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Alexithymia is characterized by impairments in emotion processing, frequently linked to facial expressions of emotion. The eye-region conveys information necessary for emotion processing. It has been demonstrated that alexithymia is associated with reduced attention to the eyes, but little is known regarding the cognitive and electrophysiological mechanisms underlying emotive eye-region processing in alexithymia. Here, we recorded behavioral and electrophysiological responses of individuals with alexithymia (ALEX; n = 25) and individuals without alexithymia (NonALEX; n = 23) while they viewed intact and eyeless faces with angry and sad expressions during a dual-target rapid serial visual presentation task. Results showed different eye-region focuses and differentiating N1 responses between intact and eyeless faces to anger and sadness in NonALEX, but not in ALEX, suggesting deficient perceptual processing of the eye-region in alexithymia. Reduced eye-region focus and smaller differences in frontal alpha asymmetry in response to sadness between intact and eyeless faces were observed in ALEX than NonALEX, indicative of impaired affective processing of the eye-region in alexithymia. These findings highlight perceptual and affective abnormalities of emotive eye-region processing in alexithymia. Our results contribute to understanding the neuropsychopathology of alexithymia and alexithymia-related disorders., (© The Author(s) 2022. Published by Oxford University Press.)

Emotional stimuli can be processed without consciousness. In the current study, we used event-related potentials (ERPs) to assess whether perceptual load influences non-conscious processing of fearful facial expressions. Perceptual load was manipulated using a letter search task with the target letter presented at the fixation point, while facial expressions were presented peripherally and masked to prevent conscious awareness. The letter string comprised six letters (X or N) that were identical (low load) or different (high load). Participants were instructed to discriminate the letters at fixation or the facial expression (fearful or neutral) in the periphery. Participants were faster and more accurate at detecting letters in the low load condition than in the high load condition. Fearful faces elicited a sustained positivity from 250 ms to 700 ms post-stimulus over fronto-central areas during the face discrimination and low-load letter discrimination conditions, but this effect was completely eliminated during high-load letter discrimination. Our findings imply that non-conscious processing of fearful faces depends on perceptual load, and attentional resources are necessary for non-conscious processing.

The decoding of social signals from nonverbal cues plays a vital role in the social interactions of socially gregarious animals such as humans. Because nonverbal emotional signals from the face and body are normally seen together, it is important to investigate the mechanism underlying the integration of emotional signals from these two sources. We conducted a study in which the time course of the integration of facial and bodily expressions was examined via analysis of event-related potentials (ERPs) while the focus of attention was manipulated. Distinctive integrating features were found during multiple stages of processing. In the first stage, threatening information from the body was extracted automatically and rapidly, as evidenced by enhanced P1 amplitudes when the subjects viewed compound face-body images with fearful bodies compared with happy bodies. In the second stage, incongruency between emotional information from the face and the body was detected and captured by N2. Incongruent compound images elicited larger N2s than did congruent compound images. The focus of attention modulated the third stage of integration. When the subjects' attention was focused on the face, images with congruent emotional signals elicited larger P3s than did images with incongruent signals, suggesting more sustained attention and elaboration of congruent emotional information extracted from the face and body. On the other hand, when the subjects' attention was focused on the body, images with fearful bodies elicited larger P3s than did images with happy bodies, indicating more sustained attention and elaboration of threatening information from the body during evaluative processes.

Using measurements of event-related potentials (ERPs) during a facial recognition task, we aimed to investigate the facial inversion effect and the role of time-based attention in processing upright and inverted faces. We presented upright and inverted faces at the T2 (target 2) position using a rapid serial visual presentation paradigm. Our results indicate that the N170 component shows the usual face inversion effect (FIE), in which inverted faces elicit larger N170 amplitudes and a longer elicit N170 latency. We also found that upright faces elicit larger P1 amplitudes than inverted faces over the left hemisphere. This study indicates that the N170 and P3, but not the P1, components are modulated by time-based attention. In addition, we found that the N170 amplitude was modulated by an attentional blink (AB) based on behavioral data. These results suggest that the disruption of facial configuration processing caused by inverted faces is relatively independent of attentional resources., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Neural responses to negatively valenced stimuli such as fear are enhanced relative to positive or neutral stimuli, reflecting an emotional negativity bias. In the present study, high time resolution event related potential (ERP) techniques were used, to investigate whether C1, the earliest visually evoked potential, is modulated by emotional valence in the executive attention network. Subjects were instructed to respond to the expression of the face, while ignoring the content of word, in an emotional face-word Stroop task. We demonstrated modulation of C1 in response to fearful faces versus happy faces. The differentiation between detection of fearful and happy faces emerged at 60-90ms after the stimulus onset at the posterior electrode sites, and this early differentiation occurred regardless of whether the subject had viewed a congruent or incongruent trials (i.e., happy face with fear label or vice versa). The present results indicate that faces with a fearful expression capture processing resources at an early sensory processing stage., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

