thus, it seems that only the non-dominant left parietal cortex can be perturbed by rTMS in this task, resulting in increased left-hemifield bias.

Poster 150

NEURAL CORRELATES OF THE EMOTIONAL ATTENTIONAL-BLINK EFFECT: A COMBINED EEG-FMRI STUDY

Ralf H. Trippe, Hôlger Hecht, Johannes Hewig, Lars Fichtner, & Wôlfgang H.R. Miltner Friedrich Schiller University of Jena

Descriptors: attentional blink, amygdala, P300

When two targets have to be identified in a rapid serial visual presentation (RSVP) paradigm, perception ôf the second target (T2) becomes significantly impaired if it is displayed 200-500 ms after the first target (T1), a phenomenon labelled as "attentional blink'' (AB). Here we investigate 28 participants in a combined EEG-fMRI study with two different RSVP paradigms (the first using words, the second using pictures from the International Affective Picture System as stimuli) with neutral T1s, and with T2s which either were neutral or ofpositive or negative emotional valence. In addition, event-related potentials in response to T2 targets were analyzed. Participants identified positive and negative T2s more often correctly than neutral T2s in both paradigms, indicating a re-ductiôn ôf the AB effect when processing emôtiônal stimuli. As expected, significantly larger P300 amplitudes in response tô correctly identified T2s were observed as compared tô incorrectly identified T2s. In addition we hypothesized a larger activation ôf the amygdala(e) in trials with emotional salient T2s as compared to trials with neutral T2s. In both paradigms such activation could be demonstrated. Another interesting result of the study revealed that emotionally salient pictures (photographs) led to stronger AB-effects in behavior, P300 amplitude and amygdala activation than emôtiônal words.

Poster 151

INTER-INDIVIDUAL DIFFERENCES IN CHANGE BLINDNESS

Andrea Schankin1, Dirk Hagemann1, & Edmund Wascher2 'University of Heidelberg, 2Leibniz Research Centre for Working Environment and Human Factors

Descriptors: change blindness, visual attention, n2pc

Changes between successively presented pictures are hardly to detect when the transient motion signal induced by the change is masked (change blindness). Interestingly, change detection performance varies widely across participants. Because it is supposed that focused attention is necessary to detect changes, we assessed whether the performance in a change blindness task can be predicted by a more general ability to allocate visual-spatial attention. Eighteen participants performed a detection task and a change-blindness task, and the N2pc component of the ERP, which is known to be related to focused attention, was analyzed. Participants were presented with two successive matrices of differently colored dots. Simultaneously with the presentation ofmudsplashes, the color or luminance of one dot changed or both matrices were identical. In a first block, observers were asked to report central color changes, not knowing about lateral luminance changes (detection task). In a second, physically identical block, participants reported color and luminance

changes (change-blindness task). Participants whose accuracy was higher in the detection task (block 1) showed better change detection in the change-blindness task (block 2, r 5 .61). The better performance in block 1, the larger was the amplitude of the N2pc for undetected changes in block 2 (r 5 .54), reflecting a higher sensitivity for the motion transient. These results point to inter-individual differences in the ability to allocate visual-spatial attention, resulting in differences to detect changes in the environment.

Poster 152

DYNAMIC MODULATION OF BRAIN ACTIVATION IN RESPONSE TO VARYING DEGREES OF TOP-DOWN/BOTTOM-UP PROCESSING CONFLICT

Rene Westerhausen, Stein-Ove Belsby, Matthias Moosmann, Karsten Specht, & Kenneth Hugdahl University of Bergen

Descriptors: cognitive control, fmri, dichotic listening

Attending to a less salient stimulus in the presence of a competing stronger one, constitutes a conflict between top-down and bottom-up processing which requires cognitive control to be resolved. The aim of this fMRI study was to examine modulation of brain activation in response to parametrically varying degree of conflict. Twenty subjects performed an auditory speech perception task using dichotically presented consonant-vowel syllables where the degree of conflict was varied by changing the (bottom-up) saliency of the stimuli through interaural intensity differences. This was done in 5 steps from — 18 dB in favor of the left ear stimulus to +18 dB in favor of the right ear stimulus, including a no-difference condition. Top-down processing was manipulated by using three attention instruction conditions (focus attention on right or left ear, and a no-instruction condition). Event-related fMRI data were acquired using a ''silent gap'' protocol to allow for scanner noise-free stimulus presentation.

Poster 153

ATTENTIONAL CONTROL AFTER DISTRACTION IS MODULATED BY THE EMOTIONAL CONTEXT

Stefan Berti Johannes Gutenberg University Mainz

Descriptors: attentional control, destraction, emotion

Cognitive processes can be modulated by the emotional valence of the processed information or the context. In the present study, I tested whether the emotional value of task irrelevant pictures presented shortly before the task relevant auditory stimulus affects attentional control. Attentional control in the present paradigm is measured by means of reaction time costs, caused by the introduction of a distracting change in the auditory stimulus, as well as event-related brain potentials (ERPs) reflecting attentional control (in detail MMN, P3a, and reorienting negativity [RON]). Auditory stimuli were sinusoidal tones with 200 and 400 ms duration (50% of the trials each); task performance was measured in a duration discrimination task. Distraction was triggered by a rare and random change of the pitch: while the standard pitch was 600 Hz (88% of the trials) the deviant pitch was 660 Hz (12%). Pictures with negative, positive, and neutral valence (three per class) were chosen from the International Affective Picture System (IAPS) and were presented with 300 ms duration 500 ms before the tones. Nine subjects performed the duration discrimination task. The emotional valence affected attentional control after distraction: distraction costs were half as big after pictures with positive and negative valence compared with neutral pictures. This effect is mirrored in the ERPs in the RON only, by a delayed peak in the neutral compared with the two other conditions. Neither MMN nor P3a reflected the effect of the emotional valence.

Poster 154

DOES STIMULUS-INDUCED TEMPORAL ORIENTING ALWAYS ATTENUATE EARLY AUDITORY PROCESSING?

Kathrin Lange Heinrich Heine University of Duesseldorf

Descriptors: attention, ERP

It has been shown recently (Lange, 2009) that stimulus-induced temporal orienting leads to faster responding and to an attenuation of the N1 of the auditory event related potential (ERP). In this first study, participants responded to target tones preceded by regular or irregular tone sequences: A regular (but not an irregular) sequence should trigger an entrainment process that orients attention to time points that continue the temporal pattern. In both conditions, the target tone appeared at the same time point (relative to the ending of the sequence), which corresponded to a continuation of the regular sequence. The time of the target tone was thus always predictable. The present study investigated whether the attenuated N1 associated with temporal orienting is still present when the timing of the target is unpredictable. The same paradigm was used as in the first study. Target timing could not be predicted, because targets appeared at one of three different time points. These time points either continued the temporal pattern of the regular sequence (as in the first study; target on time) or violated this pattern (target

early/late). Reaction times and ERPs to the on-time target were compared as a function of temporal orienting (regular versus irregular sequence). As in the first study, temporal orienting led to faster responding. In the present study, however, temporal orienting did not attenuate the auditory N1. This finding is consistent with the assumption that target predictability may have been a crucial factor for the N1 attenuation observed earlier.

