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

Social anxiety prediction based on ERP features: A deep learning approach

BACKGROUND

Social Anxiety Disorder is traditionally diagnosed using subjective scales that may lack accuracy. Recently, EEG technology has gained importance for anxiety detection due to its ability to capture stable and objective neurophysiological activities. However, existing methods mainly focus on extracting EEG features during resting states, with limited use of psychologically features like Event-Related Potential (ERP) in task-related states for anxiety detection in deep learning frameworks.

METHODS

We collected EEG data from 63 participants exposed to four facial expressions and extracted task-relevant features. Using the EEGNet model, we predicted social anxiety and evaluated its performance using metrics such as accuracy, F1 score, sensitivity, and specificity. We compared EEGNet's performance with Deep Convolutional Neural Network (DeepConvNet), ShallowConvNet, Bi-directional Long Short-Term Memory (BiLSTM), and SVM. To assess the generalizability of the results, we carried out the same procedure on our prior dataset.

RESULTS

EEGNet outperformed other models, achieving 99.16 % accuracy with Late Positive Potential (LPP). ERP components yielded higher accuracy than time-domain and frequency-domain features for social anxiety recognition. Accuracy was better for neutral and negative facial stimuli. Consistency across two datasets indicates stability of findings.

LIMITATIONS

Due to limited publicly available task-state datasets, only our own were used. Future studies could assess generalizability on larger datasets from different sources.

CONCLUSIONS

We conducted the first test of ERP features in anxiety recognition tasks. Results show ERP features have greater potential in social anxiety recognition, with LPP exhibiting high stability and accuracy. Outcomes indicate recognizing social anxiety with negative or neutral facial stimuli is more useful.

Reduced early neural processing of faces in children and adolescents with social anxiety disorder

Social anxiety disorder (SAD) is one of the most common mental disorders during childhood and adolescence. Yet, little is known about its maintenance in youth. Cognitive models of SAD indicate that attentional biases play a key role in the dysfunctional processing of social information, such as emotional faces. However, previous research investigating neural correlates of childhood SAD has produced inconsistent findings. The current study aims to investigate neural face processing in children and adolescents with SAD, while taking into consideration methodological limitations of previous studies. We measured event-related potentials (P100, N170, EPN, LPP) in response to happy, neutral, and angry adult faces, and non-social household objects, in a sample of youth (aged 10-15 years) with SAD (n = 57), clinical controls with specific phobias (SP; n = 41), and healthy controls (HC; n = 61). Participants completed an emotion/object identification task while continuous EEG was recorded. Analyses revealed lower N170 amplitudes in the SAD group compared to HCs, irrespective of emotion. In addition, younger children (aged 10-12 years) with SAD showed lower EPN amplitudes and higher early LPP amplitudes (only trend level) in response to neutral and happy faces compared to younger HCs. These effects were specific to faces and were not evident in the neural processing of non-social household objects. Overall, the findings indicate that different neural response patterns are already present in youth with SAD. Group differences, particularly in younger children, suggest age-related differences in neural face processing in childhood SAD and underpin the necessity of developmental approaches.

Differences in attentional bias between self-related information and external cues from others in individuals with social anxiety: An event-related potential study

Individuals with high social anxiety show a more considerable attentional bias toward self-relevant information and outwardly threatening stimuli than do those with low social anxiety. Some studies have investigated the attentional bias between self-relevant information and external social cues in people with high social anxiety but have not reached consistent conclusions. This study used a modified dot-probe task and collected temporal and electroencephalogram responses to three self-other face pairs among 15 people with high social anxiety and 20 people with low social anxiety. Both groups responded quicker to self-relevant information than external social cues. Others' emotional potencies moderated the attentional bias. Individuals with high social anxiety exhibited larger P1 amplitudes and smaller N170 amplitudes (mainly in the right hemisphere) for all face pairs and larger P2 amplitudes for the self-neutral and other-angry face pairs than those with low social anxiety. These findings suggest that people with social anxiety prioritize allocating attentional resources to self-relevant information, with others' angry faces having the greatest influence on the allocation. Individuals with high social anxiety initially exhibit more attentional vigilance and less structural coding for face pairs, followed by heightened engagement with threatening cues compared to those with low social anxiety.

Social anxiety modulating early processing for social threat words: an ERP study

Even though some recent research revealed individuals with HSA typically display enhanced processing in the early stages of emotional information processing due to hypervigilance and vulnerability to negative stimuli, it is still unclear whether social anxiety affects the time course underlying processing bias for emotional stimuli. Therefore, the present study aimed to explore the early stage of processing social threat stimuli in high social anxiety (HSA) individuals by recording RTs and EEG data in the emotional Stroop task. Behavioral data showed that the HSA group responded to the threat words faster than neutral words (i.e. negative bias), but no emotional effects in the low social anxiety (LSA) group. Although the P1 component did not show any early effects, ERP data exhibited an enhanced N170 for HSA than for LSA groups. Threat words elicited larger N170 than neutral words in the LSA group only; this emotion effect was not evident in the HSA group. These findings indicated that social anxiety modulates early processing for social threat words. This study revealed the neural mechanisms underlying early emotional processing in individuals with social anxiety, providing insights for the evaluation and intervention of social anxiety.

