Effects of task demands on the early neural processing of fearful and happy facial expressions

Does outcome feedback similarly impact the processing of surprised faces in competitive and cooperative contexts? Evidence from ERP

Competition and cooperation are pervasive across diverse domains of human society, and outcome feedback in these contexts has been shown to significantly influence human emotional responses and behavioral strategies. However, there is limited understanding of the mechanisms through which outcome feedback in obstructive and supportive settings affects the perception of facial expressions of interactors. To address this issue, thirty-seven participants in this event-related potential (ERP) study completed a modified version of the Tetris game with randomly assigned interactors (cooperative supporter, competitive hinderer). After receiving outcome feedback (correct, incorrect), participants were asked to rate the valence of surprised faces which were assumed to be displayed by interactors. Behaviorally, surprised faces in supportive correct feedback contexts were rated as more pleasant, while those in obstructive correct feedback contexts were rated as less pleasant. The ERP results showed a significant main effect of outcome feedback on the FRN and LPPfeedback, with enhanced amplitudes for incorrect relative to correct trials. More importantly, face-related P1, N170, and EPN components showed significant interactions between interaction type and outcome feedback. Surprised faces in obstructive correct contexts evoked larger P1 amplitudes compared to those faces in obstructive incorrect contexts. Conversely, amplified N170 and EPN responses were observed for faces in supportive correct contexts compared to those in supportive incorrect contexts. For the LPPface, an amplified response to faces was observed in correct feedback contexts compared to incorrect ones, irrespective of the influence of interaction type. Altogether, these findings offer the first empirical evidence that feedback cues in obstructive and supportive contexts can interactively influence the top-down processing of facial expressions, shifting attention away from the suppression of aversive stimuli towards a focus on self-related positive information, thus providing insights into the neurocognitive mechanisms underlying the impact of complex social information on higher-order cognitive processes.

How psychological and descriptive narratives modulate the perception of facial emotional expressions: an event-related potentials (ERPs) study

The aim of the present study was to investigate whether stories with high and low narrative transport exert different effects on neural activation in response to facial emotional expressions. Thirty-one participants were randomly assigned to two groups based on the type of story they read: psychological narrative with high narrative transport (6 women and 10 men; age M = 34.38 ± 8.77); descriptive narrative with low narrative transport (9 women and 6 men; age M = 24.07 ± 7.38). The electroencephalographic activity of the participants in response to emotional facial expressions (joy, anger, fear, sadness) was recorded before (T0) and after (T1) the reading task. The findings indicated that the reading task modulated the early brain response (P1, N170) to emotional facial expressions, irrespective of the narrative type. However, only in the psychological narrative group was the amplitude of the P100 found to be positively associated with the extent to which an individual was transported into the narrative. In summary, the findings appear to indicate that an increased degree of transport into the narrative is associated with a greater internal simulation process of emotions and mental states. This, in turn, modulates the perception of the real social world after reading.

Neurophysiological evidence for emotional attention modulation depending on goal relevance

Although threat-related stimuli can capture attention automatically, recent findings have challenged this assumption by showing that goal rather than threat can be prioritized and eventually guide attentional control. In this study, we used high density electroencephalography (EEG) in 40 participants while peripheral emotional faces (either fear or happiness) were either goal-relevant or irrelevant during a dot-probe task (DPT). The use of peripheral vision was established by eye-tracking. Both the face specific N170 component and the subsequent Early Posterior Negativity (EPN) were enhanced by fear at the cue level, yet the latter one only when fear was goal relevant. Importantly, we found that early on following target onset at the P1 level, both value and goal relevance drove spatial attention and interacted with each other such that when they were goal-relevant, fearful faces captured attention less than when they were not. These results suggest that emotional attention is flexible and it can be influenced by the goal relevance of emotion. Moreover, they shed light on the electrophysiological manifestations of this flexibility and dovetail with the assumption that sensory gain control effects occurring in the visual cortex depending on attentional control are multiplexed and determined by both value and goal.

Happy and angry facial expressions are processed independently of task demands and semantic context congruency in the first stages of vision - A mass univariate ERP analysis

Neural decoding of others' facial expressions is critical in social interactions and has been investigated using scalp event related potentials (ERPs). However, the impact of task and emotional context congruency on this neural decoding is unclear. Previous ERP studies employed classic statistical analyses that only focused on specific electrodes and time points, which inflates type I and type II errors. The present study re-analyzed the study by Aguado et al. (2019) using robust data-driven Mass Univariate Statistics across every time point and electrode and rejected trials with early reaction times to rule out motor-related activity on neural recordings. Participants viewed neutral faces paired with negative or positive situational sentences (e.g. "She catches her partner cheating on her with her best friend"), followed by the same individuals' faces expressing happiness or anger, such that the facial expressions were congruent or incongruent with the situation. Participants engaged in two tasks: an emotion discrimination task, and a situation-expression congruency discrimination task. We found significant effects of expression largest during the N170-P2 interval, and effects of congruency and task around an LPP-like component. However, the effect of congruency was significant only in the congruency task, suggesting a limited and task-dependant influence of semantic context. Importantly, emotion did not interact with any factor neurally, suggesting facial expressions were decoded automatically during the first 400 ms of vision, regardless of context congruency or task demands. The results and their discrepancies with the original findings are discussed in the context of ERP statistics and the replication crisis.

Event-Related Potentials to Facial Expressions Are Related to Stimulus-Level Perceived Arousal and Valence

Facial expressions provide critical details about social partners' inner states. We investigated whether event-related potentials (ERP) related to the visual processing of facial expressions are modulated by participants' perceived arousal and valence at the stimulus level. ERPs were recorded while participants (N = 80) categorized the gender of faces expressing fear, anger, happiness, and no emotion. Participants then viewed each face again and rated them on arousal and valence using 1-9 Likert scales. For each participant, ratings of each unique face were linked back to corresponding ERP trials. ERPs were analyzed at all time points and electrodes using hierarchical mass univariate statistics. Three different ANOVA models were employed: the original emotion model, and models with valence or arousal ratings as trial-level regressors. Results from models with ratings highly overlapped with the original model, although they were more temporally restricted. The N170 component was the most impacted by arousal and valence ratings, with four out of six emotion contrasts revealing significant valence or arousal interactions. Emotion effects on the P2 component were mostly unrelated to ratings. On the EPN component, only two contrasts related to both arousal and valence ratings. Thus, ERP emotion effects are related to participants' perceived arousal and valence of the stimuli, although this association depends on the contrast analyzed. These findings, their limitations, and generalizability are discussed in reference to existing theories and literature.