Poster 155

EEG CORRELATES OF FORCED ATTENTION TO VISUAL AND AUDITORY PRESENTATION OF NARRATIVE TEXTS

Sergey G. Danko, & Julia A. Boytsova Institute of the Human Brain, Russian Academy of Sciences

Descriptors: sustained visual and auditory attention, oscillatory eeg The purpose of the present work was to check an assumption that oscillatory EEG correlates of forced attention to narrative texts presented either in visual or in auditory modality can be significantly different. The attention to texts was forced by tasks to retell them afterwards. EEG registration took place at 38 healthy volunteers: in a referential state of rest with open eyes; in a state of perception of a text either successively presented on a screen (FAVD) or broadcasted in ear-phones (FAAU). Subject-averaged EEG power and coherence estimations were calculated in each of 19 derivations and in each of 171 pairs of derivations for every of the states. The estimations were made in frequency ranges delta, theta, alpha1, alpha2, beta1, beta2, gamma. Within-subjects dispersion analysis of variance was applied. The results suggest that EEG correlates of visual attention at text viewing and of auditory attention at text listening are essentially different. Multiple significant distinctions in comparisons of EEG power and coherence between FAVD and FAAU are manifested in different frequency ranges. In all the frequency ranges the visual attention is characterized by higher values of power (except for alpha2) and by lower values of coherence, than auditory. The distinctions are not limited to characteristics of corresponding sensory zones involvement, but are manifested on the whole of accessible cortex surface. So modalities of presentation make the most essential impact on oscillatory EEG even during complicated cognitive activity.

Poster 156

FORCED AND NON-FORCED ATTENTION IN A DICHOTIC LISTENING PARADIGM WITH DIFFERENT INTER-AURAL SOUND INTENSITY LEVELS: AN OSCILLATORY EEG STUDY.

Julia Boytsova1, Sergey Danko1, Maksim Kireev1, Svjatoslav Medvedev1, Heikki Hamalainen2, Kimmo Alho3, & Kenneth Hugdahl4 1Institute of the Human Brain, Russian Academy of Sciences, 2University of Turku, 3University of Helsinki, 4University of Bergen

Descriptors: attention, dichotic listening test, EEG

The consonant-vowel dichotic listening (DL) test with instructions for forced attention to the right or left ear is widely used for studies of cognitive control in the auditory domain (Hugdahl et al., 2000; O'Leary, 2005). Evidence regarding the underlying brain mechanisms is, however, scanty. One possible avenue is to study the interaction of cognitive control (forced attention) and bottom-up stimulus-related factors. This was done by Tallus et al. (2007) who gradually varied the inter-aural intensity levels for the right and left ear stimuli. In the present study we used a variant of the Tallus et al. (2007) study. Our objective was to reveal EEG correlates of variation of inter-aural intensity in the DL paradigm, with different instructions to attend either the right or left ear stimulus, or with no instruction. Forty volunteers listened to simultaneous presentations of two different CV-syllables, one in the right ear and one in the left ear on each trial. EEG was recorded from 19 scalp electrodes in the three conditions: no instruction, instruction to focus on the right ear stimulus, or instruction to focus on the left ear stimulus. Inter-aural intensity level was manipulated with increased intensity in the right or left ear. EEG spectral power and coherence were calculated for seven EEG frequency bands. ANOVA was applied. The results showed that forced attention to the left ear differs from forced attention to the right ear by power and coherence changes. Switching of attention in the forced-right and forced-left conditions caused more expressed EEG changes than in the no-instruction condition.

Poster 157

THE WANDERING EYE OF MEN: AN ELECTROPHYSIOLOGICAL INVESTIGATION INTO DISTRACTION BY ATTRACTION

Johanna C. Van Hooff, Helen Crawford, & Mark Van Vugt University of Kent

Descriptors: attention bias, gender difference, ERP

The main aim of our study was to find neurophysiological evidence in support of the hypothesis, derived from Darwin's sexual selection theory, that physical attractiveness plays a greater role in male- as opposed to female heterosexual mate preferences. Reaction time (RT) and event-related potential (ERP) data were collected from 20 male and 20 female participants while they were carrying out an attention orienting paradigm. Pictures of attractive, unattractive, and neutral computer-generated faces of the opposite sex were presented to participants at fixation, while they had to identify a small target (square or

cross) appearing briefly (after 600 ms) above, below, left, or right from the face images. In both male and female participants, larger P2 amplitudes were found in response to the attractive and unattractive faces as compared to the neutral faces, presumably because these faces were more distinctive, thereby automatically attracting attention. However, only in male participants this was followed by an increased late positivity for the attractive faces. This effect was characterized by a wide scalp distribution and lasted up until target presentation. In support of our evolutionary hypothesis, this late slow effect (200-650 ms) was interpreted as reflecting augmented evaluative processing of the attractive faces, potentially taking away some of the resources that would normally be attributed to target perception and motor preparation. Nevertheless, this attention 'lapse' on part of the male participants had no consequence for task performance.

Poster 158

EFFECTS OF EXPERIENCE ON A THREAT DETECTION TASK

Vladimir Zotov1, Jocelyn Keillor1, Michael Chen2, Elena Scourtoudis1, Jerzy Jarmasz1, & Stephen Boyne1

1Defence Research and Development Canada - Toronto, 2University of Waterloo

Descriptors: heart rate variability, eye movements, stress responses Physiological markers of the effects of expertise on the identification of potential threats have not been well established. Eye movements (EM), heart rates, and button presses were recorded while 12 soldiers who had never been deployed to Afghanistan and 12 experienced solders, who had been deployed recently, watched different types of video: walking in a park, driving in Toronto, and driving in Kandahar. Participants were involved in two types of task: identification of non-threatening situations (e.g., identifying a type of neighborhood) and identification of threatening situations (e.g., detecting a higher threat of encountering an improvised explosive device). An analysis of the EM was performed in order to identify differences in the scanpaths that can be associated with more experience detecting dangerous situations. EM analyses revealed that experts had smaller saccade amplitude, more fixations, and wider scanning patterns than novices did. An analysis of heart rate variability (HRV) was performed to investigate whether a higher level of stress is associated with a better ability of experts to recognize dangerous situations. HRVanalyses showed that experts experienced higher stress levels than novices. In addition, there was evidence suggesting that stress levels interacted with the similarity of the stimuli to a threatening environment. Taken together, the results support the hypothesis that experts experienced higher levels of physiological arousal than did the novices, and scanned their environment for threat more systematically.

