Direct gaze facilitates rapid orienting to faces: Evidence from express saccades and saccadic potentials

Evidence for the adaptive parsing of non-communicative eye movements during joint attention interactions

During social interactions, the ability to detect and respond to gaze-based joint attention bids often involves the evaluation of non-communicative eye movements. However, very little is known about how much humans are able to track and parse spatial information from these non-communicative eye movements over time, and the extent to which this influences joint attention outcomes. This was investigated in the current study using an interactive computer-based joint attention game. Using a fully within-subjects design, we specifically examined whether participants were quicker to respond to communicative joint attention bids that followed predictive, as opposed to random or no, non-communicative gaze behaviour. Our results suggest that in complex, dynamic tasks, people adaptively use and dismiss non-communicative gaze information depending on whether it informs the locus of an upcoming joint attention bid. We also went further to examine the extent to which this ability to track dynamic spatial information was specific to processing gaze information. This was achieved by comparing performance to a closely matched non-social task where eye gaze cues were replaced with dynamic arrow stimuli. Whilst we found that people are also able to track and use dynamic non-social information from arrows, there was clear evidence for a relative advantage for tracking gaze cues during social interactions. The implications of these findings for social neuroscience and autism research are discussed.

Inferential eye movement control while following dynamic gaze

Attending to other people's gaze is evolutionary important to make inferences about intentions and actions. Gaze influences covert attention and triggers eye movements. However, we know little about how the brain controls the fine-grain dynamics of eye movements during gaze following. Observers followed people's gaze shifts in videos during search and we related the observer eye movement dynamics to the time course of gazer head movements extracted by a deep neural network. We show that the observers' brains use information in the visual periphery to execute predictive saccades that anticipate the information in the gazer's head direction by 190-350ms. The brain simultaneously monitors moment-to-moment changes in the gazer's head velocity to dynamically alter eye movements and re-fixate the gazer (reverse saccades) when the head accelerates before the initiation of the first forward gaze-following saccade. Using saccade-contingent manipulations of the videos, we experimentally show that the reverse saccades are planned concurrently with the first forward gaze-following saccade and have a functional role in reducing subsequent errors fixating on the gaze goal. Together, our findings characterize the inferential and functional nature of social attention's fine-grain eye movement dynamics.

The effects of the presence of a face and direct eye gaze on voice identity learning

We rarely become familiar with the voice of another person in isolation but usually also have access to visual identity information, thus learning to recognize their voice and face in parallel. There are conflicting findings as to whether learning to recognize voices in audiovisual vs audio-only settings is advantageous or detrimental to learning. One prominent finding shows that the presence of a face overshadows the voice, hindering voice identity learning by capturing listeners' attention (Face Overshadowing Effect; FOE). In the current study, we tested the proposal that the effect of audiovisual training on voice identity learning is driven by attentional processes. Participants learned to recognize voices through either audio-only training (Audio-Only) or through three versions of audiovisual training, where a face was presented alongside the voices. During audiovisual training, the faces were either looking at the camera (Direct Gaze), were looking to the side (Averted Gaze) or had closed eyes (No Gaze). We found a graded effect of gaze on voice identity learning: Voice identity recognition was most accurate after audio-only training and least accurate after audiovisual training including direct gaze, constituting a FOE. While effect sizes were overall small, the magnitude of FOE was halved for the Averted and No Gaze conditions. With direct gaze being associated with increased attention capture compared to averted or no gaze, the current findings suggest that incidental attention capture at least partially underpins the FOE. We discuss these findings in light of visual dominance effects and the relative informativeness of faces vs voices for identity perception.

Explicit vs. implicit spatial processing in arrow vs. eye-gaze spatial congruency effects

Arrows and gaze stimuli lead to opposite spatial congruency effects. While standard congruency effects are observed for arrows (faster responses for congruent conditions), responses are faster when eye-gaze stimuli are presented on the opposite side of the gazed-at location (incongruent trials), leading to a reversed congruency effect (RCE). Here, we explored the effects of implicit vs. explicit processing of arrows and eye-gaze direction. Participants were required to identify the direction (explicit task) or the colour (implicit task) of left or right looking/pointing gaze or arrows, presented to either the left or right of the fixation point. When participants responded to the direction of stimuli, standard congruency effects for arrows and RCE for eye-gaze stimuli were observed. However, when participants responded to the colour of stimuli, no congruency effects were observed. These results suggest that it is necessary to explicitly pay attention to the direction of eye-gaze and arrows for the congruency effect to occur. The same pattern of data was observed when participants responded either manually or verbally, demonstrating that manual motor components are not responsible for the results observed. These findings are not consistent with some hypotheses previously proposed to explain the RCE observed with eye-gaze stimuli and, therefore, call for an alternative plausible hypothesis.