Perceiving emotions in the eyes: The biasing role of a fearful mouth

The role of the eye region in interpersonal communication and emotional recognition is widely acknowledged. However, the influence of mouth expression on perceiving and recognizing genuine emotions in the eye region, especially with limited attentional resources, remains unclear. Thirty-four participants in this study completed a dual-target rapid serial visual presentation (RSVP) task while their event-related potential (ERP) data were simultaneously recorded. They were instructed to identify the type of houses and the emotional expression displayed in the eye region. The first target (T1) consisted of three upright houses, and the second target (T2) included fearful and neutral normal faces, mouth-scrambled faces, as well as composite faces (fearful eye + neutral mouth, neutral eye + fearful mouth). A robust mass univariate statistics approach was utilized to analyze the EEG data. Behaviorally, the presence of a fearful mouth facilitated recognition of the fearful eye region but hindered recognition of the neutral eye region compared to a neutral mouth. The ERP results showed that fearful expressions elicited larger N170, early posterior negativity (EPN), and P3 amplitudes relative to neutral expressions. The P1 amplitudes were increased, whereas the N170 and EPN amplitudes were reduced in response to normal and composite faces compared to mouth-scrambled faces. Collectively, these findings indicate that an unattended fearful mouth can capture covert attention and shape evaluation of eye expressions within a face, providing novel insights into the impact of visually salient mouth cues on cognitive processes involved in mind reading.

Emotional Evaluations from Partners and Opponents Differentially Influence the Perception of Ambiguous Faces

The influence of contextual valence and interpersonal distance on facial expression perception remains unclear despite their significant role in shaping social perceptions. In this event-related potential (ERP) study, we investigated the temporal dynamics underlying the processing of surprised faces across different interpersonal distances (partner, opponent, or stranger) and contextual valence (positive, neutral, or negative) contexts. Thirty-five participants rated the valence of surprised faces. An advanced mass univariate statistical approach was utilized to analyze the ERP data. Behaviorally, surprised faces in partner-related negative contexts were rated more negatively than those in opponent- and stranger-related contexts. The ERP results revealed an increased P1 amplitude for surprised faces in negative relative to neutral contexts. Both the early posterior negativity (EPN) and late positive potentials (LPP) were also modulated by contextual valence, with larger amplitudes for faces in positive relative to neutral and negative contexts. Additionally, when compared to stranger-related contexts, faces in partner-related contexts exhibited enhanced P1 and EPN responses, while those in opponent-related contexts showed amplified LPP responses. Taken together, these findings elucidate the modulation of intricate social contexts on the perception and interpretation of ambiguous facial expressions, thereby enhancing our understanding of nonverbal communication and emotional cognition.

Predictability modulates the early neural coding of spatially unattended fearful faces

In this study, we assessed whether predictability affected the early processing of facial expressions. To achieve this, we measured lateralised early- and mid-latency event-related potentials associated with visual processing. Twenty-two participants were shown pairs of bilaterally presented fearful, happy, angry, or scrambled faces. Participants were required to identify angry faces on a spatially attended side whilst ignoring happy, fearful, and scrambled faces. Each block began with the word HAPPY or FEARFUL which informed participants the probability at which these faces would appear. Attention effects were found for the lateralised P1, suggesting that emotions do not modulate the P1 differentially, nor do predictions relating to emotions. Pairwise comparisons demonstrated that, when spatially unattended, unpredicted fearful faces produced larger lateralised N170 amplitudes compared to predicted fearful faces and unpredicted happy faces. Finally, attention towards faces increased lateralised EPN amplitudes, as did both fearful expressions and low predictability. Thus, we demonstrate that the N170 and EPN are sensitive to top-down predictions relating to facial expressions and that low predictability appears to specifically affect the early encoding of fearful faces when unattended, possibly to initiate attentional capture.

Is processing superiority a universal trait for all threats? Divergent impacts of fearful, angry, and disgusted faces on attentional capture

Fearful, angry, and disgusted facial expressions are evolutionarily salient and convey different types of threat signals. However, it remains unclear whether these three expressions impact sensory perception and attention in the same way. The present ERP study investigated the temporal dynamics underlying the processing of different types of threatening faces and the impact of attentional resources employed during a perceptual load task. Participants were asked to judge the length of bars superimposed over faces presented in the center of the screen. A mass univariate statistical approach was used to analyze the EEG data. Behaviorally, task accuracy was significantly reduced following exposure to fearful faces relative to neutral distractors, independent of perceptual load. The ERP results revealed that the P1 amplitude over the right hemisphere was found to be enhanced for fearful relative to disgusted faces, reflecting the rapid and coarse detection of fearful cues. The N170 responses elicited by fearful, angry, and disgusted faces were larger than those elicited by neutral faces, suggesting the largely automatic and preferential processing of threats. Furthermore, the early posterior negativity (EPN) component yielded increased responses to fearful and angry faces, indicating prioritized attention to stimuli representing acute threats. Additionally, perceptual load exerted a pronounced influence on the EPN and late positive potential (LPP), with larger responses observed in the low perceptual load condition, indicating goal-directed cognitive processing. Overall, the early sensory processing of fearful, angry, and disgusted faces is characterized by differential sensitivity in capturing attention automatically, despite the importance of these facial signals for survival. Fearful faces produce a strong interference effect and are processed with higher priority than angry and disgusted ones.

Mass-univariate analysis of scalp ERPs reveals large effects of gaze fixation location during face processing that only weakly interact with face emotional expression

Decoding others' facial expressions is critical for social functioning. To clarify the neural correlates of expression perception depending on where we look on the face, three combined gaze-contingent ERP experiments were analyzed using robust mass-univariate statistics. Regardless of task, fixation location impacted face processing from 50 to 350 ms, maximally around 120 ms, reflecting retinotopic mapping around C2 and P1 components. Fixation location also impacted majorly the N170-P2 interval while weak effects were seen at the face-sensitive N170 peak. Results question the widespread assumption that faces are processed holistically into an indecomposable perceptual whole around the N170. Rather, face processing is a complex and view-dependent process that continues well beyond the N170. Expression and fixation location interacted weakly during the P1-N170 interval, supporting a role for the mouth and left eye in fearful and happy expression decoding. Expression effects were weakest at the N170 peak but strongest around P2, especially for fear, reflecting task-independent affective processing. Results suggest N170 reflects a transition between processes rather than the maximum of a holistic face processing stage. Focus on this peak should be replaced by data-driven analyses of the epoch using robust statistics to fully unravel the early visual processing of faces and their affective content.

Beyond facial expressions: A systematic review on effects of emotional relevance of faces on the N170

The N170 is the most prominent electrophysiological signature of face processing. While facial expressions reliably modulate the N170, there is considerable variance in N170 modulations by other sources of emotional relevance. Therefore, we systematically review and discuss this research area using different methods to manipulate the emotional relevance of inherently neutral faces. These methods were categorized into (1) existing pre-experimental affective person knowledge (e.g., negative attitudes towards outgroup faces), (2) experimentally instructed affective person knowledge (e.g., negative person information), (3) contingency-based affective learning (e.g., fear-conditioning), or (4) the immediate affective context (e.g., emotional information directly preceding the face presentation). For all categories except the immediate affective context category, the majority of studies reported significantly increased N170 amplitudes depending on the emotional relevance of faces. Furthermore, the potentiated N170 was observed across different attention conditions, supporting the role of the emotional relevance of faces on the early prioritized processing of configural facial information, regardless of low-level differences. However, we identified several open research questions and suggest venues for further research.