Poster 159

THE ROLE OF THE DOPAMINE TRANSPORTER DAT1 GENOTYPE ON THE NEURAL MECHANISMS OF COGNITIVE FLEXIBILITY

Manuel Garcia-Garcia1, Francisco Barcelo2, Immaculada C. Clemente1, & Carles Escera1 1University of Barcelona, 2University of Balearic Islands

Descriptors: dopamine transporter, cognitive flexibility, novelty p3 event-related potential Cognitive flexibility varies widely amongst individuals, yet its underlying neural mechanisms are not fully understood. A range of neuropharmacological and human clinical studies have suggested a critical role for striatal dopaminergic function. The present study aimed at revealing the role of the DAT1 polymorphism in brain response stereotypy underlying cognitive flexibility. A task-switching protocol inspired by the Wisconsin Card Sorting Test was administered to two groups of healthy volunteers formed based on the presence or absence of the 9 repetition (9R) allele of the DAT1 gene, while registering behavioral and electrophysiological novelty-P3 (nP3) response by means of human event-related potentials. The absence of the 9R allele is related to higher gene expression and thus less synaptic dopamine available at the striatum. Individuals lacking the 9R allele showed specific task switch-related behavioral costs, F(1,36) 5 4.4, p 5 .033, and modulation of a late negative brain response, F(2,72) 5 3 .5, p 5 .041, that were not observed in participants with the allele of interest, suggesting that their trial processing depended on immediate local changes, given their more limited striatum DA availability. In contrast, the group displaying higher striatum DA showed an enhancement of a DA-regulated early positive brain response irrespective of the task condition, F(2,72) 5 5.2, p 5 .023, resulting in a stronger activation of the current task set. These distinct patterns of cerebral responses support the nP3 as an endophenotypic marker of the DAT1 gene for the cognitive flexibility.

Poster 160

VIEWING FINGERS OF THE SAME HAND CAN DISTURB TACTILE ATTENTIONAL SELECTION

Bettina Forster, & Helge Gillmeister City University London

Descriptors: tactile, attention, somatosensory erps

Viewing the body has been shown to enhance tactile spatial resolution by modifying the cortical representation of the viewed body part in primary somatosensory cortex (SI). Here we report that vision can have detrimental effects on tactile spatial processing when adjacent

body parts that compete for attentional selection are viewed simultaneously. In Experiment 1, we used somatosensory event-related potentials (ERPs) to demonstrate that viewing two fingers of the same hand substantially delays selecting one over the other. Importantly, a detrimental effect of vision does not arise when selecting between fingers of different hands. In Experiment 2, we replicated the within-hand selection task and manipulated hand posture. We found that the detrimental effect of vision on tactile attentional selection depends on the separation of adjacent fingers in external space. Taken together, we propose that visual exposure disturbs tactile spatial selection by smearing the cortical boundaries of adjacent finger representations in SI, only, when these are viewed close together.

Poster 161

DISTRACTORS IN BCI: CAN HARMFUL COMMANDS BE ACTIVATED AUTOMATICALLY?

Sergei L. Shishkin1, Ivan A. Basyul2, & Alexander Ya Kaplan1

1M.V. Lomonosov Moscow State University, 2M.V. Lomonosov Moscow State University, N.I. Lobachevsky State University of Nizhni Novgorod

Descriptors: BCI, attention, distractors

In Farwell-Donchin (P300) BCI, attention acts as a factor mediating the operator's control over a computer. However, attention can be captured by various distractors. In some contexts, a command may be unwanted or even dangerous (e.g., deleting an important file). Is it easy for a user to prevent triggering such commands occasionally? Moreover, can the expected loss associated with a command make it act as an emotional distractor, so that the attention will preferably trigger this command? Eleven normal subjects were trained to use BCI (3 x 3 matrix with simple pictorial symbols) with ~ 0.7 - 0.8 accuracy, and then played a game: correctly entering the target symbol gave one point; entering the symbol which was the previous trial's target (PTT, or dangerous symbol) led to a 5 point loss in the dangerous condition (DC, 21-42 trials) but did not change the score in the control condition (CC, same number of trials); other errors did not change the score. In each trial the target position was adjacent to the target position of the previous trial. All but one subject at least once entered a PTT in the DC. Mean number of PTTs entered was 2.0 in DC and 1.1 in CC; the difference was not significant (p 5 .16). Among the cases of high numbers of PTTs in DC were a student who had an exam 15 minutes after the experiment, and a person who felt herself especially nervous during a block where she made all such errors. Though we cannot be certain yet that harmful commands may indeed be activated preferably, it is clear that blocking random activation may be not a simple task for a BCI user.

Poster 162

RHYTHMICAL MUSCLE TENSION AND RESONANCE IN THE CARDIOVASCULAR SYSTEM

Alex Vaschillo1, Anton Manyak2, & Marsha E. Bates3 1Redmond High School, Washington, 2University of Washington, 3Rutgers, The State University of New Jersey

Descriptors: cardiovascular system, rhythmical stimulation, resonance Breathing six times per minute elicits high amplitude 0.1 Hz heart rate, blood pressure, and vascular tone oscillations due to resonance in the cardiovascular system (CVS). This technique has been used to treat asthma (Lehrer, et al., 2004), major depression (Kara-vidas, et al., 2007), and fibromyalgia (Hassett, et al., 2007). Therapeutic effect was explained by high amplitude oscillations which trained and toned reflexes (e.g., the baroreflex). The present study aimed to show that rhythmical muscle tension (MT) as well as respiration can trigger 0.1 Hz CVS resonance. Sixteen young healthy subjects (7 males) completed 5-min baseline and 0.1 Hz paced breathing tasks, and three randomized 3.5-min rhythmical paced MT tasks (arm and leg muscle tense-release cycles) at frequencies of 0.05, 0.1, and 0.2 Hz. ECG, finger pulse, respiration (RV), and skin conductance (SC) were recorded during all tasks. Beat-to-beat RRI and pulse transit time (PTT) were measured. RRI, PTT, RV, and SC spectra were calculated. The power of the spectra attesting frequencies was used to estimate CVS reaction. Only 0.1 Hz MT caused high HR oscillations similar to 0.1 Hz breathing. Subjects' average RRI reaction to MTat 0.1 Hz was 4-5 times higher than at 0.2 Hz.

Poster 163

THE ASSOCIATION BETWEEN ENERGY LEVEL AND BLOOD PRESSURE RESPONSE TO A VISUAL SCANNING TASK VARIES ACROSS LOW AND MODERATE LEVELS OF DIFFICULTY

Christopher C. Stewart1, Rex A. Wright1, Siu-kuen A. Hui1, Angel Simmons1, & Richard J. Contrada2 1University of Alabama at Birmingham, 2Rutgers - The State University of New Jersey

Descriptors: cardiovascular responses, fatigue, task difficulty

Female undergraduates completed self-report measures of naturally-occurring energy and tiredness before performing either a low or moderately difficult visual scanning task. Analysis of cardiovascular responses taken during the tasks showed that, in the low difficulty condition, blood pressure responses increased or tended to increase with decreasing energy. By contrast, in the moderately difficult condition, blood pressure

responses first rose and then declined with decreasing energy. Energy was not predictive of heart rate responses nor was tiredness predictive of any measured cardiovascular response. The observed associations between energy and blood pressure responses support a recent conceptual analysis of the influence of fatigue on effort-related cardiovascular responses. Moreover, the findings complement those of a previous study that demonstrated that blood pressure responses to a moderately difficult memorization task first rose and then declined with increasing fatigue, whereas blood pressure responses to a high difficulty memorization task decreased with increasing fatigue. Continued investigation of the influence of naturally-occurring fatigue on effort-related cardiovascular responses appears warranted, as these studies provide a degree of external validity lacking in similar studies that induce fatigue via experimental manipulation.

