Reduced processing of facial and postural cues in social anxiety: insights from electrophysiology.

Social anxiety is characterized by fear of evaluative interpersonal situations. Many studies have investigated the perception of emotional faces in socially anxious individuals and have reported biases in the processing of threatening faces. However, faces are not the only stimuli carrying an interpersonal evaluative load. The present study investigated the processing of emotional body postures in social anxiety. Participants with high and low social anxiety completed an attention-shifting paradigm using neutral, angry and happy faces and postures as cues. We investigated early visual processes through the P100 component, attentional fixation on the P2, structural encoding mirrored by the N170, and attentional orientation towards stimuli to detect with the P100 locked on target occurrence. Results showed a global reduction of P100 and P200 responses to faces and postures in socially anxious participants as compared to non-anxious participants, with a direct correlation between self-reported social anxiety levels and P100 and P200 amplitudes. Structural encoding of cues and target processing were not modulated by social anxiety, but socially anxious participants were slower to detect the targets. These results suggest a reduced processing of social postural and facial cues in social anxiety.

The impact of the stimulus features and task instructions on facial processing in social anxiety: an ERP investigation.

Social anxiety has been characterized by an attentional bias towards threatening faces. Electrophysiological studies have demonstrated modulations of cognitive processing from 100 ms after stimulus presentation. However, the impact of the stimulus features and task instructions on facial processing remains unclear. Event-related potentials were recorded while high and low socially anxious individuals performed an adapted Stroop paradigm that included a colour-naming task with non-emotional stimuli, an emotion-naming task (the explicit task) and a colour-naming task (the implicit task) on happy, angry and neutral faces. Whereas the impact of task factors was examined by contrasting an explicit and an implicit emotional task, the effects of perceptual changes on facial processing were explored by including upright and inverted faces. The findings showed an enhanced P1 in social anxiety during the three tasks, without a moderating effect of the type of task or stimulus. These results suggest a global modulation of attentional processing in performance situations.

The neural network sustaining crossmodal integration is impaired in alcohol-dependence: an fMRI study.

INTRODUCTION: Crossmodality (i.e., the integration of stimulations coming from different sensory modalities) is a crucial ability in everyday life and has been extensively explored in healthy adults. Still, it has not yet received much attention in psychiatry, and particularly in alcohol-dependence. The present study investigates the cerebral correlates of crossmodal integration deficits in alcohol-dependence to assess whether these deficits are due to the mere accumulation of unimodal impairments or rather to specific alterations in crossmodal areas. METHODS: Twenty-eight subjects [14 alcohol-dependent subjects (ADS), 14 paired controls] were scanned using fMRI while performing a categorization task on faces (F), voices (V) and face-voice pairs (FV). A subtraction contrast [FV-(F+V)] and a conjunction analysis [(FV-F) ∩ (FV-V)] isolated the brain areas specifically involved in crossmodal face-voice integration. The functional connectivity between unimodal and crossmodal areas was explored using psycho-physiological interactions (PPI). RESULTS: ADS presented only moderate alterations during unimodal processing. More centrally, in the subtraction contrast and conjunction analysis, they did not show any specific crossmodal brain activation while controls presented activations in specific crossmodal areas (inferior occipital gyrus, middle frontal gyrus, superior parietal lobule). Moreover, PPI analyses showed reduced connectivity between unimodal and crossmodal areas in alcohol-dependence. CONCLUSIONS: This first fMRI exploration of crossmodal processing in alcohol-dependence showed a specific face-voice integration deficit indexed by reduced activation of crossmodal areas and reduced connectivity in the crossmodal integration network. Using crossmodal paradigms is thus crucial to correctly evaluate the deficits presented by ADS in real-life situations.

Disrupted regulation of social exclusion in alcohol-dependence: an fMRI study.

