Emotional context enhances auditory novelty processing: behavioural and electrophysiological evidence

A sleepless night disrupts the resolution of emotional conflicts: Behavioural and neural evidence

The present study aims to investigate the influence of 24-hr sleep deprivation on implicit emotion regulation using the emotional conflict task. Twenty-five healthy young adults completed a repeated-measures study protocol involving a night of at-home normal sleep control and a night of in-laboratory sleep deprivation. Prior to the experimental session, all participants wore an actigraph watch and completed the sleep diary. Following each condition, participants performed an emotional conflict task with electroencephalographic recordings. Emotional faces (fearful or happy) overlaid with words ("fear" or "happy") were used as stimuli creating congruent or incongruent trials, and participants were instructed to indicate whether the facial expression was happy or fearful. We measured the accuracy and reaction time on the emotional conflict task, as well as the mean amplitude of the P300 component of the event-related potential at CPz. At the behavioural level, sleep-deprived participants showed reduced alertness with overall longer reaction times and higher error rates. In addition, participants in the sleep deprivation condition made more errors when the current trial followed congruent trials compared with when it followed incongruent trials. At the neural level, P300 amplitude evoked under the sleep-deprived condition was significantly more positive compared with the normal sleep condition, and this effect interacted with previous-trial and current-trial congruency conditions, suggesting that participants used more attentional resources to resolve emotional conflicts when sleep deprived. Our study provided pioneering data demonstrating that sleep deprivation may impair the regulation of emotional processing in the absence of explicit instruction among emerging adults.

Counterirritation by Pain Inhibits Responses to and Perception of Aversive Loud Tones

The application of a noxious stimulus reduces the perception of other noxious stimuli, which can be assessed by an experimental method called "counterirritation." The question arises whether this type of inhibition also affects the processing of other aversive (but not nociceptive) stimuli, such as loud tones. If aversiveness or, in other words, negative emotional valence qualifies a stimulus to be affected by counterirritation, the general emotional context may also play a role in modulating counterirritation effects. We involved 63 participants in this study (M age = 38.8, SD = 10.5 years; 33 males, 30 females). We tried to counterirritate their perceptual and startle reactions to aversively loud tones (105 db) by immersing the hand into a painful hot water bath (46°C) in two emotional valence conditions (i.e., a neutral and a negative valence block in which we showed either neutral pictures or pictures of burn wounds). We assessed Inhibition by loudness ratings and startle reflex amplitudes. Counterirritation significantly reduced both loudness ratings and startle reflex amplitudes. The emotional context manipulation did not affect this clear inhibitory effect, showing that counterirritation by a noxious stimulus affects aversive sensations not induced by nociceptive stimuli. Thus, the assumption that "pain inhibits pain" should be widened to "pain inhibits the processing of aversive stimuli." This broadened understanding of counterirritation leads to a questioning of the postulate of clear pain specificity in paradigms like "conditioned pain modulation" (CPM) or "diffuse noxious inhibitory controls" (DNIC).

Negative target stimuli do not influence cross-modal auditory distraction

The present study served to test whether emotion modulates auditory distraction in a serial-order reconstruction task. If auditory distraction results from an attentional trade-off between the targets and distractors, auditory distraction should decrease when attention is focused on targets with high negative arousal. Two experiments (with a total N of 284 participants) were conducted to test whether auditory distraction is influenced by target emotion. In Experiment 1 it was examined whether two benchmark effects of auditory distraction-the auditory-deviant effect and the changing-state effect-differ as a function of whether negative high-arousal targets or neutral low-arousal targets are used. Experiment 2 complements Experiment 1 by testing whether target emotion modulates the disruptive effects of reversed sentential speech and steady-state distractor sequences relative to a quiet control condition. Even though the serial order of negative high-arousal targets was better remembered than that of neutral low-arousal targets, demonstrating an emotional facilitation effect on serial-order reconstruction, auditory distraction was not modulated by target emotion. The results provide support of the automatic-capture account according to which auditory distraction, regardless of the specific type of auditory distractor sequence that has to be ignored, is a fundamentally stimulus-driven effect that is rooted in the automatic processing of the to-be-ignored auditory stream and remains unaffected by emotional-motivational factors.