Poster 164

DIRECT AND INDIRECT STEREOTYPE THREATS BOTH AFFECT HEART RATE ON SPATIAL REASONING TASKS

Martha A. Rotzoll, Stephanie J. Wilson, Erika K. Reckert, Alexandra M. Nobel, Elizabeth Lee Berry, Sarah E. Barowka, & Jeffrey J. Sable Rhodes College

Descriptors: stereotype threat, arousal, heart rate

Performance may suffer when one feels threatened by a negative stereotype of one's group. Physiological arousal may mediate this effect. We examined the effect of direct and indirect stereotype threat on females' performance on two spatial reasoning tests, along with corresponding heart rates (HR). Participants were randomly assigned to one of three conditions, in which they were primed (a) indirectly with remarks of expected outcomes due to the participant's gender, (b) directly with explicitly set expectations of correct responses due to the participant's gender, or (c) no prime. Participants then completed two spatial reasoning tasks (mental rotation and matrices), during which HR was measured with electrocardiography (EKG). The directly and indirectly primed groups showed a linear increase in HR across the tasks. However, the no prime group showed no change in HR over the course of either task. Although there was an increase in HR for both tasks, mental rotation scores were significantly lower than matrices scores across priming conditions. Performance on the matrices task, but not on the mental rotation task, was negatively correlated with HR. In addition, the strength of the participants' identification with their gender was negatively correlated with performance on the mental rotation task, but not on the matrices task. These results illuminate the strength ofsubtle stereotype threats on physiology and task performance.

Poster 165

THE EFFECTS OF PERSEVERATIVE COGNITION ON CARDIOVASCULAR REGULATION IN A HEALTHY COLLEGE STUDENT SAMPLE: ETHNIC DIFFERENCES

LaBarron K. Hill, John J. Sollers, III, & Julian F. Thayer The Ohio State University

Descriptors: hemodynamics, ethnic differences, worry

Cardiac output (CO) and total peripheral resistance (TPR) are critical components of blood pressure (BP) regulation. Ethnic differences in the functioning of these regulators may help explain the increased risk for cardiovascular disease observed in African Americans (Cooper & Waldstein, 2004). Research further suggests that forms of negative affect such as anger or depression may play a significant role in BP regulation (Jonas & Lando, 1999). According to the Persevarative Cognition Hypothesis (PC; Brosschot, Gerin & Thayer, 2006) worry may also lead to increased duration of negative emotional states and physiological arousal which may detrimentally affect health. The present investigation sought to explore the impact of worry (as an indicator of PC) on BP regulation in a sample of healthy White (WA) and African American (AA) college students. Hemodynamics were measured continuously during a laboratory stressor protocol. To establish high and low worry groups, a median split of total scores on a measure of worry was conducted. WA's demonstrated significantly greater CO than AA's across all experimental tasks (p 5 .04). Additionally, a significant Ethnicity x Worry interaction was observed with High Worry AA's displaying higher TPR than High Worry WA's across all tasks (p 5 .05). Similar effects were observed for diastolic and mean arterial pressure. The current study offers preliminary support for the influence of PC on BP response and suggests that its assessment may be useful in future investigations of ethnic BP differences.

Poster 166

PHYSIOLOGICAL PREDICTORS OF EXECUTIVE FUNCTIONING IN EVERYDAY CONTEXTS

Stefan Sutterlin1, Claus Vogele2, & Stein Andersson3 1University of Wurzburg, 2Roehampton University London, 3Rikshospitalet University Hospital

Descriptors: heart rate variability, neurovisceral integration, frontal inhibition

This project is a cooperation of Roehampton University London (UK), Rikshospita-

let University Hospital Oslo (Norway) and University of Wurzburg (Germany). The

results link to and expand the theoretical frameworks of self-regulation and frontal inhibition by application ofpsychophysiological measures and self-reports which have been neglected in previous research or not applied in a more comprehensive approach. Self-report measures for executive functions, emotion regulation, depressivity and motivational traits were assessed in 26 healthy adult volunteers. Electrophysiological measures of frontal alpha-asymmetry and event-related potentials (N200) in a stop-signal paradigm, heart-rate-variability and behavioral parameters ofmotor inhibition were physiological measures assessed in the same session. Significant associations of physiological parameters and self-reports have been shown. Heart-rate-variability is associated with N200 amplitude, several measures of executive functioning in everyday life and components of affective regulation. N200 amplitude predicts executive functioning in everyday context, motor response inhibition, and cognitive reappraisal in emotion regulation. Central and peripheral physiological markers predict self-regulatory performance on behavioral levels in an everyday context. Assumptions developed from central autonomic network theory have been developed and confirmed using a comprehensive methodological approach by predicting executive and emotional functioning from physiological data evoked by a response inhibition paradigm.

Poster 167

BEHAVIORAL AND CARDIOVASCULAR RESPONSES TO FRUSTRATION DURING BLOCK DESIGN AND SIMULATED DRIVING TASKS IN YOUNG ADULTS WITH AND WITHOUT ATTENTION DISORDER SYMPTOMS

Michele L. Oliver, Richard W. Backs, & Nicholas D. Cassavaugh Central Michigan University

Descriptors: attention, cardiovascular, emotion

A large percentage of automobile accidents are caused by inattention, and for drivers with ADHD the frequency of adverse driving outcomes is even greater. Previous research has shown that the relationship between ADHD and poor driving performance can be explained by factors such as increased trait anger and poor emotion control ability (disinhibition). The present study used cardio-respiratory physiological measures to examine how young adults with and without ADHD symptoms responded to frustration, and to determine how frustration generalizes to simulated driving performance. 42 (n 5 20 with high ADHD symptoms and n 5 22 with low ADHD symptoms) college students completed a computerized block design task and a simulated driving task designed to elicit frustration. Participants with high ADHD symptoms reported more frustration and exhibited more aggressive behaviors, particularly during driving. Moreover, results from the simulated driving task revealed that young adults in the high group were more likely than those in the low group to commit hazardous errors (i.e., collisions, running a red light). Physiological measures during resting baseline did not differ between groups. Although there was significant suppression of respiratory sinus arrhythmia during both tasks, it did not differ between groups. Based on our results, we propose that training for ADHD populations should focus more on control of negative emotional state rather than on attention and concentration or fundamental driving skills.