Event-related alpha power in early stage of facial expression processing in social anxiety: Influence of language context

Accurate interpretation of the emotional information conveyed by others' facial expressions is crucial for social interactions. Event-related alpha power, measured by time-frequency analysis, is a frequently used EEG index of emotional information processing. However, it is still unclear how event-related alpha power varies in emotional information processing in social anxiety groups. In the present study, we recorded event-related potentials (ERPs) while participants from the social anxiety and healthy control groups viewed facial expressions (angry, happy, neutral) preceded by contextual sentences conveying either a positive or negative evaluation of the subject. The impact of context on facial expression processing in both groups of participants was explored by assessing behavioral ratings and event-related alpha power (0-200 ms after expression presentation). In comparison to the healthy control group, the social anxiety group exhibited significantly lower occipital alpha power in response to angry facial expressions in negative contexts and neutral facial expressions in positive contexts. The influence of language context on facial expression processing in individuals with social anxiety may occur at an early stage of processing.

Neural evidence of face processing in social anxiety disorder: A systematic review with meta-analysis

Numerous previous studies have used event-related potentials (ERPs) to examine facial processing deficits in individuals with social anxiety disorder (SAD). However, researchers still need to determine whether the deficits are general or specific and what the dominant factors are behind different cognitive stages. Meta-analysis was performed to quantitatively identify face processing deficits in individuals with SAD. Ninety-seven results in 27 publications involving 1032 subjects were calculated using Hedges' g. The results suggest that the face itself elicits enlarged P1 amplitudes, threat-related facial expressions induce larger P2 amplitudes, and negative facial expressions lead to enhanced P3/LPP amplitudes in SAD individuals compared with controls. That is, there is face perception attentional bias in the early phase (P1), threat attentional bias in the mid-term phase (P2), and negative emotion attentional bias in the late phase (P3/LPP), which can be summarized into a three-phase SAD face processing deficit model. These findings provide an essential theoretical basis for cognitive behavioral therapy and have significant application value for the initial screening, intervention, and treatment of social anxiety.

The effect of sad mood on early sensory event-related potentials to task-irrelevant faces

It has been shown that the perceiver's mood affects the perception of emotional faces, but it is not known how mood affects preattentive brain responses to emotional facial expressions. To examine the question, we experimentally induced sad and neutral mood in healthy adults before presenting them with task-irrelevant pictures of faces while an electroencephalography was recorded. Sad, happy, and neutral faces were presented to the participants in an ignore oddball condition. Differential responses (emotional - neutral) for the P1, N170, and P2 amplitudes were extracted and compared between neutral and sad mood conditions. Emotional facial expressions modulated all the components, and an interaction effect of expression by mood was found for P1: an emotional modulation to happy faces, which was found in neutral mood condition, disappeared in sad mood condition. For N170 and P2, we found larger response amplitudes for both emotional faces, regardless of the mood. The results add to the previous behavioral findings showing that mood already affects low-level cortical feature encoding of task-irrelevant faces.

Up close and emotional: Electrophysiological dynamics of approaching angry faces

Recent evidence suggests that looming emotional faces are processed rapidly by the neural system, and that this apparent approach further interacts with emotion, causing an enhanced neural response for angry expressions. However, previous research has not demonstrated unequivocally if these effects are due to low-level visual features, or if they are indeed due to the emotional content of the stimuli. To address this question, the current study presented upright and inverted angry and neutral faces, which either expanded or contracted in size on a constant depth-cued background, such that they appeared to approach or retreat from the viewer. EEG/ERP measures were used to identify the time course of brain activity for these stimuli. The results showed that when faces were upright, both the P1 and N170 were enhanced for angry expressions, with the P1 being further increased with looming angry faces. The inversion of the faces caused an increase in both the P1 and N170 amplitudes, but no modulation was found for emotions. These findings show an early modulation of brain activity for upright looming angry faces and rule out the influence of low-level visual features as a contributing factor.

Influence of affective verbal context on emotional facial expression perception of social anxiety

Previous studies have shown that the perception of ambiguous facial expressions for individuals with social anxiety was influenced by the affective verbal context. However, it is still unknown how emotional facial expressions are perceived by individuals with social anxiety in the context of the verbal context. In this study, we used event-related potentials (ERPs) technology to examine how individuals with social anxiety perceive emotional facial expressions in positive and negative contexts. The results showed that: (1) Within the negative verbal contexts, the amplitude of P1 induced by facial expressions in the social anxiety group was significantly higher than that induced by the healthy control group; The N170 amplitude induced by facial expressions in social anxiety group was less negative than that in the healthy control group, and was not affected by the context. (2) The social anxiety group had significantly higher LPP in negative contexts elicited by angry expressions than by happy expressions. This study proved that the perception of emotional facial expressions was influenced by top-down information in the early and late stages of visual perception for individuals with social anxiety.

Neural Processing Differences of Facial Emotions Between Human and Vehicles: Evidence From an Event-Related Potential Study

Vehicle “faces” are a crucial factor influencing consumer intention to purchase gasoline and electric vehicles. However, little empirical evidence has demonstrated whether people process a vehicle’s face similarly to a human’s face. We investigated the neural processing relationship among human facial emotions and facial emotions of gasoline and electric vehicles using a 2 (emotional) × 3 (face type) repeated measures design and electroencephalograph (EEG) recordings. The results showed that human faces appear to share a partly similar neural processing mechanism in the latency of 100–300 ms, and that both human and vehicle faces elicited the ERP components N170, EPN, and P2. The large EPN and P2 suggest that gasoline vehicle facial emotions can be perceived more efficiently than those of electric vehicles. These findings provide an insight for vehicle designers to better understand the facial emotions presented by cars.