Brain reactivity to emotion persists in NREM sleep and is associated with individual dream recall

The waking brain efficiently detects emotional signals to promote survival. However, emotion detection during sleep is poorly understood and may be influenced by individual sleep characteristics or neural reactivity. Notably, dream recall frequency has been associated with stimulus reactivity during sleep, with enhanced stimulus-driven responses in high vs. low recallers. Using electroencephalography (EEG), we characterized the neural responses of healthy individuals to emotional, neutral voices, and control stimuli, both during wakefulness and NREM sleep. Then, we tested how these responses varied with individual dream recall frequency. Event-related potentials (ERPs) differed for emotional vs. neutral voices, both in wakefulness and NREM. Likewise, EEG arousals (sleep perturbations) increased selectively after the emotional voices, indicating emotion reactivity. Interestingly, sleep ERP amplitude and arousals after emotional voices increased linearly with participants' dream recall frequency. Similar correlations with dream recall were observed for beta and sigma responses, but not for theta. In contrast, dream recall correlations were absent for neutral or control stimuli. Our results reveal that brain reactivity to affective salience is preserved during NREM and is selectively associated to individual memory for dreams. Our findings also suggest that emotion-specific reactivity during sleep, and not generalized alertness, may contribute to the encoding/retrieval of dreams.

Positive and negative mood states do not influence cross-modal auditory distraction in the serial-recall paradigm

The aim of this study was to examine whether positive and negative mood states affect auditory distraction in a serial-recall task. The duplex-mechanism account differentiates two types of auditory distraction. The changing-state effect is postulated to be rooted in interference-by-process and to be automatic. The auditory-deviant effect is attributed to attentional capture by the deviant distractors. Only the auditory-deviant effect, but not the changing-state effect, should be influenced by emotional mood states according to the duplex-mechanism account. Four experiments were conducted to test how auditory distraction is affected by emotional mood states. Mood was induced by autobiographical recall (Experiments 1 and 2) or the presentation of emotional pictures (Experiments 3 and 4). Even though the manipulations were successful in inducing changes in mood, neither positive mood (Experiments 1 and 3) nor negative mood (Experiments 2 and 4) had any effect on distraction despite large samples sizes (N = 851 in total). The results thus are not in line with the hypothesis that auditory distraction is affected by changes in mood state. The results support an automatic-capture account according to which the auditory-deviant effect and the changing-state effect are mainly stimulus-driven effects that are rooted in the automatic processing of the to-be-ignored auditory stream.

Review: Exteroceptive Sensory Abnormalities in Childhood and Adolescent Anxiety and Obsessive-Compulsive Disorder: A Critical Review

OBJECTIVE

Childhood anxiety and obsessive-compulsive disorder (OCD) are defined by fear, worry, and uncertainty, but there is also evidence that affected children possess exteroceptive sensory abnormalities. These sensory features may often instigate symptoms and cause significant distress and functional impairment. In addition, a purported class of conditions known as "sensory processing disorders" may significantly overlap with childhood anxiety and OCD, which provides further support for a connection between abnormal sensation and fear-based psychopathology.

METHOD

The current review was conducted to synthesize and to critically evaluate the existing research on exteroceptive sensory abnormalities in childhood anxiety and OCD. Because of the paucity of research in this area, studies with adult populations were also briefly reviewed.

RESULTS

The review found significant support for the notion that sensory abnormalities are common in children with anxiety disorders and OCD, but there are significant limitations to research in this area that prevent firm conclusions.

CONCLUSION

Potential avenues for future research on sensory features of pediatric anxiety and OCD are discussed.

Increased Awakenings From Non-rapid Eye Movement Sleep Explain Differences in Dream Recall Frequency in Healthy Individuals

Background

Dreaming is a universal experience, yet there is considerable inter-individual variability in dream recall frequency (DRF). One dominant model, the “arousal-retrieval” model, posits that intra-sleep wakefulness is required for dream traces to be encoded into long-term storage, essentially proposing that a better memory for dreams underlie increased DRF. A recent study utilizing polysomnography combined with an event-related potentials paradigm, provides direct support for this model by demonstrating increased intra-sleep wakefulness in a healthy population by comparing high frequency recallers (HFRs) and low frequency recallers (LFRs). Another study by the same group demonstrated increased regional cerebral blood flow in regions associated with dream production, supporting the premise that HFRs also may produce more dreams.

Hypotheses

This study investigated the profile of nocturnal awakenings and dream production in healthy HFRs and LFRs. Hypothesis (1a): HFRs will spend significantly more time awake after sleep onset; (1b): HFRs will experience significantly more awakenings across the night, and from rapid eye movement (REM) sleep in particular; (2) HFRs will have significantly higher rates of dream production across the night as measured by REM density.