The influence of selective attention to specific emotions on the processing of faces as revealed by event-related brain potentials

Event-related potential studies using affective words have indicated that selective attention to valence can increase affective discrimination at early perceptual stages. This effect most likely relies on neural associations between perceptual features of a stimulus and its affective value. Similar to words, emotional expressions in human faces are linked to specific visual elements. Therefore, selectively attending to a given emotion should allow for the preactivation of neural networks coding for the emotion and associated first-order visual elements, leading to enhanced early processing of faces expressing the attended emotion. To investigate this, we employed an expression detection task (N = 65). Fearful, happy, and neutral faces were randomly presented in three blocks while participants were instructed to respond only to one predefined target level of expression in each block. Reaction times were the fastest for happy target faces, which was accompanied by an increased occipital P1 for happy compared with fearful faces. The N170 yielded an arousal effect (emotional > neutral) while both components were not modulated by target status. In contrast, the early posterior negativity (EPN) arousal effect tended to be larger for target compared with nontarget faces. The late positive potential (LPP) revealed large effects of status and expression as well as an interaction driven by an increased LPP specifically for nontarget fearful faces. These findings tentatively indicate that selective attention to facial affect may enhance early emotional processing (EPN) even though further research is needed. Moreover, late controlled processing of facial emotions appears to involve a negativity bias.

Motivated attention and task relevance in the processing of cross-modally associated faces: Behavioral and electrophysiological evidence

It has repeatedly been shown that visually presented stimuli can gain additional relevance by their association with affective stimuli. Studies have shown effects of associated affect in event-related potentials (ERP) like the early posterior negativity (EPN), late positive complex (LPC), and even earlier components as the P1 or N170. However, findings are mixed as to the extent associated affect requires directed attention to the emotional quality of a stimulus and which ERP components are sensitive to task instructions during retrieval. In this preregistered study ( https://osf.io/ts4pb ), we tested cross-modal associations of vocal affect-bursts (positive, negative, neutral) to faces displaying neutral expressions in a flash-card-like learning task, in which participants studied face-voice pairs and learned to correctly assign them to each other. In the subsequent EEG test session, we applied both an implicit ("old-new") and explicit ("valence-classification") task to investigate whether the behavior at retrieval and neurophysiological activation of the affect-based associations were dependent on the type of motivated attention. We collected behavioral and neurophysiological data from 40 participants who reached the preregistered learning criterium. Results showed EPN effects of associated negative valence after learning and independent of the task. In contrast, modulations of later stages (LPC) by positive and negative associated valence were restricted to the explicit, i.e., valence-classification, task. These findings highlight the importance of the task at different processing stages and show that cross-modal affect can successfully be associated to faces.

Reduced attentional inhibition for peripheral distractors of angry faces under central perceptual load in deaf individuals: evidence from an event-related potentials study

Background

Studies have shown that deaf individuals distribute more attention to the peripheral visual field and exhibit enhanced visual processing for peripheral stimuli relative to hearing individuals. This leads to better detection of peripheral target motion and simple static stimuli in hearing individuals. However, when threatening faces that represent dangerous signals appear as non-targets in the periphery, it remains unclear whether deaf individuals would retain an advantage over hearing individuals in detecting them.

Methods

In this study, 23 deaf and 28 hearing college students were included. A modified perceptual load paradigm and event-related potentials (ERPs) were adopted. In the task, participants were instructed to search for a target letter in a central letter array, while task-irrelevant face distractors (happy, neutral, and angry faces) were simultaneously presented in the periphery while the central perceptual load was manipulated.

Results

Behavioral data showed that angry faces slowed deaf participants' responses to the target while facilitating the responses of hearing participants. At the electrophysiological level, we found modulation of P1 amplitude by central load only in hearing individuals. Interestingly, larger interference from angry face distractors was associated with higher P1 differential amplitude only in deaf individuals. Additionally, the amplitude of N170 for happy face distractors was smaller than that for angry and neutral face distractors in deaf participants.

Conclusion

The present data demonstrates that, despite being under central perceptual load, deaf individuals exhibit less attentional inhibition to peripheral, goal-irrelevant angry faces than hearing individuals. The result may reflect a compensatory mechanism in which, in the absence of auditory alertness to danger, the detection of visually threatening information outside of the current attentional focus has a high priority.

Fixation-related electrical potentials during a free visual search task reveal the timing of visual awareness

It has been repeatedly claimed that emotional faces readily capture attention, and that they may be processed without awareness. Yet some observations cast doubt on these assertions. Part of the problem may lie in the experimental paradigms employed. Here, we used a free viewing visual search task during electroencephalographic recordings, where participants searched for either fearful or neutral facial expressions among distractor expressions. Fixation-related potentials were computed for fearful and neutral targets and the response compared for stimuli consciously reported or not. We showed that awareness was associated with an electrophysiological negativity starting at around 110 ms, while emotional expressions were distinguished on the N170 and early posterior negativity only when stimuli were consciously reported. These results suggest that during unconstrained visual search, the earliest electrical correlate of awareness may emerge as early as 110 ms, and fixating at an emotional face without reporting it may not produce any unconscious processing.

EEG alpha band functional connectivity reveals distinct cortical dynamics for overt and covert emotional face processing

Current knowledge regarding how the focus of our attention during face processing influences neural responses largely comes from neuroimaging studies reporting on regional brain activations. The present study was designed to add novel insights to this research by studying how attention can differentially impact the way cortical regions interact during emotional face processing. High-density electroencephalogram was recorded in a sample of fifty-two healthy participants during an emotional face processing task. The task required participants to either attend to the expressions (i.e., overt processing) or attend to a perceptual distractor, which rendered the expressions task-irrelevant (i.e., covert processing). Functional connectivity in the alpha band was estimated in source space and modeled using graph theory to quantify whole-brain integration and segregation. Results revealed that overt processing of facial expressions is linked to reduced cortical segregation and increased cortical integration, this latter specifically for negative expressions of fear and sadness. Furthermore, we observed increased communication efficiency during overt processing of negative expressions between the core and the extended face processing systems. Overall, these findings reveal that attention makes the interaction among the nodes involved in face processing more efficient, also uncovering a connectivity signature of the prioritized processing mechanism of negative expressions, that is an increased cross-communication within the nodes of the face processing network.

The impact of emotional facial expressions on reflexive attention depends on the aim of dynamic gaze changes: An ERP study

The emotional expression and gaze direction of a face are important cues for human social interactions. However, the interplay of these factors and their neural correlates are only partially understood. In the current study, we investigated ERP correlates of gaze and emotion processing following the initial presentation of faces with different emotional expressions (happy, neutral, angry) and an averted or direct gaze direction as well as following a subsequent change in gaze direction that occurred in half of the trials. We focused on the time course and scalp topography of the N170 and EPN components. The N170 amplitude was larger to averted than direct gaze for the initial face presentation and larger to gaze changes from direct to averted than from averted to direct in response to the gaze change. For the EPN component in response to the initial face presentation, we replicate classic effects of emotion, which did not interact with gaze direction. As a major new finding, changes from direct to averted gaze elicited an EPN-like effect when the face showed a happy expression. No such effect was seen for angry expressions. We conclude that happy faces reflexively attract attention when they look at the observer rather than away from the observer. These results for happy expressions are in line with the shared signal hypothesis that posits a better processing of expressions if their approach or avoidance tendency is consistent with gaze direction. However, the shared signal hypothesis is not supported by the present results for angry faces.