Am I really seeing what's around me? An ERP study on social anxiety under speech induction, uncertainty and social feedback

Cognitive models of social anxiety propose that socially anxious individuals engage in excessive self-focusing attention when entering a social situation. In the present study, speech anxiety was induced to socially anxious and control participants. Event-related potentials were recorded while participants performed a perceptual judgment task using distinct or ambiguous stimuli, before and after social feedback. Disputed feedback led to more revisions and decreased levels of confidence, especially among socially anxious individuals. Prior feedback, greater occipital P1 amplitudes in both groups for ambiguous probes indicated heightened sensory facilitation to ambiguous information, and greater anterior N1 amplitudes for ambiguous stimuli in highly anxious participants suggested anticipation of negative feedback in this group. Post-feedback, P1, N1 and LPP amplitudes were reduced overall among socially anxious individuals indicating a reduction in sensory facilitation of visual information. These results suggest excessive self-focusing among socially anxious individuals, possibly linked to anticipation of an anxiety-provoking social situation.

The recognition of dynamic-emotional faces in individuals with high and low social anxiety: An ERP study

Individuals with high social anxiety (HSA) show abnormal processing of emotional faces, which may increase their social anxiety. A growing number of event-related potential (ERP) studies have explored the neural mechanisms underlying the static-emotional face processing of HSA individuals. In view of the ecological validity of dynamic faces, this study will further explore the time course of dynamic-emotional face processing in individuals with HSA. To this end, 30 high and 30 low social anxiety (LSA) participants were asked to perform an identification task of dynamic-emotional faces while their brain responses were recorded using an ERP technique. The behavioral results showed the recognition accuracy of dynamic faces was higher than static faces when these faces were happy. For the P100 component, HSA participants showed higher P100 mean amplitudes of dynamic than static faces in the left hemisphere when they viewed happy, but not angry faces. In addition, increased N170 mean amplitudes of dynamic-happy faces were showed. Furthermore, the LPP mean amplitudes of dynamic faces were smaller than those of static faces. In sum, this study could provide a better understanding of the time course of dynamic-emotional face processing in HSA individuals.

Neural correlates of negative expectancy and impaired social feedback processing in social anxiety

Social anxiety has been associated with abnormalities in cognitive processing in the literature, manifesting as various cognitive biases. To what extent these biases interrupt social interactions remains largely unclear. This study used the Social Judgment Paradigm that could separate the expectation and experience stages of social feedback processing. Event-related potentials (ERPs) in these two stages were recorded to detect the effect of social anxiety that might not be reflected by behavioral data. Participants were divided into two groups according to their social anxiety level. Participants in the high social anxiety (HSA) group were more likely to predict that they would be socially rejected by peers than did their low social anxiety (LSA) counterparts (i.e. the control group). Compared to the ERP data of the LSA group, the HSA group showed: (a) a larger P1 component to social cues (peer faces) prior to social feedback presentation, possibly indicating an attention bias; (b) a difference in feedback-related negativity amplitude between unexpected social acceptance and unexpected social rejection, possibly indicating an expectancy bias; and (c) a diminished sensitivity of the P3 amplitude to social feedback valence (be accepted/be rejected), possibly indicating an experience bias. These results could help understand the cognitive mechanisms that comprise and maintain social anxiety.

Facial emotion perception in young female students with subsyndromal panic disorder. Behavioral and ERP study

This study aimed to examine the behavioral and neural correlates of facial emotion recognition in young women with subsyndromal panic disorder (SPD). In the experiment 15 non-medicated women with SPD and 17 matched healthy controls were tasked with recognizing angry, fearful, happy, and neutral facial expressions, and accuracy, reaction time (RT), and event-related potentials (ERPs) were recorded. Significant between-group differences in behavioral characteristics (accuracy of emotion recognition and RT) were not found, however, the SPD subjects demonstrated a slower response to fearful expressions compared to neutral and happy expressions. More distinct between-group differences were observed for the EPRs. The SPD subjects demonstrated increased amplitudes of the P100 ERP component in the occipital area and the P200 component over the occipital and temporal regions. In the frontal regions the SPD group showed a greater amplitude of the N200 component and also an increased negativity 350-450 ms after stimulus presentation. According to the dipole source modeling data, the SPD subjects showed enhanced activation in the extra-striate cortex which increased in intensity when angry and fearful faces were presented. Thus, young women with SPD which manifested in infrequent panic attacks showed significant alterations in ERP characteristics of emotional processing, which may be considered as a more sensitive indicator of early-stage panic disorder than the observed behavioral measures.

Turning to the negative: attention allocation to emotional faces in adolescents with dysregulation profile-an event-related potential study

Patients with irritability, temper outbursts, hyperactivity and mood swings often meet the dysregulation profile (DP) of the Child Behavior Checklist (CBCL) or the Strengths and Difficulties Questionnaire (SDQ), which have been investigated over the past few decades. While the DP has emerged as a transdiagnostic marker with a negative impact on therapeutic outcome and psychosocial functioning, little is known about its underlying mechanisms such as attention and emotion regulation processes. In this study, we tested whether adolescent psychiatric patients (n = 27) with the SDQ-DP show impaired emotional face processing for task-irrelevant stimuli compared to psychiatric patients without the SDQ-DP (n = 30) and non-clinical adolescents (n = 21). Facial processing was tested with event-related potential (ERP) measures known to be modulated by attention (i.e., P1, N1, N170, P2, and Nc) during a modified Attention Network Task, to which task-irrelevant emotional stimuli (sad, fearful, and neutral faces) were added prior to the actual trial. The results reveal group differences in the orienting and in the conflicting network. Patients with DP showed a less efficient orienting network and the clinical control group showed a less efficient conflicting network. Moreover, patients with the dysregulation profile had a shorter N1/N170 latency than did the two control groups, suggesting that dysregulation in adolescents is associated with a faster but less arousing encoding of (task-irrelevant) emotional information and less top-down control.