Poster 168

CARDIAC PEP RESPONDING TO INCENTIVES AMONG CHILDREN PREDICTS LEVELS OF ALCOHOL USE 3 YEARS LATER

Theodore P. Beauchaine, & Sharon L. Brenner University of Washington

Descriptors: PEP, adolescents, alcohol use

Cardiac pre-ejection period (PEP) is a well validated index of sympathetic nervous system (beta-adrenergic) influences on the heart. In our previous work, we have demonstrated lengthened baseline PEP and reduced PEP reactivity to incentives among children with oppositional defiant disorder and conduct disorder. As a result of these and other findings, we have proposed that attenuated PEP reactivity to rewards marks low central dopamine responding in the striatum, which is an established risk factor for substance abuse. In this study, we report data collected from 212 children, including those with conduct disorder, depression, comorbid conduct disorder and depression, and no psychiatric condition, at four annual assessment points. Children were 8 - 12 at Year 1. For the first three assessments, participants played a simple video game for monetary incentives, and PEP activity and reactivity were recorded. PEP was scored by ensemble-averaging 32 second epochs, sampled at 1000 Hertz. Multilevel modeling analyses of growth in PEP reactivity across Years 1 -3 revealed both intercept and slope effects on levels of alcohol use at Year 4, when children were 12-16. Controlling for age at assessment, those with lower baseline PEP responding at Year 1 reported more alcohol use at Year 4, beta 5 0.03, t(525) 5 3.36, p < .001. Those with less growth in PEP responding across Years 1-3 also reported more alcohol use at Year 4, beta 5 0.004, t(525) 5 2.03, p 5 .04. These findings suggest a potential prospective biomarker of risk for substance use among children.

Poster 169

REDUCTION IN PAIN SENSITIVITY DUE TO PHARMACOLOGICAL BLOOD PRESSURE ELEVATION IN CHRONICALLY LOW BLOOD PRESSURE

Stefan Duschek, Heike Heiss, Natalie Werner, & Rainer Schandry University of Munich

Descriptors: blood pressure, pain, hypotension

Recent studies have revealed evidence for increased pain sensitivity in individuals with chronically low blood pressure. The present trial explored whether pain sensitivity can be reduced by pharmacological blood pressure elevation. Effects of the sympathomimetic midodrine on threshold and tolerance to heat pain were examined in 52 hypotensive persons (mean blood pressure 96/61 mmHg) based on a randomized, placebo controlled double blind design. Employing a contact thermode, heat stimuli were applied to the forearm. Possible confounding of the drug effects on pain perception with changes in skin temperature, temperature sensitivity and mood was controlled for. As compared to placebo, higher pain threshold and tolerance, increased blood pressure, as well as reduced heart rate were observed under the sympathomimetic. Increases in systolic blood pressure between measurement occasions correlated positively with increases in pain threshold and tolerance, and decreases in heart rate were associated with increases in pain threshold. The findings underline the causal role of hypotension in the augmented pain sensitivity related to this condition. Pain reduction as a function of heart rate decrease suggests the involvement of a baroreceptor related mechanism in the pain attrition. Increased prone-ness of persons with chronic hypotension to clinical pain may be discussed.

Poster 170

THE RELATIONSHIP OF AGGRESSIVE BEHAVIOR TO CARDIOVASCULAR AND HPA AXIS ACTIVITY

Robina Khan1, Alex Bender1, Katja Bertsch1, Menno R. Kruk2, Steffen Richter1, & Ewald Naumann1 1University of Trier, 2Leiden University

Descriptors: aggression, hpa axis, heart rate

Results from animal and human studies suggest that basal cardiovascular and HPA axis activity are related to aggressive behavior, as well as reactivity in these systems. We therefore pharmacologically enhanced cortisol levels in 28 healthy subjects by administering 20 mg of hydrocortisone (cortisol group), while 28 other participants were given a placebo (placebo group). We then induced aggressive behavior with the Taylor Aggression Paradigm in half of the cortisol and half of the placebo group, respectively. We measured cardiovascular activity (heart rate and heart rate variability) and cortisol levels in baseline conditions, during, and after the aggression induction procedure. Preliminary results indicate that the administration of cortisol significantly changed the amount of displayed aggressive behavior. Furthermore, aggressive behavior was associated with heart rate and heart rate variability. Results are discussed in the context of animal, clinical and experimental studies.

Poster 171

EVALUATION OF WORKLOAD CHANGES DURING AN AVIATOR SELECTION TEST BATTERY

Jason D. Moss1, Alexander D. Walker1, Karin Meissner2, & Eric R. Muth1 1Clemson University, 2Ludwig Maximilian University of Munich

Descriptors: workload, heart rate variability

The US Navy is validating a PC-based test battery, the Performance Based Measure (PBM), to aid in aviator selection. The PBM consists of seven subsections which have varying workload. This study examined indices of workload across the PBM; namely heart rate variability (HRV) and the NASA-Task Load Index (TLX; Hart & Staveland, 1988). We hypothesized that HRV would differ between PBM subsections and correspond with changes in the TLX. Two hundred one subjects (93 M) completed the PBM. Inter-beat-intervals were recorded continuously. The TLX was completed after each subsection. A fast-Fourier-transform was used to obtain a measure of respiratory sinus arrhythmia (RSA) for each subsection. Respiration changes were controlled by using an RSA residual approach. Two separate repeated measures ANOVAs were conducted for RSA and TLX across all subsections. A main effect of RSA, F(6,195) 5 13.93, p < .01, and TLX total workload, F(6,195) 5 171.18, p < .01, were found. Post hoc analyses revealed a similar trend ofsignificant differences between several multitasking and single task subsections of the PBM as measured by RSA and TLX. A Pearson's correlation revealed a significant correlation between RSA and total workload scores, r 5 _ .10, p < .01. The results suggest that RSA distinguished between the workload induced by several subsections of the PBM and corresponded to a gold standard measure of workload. This suggests that RSA could be used to obtain an objective measure ofworkload during the PBM with the advantage of continuous measurement without task interruption.

Poster 172

HEART RATE VARIABILITY AND SEVERITY OF DEPRESSION BEFORE AND AFTER ELECTROCONVULSIVE THERAPY

Joke H.M. Tulen, & Walter W. Van den Broek Erasmus Medical Center Rotterdam

Descriptors: depression, cardiovascular variability, electroconvulsive therapy Diminished heart rate variability (HRV), in particular its vagal (high frequency, HF) component, is considered to play a role in the relationship between depression and risk of cardiovascular disease. Electroconvulsive therapy (ECT) is an effective treatment in patients suffering from severe depression, yet little is known about the sustained cardiovascular effects of ECT in relation to clinical state. We studied cardiovascular variability during supine rest and orthostatic challenge in relation to severity of depression before and after a course of ECT in 18 inpatients with a major depressive disorder (mean score Hamilton Depression Rating Scale, HDRS: 28.3). Data were compared with 59 healthy controls with gender, age, and smoking included as covariates.