Potentiated early neural responses to fearful faces are not driven by specific face parts

Prioritized processing of fearful compared to neutral faces is reflected in increased amplitudes of components of the event-related potential (ERP). It is unknown whether specific face parts drive these modulations. Here, we investigated the contributions of face parts on ERPs to task-irrelevant fearful and neutral faces using an ERP-dependent facial decoding technique and a large sample of participants (N = 83). Classical ERP analyses showed typical and robust increases of N170 and EPN amplitudes by fearful relative to neutral faces. Facial decoding further showed that the absolute amplitude of these components, as well as the P1, was driven by the low-frequency contrast of specific face parts. However, the difference between fearful and neutral faces was not driven by any specific face part, as supported by Bayesian statistics. Furthermore, there were no correlations between trait anxiety and main effects or interactions. These results suggest that increased N170 and EPN amplitudes to task-irrelevant fearful compared to neutral faces are not driven by specific facial regions but represent a holistic face processing effect.

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.

Testing stimulus exposure time as the critical factor of increased EPN and LPP amplitudes for fearful faces during perceptual distraction tasks

Fearful facial expressions are prioritized across different information processing stages, as evident in early, intermediate, and late components of event-related brain potentials (ERPs). Recent studies showed that, in contrast to early N170 modulations, mid-latency (Early Posterior Negativity, EPN) and late (Late Positive Potential, LPP) emotional modulations depend on the attended perceptual feature. Nevertheless, several studies reported significant differences between emotional and neutral faces for the EPN or LPP components during distraction tasks. One cause for these conflicting findings might be that when faces are presented sufficiently long, participants attend to task-irrelevant features of the faces. In this registered report, we tested whether the presentation duration of faces is the critical factor for differences between reported emotional modulations during perceptual distraction tasks. To this end, 48 participants were required to discriminate the orientation of lines overlaid onto fearful or neutral faces, while face presentation varied (100 msec, 300 msec, 1,000 msec, 2,000 msec). While participants did not need to pay attention to the faces, we observed main effects of emotion for the EPN and LPP, but no interaction between emotion and presentation duration. Of note, unregistered exploratory tests per presentation duration showed no significant EPN and LPP emotion differences during short durations (100 and 300 msec) but significant differences with longer durations. While the presentation duration seems not to be a critical factor for EPN and LPP emotion effects, future studies are needed to investigate the role of threshold effects and the applied analytic designs to explain conflicting findings in the literature.

Function without feeling: neural reactivity and intercommunication during flexible motor adjustments evoked by emotional and neutral stimuli

Motor conflicts arise when we need to quickly overwrite prepotent behavior. It has been proposed that affective stimuli modulate the neural processing of motor conflicts. However, previous studies have come to inconsistent conclusions regarding the neural impact of affective information on conflict processing. We employed functional magnetic resonance imaging during a Go/Change-Go task, where motor conflicts were either evoked by neutral or emotionally negative stimuli. Dynamic causal modeling was used to investigate how motor conflicts modulate the intercommunication between the anterior cingulate cortex (ACC) and the anterior insula (AI) as 2 central regions for cognitive control. Conflicts compared to standard actions were associated with increased BOLD activation in several brain areas, including the dorsal ACC and anterior insula. There were no differences in neural activity between emotional and non-emotional conflict stimuli. Conflicts compared to standard actions lowered neural self-inhibition of the ACC and AI and led to increased effective connectivity from the ACC to AI contralateral to the acting hand. Thus, our study indicates that neural conflict processing is primarily driven by the functional relevance of action-related stimuli, not their inherent affective meaning. Furthermore, it sheds light on the role of interconnectivity between ACC and AI for the implementation of flexible behavioral change.

Predictability modulates neural response to eye contact in ASD

BACKGROUND

Deficits in establishing and maintaining eye-contact are early and persistent vulnerabilities of autism spectrum disorder (ASD), and the neural bases of these deficits remain elusive. A promising hypothesis is that social features of autism may reflect difficulties in making predictions about the social world under conditions of uncertainty. However, no research in ASD has examined how predictability impacts the neural processing of eye-contact in naturalistic interpersonal interactions.

METHOD

We used eye tracking to facilitate an interactive social simulation wherein onscreen faces would establish eye-contact when the participant looked at them. In Experiment One, receipt of eye-contact was unpredictable; in Experiment Two, receipt of eye-contact was predictable. Neural response to eye-contact was measured via the N170 and P300 event-related potentials (ERPs). Experiment One included 23 ASD and 46 typically developing (TD) adult participants. Experiment Two included 25 ASD and 43 TD adult participants.

RESULTS

When receipt of eye-contact was unpredictable, individuals with ASD showed increased N170 and increased, but non-specific, P300 responses. The magnitude of the N170 responses correlated with measures of sensory and anxiety symptomology, such that increased response to eye-contact was associated with increased symptomology. However, when receipt of eye-contact was predictable, individuals with ASD, relative to controls, exhibited slower N170s and no differences in the amplitude of N170 or P300.

LIMITATIONS

Our ASD sample was composed of adults with IQ > 70 and included only four autistic women. Thus, further research is needed to evaluate how these results generalize across the spectrum of age, sex, and cognitive ability. Additionally, as analyses were exploratory, some findings failed to survive false-discovery rate adjustment.

CONCLUSIONS

Neural response to eye-contact in ASD ranged from attenuated to hypersensitive depending on the predictability of the social context. These findings suggest that the vulnerabilities in eye-contact during social interactions in ASD may arise from differences in anticipation and expectation of eye-contact in addition to the perception of gaze alone.

Spatiotemporal Dynamics of Covert vs. Overt Emotional Face Processing in Dysphoria

People at risk of developing clinical depression exhibit attentional biases for emotional faces. To clarify whether such effects occur at an early, automatic, or at a late, deliberate processing stage of emotional processing, the present study used high-density electroencephalography during both covert and overt processing of sad, fearful, happy, and neutral expressions in healthy participants with high dysphoria (n = 16) and with low dysphoria (n = 19). A state-of-the-art non-parametric permutation-based statistical approach was then used to explore the effects of emotion, attentional task demands, and group. Behaviorally, participants responded faster and more accurately when overtly categorizing happy faces and they were slower and less accurate when categorizing sad and fearful faces, independent of the dysphoria group. Electrophysiologically, in an early time-window (N170: 140-180 ms), there was a significant main effect for the dysphoria group, with greater negative voltage for the high vs. low dysphoria group over the left-sided temporo-occipital scalp. Furthermore, there was a significant group by emotional interaction, with the high dysphoria group displaying greater negative amplitude N170 for happy than fearful faces. Attentional task demands did not influence such early effects. In contrast, in an intermediate time-window (EPN: 200-400 ms) and in a late time-window (LPP: 500-750 ms) there were no significant main effects nor interactions involving the dysphoria Group. The LPP results paralleled the behavioral results, with greater LPP voltages for sad and fearful relative to happy faces only in the overt task, but similarly so in the two dysphoria groups. This study provides novel evidence that alterations in face processing in dysphoric individuals can be seen at the early stages of face perception, as indexed by the N170, although not in the form of a typical pattern of mood-congruent attentional bias. In contrast, intermediate (EPN) and late (LPP) stages of emotional face processing appear unaffected by dysphoria. Importantly, the early dysphoria effect appears to be independent of the top-down allocation of attention, further supporting the idea that dysphoria may influence a stage of automatic emotional appraisal. It is proposed that it may be a consequence of a shift from holistic to feature-based processing of facial expressions, or may be due to the influence of negative schemas acting as a negative context for emotional facial processing.