Alcohol-dependence is associated with cognitive and biological alterations, and also with interpersonal impairments. Although overwhelming in clinical settings and involved in relapse, these social impairments have received little attention from researchers. Particularly, brain alterations related to social exclusion have not been explored in alcohol-dependence. Our primary purpose was to determine the neural correlates of social exclusion feelings in this population. In all, 44 participants (22 abstinent alcohol-dependent patients and 22 paired controls) played a virtual game ('cyberball') during fMRI recording. They were first included by other players, then excluded, and finally re-included. Brain areas involved in social exclusion were identified and the functional connectivity between these areas was explored using psycho-physiological interactions (PPI). Results showed that while both groups presented dorsal anterior cingulate cortex (dACC) activations during social exclusion, alcohol-dependent participants exhibited increased insula and reduced frontal activations (in ventrolateral prefrontal cortex) as compared with controls. Alcohol-dependence was also associated with persistent dACC and parahippocampal gyrus activations in re-inclusion. PPI analyses showed reduced frontocingulate connectivity during social exclusion in alcohol-dependence. Alcohol-dependence is thus linked with increased activation in areas eliciting social exclusion feelings (dACC-insula), and with impaired ability to inhibit these feelings (indexed by reduced frontal activations). Altered frontal regulation thus appears implied in the interpersonal alterations observed in alcohol-dependence, which seem reinforced by impaired frontocingulate connectivity. This first exploration of the neural correlates of interpersonal problems in alcohol-dependence could initiate the development of a social neuroscience of addictive states.

A common right fronto-parietal network for numerosity and duration processing: an fMRI study.

Numerosity and duration processing have been modeled by a functional mechanism taking the form of an accumulator working under two different operative modes. Separate investigations of their cerebral substrates have revealed partly similar patterns of activation, mainly in parietal and frontal areas. However, the precise cerebral implementation of the accumulator model within these areas has not yet been directly assessed. In this study, we asked participants to categorize the numerosity of flashed dot sequences or the duration of single dot displays, and we used functional magnetic resonance imaging (fMRI) to examine the common neural correlates of these processes. The results reveal a large right-lateralized fronto-parietal network, including the intraparietal sulcus (IPS) and areas in the precentral, middle and superior frontal gyri, which is activated by both numerosity and duration processing. Complementary psychophysiological interaction (PPI) analyses show a functional connectivity between the right IPS and the frontal areas in both tasks, whereas the right IPS was functionally connected to the left IPS and the right precentral area in the numerosity categorization task only. We propose that the right IPS underlies a common magnitude processing system for both numerosity and duration, possibly corresponding to the encoding and accumulation stages of the accumulator model, whereas the frontal areas are involved in subsequent working-memory storage and decision-making processes.

The "Reading the Mind in the Eyes" test as a new way to explore complex emotions decoding in alcohol dependence.

It has been repeatedly shown that alcohol dependence is associated with emotional impairments, particularly for emotional facial expression decoding. Nevertheless, most earlier studies focused on basic emotions and did not explore more subtle affective states. In order to obtain a more accurate evaluation, and in view of earlier results showing impaired performance for this task among high-risk children of alcohol-dependent participants, the "Reading the Mind in the Eyes" test was used here to explore emotional recognition in alcohol dependence. We showed that the deficit described earlier for basic negative emotions is (1) generalizable to complex and positive emotions; and (2) specific for emotional features. This strengthens the proposition of a general face recognition impairment in alcohol dependence.

Dissociation between affective and cognitive empathy in alcoholism: a specific deficit for the emotional dimension.

BACKGROUND: Emotional impairments constitute a crucial and widely described dimension of alcoholism, but several affective abilities are still to be thoroughly explored among alcohol-dependent patients. This is particularly true for empathy, which constitutes an essential emotional competence for interpersonal relations and has been shown to be highly impaired in various psychiatric states. The present study aimed at exploring empathic abilities in alcoholism, and notably the hypothesis of a differential deficit between emotional and cognitive empathy. METHODS: Empathy abilities were evaluated among 30 recently detoxified inpatients diagnosed with alcohol dependence and 30 paired healthy controls, using highly validated questionnaires (Interpersonal Reactivity Index [J Pers Soc Psychol44:113] and Empathy Quotient [J Autism Dev Disord34:163]). Correlational analyses were performed to evaluate the links between empathy scores and psychopathological measures (i.e., depression, anxiety, interpersonal problems, and alexithymia). RESULTS: When psychiatric comorbities are controlled for, alcoholism is not associated with a general empathy deficit, but rather with a dissociated pattern combining impaired emotional empathy and preserved cognitive one. Moreover, this emotional empathy deficit is not associated with depression or anxiety scores, but is negatively correlated with alexithymia and the severity of interpersonal problems. CONCLUSIONS: At the theoretical level, this first observation of a specific deficit for emotional empathy in alcoholism, combined with the exact inverse pattern observed in other psychiatric populations, leads to a double-dissociation, which supports the notion that emotional and cognitive empathy are 2 distinct abilities. At the clinical level, this deficit calls for considering emotional empathy rehabilitation as a crucial concern in psychotherapy.