Methods

We studied two groups of healthy adults: HFRs (n = 19) and LFRs (n = 17) who underwent polysomnographic recordings on two non-consecutive nights.

Results

Hypothesis (1a) was confirmed: HFRs spent significantly more time awake after sleep onset. Hypothesis (1b) was partially confirmed: HFRs experienced significantly more awakenings across the night; however, awakenings from REM sleep were comparable. Interestingly, HFRs had significantly more awakenings, as well as a higher number of longer awakenings, from non-rapid eye movement (NREM) stage 2 sleep. Hypothesis (2) was not confirmed: There was no significant difference in rates of REM density between groups.

Conclusion

This is the first study to provide evidence that awakenings from NREM 2 sleep might underlie increased DRF in HFRs. This finding coupled with null findings in relation to REM sleep variables, support the premise that inter-individual variability in DRF cannot be ascribed to differences in REM sleep parameters in healthy individuals. Instead, the data indicates that awakenings from NREM sleep is of particular importance in relation to DRF in a healthy population.

Distraction and facilitation: The impact of emotional sounds in an emoji oddball task

Emotional stimuli are argued to capture attention and consume attentional resources differently depending on their emotional content. The present study investigates the impact of the automatic detection of unexpected and to-be-ignored emotional stimuli on human behavioral responses, and aims to unravel the differences in distraction between two negative emotional stimuli: sadness and anger. Forty participants (M_age = 25.5 years) performed a visual categorization task where angry and sad emoji faces were presented after either a standard neutral tone (in 80% of trials) or a deviant emotional sound (tone changing in pitch; sad or angry sound in 10% of trials each) that was to be ignored. Deviant trials were either congruent (e.g., sad sound-sad face) or incongruent (e.g., angry sound-sad face). Although the stimuli presented to the participants were brief and to-be-ignored, results indicate that participants were significantly more distracted by sad compared to angry stimuli (seen as prolonged response times). Findings are discussed with reference to the nature of the two negative emotions.

Fronto-central P3a to distracting sounds: An index of their arousing properties

The P3a observed after novel events is an event-related potential comprising an early fronto-central phase and a late fronto-parietal phase. It has classically been considered to reflect the attention processing of distracting stimuli. However, novel sounds can lead to behavioral facilitation as much as behavioral distraction. This illustrates the duality of the orienting response which includes both an attentional and an arousal component. Using a paradigm with visual or auditory targets to detect and irrelevant unexpected distracting sounds to ignore, we showed that the facilitation effect by distracting sounds is independent of the target modality and endures more than 1500 ms. These results confirm that the behavioral facilitation observed after distracting sounds is related to an increase in unspecific phasic arousal on top of the attentional capture. Moreover, the amplitude of the early phase of the P3a to distracting sounds positively correlated with subjective arousal ratings, contrary to other event-related potentials. We propose that the fronto-central early phase of the P3a would index the arousing properties of distracting sounds and would be linked to the arousal component of the orienting response. Finally, we discuss the relevance of the P3a as a marker of distraction.

Fear Spreading Across Senses: Visual Emotional Events Alter Cortical Responses to Touch, Audition, and Vision

Attention and perception are potentiated for emotionally significant stimuli, promoting efficient reactivity and survival. But does such enhancement extend to stimuli simultaneously presented across different sensory modalities? We used functional magnetic resonance imaging in humans to examine the effects of visual emotional signals on concomitant sensory inputs in auditory, somatosensory, and visual modalities. First, we identified sensory areas responsive to task-irrelevant tones, touches, or flickers, presented bilaterally while participants attended to either a neutral or a fearful face. Then, we measured whether these responses were modulated by the emotional content of the face. Sensory responses in primary cortices were enhanced for auditory and tactile stimuli when these appeared with fearful faces, compared with neutral, but striate cortex responses to the visual stimuli were reduced in the left hemisphere, plausibly as a consequence of sensory competition. Finally, conjunction and functional connectivity analyses identified 2 distinct networks presumably responsible for these emotional modulatory processes, involving cingulate, insular, and orbitofrontal cortices for the increased sensory responses, and ventrolateral prefrontal cortex for the decreased sensory responses. These results suggest that emotion tunes the excitability of sensory systems across multiple modalities simultaneously, allowing the individual to adaptively process incoming inputs in a potentially threatening environment.