This study used the location negative priming (NP) paradigm and the recording of event-related potentials to examine the mechanism of the impact of emotional stimulus on subsequent spatial attentional processing. The results shown to be relative to the happy and neutral condition, a significant behavioural NP effect, as well as decreased N2, increased N2pc, and P3 amplitudes for NP condition, were found selectively in the fearful prime distractor condition. These findings suggest that the effect of fearful stimulus on location NP may be related to early-inhibition processing. Larger P3 amplitudes may reflect the use of increased cognitive resources when one is necessary for overcoming the tendency to avoid viewing the position where a fearful stimulus has recently been seen.

The perceptual processing of emotional conflict was studied using electrophysiological techniques to measure event-related potentials (ERPs). The emotional face-word Stroop task in which emotion words are written in prominent red color across a face was use to study emotional conflict. In each trial, the emotion word and facial expression were either congruent or incongruent (in conflict). When subjects were asked to identify the expression of the face during a trial, the incongruent condition evoked a more negative N170 ERP component in posterior lateral sites than in the congruent condition. In contrast, when subjects were asked to identify the word during a trial, the incongruent condition evoked a less negative N170 component than the congruent condition. The present findings extend our understanding of the control processes involved in emotional conflict by demonstrating that differentiation of emotional congruency begins at an early perceptual processing stage., ((c) 2010 Elsevier Ireland Ltd. All rights reserved.)

Electrophysiological correlates of the processing facial expressions were investigated in subjects performing the rapid serial visual presentation (RSVP) task. The peak latencies of the event-related potential (ERP) components P1, vertex positive potential (VPP), and N170 were 165, 240, and 240 ms, respectively. The early anterior N100 and posterior P1 amplitudes elicited by fearful faces were larger than those elicited by happy or neutral faces, a finding which is consistent with the presence of a 'negativity bias.' The amplitude of the anterior VPP was larger when subjects were processing fearful and happy faces than when they were processing neutral faces; it was similar in response to fearful and happy faces. The late N300 and P300 not only distinguished emotional faces from neutral faces but also differentiated between fearful and happy expressions in lag2. The amplitudes of the N100, VPP, N170, N300, and P300 components and the latency of the P1 component were modulated by attentional resources. Deficient attentional resources resulted in decreased amplitude and increased latency of ERP components. In light of these results, we present a hypothetical model involving three stages of facial expression processing.

Males have been suggested to have advantages over females in reactions to child facial resemblance, which reflects the evolutionary pressure on males to solve the adaptive paternal uncertainty problem and to identify biological offspring. However, previous studies showed inconsistent results and the male advantage in child facial resemblance perception, as a kin detection mechanism, is still unclear. Here, we investigated the behavioral and brain mechanisms underlying the self-resembling faces processing and how it interacts with sex and age using event-related potential (ERP) technique. The results showed a stable male advantage in self-resembling child faces processing, such that males have higher detectability to self-resembling child faces than females. For ERP results, males showed smaller N2 and larger late positive component (LPC) amplitudes for self-resembling child faces, which may reflect face-matching and self-referential processing in kin detection, respectively. Further source analysis showed that the N2 component and LPC were originated from the anterior cingulate cortex and medial frontal gyrus, respectively. Our results support the male advantage in self-resembling child detection and further indicate that such distinctions can be found in both early and late processing stages in the brain at different regions. [ABSTRACT FROM AUTHOR]

Previous studies with Westerners have found that both the mouth and eyes are crucial in identifying and interpreting smiles. We proposed that Easterners (e.g., Chinese and Japanese) evaluate the role of the mouth and eyes in smiles differently from Westerners. Individuals in collectivistic Eastern society heavily rely on information from the eyes to identify and interpret the meaning of smiles. [ABSTRACT FROM AUTHOR]