The neural network sustaining the crossmodal processing of human gender from faces and voices: an fMRI study.

The aim of this fMRI study was to investigate the cerebral crossmodal interactions between human faces and voices during a gender categorization task. Twelve healthy male participants took part to the study. They were scanned in 4 runs that contained 3 conditions consisting in the presentation of faces, voices or congruent face-voice pairs. The task consisted in categorizing each trial (visual, auditory or associations) according to its gender (male or female). The subtraction between the bimodal condition and the sum of the unimodal ones showed that categorizing face/voice associations according to their gender produced unimodal activations of the visual (right calcarine sulcus) and auditory regions (bilateral superior temporal gyri), and specific supramodal activations of the left superior parietal gyrus and the right inferior frontal gyrus. Moreover, psychophysiological interaction analyses (PPI) revealed that both unimodal regions were inter-connected and connected to the prefrontal gyrus and the putamen, and that the left parietal gyrus had an enhanced connectivity with a parieto-premotor circuit involved in the crossmodal control of attention. This fMRI study showed that the crossmodal auditory-visual categorization of human gender is sustained by a network of cerebral regions highly similar to those observed in our previous studies examining the crossmodal interactions involved in face/voice recognition (Joassin et al., 2010). This suggests that the crossmodal processing of human stimuli requires the activation of a network of cortical regions, including both unimodal visual and auditory regions and supramodal parietal and frontal regions involved in the integration of both faces and voices and in the crossmodal attentional processes, and activated independently from the task to perform or the cognitive level of processing.

Cross-modal interactions between human faces and voices involved in person recognition.

Faces and voices are key features of human recognition but the way the brain links them together is still unknown. In this study, we measured brain activity using functional magnetic resonance imaging (fMRI) while participants were recognizing previously learned static faces, voices and voice-static face associations. Using a subtraction method between bimodal and unimodal conditions, we observed that voice-face associations activated both unimodal visual and auditory areas, and specific multimodal regions located in the left angular gyrus and the right hippocampus. Moreover, a functional connectivity analysis confirmed the connectivity of the right hippocampus with the unimodal areas. These findings demonstrate that binding faces and voices rely on a cerebral network sustaining different aspects of integration such as sensory inputs processing, attention and memory.

Is two better than one? A cross-modal oddball paradigm reveals greater sensitivity of the P300 to emotional face-voice associations.

OBJECTIVE: Studies exploring neurophysiological correlates of main psychiatric disorders have commonly used event-related potentials (ERP) during a visual or an auditory oddball task. The main results concern modulations of the P3b amplitude and/or latency. The present study aims to increase the clinical sensitivity of these P3b modulations by using a more ecological oddball design, using synchronized pairs of audio-visual emotional stimuli. METHOD: Two groups of healthy participants, one composed of controls and the other of students displaying anxious and depressive tendencies completed visual, auditory and audio-visual (cross-modal) oddball tasks, in which they had to detect deviant happy and sad stimuli among neutral ones as quickly as possible. Behavioral performance and P3b ERP data were analyzed. RESULTS: Subjects displaying anxious and depressive tendencies exhibited lower P3b amplitude than the controls, but only in the cross-modal oddball task. CONCLUSIONS: Although the two groups of subjects differed in their levels of co-morbid anxiety and depression, unimodal visual and auditory oddball tasks did not allow us to detect this difference by P3b amplitude modulations, but the cross-modal task did. SIGNIFICANCE: These results suggest that a cross-modal oddball design should be used in future studies to increase the sensitivity of the P300 amplitude differences between healthy participants and those with clinical symptoms.