Happiness increases distraction by auditory deviant stimuli

Rare and unexpected changes (deviants) in an otherwise repeated stream of task-irrelevant auditory distractors (standards) capture attention and impair behavioural performance in an ongoing visual task. Recent evidence indicates that this effect is increased by sadness in a task involving neutral stimuli. We tested the hypothesis that such effect may not be limited to negative emotions but reflect a general depletion of attentional resources by examining whether a positive emotion (happiness) would increase deviance distraction too. Prior to performing an auditory-visual oddball task, happiness or a neutral mood was induced in participants by means of the exposure to music and the recollection of an autobiographical event. Results from the oddball task showed significantly larger deviance distraction following the induction of happiness. Interestingly, the small amount of distraction typically observed on the standard trial following a deviant trial (post-deviance distraction) was not increased by happiness. We speculate that happiness might interfere with the disengagement of attention from the deviant sound back towards the target stimulus (through the depletion of cognitive resources and/or mind wandering) but help subsequent cognitive control to recover from distraction.

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEAS) and emotional processing - A behavioral and electrophysiological approach

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEAS) may have mood enhancement effects: higher DHEAS concentrations and DHEA/cortisol ratio have been related to lower depression scores and controlled trials of DHEA administration have reported significant antidepressant effects. The balance between DHEAS and DHEA has been suggested to influence brain functioning. We explored DHEAS, DHEA, cortisol, DHEA/cortisol and DHEAS/DHEA ratios relations to the processing of negative emotional stimuli at behavioral and brain levels by recording the electroencephalogram of 21 young women while performing a visual task with implicit neutral or negative emotional content in an audio-visual oddball paradigm. For each condition, salivary DHEA, DHEAS and cortisol were measured before performing the task and at 30 and 60min intervals. DHEA increased after task performance, independent of the implicit emotional content. With implicit negative emotion, higher DHEAS/DHEA and DHEA/cortisol ratios before task performance were related to shorter visual P300 latencies suggesting faster brain processing under a negative emotional context. In addition, higher DHEAS/DHEA ratios were related to reduced visual P300 amplitudes, indicating less processing of the negative emotional stimuli. With this study, we could show that at the electrophysiological level, higher DHEAS/DHEA and DHEA/cortisol ratios were related to shorter stimulus evaluation times suggesting less interference of the implicit negative content of the stimuli with the task. Furthermore, higher DHEAS/DHEA ratios were related to reduced processing of negative emotional stimuli which may eventually constitute a protective mechanism against negative information overload.

Emotional pictures and sounds: a review of multimodal interactions of emotion cues in multiple domains

In everyday life, multiple sensory channels jointly trigger emotional experiences and one channel may alter processing in another channel. For example, seeing an emotional facial expression and hearing the voice’s emotional tone will jointly create the emotional experience. This example, where auditory and visual input is related to social communication, has gained considerable attention by researchers. However, interactions of visual and auditory emotional information are not limited to social communication but can extend to much broader contexts including human, animal, and environmental cues. In this article, we review current research on audiovisual emotion processing beyond face-voice stimuli to develop a broader perspective on multimodal interactions in emotion processing. We argue that current concepts of multimodality should be extended in considering an ecologically valid variety of stimuli in audiovisual emotion processing. Therefore, we provide an overview of studies in which emotional sounds and interactions with complex pictures of scenes were investigated. In addition to behavioral studies, we focus on neuroimaging, electro- and peripher-physiological findings. Furthermore, we integrate these findings and identify similarities or differences. We conclude with suggestions for future research.

Neither state or trait anxiety alter the response to distracting emotionally neutral sounds

Attentional control theory suggests that heightened anxiety, whether due to trait or state factors, causes an increased vulnerability to distraction even when the distracters are emotionally neutral. Recent passive oddball studies appear to support this theory in relation to the distraction caused by emotionally neutral sounds. However such studies have manipulated emotional state via the content of task stimuli, thus potentially confounding changes in emotion with differences in task demands. To identify the effect of anxiety on the distraction caused by emotionally neutral sounds, 50 participants completed a passive oddball task requiring emotionally neutral sounds to be ignored. Crucially, state anxiety was manipulated independent of the task stimuli (via unrelated audiovisual stimuli) thus removing confounds relating to task demands. Neither state or trait anxiety was found to influence the susceptibility to distraction by emotionally neutral sounds. These findings contribute to the ongoing debate concerning the impact of emotion on attention.