ERP evidence for emotional sensitivity in social anxiety

BACKGROUND

Emotional sensitivity involves the ability to recognize and interpret facial expressions. This is very important for interpersonal communication. Previous studies found differences in emotional sensitivity between high social anxiety (HSA) individuals and low social anxiety (LSA) individuals. However, the underlying neural mechanisms are still unclear. The present study explored the effects of expression intensity and social anxiety on emotional sensitivity and their neural mechanisms.

METHODS

The HSA group (n = 20) and the LSA group (n = 20) were asked to recognize anger expressions with different intensities in an emotion recognition task. The hit rate, reaction time, early time window (P1, N170), and late time window (LPP) were recorded.

RESULTS

The results showed that individuals with HSA had a significantly higher hit rate and shorter reaction time than individuals with LSA (p < 0.01). Event-related potential (ERP) results showed that, compared to the LSA group, the HSA group exhibited significantly enhanced N170 and LPP amplitude (p < 0.01). However, the difference in P1 amplitude was not significant (p > 0.05).

LIMITATIONS

The participants in this study were a subclinical social anxiety sample, and the effects of other mood disorders were not excluded, partially limiting the generalizability of the results.

CONCLUSIONS

Our findings suggest that, compared to LSA individuals, HSA individuals are more sensitive to all presented faces. The ERP results indicated that HSA individuals' high sensitivity to threatening expressions is related to stronger structural encoding and fine processing.

Review of EEG, ERP, and Brain Connectivity Estimators as Predictive Biomarkers of Social Anxiety Disorder

Social anxiety disorder (SAD) is characterized by a fear of negative evaluation, negative self-belief and extreme avoidance of social situations. These recurrent symptoms are thought to maintain the severity and substantial impairment in social and cognitive thoughts. SAD is associated with a disruption in neuronal networks implicated in emotional regulation, perceptual stimulus functions, and emotion processing, suggesting a network system to delineate the electrocortical endophenotypes of SAD. This paper seeks to provide a comprehensive review of the most frequently studied electroencephalographic (EEG) spectral coupling, event-related potential (ERP), visual-event potential (VEP), and other connectivity estimators in social anxiety during rest, anticipation, stimulus processing, and recovery states. A search on Web of Science provided 97 studies that document electrocortical biomarkers and relevant constructs pertaining to individuals with SAD. This study aims to identify SAD neuronal biomarkers and provide insight into the differences in these biomarkers based on EEG, ERPs, VEP, and brain connectivity networks in SAD patients and healthy controls (HC). Furthermore, we proposed recommendations to improve methods of delineating the electrocortical endophenotypes of SAD, e.g., a fusion of EEG with other modalities such as functional magnetic resonance imaging (fMRI) and magnetoencephalograms (MEG), to realize better effectiveness than EEG alone, in order to ultimately evolve the treatment selection process, and to review the possibility of using electrocortical measures in the early diagnosis and endophenotype examination of SAD.

Effects of working memory training on EEG, cognitive performance, and self-report indices potentially relevant for social anxiety

Social anxiety (SA) is quite common and associated with multiple comorbidities. Here, we examined the effects of working memory (WM) training on various indices potentially related to SA. Pre-selected university students with elevated self-reported SA symptoms were assigned to a WM training (n = 21) or an active control treatment condition (n = 21). Pre- and post-treatment assessments were made using questionnaires related to (social) anxiety and depression, and tasks measuring WM, interference control, and attentional biases towards, and event-related potentials (ERPs) elicited by, angry faces. The training enhanced WM transfer task performance, reduced SA symptoms, and changed the amplitude of the P1, N170, P2, and N2 ERP components. However, the latter changes did not mediate the effect of WM training on SA symptoms. These data provide preliminary evidence of the usefulness of WM trainings to reduce potential indices of SA, but further research is necessary to unravel the causal relation among these indices.

The neural chronometry of threat-related attentional bias: Event-related potential (ERP) evidence for early and late stages of selective attentional processing

Rapid and accurate detection of threat is adaptive. Yet, threat-related attentional biases, including hypervigilance, avoidance, and attentional disengagement delays, may contribute to the etiology and maintenance of anxiety disorders. Behavioral measures of attentional bias generally indicate that threat demands more attentional resources; however, indices exploring differential allocation of attention using reaction time fail to clarify the time course by which attention is deployed under threatening circumstances in healthy and anxious populations. In this review, we conduct an interpretive synthesis of 28 attentional bias studies focusing on event-related potentials (ERPs) as a primary outcome to inform an ERP model of the neural chronometry of attentional bias in healthy and anxious populations. The model posits that both healthy and anxious populations display modulations of early ERP components, including the P1, N170, P2, and N2pc, in response to threatening and emotional stimuli, suggesting that both typical and abnormal patterns of attentional bias are characterized by enhanced allocation of attention to threat and emotion at earlier stages of processing. Compared to anxious populations, healthy populations more clearly demonstrate modulations of later components, such as the P3, indexing conscious and evaluative processing of threat and emotion and disengagement difficulties at later stages of processing. Findings from the interpretive synthesis, existing bias models, and extant neural literature on attentional systems are then integrated to inform a conceptual model of the processes and substrates underlying threat appraisal and resource allocation in healthy and anxious populations. To conclude, we discuss therapeutic interventions for attentional bias and future directions.