Poster 173

INSTITUTIONAL SUPPORT OF PERSONS WITH SCHIZOPHRENIA IS RELEVANT FOR THE HEART RATE RESPONSE TO STRESS OF THEIR CAREGIVERS

Esperanza Gonzalez-Bono, Sara de Andres-Garcia, David Castillo-Pelegrin, & Luis Moya-Albiol University of Valencia

Descriptors: caregivers, stress, institutional support

Caring for a relative with a chronic illness can produce autonomic imbalance in the caregiver (Lucini et al., 2008), but scarce data about the variables involved are available. The aim of this study is to know whether institutional support for patients is a relevant factor on the caregiver's heart rate response (HR) to stress. With this purpose, 26 caregivers—mothers of persons with schizophrenia, 16 with (CARE+) and 11 without (CARE-) institutional support—were exposed to two stressors while HR was continuously registered before (baseline), during (task) and 5 minutes after stressors (recovery). Time spent in care, caregiver's burden and the relative's severity of illness were also evaluated. Results showed a main effect of 'group' factor, F(1,24) 5 9.79, p < .005), with the CARE- group displaying higher HR than the CARE+ group in all periods registered but especially during baseline and recovery (for all, p < 0.04). While non-significant differences were found in caregiver's burden, the CARE- group spent nearly significantly more time in caring and their relatives were less functional and suffered more positive symptoms and general psychopa-thology than in the CARE+ group (for all, p < 0.01). Although no significant correlations were found between HR and other variables, the existing 35.2% of variance in HR mean is explained by the caregiver's age and the relative's symptoms. Thus, although institutional support is relevant for autonomic balance of relative caregivers, further research is necessary to clarify the role played by other variables involved.

Poster 174

EXCITATION TRANSFER IN DECISION MAKING: DOES TRANSFERRED AROUSAL INCREASE DEVIATION FROM RATIONAL CHOICE?

Dennis Küster1, Olivier Corneille1,2, & Pierre Philippot1,2 1Universitee Catholiqüe de Loüvain, Jacobs University Bremen

Descriptors: excitation transfer, decision making, heart rate

We investigate if and how physiological arousal can become associated with, and influence, decision making. Towards this aim, findings of research on the effect of emotional content on decision making (e.g., Rottenstreich & Hsee, 2001; Hsee & Rottenstreich, 2004) are integrated with previous research of excitation transfer theory (e.g., Zillmann, 1971; Zillmann 1983). In a stüdy with 41 participants, we show that participants are willing to offer significantly more money for a lottery ticket with a small chance to win 500 Euro, if excitation transfer is elicited by physical exercise (exercise bike; n 5 21) as opposed to merely sitting on the bike (n 5 20). Oür findings failed to show a direct mediation of the effect on decision making by either aroüsal or skin condüctance. However, initial evidence appears to süggest an amplification of an acoüstic startle eyeblink response immediately following the decision correlated with residüally elevated heart rate. These findings may indicate that physiological aroüsal can interact with decisions, and possibly change emotional properties of the decision, withoüt any changes of the affect richness of the stimülüs.

CARDIAC AUTONOMIC REGULATION AND ANGER COPING IN ADOLESCENTS

Claus Vogele1, Sonja Sorg2, Markus Studtmann3, & Hannelore Weber4 'Roehampton University, 2University of Ulm, 3Max Planck Institute for Human Development, 4University of Greifswald

Descriptors: cardiac autonomic regulation, emotion regulation, adolescent The current study investigated cardiac autonomic balance and anger coping in adolescents. We hypothesized that adolescents would used cognitive reappraisal strategies to re-frame the anger-provoking situation in terms of minimization, extenuation and humor would be characterized by heart rate variability suggesting increased vagal activity and a less marked cardiac deceleration to anger provocation when compared with participants who emphasized the experienced injustice. Thirteen male and 21 female adolescents (mean age 14.7 years) attended the single experimental session which included monitoring of continuous heart rate and blood pressure responses to anger provocation (i.e., receiving an unfair offer) using a modified version of the Ultimatum Game. Spectral components of heart rate variability were calculated on heart rate data from rest periods using autoregressive analysis. The results showed that adolescents employing cognitive reappraisal strategies were characterized by increased vagal activity under resting conditions. Re-appraisers also responded with a faster recovery in terms of an attenuated heart rate deceleration after receiving the unfair offer, as well as higher baroreceptor reflex sensitivity compared with participants who tended to ruminate about the experienced injustice. These results provide further support for the specificity and sensitivity of vagal responses to higher cortical functions.

Poster 176

ISOLATED CLINIC HYPERTENSION AND ORIENTING/DEFENSIVE RESPONSE PATTERN

Alfonso Salgado1, & Almudena Duque2 1Pontificia University of Salamanca, 2Complutense University of Madrid

Descriptors: defensive response, arterial hypertension, stress

The causes and significance of isolated clinic hypertension (ICH) are a matter of debate. It has been suggested that this condition originates as part of the cardiac defense response, which produces cardiac reaction and habituates very slowly. These characteristics of the defense response are very close to those of ICH. In this condition, it is supposed that the clinic-nonclinic blood pressure (BP) difference would reflect the increase of BP and HR which occurs in response to the potentially threatening figure of the physician carrying out the BP measurement at the clinic. The aim is to know if hypertensive patients differing in Orienting/Defensive response (OR/DR) cardiac pattern differ on clinical and ambulatory BP measures. Twenty hypertensive patients participated in this study. OR/ DR pattern was identified using an auditory stimuli task. HR increases post-stimuli reflected DR; HR decreases reflected OR. Non-clinic BP readings were taken in three different moments of the day: in the morning, at work, and in the evening at home. Differences between clinic-nonclinic BP readings were calculated. When OR/DR was analyzed, three patterns resulted: OR pattern, DR pattern and OR/DR pattern. Clinic-nonclinic BP differences in every OR/DR group were calculated. ANOVAs showed a difference between groups in clinic-nonclinic contrasts on systolic BP readings and were close to significance on dyastolic BP readings. The DR group showed a greater difference between clinic and ambulatory. A relationship between OR/DR pattern and ICH is discussed: it may be a cardiac pattern which increases BP clinic readings.

time, that sex differences in performance are accompanied by differences in cerebral asymmetry in preschool children, i.e., long before puberty.

Poster 178

DEVELOPMENT OF FUNCTIONAL BRAIN ORGANIZATION: HERITABILITY AND STABILITY ACROSS THE LIFE SPAN

Dirk J.A. Smit1, Klaus Linkenkaer-Hansen1, Maria Boersma2, Toos C.E.M. van Beijsterveldt1, Danielle Posthuma1, Dorret I. Boomsma1, Kees J. Stam2, & Eco J.C. de Geus1 1Vrije University - Amsterdam, 2Vrije University Medical Center

Descriptors: twin study, brain organization, resting state eeg

We examined the development and genetic architecture of several parameters that index temporal and spatial organization of the brain. Temporal structure of EEG oscillations was indexed by the decay of the autocorrelation function spanning seconds of data (long range temporal correlations, LRTC). Spatial structure was indexed by applying graph theory to connectivity matrices obtained by calculating the synchronization likelihood between all pairs of EEG signals. We measured resting state EEG from 1606 monozygotic and dizygotic twins and their siblings in six age groups of about 5, 7, 16, 18, 25 and 50 years. Results for EEG alpha oscillations showed that (temporal) LRTC were moderately heritable (.3 - .6) across the scalp, tapering off for the youngest and oldest age groups. Genetic overlap between age groups was low: age-specific genes were found at all ages. (Spatial) graph parameters showed moderate to high heritability (.3 - .7). High genetic stability was found in adulthood. Results for other frequency bands were similar. Both LRTC and graph parameters showed a clear developmental trend from a more random (noisy) brain organization in childhood to more ordered/temporally structured in young adulthood. In later life, most parameters showed a reduction towards more noise/less structure. Importantly, individual differences in these parameters all reflected separate, non-overlapping sources of (genetic) variation. We conclude that (temporal) LRTC and (spatial) graph theoretical parameters are good endophenotypes for developmental changes in brain organization.