Auditory pre-experience modulates classification of affect intensity: evidence for the evaluation of call salience by a non-human mammal, the bat Megaderma lyra

INTRODUCTION

Immediate responses towards emotional utterances in humans are determined by the acoustic structure and perceived relevance, i.e. salience, of the stimuli, and are controlled via a central feedback taking into account acoustic pre-experience. The present study explores whether the evaluation of stimulus salience in the acoustic communication of emotions is specifically human or has precursors in mammals. We created different pre-experiences by habituating bats (Megaderma lyra) to stimuli based on aggression, and response, calls from high or low intensity level agonistic interactions, respectively. Then we presented a test stimulus of opposite affect intensity of the same call type. We compared the modulation of response behaviour by affect intensity between the reciprocal experiments.

RESULTS

For aggression call stimuli, the bats responded to the dishabituation stimuli independent of affect intensity, emphasising the attention-grabbing function of this call type. For response call stimuli, the bats responded to a high affect intensity test stimulus after experiencing stimuli of low affect intensity, but transferred habituation to a low affect intensity test stimulus after experiencing stimuli of high affect intensity. This transfer of habituation was not due to over-habituation as the bats responded to a frequency-shifted control stimulus. A direct comparison confirmed the asymmetric response behaviour in the reciprocal experiments.

CONCLUSIONS

Thus, the present study provides not only evidence for a discrimination of affect intensity, but also for an evaluation of stimulus salience, suggesting that basic assessment mechanisms involved in the perception of emotion are an ancestral trait in mammals.

Phasic boosting of auditory perception by visual emotion

Emotionally negative stimuli boost perceptual processes. There is little known, however, about the timing of this modulation. The present study aims at elucidating the phasic effects of, emotional processing on auditory processing within subsequent time-windows of visual emotional, processing in humans. We recorded the electroencephalogram (EEG) while participants responded to a, discrimination task of faces with neutral or fearful expressions. A brief complex tone, which subjects, were instructed to ignore, was displayed concomitantly, but with different asynchronies respective to, the image onset. Analyses of the N1 auditory event-related potential (ERP) revealed enhanced brain, responses in presence of fearful faces. Importantly, this effect occurred at picture-tone asynchronies of, 100 and 150ms, but not when these were displayed simultaneously, or at 50ms or 200ms asynchrony. These results confirm the existence of a fast-operating crossmodal effect of visual emotion on auditory, processing, suggesting a phasic variation according to the time-course of emotional processing.

Emotional processing modulates attentional capture of irrelevant sound input in adolescents

The main goal of this study was to investigate how emotional processing modulates the allocation of attention to irrelevant background sound events in adolescence. We examined the effect of viewing positively and negatively valenced video clips on components of event-related brain potentials (ERPs), while irrelevant sounds were presented to the ears. All sounds evoked the P1, N1, P2, and N2 components. The infrequent, randomly occurring novel environmental sounds evoked the P3a component in all trial types. The main finding was that the P3a component was larger in amplitude when evoked by salient, distracting background sound events when participants were watching negatively charged video clips, compared to when viewing of the positive or neutral video clips. The results suggest that the threshold for involuntary attention to the novel sounds was lowered during viewing of the negative movie contexts. This indicates a survival mechanism, which would be needed for more automatic processing of irrelevant sounds to monitor the unattended environment in situations perceived as more threatening.

Brain reactivity differentiates subjects with high and low dream recall frequencies during both sleep and wakefulness

The neurophysiological correlates of dreaming remain unclear. According to the "arousal-retrieval" model, dream encoding depends on intrasleep wakefulness. Consistent with this model, subjects with high and low dream recall frequency (DRF) report differences in intrasleep awakenings. This suggests a possible neurophysiological trait difference between the 2 groups. To test this hypothesis, we compared the brain reactivity (evoked potentials) of subjects with high (HR, N = 18) and low (LR, N = 18) DRF during wakefulness and sleep. During data acquisition, the subjects were presented with sounds to be ignored (first names randomly presented among pure tones) while they were watching a silent movie or sleeping. Brain responses to first names dramatically differed between the 2 groups during both sleep and wakefulness. During wakefulness, the attention-orienting brain response (P3a) and a late parietal response were larger in HR than in LR. During sleep, we also observed between-group differences at the latency of the P3a during N2 and at later latencies during all sleep stages. Our results demonstrate differences in the brain reactivity of HR and LR during both sleep and wakefulness. These results suggest that the ability to recall dreaming is associated with a particular cerebral functional organization, regardless of the state of vigilance.