Effects of task load, spatial attention, and trait anxiety on neuronal responses to fearful and neutral faces

There is an ongoing debate on how different components of the event-related potential (ERP) to threat-related facial expressions are modulated by attentional conditions and interindividual differences in trait anxiety. In the current study (N = 80), we examined ERPs to centrally presented, task-irrelevant fearful and neutral faces, while participants had to solve a face-unrelated visual task, which differed in difficulty and spatial position. Critically, we used a fixation-controlled experimental design and ensured the spatial attention manipulation by spectral analysis of the EEG. Besides the factors emotion, spatial attention, and perceptual load, we also investigated correlations between trait anxiety and ERPs. While P1 emotion effects were insignificant, the N170 was increased to fearful faces regardless of load and spatial attention conditions. During the EPN time window, a significantly increased negativity for fearful faces was observed only during low load and spatial attention to the face. We found no significant relationship between ERPs and trait anxiety, questioning the hypothesis of a general hypersensitivity toward fearful expressions in anxious individuals. These results show a high resistance of the N170 amplitude increase for fearful faces to spatial attention and task load manipulations. By contrast, the EPN modulation by fearful faces index a resource-dependent stage of the ERP, requiring both spatial attention at the location of faces and low load of the face-irrelevant task.

Attention to affect 2.0: Multiple effects of emotion and attention on event-related potentials of visual word processing in a valence-detection task

Here we continue recent work on the specific mental processes engaged in a valence-detection task. Fifty-seven participants responded to one predefined target level of valence (negative, neutral, or positive), and ignored the remaining two levels. This enables more precise fine-tuning of neuronal pathways, compared to valence categorization where attention is divided between different levels of valence. Our group recently used valence detection with emotional words. Posterior P1 and N170 effects in the event-related potential (ERP) supported the idea of valent word forms that can be tuned by selective attention to valence. Here we report findings on three distinct posterior N2 components, P300, N400, and the late positive potential (LPP). Target but not nontarget words showed an arousal effect (emotional > neutral) on left-side early posterior negativity (180-280 ms). In contrast, an arousal effect on a sharp N2 deflection in left-minus-right difference ERPs (230-270 ms), suggesting facilitation of lexical access for emotional words, was independent of target status. This also applied to increased medial parieto-occipital N2 (260-300 ms) specific to negative words, indicating attentional capture. Medial-central N400 was specifically enhanced for negative nontarget words, further supporting attentional capture. The typical LPP arousal effect was observed, being stronger and more left-lateralized in target words. An exploratory finding concerned a broad component-overarching ERP valence effect (250-650 ms). Independent of target status, ERPs were more positive for positive than negative words. Combined with our previous results, data suggest multiple loci of emotion-attention interactions in valence detection.

Shared Attention Amplifies the Neural Processing of Emotional Faces

Sharing an experience, without communicating, affects people's subjective perception of the experience, often by intensifying it. We investigated the neural mechanisms underlying shared attention by implementing an EEG study where participants attended to and rated the intensity of emotional faces, simultaneously or independently. Participants performed the task in three experimental conditions: (a) alone; (b) simultaneously next to each other in pairs, without receiving feedback of the other's responses (shared without feedback); and (c) simultaneously while receiving the feedback (shared with feedback). We focused on two face-sensitive ERP components: The amplitude of the N170 was greater in the "shared with feedback" condition compared to the alone condition, reflecting a top-down effect of shared attention on the structural encoding of faces, whereas the EPN was greater in both shared context conditions compared to the alone condition, reflecting an enhanced attention allocation in the processing of emotional content of faces, modulated by the social context. Taken together, these results suggest that shared attention amplifies the neural processing of faces, regardless of the valence of facial expressions.

Enhanced early ERP responses to looming angry faces

Although the brain is known to process threatening emotional stimuli and looming motion rapidly, little is known about how the emotion and motion interact. To address this question, two experiments were carried out which presented angry and neutral emotional faces on a depth-cued background that induced the perception of distance, or a non-cued background. Furthermore, faces either expanded or contracted in size such that they appeared to approach or recede from the viewer. EEG/ERP measures were used to identify the time course of brain activity for these looming and receding, angry and neutral emotional faces. The results of both experiments revealed that the P1 was enhanced by looming angry faces on the depth-cued background, compared to neutral approaching faces, as well as all receding faces, indicating an early interaction of emotion and motion within 100 ms of presentation. Angry expressions were also found to enhance the N170 regardless of movement. These findings suggest that processing of threat and looming motion interact at the very early stages of visual processing. Furthermore, as the modulating effect of looming motion on angry expressions only arose on the depth-cued background, the findings highlight the importance of approaching movements rather than sole increases in the retinal size of the stimuli.

The Effect of Task on Object Processing revealed by EEG decoding

Recent studies showed that task demand affects object representations in higher-level visual areas and beyond, but not so much in earlier areas. There are, however, limitations in those studies including the relatively weak manipulation of task due to the use of familiar real-life objects, the low temporal resolution in fMRI, and the emphasis on the amount and not the source of information carried by brain activations. In the current study, observers categorized images of artificial objects in one of two orthogonal dimensions, shape and texture, while their brain activity was recorded with electroencephalogram (EEG). Results showed that object processing along the texture dimension was affected by task demand starting from a relatively late time (320-370ms time window) after image onset. The findings are consistent with the view that task exerts an effect on the later phases of object processing.

The effect of fearful faces on the attentional blink is modulated by emotional task relevance: An event-related potential study

A fearful face as second visual target (T2) was detected better than a neutral T2 in a Rapid Serial Visual Presentation (RSVP) task. The advantage of fear over neutral emotion was originally attributed to a limited-capacity mechanism, in which fearful stimuli are prioritized for attention over neutral stimuli. However, more recent studies have shown that the prioritization of the processing of fear is strongly dependent on the emotional task relevance. Combining the RSVP task and Garner's paradigm, by varying the expression (fearful and neutral faces) and the emotional task relevance of the T2 (relevance: emotion classification task; irrelevance: gender classification task), this study aims to investigate the role of emotional task relevance on the advantage of fear during an RSVP task in which participants have to identify two visual targets in a stream of distractors. The behavioral results revealed that there was no significant effect of the expression on the task performance in the gender classification task. Fearful faces were easier to detect than neutral faces, but the T2 accuracy of fearful faces was lower than that of neutral faces in the emotion classification task. Furthermore, we found that the vertex positive potential and P100 components were enhanced for fearful faces compared to neutral faces independent of the emotional task relevance. For the P300 component, there was no significant difference in the gender classification task, but fearful faces elicited enhanced P300 amplitudes compared to neutral faces in the emotion classification task. These results indicated that the early processing of fear is automatic, while the late processing of fear is dependent on the emotional task relevance under limited attentional resources.