Latent deleterious effects of binge drinking over a short period of time revealed only by electrophysiological measures.

BACKGROUND: Episodic excessive alcohol consumption (i.e., binge drinking) is now considered to be a major public health problem, but whereas short-and long-term harmful consequences of this behaviour are clearly established at medical, social and cognitive levels, the cerebral correlates of these impairments are still unknown. Our study explores the midterm cerebral effects of binge-drinking behaviours among young adults. METHODS: We selected 2 groups of first-year university students with no history of drinking habits, paired for psychological and behavioural measures on the basis of their expected alcohol consumption during the forthcoming academic year. The binge drinker group expected to have high personal alcohol consumption, whereas the control group expected low consumption. We used a test-retest paradigm within a 9-month period (session 1 in September 2005, session 2 in May 2006). At each testing session, we recorded auditory event-related potentials while the participants performed an emotional valence judgment task. RESULTS: There were no differences between the groups in behavioural or electrophysiological measures at baseline. After 9 months, the binge drinkers had significantly delayed latencies for all event-related potential components (P1, N2, P3b) of emotional auditory processing compared with the control group (p < 0.006), with no behavioural differences. LIMITATIONS: As the present study explored the electrophysiological correlates of binge drinking with an emotional task only, the results will have to be extended to other cognitive processes using various experimental tasks. CONCLUSION: We report the first direct evidence that short-term binge drinking can produce marked cerebral dysfunction undetectable by behavioural measures alone. The observed latency abnormalities, similar to those observed in long-term alcoholism, constitute an electrophysiological marker of slowed cerebral activity associated with binge drinking.

The auditory-visual integration of anger is impaired in alcoholism: an event-related potentials study.

OBJECTIVES: Chronic alcoholism leads to impaired visual and auditory processing of emotions, but the cross-modal (auditory-visual) processing of emotional stimuli has not yet been explored. Our objectives were to describe the electrophysiological correlates of unimodal (visual and auditory) impairments in emotion processing in people suffering from alcoholism, to determine whether this deficit is general or emotion-specific, and to explore potential deterioration in the specific cross-modal integration processes in alcoholism. METHODS: We used an emotion-detection task, with recording of event-related potentials (ERPs), in which 15 patients suffering from alcoholism and 15 matched healthy control subjects were asked to detect the emotion (angry, happy or neutral) displayed by auditory, visual or auditory-visual stimuli. Behavioural performance and ERP data recorded between June 2005 and April 2006 were analyzed. RESULTS: ERPs demonstrated that the deficit in alcoholism originates earlier in the cognitive stream than has previously been described (mainly P300), namely, at the level of specific face (N170) and voice (N2) perceptive processing. Moreover, while patients with alcoholism did not show impaired processing of happy and neutral audio-visual stimuli, they did have a specific impairment in the cross-modal processing of anger. A source location analysis was used to confirm and illustrate the results. CONCLUSION: These results suggest that the specific deficit that people with alcoholism demonstrate in processing anger stimuli, widely described in clinical situations but not clearly identified in earlier studies (using unimodal stimuli), is particularly obvious during cross-modal processing, which is more common than unimodal processing in everyday life.

The associative processes involved in faces-proper names versus animals-common names binding: a comparative ERP study.

Recognizing people involves creating and retrieving links between distinct representations such as faces and names. In previous research we have shown that the retrieval of face/name associations produced cerebral activities lateralized in the left hemisphere and spreading from posterior to anterior sites after about 300ms. The present ERP study was performed to compare the specific electrophysiological activities elicited by the retrieval of face/proper name (FP) and animal/common name (AC) associations. Using a subtraction method to isolate the specific binding activities, we showed that both kinds of association produced two main posterior negative/anterior positive complexes, with a more frontal distribution for AC, and bilateral temporal activities. These findings confirm that general associative processes - independent of the kind of association - are not simply the sum of the activities elicited by each stimulus, and that they could involve both unimodal sensory and multimodal convergence regions of the brain.