Mood modulates auditory laterality of hemodynamic mismatch responses during dichotic listening

Hemodynamic mismatch responses can be elicited by deviant stimuli in a sequence of standard stimuli even during cognitive demanding tasks. Emotional context is known to modulate lateralized processing. Right-hemispheric negative emotion processing may bias attention to the right and enhance processing of right-ear stimuli. The present study examined the influence of induced mood on lateralized pre-attentive auditory processing of dichotic stimuli using functional magnetic resonance imaging (fMRI). Faces expressing emotions (sad/happy/neutral) were presented in a blocked design while a dichotic oddball sequence with consonant-vowel (CV) syllables in an event-related design was simultaneously administered. Twenty healthy participants were instructed to feel the emotion perceived on the images and to ignore the syllables. Deviant sounds reliably activated bilateral auditory cortices and confirmed attention effects by modulation of visual activity. Sad mood induction activated visual, limbic and right prefrontal areas. A lateralization effect of emotion-attention interaction was reflected in a stronger response to right-ear deviants in the right auditory cortex during sad mood. This imbalance of resources may be a neurophysiological correlate of laterality in sad mood and depression. Conceivably, the compensatory right-hemispheric enhancement of resources elicits increased ipsilateral processing.

Emotional cues during simultaneous face and voice processing: electrophysiological insights

Both facial expression and tone of voice represent key signals of emotional communication but their brain processing correlates remain unclear. Accordingly, we constructed a novel implicit emotion recognition task consisting of simultaneously presented human faces and voices with neutral, happy, and angry valence, within the context of recognizing monkey faces and voices task. To investigate the temporal unfolding of the processing of affective information from human face-voice pairings, we recorded event-related potentials (ERPs) to these audiovisual test stimuli in 18 normal healthy subjects; N100, P200, N250, P300 components were observed at electrodes in the frontal-central region, while P100, N170, P270 were observed at electrodes in the parietal-occipital region. Results indicated a significant audiovisual stimulus effect on the amplitudes and latencies of components in frontal-central (P200, P300, and N250) but not the parietal occipital region (P100, N170 and P270). Specifically, P200 and P300 amplitudes were more positive for emotional relative to neutral audiovisual stimuli, irrespective of valence, whereas N250 amplitude was more negative for neutral relative to emotional stimuli. No differentiation was observed between angry and happy conditions. The results suggest that the general effect of emotion on audiovisual processing can emerge as early as 200 msec (P200 peak latency) post stimulus onset, in spite of implicit affective processing task demands, and that such effect is mainly distributed in the frontal-central region.

Brain mechanisms for emotional influences on perception and attention: what is magic and what is not

The rapid and efficient selection of emotionally salient or goal-relevant stimuli in the environment is crucial for flexible and adaptive behaviors. Converging data from neuroscience and psychology have accrued during the last decade to identify brain systems involved in emotion processing, selective attention, and their interaction, which together act to extract the emotional or motivational value of sensory events and respond appropriately. An important hub in these systems is the amygdala, which may not only monitor the emotional value of stimuli, but also readily project to several other areas and send feedback to sensory pathways (including striate and extrastriate visual cortex). This system generates saliency signals that modulate perceptual, motor, as well as memory processes, and thus in turn regulate behavior appropriately. Here, we review our current views on the function and properties of these brain systems, with an emphasis on their involvement in the rapid and/or preferential processing of threat-relevant stimuli. We suggest that emotion signals may enhance processing efficiency and competitive strength of emotionally significant events through gain control mechanisms similar to those of other (e.g. endogenous) attentional systems, but mediated by distinct neural mechanisms in amygdala and interconnected prefrontal areas. Alterations in these brain mechanisms might be associated with psychopathological conditions, such as anxiety or phobia. We conclude that attention selection and awareness are determined by multiple attention gain control systems that may operate in parallel and use different sensory cues but act on a common perceptual pathway.