Poster 179

DEVELOPMENT OF FACE RECOGNITION IN PRIMARY SCHOOL CHILDREN

Eveline A. De Bruin1, Vanessa E.G. Martens1, Johanna C. Glimmerveen2, & Jan W. Van Strien2 1Unilever Research and Development Vlaardingen, 2Erasmus University Rotterdam

Descriptors: child development, face recognition, N400

ERPs elicited during a continuous recognition paradigm consist of early old/new effects reflecting automatic matching processes, and late old/new effects reflecting memory trace strength. To investigate development of face recognition in primary-school children, 36 younger children (8-9 years old) and 36 older children (11-12 years old) participated in an ERP study with an extended continuous face recognition task. Children were shown 90 pictures ofdifferent faces, ofwhich 30 were repeated five times, and were required to make old versus new decisions. Older children responded faster to all faces, and more accurately to new faces, than younger children. Younger children exhibited larger frontocentral N2 and N400 old/new effects than older children when correctly recognizing an old face. No significant old/new effects were found for the late positive complex in either younger or older children. In conclusion, in school-aged children, face recognition is mediated by early and relatively automatic recognition processes that show gradual, quantitative changes during development.

Poster 177

MENTAL ROTATION IN PRESCHOOLERS: SEX DIFFERENCES IN HEMISPHERIC ASYMMETRY

Nicola Hahn1, Jan-Henryk Dombrowski2, Petra Jansen1, & Martin Heil2 1University of Regensburg, 2Heinrich Heine University of Duesseldorf

Descriptors: developmental, EEG/ERP

Mental rotation performance has been found to produce one of the largest sex differences in cognition accompanied by sex differences in functional cerebral asymmetry. Performance difference can already be observed in children. However, nothing is known about the hemispheric lateralization of mental rotation at this age. In this study, blocks with rotated pairs of animal drawings versus blocks with upright animals only were presented and the children had to decide whether the two drawings were the same or mirror-reversed. Response time (RT), error rates and average ERP amplitudes were analyzed. Hemispheric lateralization was determined by comparing mental rotation related amplitude modulations between the left versus the right electrode leads. We obtained no sex effects in RT data. Boys outperformed girls in accuracy only when rotated pairs of drawings werepresented. For upright stimuli neither sex nor hemisphere affected ERP amplitudes. The additional electrical brain activity observed at parietal leads when mental rotation was required, however, differed as a function of sex and hemisphere. Whereas boys revealed a more bilateral pattern ofbrain activity, girls' brain activity was clearly lateralized towards the left hemisphere. The results show for the first

Poster 180

DEVELOPMENT OF AUTOMATIC MUSICAL MEMORY FUNCTIONS IN CHILDREN FROM 2 TO 4 YEARS OF AGE.

Vesa Putkinen, Mari Tervaniemi, & Minna Huotilainen University of Helsinki

Descriptors: music perception

The ability to simultaneously keep track of repetition and change in various aspects of rapidly varying sound sequences is a key component of music processing. We developed a stimulation paradigm termed the Roving Melody paradigm (RMP) to investigate children's capabilities in recognizing repetition and change in different features of short musical entities during event-related potential (ERP) recordings. Changes included melodic and rhythmic ones, as well as variations in key and timbre. Since all change types were presented within the same sequence, their detection required simultaneous (passive) monitoring of all the corresponding regularities. In addition, the musical entity was repeated in its new form only 2-3 times after each melodic and rhythmic change before the next such change. Therefore, the auditory system had to detect these changes on the basis of rapidly formed and dynamic regularity representations. We used the RMP to record ERPs in a passive condition from children aged 2 and 4 years. The 2-year-olds discriminated several of the repetitive aspects of the sounds, displaying brain responses specific to the detection of change. Compared to the younger subjects, the 4-year-olds showed faster and, for some changes, larger and more adult-like responses.

These results indicate developmental changes occurring between these ages in the processing of musical sounds. Overall, the RMP is a promising tool for assessing the development of short term memory for musical sounds and the automatic detection of repetition and change in different dimensions of music.

Poster 181

BEHAVIORAL AND ERP CORRELATES OF CONCEPTUAL AND PERCEPTUAL REPETITION IN CHILDREN AND YOUNG ADULTS

Daniela Czernochowski1, Martina K. Becker2, & Axel Mecklinger2 1Heinrich Heine University of Duesseldorf, 2Saarland University

Descriptors: erps, memory, children

ERP measures can be used to distinguish the two processes contributing to recognition memory. In adults, a mid-frontal old/new effect ~ 300 ms and a parietal old/new effect ~ 500 ms are taken as the putative ERP correlates of familiarity and recollection, respectively. However, previous studies with children have not reported an ERP correlate of familiarity. In order to distinguish between perceptual and conceptual aspects of familiarity, children (aged 10-12 years) and young adults (aged 19-27 years) studied pictures and words while ERPs were recorded. During retrieval, participants indicated whether pictures were perceptual or conceptual repetitions of items from a prior study phase or new pictures. In both groups, memory performance was superior for perceptual repetitions, but young adults recognized more pictures than children. ERPs for perceptual item repetitions revealed neuronal correlates of familiarity and recollection in both groups. By contrast, conceptual item repetitions were associated with smaller parietal old/new effects in both groups. For adults only, there was an additional right-frontal old/ new effect with longer latencies for conceptual repetitions. Together, early frontal old/ new effects in children following perceptual, but not conceptual repetition suggest that perceptual features play a larger role in recognition memory for children than for adults.

Poster 182

THE HEART-BRAKE OF SOCIAL REJECTION: A HEART RATE ANALYSIS OF DEVELOPMENTAL CHANGE IN SENSITIVITY TO PEER REJECTION

Bregtje Gunther Moor1, Marieke G.N. Bos1, Eveline A. Crone2, & Maurits W. Van der Molen1 1University of Amsterdam, 2Leiden University

Descriptors: social rejection, development, heart rate

Children's concerns about social rejection increase during middle childhood and reach a sensitivity peak at adolescence. The present study examined developmental trends in sensitivity to peer rejection by examining the beat-by-beat heart rate response associated with the processing of social rejection. Eighty-one children participated in the study, equally divided in two age groups which are thought to be associated with distinct phases of development: pre-pubertal children (aged 8 -11 years) and pubertal adolescents (aged 12-14 years). The participants performed a social judgment task adopted from Somerville et al. (2006). Prior to the experiment, a cover story was presented suggesting that their picture was rated by peers on first impression. During the experiment, participants were presented with a series of unfamiliar faces and were asked to predict whether they would be liked by the other person. Each judgment was followed by feedback indicating acceptance or rejection by the person on the picture. A non-social control task was used to examine cardiac responses to feedback outcomes that did not have a social component. Consistent with adult findings, feedback was associated with a transient heart rate slowing and a return to baseline that was considerably delayed when feedback communicated unexpected social rejection. Although no developmental differences were found, this cardiac response was most pronounced in girls. Findings reveal that the processing of unexpected social rejection is associated with a sizeable response of the parasympathetic nervous system across development.