Impaired early visual categorization of fear in social anxiety

Social anxiety is associated with biased social perception, especially of ambiguous cues. While aberrations in high-level processes (e.g., cognitive appraisal and interpretation) have been implicated in such biases, contributions of early, low-level stimulus processing remain unclear. Categorical perception represents an efficient process to resolve signal ambiguity, and categorical emotion perception can swiftly classify sensory input, "tagging" biologically important stimuli at early stages of processing to facilitate ecological response. However, early threat categorization could be disrupted by exaggerated (or disinhibited) threat processing in anxiety, resulting in biased perception of ambiguous signals. We tested this hypothesis among individuals with low and high trait social anxiety (LSA/HSA; defined relative to the current sample), who performed a two-alternative forced-choice (fear or neutral) task on facial expressions parametrically varied along a neutral-fear continuum. The groups diverged in the reaction time (RT) profile along the neutral-fear continuum, which was characteristic of categorical perception in the LSA (vs. HSA) group with drastically increased RT from neutral to intermediate (boundary) fear intensities, contrasting monotonic, nonsignificant RT changes in the HSA group. Neurometric analysis along the continuum identified an early neutral-fear categorization operation (arising in the P1, an early visual ERP at 100 ms), which was nonetheless impaired in the HSA group (due to disinhibited response at the neutral-fear boundary). Absent group differences in higher-level cognitive operations (identified by later ERPs), current findings highlight a dispositional cognitive vulnerability in early visual categorization of social threat, which could precipitate further cognitive aberrations and, eventually, the onset of social anxiety disorder.

The Perception of Facial Emotional Change in Social Anxiety: An ERP Study

Social anxiety is one of the psychological symptoms that most commonly occur in social interaction. Although previous behavioral studies have investigated the neutral-angry facial emotion change in social anxiety, none of the previous studies have, however, directly investigated the angry-neutral facial emotional change. Furthermore, less is known about the neural correlates of the facial emotion changes in individuals with social anxiety. The main goal of the present study was to explore the perception of facial emotional changes in individuals with social anxiety, using high temporal resolution event-related potential techniques. Behaviorally, accuracy in the angry-neutral facial emotional change trail was lower than that in the neutral-neutral case. Neurally, we found that the N170 amplitudes in angry-neutral facial emotional change trial were larger than those in the neutral-neutral case for high social anxiety (HAS) participants, probably reflecting that they might engage in more analytical processing of different facial elements. Interestingly, HSA participants showed smaller P200 left hemisphere amplitudes in the angry-neutral facial emotional change trial when compared with the neutral-neutral case, which suggested that they might have difficulties in processing emotions when they encounter these facial emotional changes. Finally, the late positive potential amplitudes in the neutral-angry and angry-neutral facial emotional change trials were smaller than those in the neutral-neutral case, regardless of the social anxiety. These results suggest that social anxiety influences the facial emotional changes mainly at an earlier stage of processing.

Facial emotion processing in pediatric social anxiety disorder: Relevance of situational context

Social anxiety disorder (SAD) typically begins in childhood. Previous research has demonstrated that adult patients respond with elevated late positivity (LP) to negative facial expressions. In the present study on pediatric SAD, we investigated responses to negative facial expressions and the role of social context information. Fifteen children with SAD and 15 non-anxious controls were first presented with images of negative facial expressions with masked backgrounds. Following this, the complete images which included context information, were shown. The negative expressions were either a result of an emotion-relevant (e.g., social exclusion) or emotion-irrelevant elicitor (e.g., weight lifting). Relative to controls, the clinical group showed elevated parietal LP during face processing with and without context information. Both groups differed in their frontal LP depending on the type of context. In SAD patients, frontal LP was lower in emotion-relevant than emotion-irrelevant contexts. We conclude that SAD patients direct more automatic attention towards negative facial expressions (parietal effect) and are less capable in integrating affective context information (frontal effect).

Cognitive behavioural therapy attenuates the enhanced early facial stimuli processing in social anxiety disorders: an ERP investigation

Background

Previous studies of patients with social anxiety have demonstrated abnormal early processing of facial stimuli in social contexts. In other words, patients with social anxiety disorder (SAD) tend to exhibit enhanced early facial processing when compared to healthy controls. Few studies have examined the temporal electrophysiological event-related potential (ERP)-indexed profiles when an individual with SAD compares faces to objects in SAD. Systematic comparisons of ERPs to facial/object stimuli before and after therapy are also lacking. We used a passive visual detection paradigm with upright and inverted faces/objects, which are known to elicit early P1 and N170 components, to study abnormal early face processing and subsequent improvements in this measure in patients with SAD.

Methods

Seventeen patients with SAD and 17 matched control participants performed a passive visual detection paradigm task while undergoing EEG. The healthy controls were compared to patients with SAD pre-therapy to test the hypothesis that patients with SAD have early hypervigilance to facial cues. We compared patients with SAD before and after therapy to test the hypothesis that the early hypervigilance to facial cues in patients with SAD can be alleviated.