Early ERP functions are indexed by lateralized effects to peripherally presented emotional faces and scrambles

A large body of research suggests that early event-related potentials (ERPs), such as the P1 and N1, are potentiated by attention and represent stimulus amplification. However, recent accounts suggest that the P1 is associated with inhibiting the irrelevant visual field evidenced by a pronounced ipsilateral P1 during sustained attention to peripherally presented stimuli. The current EEG study further investigated this issue to reveal how lateralized ERP findings are modulated by face and emotional information. Therefore, participants were asked to fixate the center of the screen and pay sustained attention either to the right or left visual field, where angry or neutral faces or their Fourier phase-scrambled versions were presented. We found a bilateral P1 to all stimuli with relatively increased, but delayed, ipsilateral P1 amplitudes to faces but not to scrambles. Explorative independent component analyses dissociated an earlier lateralized larger contralateral P1 from a later bilateral P1. By contrast, the N170 showed a contralateral enhancement to all stimuli, which was most pronounced for neutral faces attended in the left hemifield. Finally, increased contralateral alpha power was found for both attended hemifields but was not significantly related to poststimulus ERPs. These results provide evidence against a general inhibitory role of the P1 but suggest stimulus-specific relative enhancements of the ipsilateral P1 for the irrelevant visual hemifield. The lateralized N170, however, is associated with stimulus amplification as a function of facial features.

Emotion, Gender and Gaze Discrimination Tasks do not Differentially Impact the Neural Processing of Angry or Happy Facial Expressions-a Mass Univariate ERP Analysis

Facial expression processing is a critical component of social cognition yet, whether it is influenced by task demands at the neural level remains controversial. Past ERP studies have found mixed results with classic statistical analyses, known to increase both Type I and Type II errors, which Mass Univariate statistics (MUS) control better. However, MUS open-access toolboxes can use different fundamental statistics, which may lead to inconsistent results. Here, we compared the output of two MUS toolboxes, LIMO and FMUT, on the same data recorded during the processing of angry and happy facial expressions investigated under three tasks in a within-subjects design. Both toolboxes revealed main effects of emotion during the N170 timing and main effects of task during later time points typically associated with the LPP component. Neither toolbox yielded an interaction between the two factors at the group level, nor at the individual level in LIMO, confirming that the neural processing of these two face expressions is largely independent from task demands. Behavioural data revealed main effects of task on reaction time and accuracy, but no influence of expression or an interaction between the two. Expression processing and task demands are discussed in the context of the consistencies and discrepancies between the two toolboxes and existing literature.

I can see it in your eyes: Perceived gaze direction impacts ERP and behavioural measures of affective theory of mind

Looking at someone's eyes is thought to be important for affective theory of mind (aTOM), our ability to infer their emotional state. However, it is unknown whether an individual's gaze direction influences our aTOM judgements and what the time course of this influence might be. We presented participants with sentences describing individuals in positive, negative or neutral scenarios, followed by direct or averted gaze neutral face pictures of those individuals. Participants made aTOM judgements about each person's mental state, including their affective valence and arousal, and we investigated whether the face gaze direction impacted those judgements. Participants rated that gazers were feeling more positive when they displayed direct gaze as opposed to averted gaze, and that they were feeling more aroused during negative contexts when gaze was averted as opposed to direct. Event-related potentials associated with face perception and affective processing were examined using mass-univariate analyses to track the time-course of this eye-gaze and affective processing interaction at a neural level. Both positive and negative trials were differentiated from neutral trials at many stages of processing. This included the early N200 and EPN components, believed to reflect automatic emotion areas activation and attentional selection respectively. This also included the later P300 and LPP components, thought to reflect elaborative cognitive appraisal of emotional content. Critically, sentence valence and gaze direction interacted over these later components, which may reflect the incorporation of eye-gaze in the cognitive evaluation of another's emotional state. The results suggest that gaze perception directly impacts aTOM processes, and that altered eye-gaze processing in clinical populations may contribute to associated aTOM impairments.

How Task Set and Task Switching Modulate Perceptual Processes: Is Recognition of Facial Emotion an Exception?

In Part 1 we review task-switching and other studies showing that, even with time for preparation, participants' ability to shift attention to a relevant attribute or object before the stimulus onset is limited: there is a 'residual cost'. In particular, several brain potential markers of perceptual encoding are delayed on task-switch trials, compared to task-repeat trials that require attention to the same attribute as before. Such effects have been documented even for a process often considered 'automatic' - visual word recognition: ERP markers of word frequency and word/nonword status are (1) delayed when the word recognition task follows a judgement of a perceptual property compared to repeating the lexical task, and (2) strongly attenuated during the perceptual judgements. Thus, even lexical access seems influenced by the task/attentional set. In Part 2, we report in detail a demonstration of what seems to be a special case, where task-set and a task switch have no such effect on perceptual encoding. Participants saw an outline letter superimposed on a face expressing neutral or negative emotion, and were auditorily cued to categorise the letter as vowel/consonant, or the face as emotional/neutral. ERPs exhibited a robust emotional-neutral difference (Emotional Expression Effect) no smaller or later when switching to the face task than when repeating it; in the first half of its time-course it did not vary with the task at all. The initial encoding of the valence of a fixated facial emotional expression appears to be involuntary and invariant, whatever the endogenous task/attentional set.

Charged With a Crime: The Neuronal Signature of Processing Negatively Evaluated Faces Under Different Attentional Conditions

Our brains rapidly respond to human faces and can differentiate between many identities, retrieving rich semantic emotional-knowledge information. Studies provide a mixed picture of how such information affects event-related potentials (ERPs). We systematically examined the effect of feature-based attention on ERP modulations to briefly presented faces of individuals associated with a crime. The tasks required participants ( N = 40 adults) to discriminate the orientation of lines overlaid onto the face, the age of the face, or emotional information associated with the face. Negative faces amplified the N170 ERP component during all tasks, whereas the early posterior negativity (EPN) and late positive potential (LPP) components were increased only when the emotional information was attended to. These findings suggest that during early configural analyses (N170), evaluative information potentiates face processing regardless of feature-based attention. During intermediate, only partially resource-dependent, processing stages (EPN) and late stages of elaborate stimulus processing (LPP), attention to the acquired emotional information is necessary for amplified processing of negatively evaluated faces.