What is the specificity of the response to the own first-name when presented as a novel in a passive oddball paradigm? An ERP study

One's own first-name is a special stimulus: one's attention is more likely captured by hearing one's own first-name than by hearing another first-name. Previous event-related potential (ERP) studies demonstrated that this special stimulus produces differential responses both in active and in passive condition. Such results suggest that passively hearing one's own first-name triggers processing levels generally activated by the explicit detection of stimuli. This questions about the particular power of the own first-name to automatically orient attention, but no study investigated the specific response to this special stimulus in a paradigm designed to study automatic attention orienting. In this ERP study, we compared the responses elicited by the own first-name (OWN) and one unfamiliar first-name (OTHER) presented, rarely, randomly and at the same frequency among repetitive tones (i.e., as novel stimuli in an oddball paradigm) while subjects (N=36) were watching a silent movie with subtitles. We tested at what latency the responses to OWN and OTHER diverge, and whether OWN modulates the brain orienting response (novelty P3). Data analysis showed specific responses to OWN after 300 ms. OWN only evoked a central negativity (320 ms) and a parietal positivity (550 ms). However, OWN had no significant effect on the brain orienting response (260 ms). Our results confirm that the own first-name does elicit a late specific brain response. However, they challenge the idea that in passive condition, the own first-name is systematically more powerful than another first-name to orient attention when it is heard unexpectedly.

Phase re-setting of gamma neural oscillations during novelty processing in an appetitive context

Based on the previous study where phase-synchronization (PS) of gamma-band responses (GBRs) proved a reliable cerebral correlate of involuntary attention and its enhancement under threat, we measured gamma-PS elicited by novel sounds from human electroencephalogram (EEG) scalp-recordings when participants responded to visual stimuli displaying either highly motivational or neutral sceneries. We then tested the modulatory effect of the emotional conditions on auditory responses. Novel distractor sounds did not affect behavioural accuracy on subjects' visual task performance in neutral context but markedly decreased hit rate in the appetitive one. Similarly, gamma-PS to novel sounds remained intact in neutral context, whereas it showed an increase, within the 35-Hz sub-range, in the appetitive context. These results suggest that a context of processing positive emotional stimuli results into an enhanced processing of task-irrelevant novel auditory events, and, furthermore, that gamma-PS is tuned under conditions that could promote long-term survival.

Auditory novelty processing is enhanced in obsessive-compulsive disorder

BACKGROUND

Cognitive models propose that anxiety disorders are associated with an attentional bias toward potentially threatening stimuli. In this study, it was analyzed whether patients with obsessive-compulsive disorder (OCD) show enhanced responses of their event-related brain potentials to novel stimuli, either in a context of potential threat or in a neutral context.

METHODS

In this study, 20 OCD patients and 20 matched healthy control subjects performed a visual recognition task during which irrelevant repeated standard sounds and unitary novel sounds were interspersed.

RESULTS

As expected, OCD patients showed an increase in the novelty-P3 amplitude elicited by unitary novel sounds. However, no effect of emotional context conditions was observed.

CONCLUSION

It is suggested that the novelty P3 amplitude increase in OCD patients represents a physiological indicator of an enhanced cortical orienting response implicating stronger involuntary shifts of attention. This characteristic is driven by novelty per se and not moderated by potential threat of upcoming events.

Dopamine transporter regulates the enhancement of novelty processing by a negative emotional context

The dopaminergic (DA) system has been recently related the emotional modulation of cognitive processes. Moreover, patients with midbrain DA depletion, such as Parkinson's Disease (PD), have shown diminished reactivity during unpleasant events. Here, we examined the role of DA in the enhancement of novelty processing during negative emotion. Forty healthy volunteers were genotyped for the dopamine transporter (DAT) gene SLC6A3 or DAT1 and performed an auditory-visual distraction paradigm in negative and neutral emotional context conditions. 9R- individuals, associated to a lesser striatal DA display, failed to show increased distraction during negative emotion, but experienced an enhancement of the early phase of the novelty-P3 brain response, associated to the evaluation of novel events, in the negative relative to the neutral context. However, 9R+ individuals (associated to larger striatal DA display) showed larger distraction during negative emotion and larger amplitudes of the novelty-P3, irrespective of the condition. These results suggest a blunted reactivity to novelty during negative emotion in 9R- individuals due to a lesser DA display and stronger activation of the representation of novel events in the 9R+ group, due to a larger DA availability, thus reaching a ceiling effect in the neutral context condition with no further enhancement during negative emotion. The present results might help to understand the functional implications of dopamine in some neuropsychiatric disorders.