Results

Compared to healthy control (HC) participants, patients with SAD had more robust P1–N170 slope but no amplitude effects in response to both upright and inverted faces and objects. Interestingly, we found that patients with SAD had reduced P1 responses to all objects and faces after therapy, but had selectively reduced N170 responses to faces, and especially inverted faces. Interestingly, the slope from P1 to N170 in patients with SAD was flatter post-therapy than pre-therapy. Furthermore, the amplitude of N170 evoked by the facial stimuli was correlated with scores on the interaction anxiousness scale (IAS) after therapy.

Conclusions

Our results did not provide electrophysiological support for the early hypervigilance hypothesis in SAD to faces, but confirm that cognitive-behavioural therapy can reduce the early visual processing of faces. These findings have potentially important therapeutic implications in the assessment and treatment of social anxiety.

Trial registration HEBDQ2014021

The Impact of Top-Down Prediction on Emotional Face Processing in Social Anxiety

There is evidence that people with social anxiety show abnormal processing of emotional faces. To investigate the impact of top-down prediction on emotional face processing in social anxiety, brain responses of participants with high and low social anxiety (LSA) were recorded, while they performed a variation of the emotional task, using high temporal resolution event-related potential techniques. Behaviorally, we reported an effect of prediction with higher accuracy for predictable than unpredictable faces. Furthermore, we found that participants with high social anxiety (HSA), but not with LSA, recognized angry faces more accurately than happy faces. For the P100 and P200 components, HSA participants showed enhanced brain activity for angry faces compared to happy faces, suggesting a hypervigilance to angry faces. Importantly, HSA participants exhibited larger N170 amplitudes in the right hemisphere electrodes than LSA participants when they observed unpredictable angry faces, but not when the angry faces were predictable. This probably reflects the top-down prediction improving the deficiency at building a holistic face representation in HSA participants.

Long-term academic stress enhances early processing of facial expressions

Exposure to long-term stress can lead to a variety of emotional and behavioral problems. Although widely investigated, the neural basis of how long-term stress impacts emotional processing in humans remains largely elusive. Using event-related brain potentials (ERPs), we investigated the effects of long-term stress on the neural dynamics of emotionally facial expression processing. Thirty-nine male college students undergoing preparation for a major examination and twenty-one matched controls performed a gender discrimination task for faces displaying angry, happy, and neutral expressions. The results of the Perceived Stress Scale showed that participants in the stress group perceived higher levels of long-term stress relative to the control group. ERP analyses revealed differential effects of long-term stress on two early stages of facial expression processing: 1) long-term stress generally augmented posterior P1 amplitudes to facial stimuli irrespective of expression valence, suggesting that stress can increase sensitization to visual inputs in general, and 2) long-term stress selectively augmented fronto-central P2 amplitudes for angry but not for neutral or positive facial expressions, suggesting that stress may lead to increased attentional prioritization to processing negative emotional stimuli. Together, our findings suggest that long-term stress has profound impacts on the early stages of facial expression processing, with an increase at the very early stage of general information inputs and a subsequent attentional bias toward processing emotionally negative stimuli.

Social Anxiety and Interpretation Bias

This study examined how positive-scale assessment of ambiguous social stimuli affects interpretation bias in social anxiety. Participants with high and low social anxiety ( N = 60) performed a facial expression discrimination task to assess interpretation bias. Participants were then randomly assigned to assess the emotion of briefly presented faces either on a negative or on a positive scale. They subsequently repeated the facial expression discrimination task. Participants with high versus low social anxiety made more negative interpretations of ambiguous facial expressions. However, those in the positive-scale assessment condition subsequently showed reduced negative interpretations of ambiguous facial expressions. These results suggest that interpretation bias in social anxiety could be mediated by positive priming rather than an outright negative bias.

Influence of spatial frequency and emotion expression on face processing in patients with panic disorder

BACKGROUND

Deficits in facial emotion processing is a major characteristic of patients with panic disorder. It is known that visual stimuli with different spatial frequencies take distinct neural pathways. This study investigated facial emotion processing involving stimuli presented at broad, high, and low spatial frequencies in patients with panic disorder.

METHODS

Eighteen patients with panic disorder and 19 healthy controls were recruited. Seven event-related potential (ERP) components: (P100, N170, early posterior negativity (EPN); vertex positive potential (VPP), N250, P300; and late positive potential (LPP)) were evaluated while the participants looked at fearful and neutral facial stimuli presented at three spatial frequencies.

RESULTS

When a fearful face was presented, panic disorder patients showed a significantly increased P100 amplitude in response to low spatial frequency compared to high spatial frequency; whereas healthy controls demonstrated significant broad spatial frequency dependent processing in P100 amplitude. Vertex positive potential amplitude was significantly increased in high and broad spatial frequency, compared to low spatial frequency in panic disorder. Early posterior negativity amplitude was significantly different between HSF and BSF, and between LSF and BSF processing in both groups, regardless of facial expression.

LIMITATION

The possibly confounding effects of medication could not be controlled.

CONCLUSIONS

During early visual processing, patients with panic disorder prefer global to detailed information. However, in later processing, panic disorder patients overuse detailed information for the perception of facial expressions. These findings suggest that unique spatial frequency-dependent facial processing could shed light on the neural pathology associated with panic disorder.