Poster 183

EFFECTS OF AUDITORY NOVELTY AND TASK LOAD ON AUDITORY AND VISUAL BRAIN RESPONSES IN CHILDREN AND ADULTS

Philipp Ruhnau, Nicole Wetzel, Andreas Widmann, & Erich Schroger Institute for Psychology I, University of Leipzig

Descriptors: auditory novelty, event related potentials, working memory We investigated the influence of memory load (visual 0- vs. 2-back task), novelty of task-irrelevant preceding sounds (novel vs. standard sound), and age (adults 18-33 years, children 9 - 10 years) on auditory and visual ERPs. As to be expected, novel sounds elicited the novelty complex, with a transient mismatch response, P3a, and RON. This novelty complex was not significantly affected by load or age initially; however, at around 500 ms all three factors interacted. Interestingly, the visual ERPs revealed a reduced P3b in novel relative to standard trials. This shows that novelty effects are even present in the processing of the visual target. In conclusion, our results support recent

research aboüt the similarity of the novelty system in children and adülts, büt indicate less developed top-down control mechanisms in children.

Poster 184

PSYCHOPHYSIOLOGICAL EFFECTS OF ENHANCED SUSTAINED ATTENTION IN RECURRENTLY DEPRESSED PATIENTS AFTER MINDFULNESS TRAINING

Philipp M. Keüne, Vladimir Bostanov, Boris Kotchoübey, & Martin Haützinger University of Tübingen

Descriptors: major depression, mindfulness-based cognitive therapy, CNV Rümination, the repeated and excessive engagement in thoüghts which focüs on possible reasons and conseqüences of present distress, has been identified as one of the major risk factors for relapse in formerly depressed individüals. Fifteen recürrently depressed patients, cürrently in remission, participated in a coürse of mindfülness-based cognitive therapy (MBCT), intended to decrease rüminative tendencies throügh meditation exercises. EEG recordings of patients and twelve healthy controls who did not take part in the intervention, occurred prior to and following the 8-week mindfulness coürse. The experiment focüsed on the contingent negative variation (CNV) in a passive paradigm. Participants were confronted with aüditory and tactile stimüli and instrücted to attend to their own breath, while ignoring the stimüli. The MBCT groüp showed a significant amplitüde increase and the control groüp an insignificant amplitüde decrease of the ERP to aüditory stimüli in the late CNV domain (1300 -1500 ms) at the second measürement compared to the first. The late CNV is associated with the mobilization of perceptüal, cognitive and attentional resoürces. Oür resülts süggest that as few as 8 weeks of intensive mindfülness training can significantly increase participants' ability to süstain their attention and as süch enable them to gain control over rüminative tendencies. Despite the passive natüre of the task (ignoring the stimüli and focüsing on the breath), participants apparently mobilized more cognitive resoürces and processed the stimüli more conscioüsly after the intervention.

Poster 185

FACILITATED PROCESSING OF POSITIVE EMOTIONAL INFORMATION BY VERBAL STRUCTURAL PARALLELISMS: AN ERP STUDY

Beate Czerwon1, Annette Hohlfeld2, Heike Wiese2, & Katja Werheid1 1Hümboldt University, Berlin, 2University of Potsdam

Descriptors: ERP, language, emotion

Strüctüral parallelisms are a main characteristic of emotionally involving texts like poems or prayers. They typically involve repetitions of semantic, syntactic, or phonological featüres. Recent research in social science has shown that strüctürally parallel non-verbal behavior facilitates the synchronization of emotion. However, experimental evidence on emotion effects of verbal strüctüral parallelisms is scarce. In the present stüdy we examined the impact ofverbal strüctüral parallelisms on sübseqüent processing of emotional facial expressions in a cross-modal priming task. Event-related brain potentials (ERPs) were recorded while participants (N 5 25) classified positive, negative, or neütral facial expressions as emotional or non-emotional. The faces were preceded by verbal stimüli extracted from prayers, in which content words were replaced by nonsense words. Data analysis in a 2 (prime: parallel vs. non-parallel) by 2 (target: emotional vs. non-emotional) factorial design revealed significant behavioral priming effects: Classification of positive facial expressions was accelerated if the preceding verbal prime was parallel. Preliminary analysis of emotion-sensitive ERP components in this primed condition revealed enhanced amplitüdes of early posterior negativity (EPN) and late positive potential (LPP), indicating that strüctüral parallelisms facilitate both early and late processing of positive emotional information.

Poster 186

EYE BLINK CONDITIONING DURING PPI MEASUREMENT IN NEONATES

Süsanne E. Süter1, Harriet J. Hüggenberger1, Terry D. Blümenthal2, & Hartmüt

Schachinger3

1University of Basel, 2Wake Forest University, 3University of Trier Descriptors: startle eye blink, conditioning, development

Recently, it was shown in adülts that the pairing of a weak prepülse with a startle eliciting stimülüs in a prepülse inhibition (PPI) paradigm indüced larger startle eye blinks to intense versions of these prepülses. This effect was attribüted to the pairing of prepülses with aversive acoüstic white noise stimüli. In the present stüdy we asked whether a similar effect may be seen in neonates. Sixty-three healthy füll-term neonates were tested while they were asleep. They ünderwent PPI testing with ünilaterally presented 95 dB white noise startle stimüli preceded by weak (75 dB) tones of either 1200 or 1800 Hz pitch. The other tone was presented eqüally often, büt randomly and never paired with startle stimüli. Düring an extinction phase, intense (95 dB) and brief (50 ms) startle eliciting versions of these tones were presented ünilaterally in randomized order,

counter-balanced across infants. EMG eye blink responses were measured at the ipsi-lateral eye. Startle eye blink responding induced by the intense versions of tones having served as prepulses during the PPI assessment was different (interaction of tone and time during extinction: p 5 .04) from that to intense versions of tones which had never served as prepulses. This difference was more pronounced in the second half of the extinction phase. Thus, previous pairing with blink inducing acoustic white noise enhances the ability of a tone to induce startle in neonates. Our data show that eye blink conditioning effects are present during PPI assessment in very early life.

_CLUSTERED POSTER SESSION #2_

NEURAL BASIS OF ANXIETY DISORDERS

Chair: Thomas Straube Friedrich-Schiller-University Jena

Descriptors: fear, functional imaging, anxiety disorders

Based on structural and functional imagin