• Brain organizations of facial expression recognition support the constructionist hypothesis. • Common brain activation and connectivity distributions are shared by different discrete/dimensional facial expressions. • The amygdala-centered 'core' affect system are connected to distributed networks. • The brain organizations of facial expression recognition are flexibly asymmetrical. Discrimination of facial expressions is an elementary function of the human brain. While the way emotions are represented in the brain has long been debated, common and specific neural representations in recognition of facial expressions are also complicated. To examine brain organizations and asymmetry on discrete and dimensional facial emotions, we conducted an activation likelihood estimation meta-analysis and meta-analytic connectivity modelling on 141 studies with a total of 3138 participants. We found consistent engagement of the amygdala and a common set of brain networks across discrete and dimensional emotions. The left-hemisphere dominance of the amygdala and AI across categories of facial expression, but category-specific lateralization of the vmPFC, suggesting a flexibly asymmetrical neural representations of facial expression recognition. These results converge to characteristic activation and connectivity patterns across discrete and dimensional emotion categories in recognition of facial expressions. Our findings provide the first quantitatively meta-analytic brain network-based evidence supportive of the psychological constructionist hypothesis in facial expression recognition. [ABSTRACT FROM AUTHOR]

The quick and efficient perception of facial expressions represents a special and fundamental capacity of humans to engage in social communication. Here, we examined the effects of vasopressin (AVP, a neuropeptide) on the processing of same- and other-gender facial expressions among males and females. After receiving either AVP or placebo (PBO) intranasally in a randomized and double-blind manner, participants were asked to rate their approachability to facial expressions while event-related potentials (ERPs) were recorded. Males rated lower approachability scores to neutral and positive male faces relative to the scores to emotion-matched female faces after AVP but not following PBO administration. These behavioral effects were correlated with the AVP-induced increased P1 and decreased N170 responses to male faces among male participants. Females rated higher approachability scores to negative female faces than the scores to negative male faces after AVP but not following PBO treatment. These results suggest that AVP decreases friendly responses to neutral/positive male faces in males and increases friendly responses to negative female faces in females. Overall, these results demonstrate the gender-specific effects of AVP in response to same- and other-gender facial expressions, indicating there are sex- and context-dependent effects of AVP on socioemotional processes. • Effects of AVP on the time course of emotional processing were studied. • AVP had opposite effects on approach to same- and opposite-sex faces in males. • The behavioral effects were parallel with modulations of P1 and N170 responses. • AVP modulated negative face processing at behavioral and ERP levels in females. [ABSTRACT FROM AUTHOR]

Abstract: To investigate whether the non-conscious processing of fearful faces exist in unattended condition, event-related potentials (ERPs) were recorded in a facial expression detection task. Participants were asked to discriminate the facial expressions (fearful or neutral) at the attended location. Unattended faces were associated with a response that was either congruent or in conflict with the response to the attended face. ERP results showed that the trials with response conflict between attended and unattended faces enhanced the amplitude of the P3 component when the neutral face was presented at attended location and the fearful face was presented at the unattended location. Our findings imply that the non-conscious fearful faces can be processed in the unattended condition. [Copyright &y& Elsevier]

Abstract: Previous studies have shown differential event-related potentials (ERPs) to intensities of fearful facial expressions. There are indications that the eyes may be particularly relevant for the recognition of fearful expressions, even the amount of white sclera exposed above and on sides of the dark pupil could activate the amygdala response. To investigate whether the ERP differences between intensities of fearful expressions are driven by the differential salience of the eyes in the fearful faces, ERPs were measured within a backward masking paradigm, where observers were asked to do a gender-decision task with male and female neutral faces. The emotional stimuli used were low-intensity (50%), prototypical (100%), and caricatured (150%) fearful eye whites that were derived from corresponding intensities of fearful faces respectively. Three groups of white squares that have the same pixels as the eye whites were created as control conditions. Analysis of the ERP data showed a linear increase in amplitudes of the parietal–occipital P120 by three intensities of fearful eye whites. These ERP effects were proved sensitive to intensities of negative emotions but not to the simple physical features as the same patterns of differences were not observed on white squares. Larger parietal–occipital P250 amplitudes were observed for caricatured 150% than low-intensity 50% fearful eye whites. It might reflect the subcortical pathway of emotion-specific, fearful processing. The results demonstrate that the human brain is sensitive to intensities of fear, even if just shown intensities of fearful eye white in the absence of awareness. [Copyright &y& Elsevier]