Emotional Processing and Attention Control Impairments in Children with Anxiety: An Integrative Review of Event-Related Potentials Findings

Anxiety disorders in adults have been associated with biased processing of emotional information which may be due to a deficit in attentional control. This deficit leads to an hypervigilance and a selective attention toward threatening information. Event-related potentials (ERPs) have been used to study this topic in anxious adults. Similar biases have been reported in children with anxiety but researches investigating the ERPs components underpinning these biases are more scarce. However, the understanding of the neural correlates of attentional biases in anxious children seem quite important since they could play a role in the etiology and the maintenance of this disorder. This review summarizes the results of researches having used ERPs to index emotional processing and attention control in children suffering from anxiety. We will focus on the P1, indexing basic visual perceptual processing, the N2, thought to reflect cognitive control process, the P3 typically associated with response inhibition, and the late positive potential (LPP) that indicates sustained attention toward motivationally salient stimuli. We will also examine the error-related negativity (ERN) that indexes monitoring system for detecting errors. Electro-physiological studies generally reported increased amplitudes of these components in anxious children, even when they did not differ from typically developing children at a behavioral level. These results suggest diminished cognitive control that influences children's selective attention mechanisms toward threatening information. Theoretical perspectives and implications for future researches will be discussed in the framework of current models of childhood anxiety.

The Effect of Affective Context on Visuocortical Processing of Neutral Faces in Social Anxiety

It has been demonstrated that verbal context information alters the neural processing of ambiguous faces such as faces with no apparent facial expression. In social anxiety, neutral faces may be implicitly threatening for socially anxious individuals due to their ambiguous nature, but even more so if these neutral faces are put in self-referential negative contexts. Therefore, we measured event-related brain potentials (ERPs) in response to neutral faces which were preceded by affective verbal information (negative, neutral, positive). Participants with low social anxiety (LSA; n = 23) and high social anxiety (HSA; n = 21) were asked to watch and rate valence and arousal of the respective faces while continuous EEG was recorded. ERP analysis revealed that HSA showed elevated P100 amplitudes in response to faces, but reduced structural encoding of faces as indexed by reduced N170 amplitudes. In general, affective context led to an enhanced early posterior negativity (EPN) for negative compared to neutral facial expressions. Moreover, HSA compared to LSA showed enhanced late positive potentials (LPP) to negatively contextualized faces, whereas in LSA this effect was found for faces in positive contexts. Also, HSA rated faces in negative contexts as more negative compared to LSA. These results point at enhanced vigilance for neutral faces regardless of context in HSA, while structural encoding seems to be diminished (avoidance). Interestingly, later components of sustained processing (LPP) indicate that LSA show enhanced visuocortical processing for faces in positive contexts (happy bias), whereas this seems to be the case for negatively contextualized faces in HSA (threat bias). Finally, our results add further new evidence that top-down information in interaction with individual anxiety levels can influence early-stage aspects of visual perception.

Revisiting attentional processing of non-emotional cues in social anxiety: A specific impairment for the orienting network of attention

People with social anxiety disorder (SAD) exhibit an attentional bias for threat (AB). Nevertheless, the focus on AB for emotional stimuli has led to neglect the exploration of basic attention deficits for non-emotional material among SAD patients. This study aimed to investigate the integrity of the attentional system in SAD. The Attention Network Test was used to precisely explore attentional deficits, and centrally the differential deficit across the three attentional networks, namely alerting (allowing to achieve and maintain a state of alertness), orienting (allowing to select information from sensory input by engaging or disengaging attention to one stimulus among others and/or shifting the attentional resources from one stimulation to another), and executive control (involving the top-down control of attention and allowing to resolve response conflicts). Twenty-five patients with SAD were compared to 25 matched controls. SAD patients exhibited a specific impairment for the orienting network (p < 0.001) but preserved performance for the alerting and executive networks. Complementary analyses revealed that this impairment may result from a faster attentional engagement to task-irrelevant material. The orienting impairment was highly correlated with the intensity of the social anxiety symptoms, but did not correlate either with trait-anxiety, state-anxiety, or depressive symptoms.

The neural substrates of response inhibition to negative information across explicit and implicit tasks in GAD patients: electrophysiological evidence from an ERP study

Background: It has been established that the inability to inhibit a response to negative stimuli is the genesis of anxiety. However, the neural substrates of response inhibition to sad faces across explicit and implicit tasks in general anxiety disorder (GAD) patients remain unclear.

Methods: Electrophysiological data were recorded when subjects performed two modified emotional go/no-go tasks in which neutral and sad faces were presented: one task was explicit (emotion categorization), and the other task was implicit (gender categorization).

Results: In the explicit task, electrophysiological evidence showed decreased amplitudes of no-go/go difference waves at the N2 interval in the GAD group compared to the control group. However, in the implicit task, the amplitudes of no-go/go difference waves at the N2 interval showed a reversed trend. Source localization analysis on no-go/N2 components revealed a decreased current source density (CSD) in the right dorsal lateral prefrontal cortex in GAD individuals relative to controls. In the implicit task, the left superior temporal gyrus and the left inferior parietal lobe showed enhanced activation in GAD individuals and may compensate for the dysfunction of the right dorsal lateral prefrontal cortex.

Conclusion: These findings indicated that the processing of response inhibition to socially sad faces in GAD individuals was interrupted in the explicit task. However, this processing was preserved in the implicit task. The neural substrates of response inhibition to sad faces were dissociated between implicit and explicit tasks.