Spatiotemporal Dynamics of Covert Versus Overt Processing of Happy, Fearful and Sad Facial Expressions

Behavioral and electrophysiological correlates of the influence of task demands on the processing of happy, sad, and fearful expressions were investigated in a within-subjects study that compared a perceptual distraction condition with task-irrelevant faces (e.g., covert emotion task) to an emotion task-relevant categorization condition (e.g., overt emotion task). A state-of-the-art non-parametric mass univariate analysis method was used to address the limitations of previous studies. Behaviorally, participants responded faster to overtly categorized happy faces and were slower and less accurate to categorize sad and fearful faces; there were no behavioral differences in the covert task. Event-related potential (ERP) responses to the emotional expressions included the N170 (140-180 ms), which was enhanced by emotion irrespective of task, with happy and sad expressions eliciting greater amplitudes than neutral expressions. EPN (200-400 ms) amplitude was modulated by task, with greater voltages in the overt condition, and by emotion, however, there was no interaction of emotion and task. ERP activity was modulated by emotion as a function of task only at a late processing stage, which included the LPP (500-800 ms), with fearful and sad faces showing greater amplitude enhancements than happy faces. This study reveals that affective content does not necessarily require attention in the early stages of face processing, supporting recent evidence that the core and extended parts of the face processing system act in parallel, rather than serially. The role of voluntary attention starts at an intermediate stage, and fully modulates the response to emotional content in the final stage of processing.

Increased early and late neuronal responses to aversively conditioned faces across different attentional conditions

Faces with emotional information-by virtue of their expression or their history of affective learning-are prioritized during neuronal processing as compared to neutral faces. Classical conditioning studies have shown that aversively conditioned (CS+) faces potentiate different face processing stages as evidenced by increased early and late event-related potential (ERPs) components. However, it is unknown whether and how ERP modulations depend on certain attentional conditions. To examine this question, this preregistered study investigated ERPs to faces paired with aversive screams or neutral sounds under three tasks with increasing attention to CS + relevant features of the face: Participants (N = 40) had to discriminate either the orientation of superimposed lines, perceived gender, or the CS association. We found potentiation of the N170, the Early Posterior Negativity (EPN), and, most remarkably, the Late Positive Potential (LPP) to CS + faces regardless of task condition. This finding suggests that, in contrast to other types of emotional information and learning, classical conditioning boosts early and late processing stages, even if no explicit attention to the face information or the CS association is required.

Beyond imagination: Hypnotic visual hallucination induces greater lateralised brain activity than visual mental imagery

Hypnotic suggestions can produce a broad range of perceptual experiences, including hallucinations. Visual hypnotic hallucinations differ in many ways from regular mental images. For example, they are usually experienced as automatic, vivid, and real images, typically compromising the sense of reality. While both hypnotic hallucination and mental imagery are believed to mainly rely on the activation of the visual cortex via top-down mechanisms, it is unknown how they differ in the neural processes they engage. Here we used an adaptation paradigm to test and compare top-down processing between hypnotic hallucination, mental imagery, and visual perception in very highly hypnotisable individuals whose ability to hallucinate was assessed. By measuring the N170/VPP event-related complex and using multivariate decoding analysis, we found that hypnotic hallucination of faces involves greater top-down activation of sensory processing through lateralised neural mechanisms in the right hemisphere compared to mental imagery. Our findings suggest that the neural signatures that distinguish hypnotically hallucinated faces from imagined faces lie in the right brain hemisphere.

The early processing of fearful and happy facial expressions is independent of task demands - Support from mass univariate analyses

Most ERP studies on facial expressions of emotion have yielded inconsistent results regarding the time course of emotion effects and their possible modulation by task demands. Most studies have used classical statistical methods with a high likelihood of type I and type II errors, which can be limited with Mass Univariate statistics. FMUT and LIMO are currently the only two available toolboxes for Mass Univariate analysis of ERP data and use different fundamental statistics. Yet, no direct comparison of their output has been performed on the same dataset. Given the current push to transition to robust statistics to increase results replicability, here we compared the output of these toolboxes on data previously analyzed using classic approaches (Itier & Neath-Tavares, 2017). The early (0-352 ms) processing of fearful, happy, and neutral faces was investigated under three tasks in a within-subject design that also controlled gaze fixation location. Both toolboxes revealed main effects of emotion and task but neither yielded an interaction between the two, confirming the early processing of fear and happy expressions is largely independent of task demands. Both toolboxes found virtually no difference between neutral and happy expressions, while fearful (compared to neutral and happy) expressions modulated the N170 and EPN but elicited maximum effects after the N170 peak, around 190 ms. Similarities and differences in the spatial and temporal extent of these effects are discussed in comparison to the published classical analysis and the rest of the ERP literature.

Reduced early fearful face processing during perceptual distraction in high trait anxious participants

Fearful facial expressions are prioritized across different stages of information processing as reflected by early, mid-latency, and late components of event-related brain potentials (ERP). Trait anxiety has been proposed to modulate these responses, but it is yet unclear how such modulations depend on feature-based attention. In this preregistered study (N = 80), we investigated the effects of trait anxiety on ERP differences between fearful and neutral faces across three different tasks. Participants had to discriminate either the orientation of lines overlaid onto the faces, the gender of the face, or the emotional expression, thus increasing attention to emotionally relevant facial features across the tasks. Fearful versus neutral faces elicited increased P1 and N170 amplitudes across tasks and potentiated amplitudes when attention was directed to faces (early posterior negativity [EPN]) or the expression (EPN and late positive potential). Higher trait anxiety was related to smaller EPN differences between fearful and neutral faces during the perceptual discrimination task. This early relationship suggests reduced instead of amplified processing of fearful faces for high trait anxious participants under perceptual distraction.

Face and emotional expression processing under continuous perceptual load tasks: An ERP study

High perceptual load is thought to impair already the early stages of visual processing of task-irrelevant visual stimuli. However, recent studies showed no effects of perceptual load on early ERPs in response to task-irrelevant emotional faces. In this preregistered EEG study (N = 40), we investigated the effects of continuous perceptual load on ERPs to fearful and neutral task-irrelevant faces and their phase-scrambled versions. Perceptual load did not modulate face or emotion effects for the P1 or N170. In contrast, larger face-scramble and fearful-neutral differentiation were found during low as compared to high load for the Early Posterior Negativity (EPN). Further, face-independent P1, but face-dependent N170 emotional modulations were observed. Taken together, our findings show that P1 and N170 face and emotional modulations are highly resistant to load manipulations, indicating a high degree of automaticity during this processing stage, whereas the EPN might represent a bottleneck in visual information processing.

Effects of low-level visual information and perceptual load on P1 and N170 responses to emotional expressions

Emotional facial expressions lead to modulations of early event-related potentials (ERPs). However, it has so far remained unclear how far these modulations represent face-specific effects rather than differences in low-level visual features, and to which extent they depend on available processing resources. To examine these questions, we conducted two preregistered independent experiments (N = 40 in each experiment) using different variants of a novel task that manipulates peripheral perceptual load across levels but keeps overall visual stimulation constant. At the display center, we presented task-irrelevant angry, neutral, and happy faces and their Fourier phase-scrambled versions, which preserved low-level visual features. The results of both studies showed load-independent P1 and N170 emotional expression effects. Importantly, by using Bayesian analyses we could confirm that these facial expression effects were face-independent for the P1 but not for the N170 component. We conclude that firstly, ERP modulations during the P1 interval strongly depend on low-level visual information, while the N170 modulation requires the processing of figural facial expression features. Secondly, both P1 and N170 modulations appear to be immune to a large range of variations in perceptual load.