Towards a cross-modal perspective of emotional perception in social anxiety: review and future directions

The excessive fear of being negatively evaluated constitutes a central component of social anxiety (SA). Models posit that selective attention to threat and biased interpretations of ambiguous stimuli contribute to the maintenance of this psychopathology. There is strong support for the existence of processing biases but most of the available evidence comes from face research. Emotions are, however, not only conveyed through facial cues, but also through other channels, such as vocal and postural cues. These non-facial cues have yet received much less attention. We therefore plead for a cross-modal investigation of biases in SA. We argue that the inclusion of new modalities may be an efficient research tool to (1) address the specificity or generalizability of these biases; (2) offer an insight into the potential influence of SA on cross-modal processes; (3) operationalize emotional ambiguity by manipulating cross-modal emotional congruency; (4) inform the debate about the role of top-down and bottom-up factors in biasing attention; and (5) probe the cross-modal generalizability of cognitive training. Theoretical and clinical implications as well as potential fruitful avenues for research are discussed.

Subclinical alexithymia modulates early audio-visual perceptive and attentional event-related potentials

INTRODUCTION

Previous studies have highlighted the advantage of using audio-visual oddball tasks (instead of unimodal ones) in order to electrophysiologically index subclinical behavioral differences. Since alexithymia is highly prevalent in the general population, we investigated whether the use of various bimodal tasks could elicit emotional effects in low- vs. high-alexithymic scorers.

METHODS

Fifty students (33 females and 17 males) were split into groups based on low and high scores on the Toronto Alexithymia Scale (TAS-20). During event-related potential (ERP) recordings, they were exposed to three kinds of audio-visual oddball tasks: neutral-AVN-(geometrical forms and bips), animal-AVA-(dog and cock with their respective shouts), or emotional-AVE-(faces and voices) stimuli. In each condition, participants were asked to quickly detect deviant events occurring amongst a train of repeated and frequent matching stimuli (e.g., push a button when a sad face-voice pair appeared amongst a train of neutral face-voice pairs). P100, N100, and P300 components were analyzed: P100 refers to visual perceptive and attentional processing, N100 to auditory ones, and the P300 relates to response-related stages, involving memory processes.

RESULTS

High-alexithymic scorers presented a particular pattern of results when processing the emotional stimulations, reflected in early ERP components by increased P100 and N100 amplitudes in the emotional oddball tasks [P100: F (2, 48) = 20,319, p < 0.001; N100: F (2, 96) = 8,807, p = 0.001] as compared to the animal or neutral ones. Indeed, regarding the P100, subjects exhibited a higher amplitude in the AVE condition (8.717 μV), which was significantly different from that observed during the AVN condition (4.382 μV, p < 0.001). For the N100, the highest amplitude was found in the AVE condition (-4.035 μV) and the lowest was observed in the AVN condition (-2.687 μV, p = 0.003). However, no effect was found on the later P300 component.

CONCLUSIONS

Our findings suggest that high-alexithymic scorers require heightened early attentional resources in comparison to low scorers, particularly when confronted with emotional bimodal stimuli.

More than a face: a unified theoretical perspective on nonverbal social cue processing in social anxiety

Processing of nonverbal social cues (NVSCs) is essential to interpersonal functioning and is particularly relevant to models of social anxiety. This article provides a review of the literature on NVSC processing from the perspective of social rank and affiliation biobehavioral systems (ABSs), based on functional analysis of human sociality. We examine the potential of this framework for integrating cognitive, interpersonal, and evolutionary accounts of social anxiety. We argue that NVSCs are uniquely suited to rapid and effective conveyance of emotional, motivational, and trait information and that various channels are differentially effective in transmitting such information. First, we review studies on perception of NVSCs through face, voice, and body. We begin with studies that utilized information processing or imaging paradigms to assess NVSC perception. This research demonstrated that social anxiety is associated with biased attention to, and interpretation of, emotional facial expressions (EFEs) and emotional prosody. Findings regarding body and posture remain scarce. Next, we review studies on NVSC expression, which pinpointed links between social anxiety and disturbances in eye gaze, facial expressivity, and vocal properties of spontaneous and planned speech. Again, links between social anxiety and posture were understudied. Although cognitive, interpersonal, and evolutionary theories have described different pathways to social anxiety, all three models focus on interrelations among cognition, subjective experience, and social behavior. NVSC processing and production comprise the juncture where these theories intersect. In light of the conceptualizations emerging from the review, we highlight several directions for future research including focus on NVSCs as indexing reactions to changes in belongingness and social rank, the moderating role of gender, and the therapeutic opportunities offered by embodied cognition to treat social anxiety.

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.

Fear of negative evaluation and attentional bias for facial expressions: an event-related study

Numerous studies have shown an exacerbation of attentional bias towards threat in anxiety states. However, the cognitive mechanisms responsible for these attentional biases remain largely unknown. Further, the authors outline the need to consider the nature of the attentional processes in operation (hypervigilance, avoidance, or disengagement). We adapted a dot-probe paradigm to record behavioral and electrophysiological responses in 26 participants reporting high or low fear of evaluation, a major component of social anxiety. Pairs of faces including a neutral and an emotional face (displaying anger, fear, disgust, or happiness) were presented during 200 ms and then replaced by a neutral target to discriminate. Results show that anxious participants were characterized by an increased P1 in response to pairs of faces, irrespective of the emotional expression included in the pair. They also showed an increased P2 in response to angry-neutral pairs selectively. Finally, in anxious participants, the P1 response to targets was enhanced when replacing emotional faces, whereas non-anxious subjects showed no difference between the two conditions. These results indicate an early hypervigilance to face stimuli in social anxiety, coupled with difficulty in disengaging from threat and sustained attention to emotional stimuli. They are discussed within the framework of current models of anxiety and psychopathology.