Responses to External Emotions or their Transitions at Central to Peripheral Nervous System Levels: A Methodological Contribution to Mental Health

Background:

Responses to external emotional-stimuli or their transitions might help to elucidate the scientific background and assist the clinical management of psychiatric problems, but pure emotional-materials and their utilization at different levels of neurophysiological processing are few.

Objective:

We aimed to describe the responses at central and peripheral levels in healthy volunteers and psychiatric patients when facing external emotions and their transitions.

Methods:

Using pictures and sounds with pure emotions of Disgust, Erotica, Fear, Happiness, Neutral, and Sadness or their transitions as stimuli, we have developed a series of non-invasive techniques, i.e., the event-related potentials, functional magnetic resonance imaging, excitatory and inhibitory brainstem reflexes, and polygraph, to assess different levels of neurophysiological responses in different populations.

Results:

Sample outcomes on various conditions were specific and distinguishable at cortical to peripheral levels in bipolar I and II disorder patients compared to healthy volunteers.

Conclusions:

Methodologically, designs with these pure emotions and their transitions are applicable, and results per se are specifically interpretable in patients with emotion-related problems.

Feeling through another's eyes: Perceived gaze direction impacts ERP and behavioural measures of positive and negative affective empathy

Looking at the eyes informs us about the thoughts and emotions of those around us, and impacts our own emotional state. However, it is unknown how perceiving direct and averted gaze impacts our ability to share the gazer's positive and negative emotions, abilities referred to as positive and negative affective empathy. We presented 44 participants with contextual sentences describing positive, negative and neutral events happening to other people (e.g. "Her newborn was saved/killed/fed yesterday afternoon."). These were designed to elicit positive, negative, or little to no empathy, and were followed by direct or averted gaze images of the individuals described. Participants rated their affective empathy for the individual and their own emotional valence on each trial. Event-related potentials time-locked to face-onset and associated with empathy and emotional processing were recorded to investigate whether they were modulated by gaze direction. Relative to averted gaze, direct gaze was associated with increased positive valence in the positive and neutral conditions and with increased positive empathy ratings. A similar pattern was found at the neural level, using robust mass-univariate statistics. The N100, thought to reflect an automatic activation of emotion areas, was modulated by gaze in the affective empathy conditions, with opposite effect directions in positive and negative conditions.. The P200, an ERP component sensitive to positive stimuli, was modulated by gaze direction only in the positive empathy condition. Positive and negative trials were processed similarly at the early N200 processing stage, but later diverged, with only negative trials modulating the EPN, P300 and LPP components. These results suggest that positive and negative affective empathy are associated with distinct time-courses, and that perceived gaze direction uniquely modulates positive empathy, highlighting the importance of studying empathy with face stimuli.

Attentional conditions differentially affect early, intermediate and late neural responses to fearful and neutral faces

The processing of fearful facial expressions is prioritized by the human brain. This priority is maintained across various information processing stages as evident in early, intermediate and late components of event-related potentials (ERPs). However, emotional modulations are inconsistently reported for these different processing stages. In this pre-registered study, we investigated how feature-based attention differentially affects ERPs to fearful and neutral faces in 40 participants. The tasks required the participants to discriminate either the orientation of lines overlaid onto the face, the sex of the face or the face's emotional expression, increasing attention to emotion-related features. We found main effects of emotion for the N170, early posterior negativity (EPN) and late positive potential (LPP). While N170 emotional modulations were task-independent, interactions of emotion and task were observed for the EPN and LPP. While EPN emotion effects were found in the sex and emotion tasks, the LPP emotion effect was mainly driven by the emotion task. This study shows that early responses to fearful faces are task-independent (N170) and likely based on low-level and configural information while during later processing stages, attention to the face (EPN) or-more specifically-to the face's emotional expression (LPP) is crucial for reliable amplified processing of emotional faces.

Meaningful faces: Self-relevance of semantic context in an initial social encounter improves later face recognition

Self-relevant stimuli (i.e. meaningful/important to the observer and related to the self) are typically remembered better than other-relevant stimuli. However, whether a self-relevance memory benefit could be conferred to a novel neutral face, remains to be seen. Recent studies have shown that emotional responses to neutral faces can be altered by using a preceding sentence as context that varies in terms of self-relevance (self/other-relevant) and valence (positive/negative; e.g. "S/he thinks your comment is dumb/smart"). We adapted this paradigm to investigate whether the context conferred by the preceding sentence also impacts memorability of the subsequently presented face. Participants saw faces primed with contextual sentences and rated how aroused, and how positive or negative, the faces made them feel. Later incidental recognition accuracy for the faces was greater when these had been preceded by self-relevant compared to other-relevant sentences. Faces preceded by self-relevant contexts were also rated as more arousing. There was no impact of sentence valence on arousal ratings or on recognition memory for faces. Sentence self-relevance and valence interacted to affect participants' ratings of how positive or negative the faces made them feel during encoding, but did not interact to impact later recognition. Our results indicate that initial social encounters can have a lasting effect on one's memory of another person, producing an enhanced memory trace of that individual. We propose that the effect is driven by an arousal-based mechanism, elicited by faces perceived to be self-relevant.

Sincerity Is in the Eye of the Beholder: Using Eye Tracking to Understand How Victims Interpret an Offender's Apology in a Simulation of Victim-Offender Mediation

The objective of this study was to gain insights into how victims use their visual attention to determine the sincerity of an offender's apology during simulated victim-offender mediation. We hypothesized that the victims' visual attention (gaze fixation duration) would be focused more on the offender's upper (than lower) face area, especially the eyes and the eyebrows, to infer the degree to which the offender suffers, takes responsibility, and has empathy for the victim. In turn, we expected these inferences to positively predict the perceived sincerity of the apology. Additionally, we took into account the victims' a priori expectations regarding the sincerity of the apology and (positive) attitudes toward resocialization programs (ARPs). We expected both variables to enhance the above proposed process through which victims determine the sincerity of the apology. Fifty-eight students took the victim's role in a fictitious crime scenario and watched a video in which the offender offered a remorseful apology. We obtained eye tracking data to determine the participants' fixation and attention distribution. As expected, the participants' gaze fixated significantly longer on the upper face. The results also showed that their prior expectations, positive ARPs, and inferences of suffering and responsibility taking after the apology all positively predicted the perceived sincerity. However, unexpectedly, gaze duration was not directly associated with these inferences. The fixation duration on the upper face instead appeared to moderate how ARPs predicted inferences of responsibility taking. More concretely, the exploratory path model analyses revealed that when the participants had more positive a priori ARPs, the longer they focused on the offender's eyes and eyebrows and the more they concluded that he took responsibility for his actions (which in turn predicted more sincerity). However, for those with relatively negative ARPs, it was the other way around: the more they focused on the eyes and the eyebrows, the stronger they inferred that the offender did not take responsibility (which predicted less sincerity). Our findings demonstrate the vital role of the victims' a priori attitudes, expectations, and eye gaze behavior in understanding the reception and the evaluation of offenders' apologies. This study also suggests how novel technology can be used to investigate gaze behavior in the field of victim-offender mediation.