Exploring the Social Environment with the Eyes: A Review of the Impact of Facial Stimuli on Saccadic Trajectories

Eye movement parameters can be highly informative regarding how people explore the social environment around them. This theoretical review examines how human faces and their features (e.g., eye-gaze direction, emotional expressions) can modulate saccadic trajectories. In the first part, studies in which facial stimuli were presented in a central location, such as during a face-to-face social interaction, are illustrated. The second part focuses on studies in which facial stimuli were placed in the periphery. Together, these works confirm the presence of an intriguing link between eye movements and facial processing, and invite consideration of saccadic trajectories as a useful (and still underused) opportunity to track ongoing mechanisms that support the social vision. Some directions for future research are also discussed.

Face masks inhibit facial cues for approachability and trustworthiness: an eyetracking study

Wearing face masks during the Covid-19 pandemic has undeniable benefits from our health perspective. However, the interpersonal costs on social interactions may have been underappreciated. Because masks obscure critical facial regions signaling approach/avoidance intent and social trust, this implies that facial inference of approachability and trustworthiness may be severely discounted. Here, in our eyetracking experiment, we show that people judged masked faces as less approachable and trustworthy. Further analyses showed that the attention directed towards the eye region relative to the mouth region mediated the effect on approachability, but not on trustworthiness. This is because for masked faces, with the mouth region obscured, visual attention is then automatically diverted away from the mouth and towards the eye region, which is an undiagnostic cue for judging a target's approachability. Together, these findings support that mask-wearing inhibits the critical facial cues needed for social judgements.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12144-022-03705-8.

Direct eye gaze enhances the ventriloquism effect

The “ventriloquism effect” describes an illusory phenomenon where the perceived location of an auditory stimulus is pulled toward the location of a visual stimulus. Ventriloquists use this phenomenon to create an illusion where an inanimate puppet is perceived to speak. Ventriloquists use the expression and suppression of their own and the puppet’s mouth movements as well the direction of their respective eye gaze to maximize the illusion. While the puppet’s often exaggerated mouth movements have been demonstrated to enhance the ventriloquism effect, the contribution of direct eye gaze remains unknown. In Experiment 1, participants viewed an image of a person’s face while hearing a temporally synchronous recording of a voice originating from different locations on the azimuthal plane. The eyes of the facial stimuli were either looking directly at participants or were closed. Participants were more likely to misperceive the location of a range of voice locations as coming from a central position when the eye gaze of the facial stimuli were directed toward them. Thus, direct gaze enhances the ventriloquist effect by attracting participants’ perception of the voice locations toward the location of the face. In an exploratory analysis, we furthermore found no evidence for an other-race effect between White vs Asian listeners. In Experiment 2, we replicated the effect of direct eye gaze on the ventriloquism effect, also showing that faces per se attract perceived sound locations compared with audio-only sound localization. Showing a modulation of the ventriloquism effect by socially-salient eye gaze information thus adds to previous findings reporting top-down influences on this effect.

Direct Gaze Holds Attention, but Not in Individuals with Obsessive-Compulsive Disorder

The attentional response to eye-gaze stimuli is still largely unexplored in individuals with obsessive-compulsive disorder (OCD). Here, we focused on an attentional phenomenon according to which a direct-gaze face can hold attention in a perceiver. Individuals with OCD and a group of matched healthy controls were asked to discriminate, through a speeded manual response, a peripheral target. Meanwhile, a task-irrelevant face displaying either direct gaze (in the eye-contact condition) or averted gaze (in the no-eye-contact condition) was also presented at the centre of the screen. Overall, the latencies were slower for faces with direct gaze than for faces with averted gaze; however, this difference was reliable in the healthy control group but not in the OCD group. This suggests the presence of an unusual attentional response to direct gaze in this clinical population.

Rapid saccadic categorization of other-race faces

The human visual system is very fast and efficient at extracting socially relevant information from faces. Visual studies employing foveated faces have consistently reported faster categorization by race response times for other-race compared with same-race faces. However, in everyday life we typically encounter faces outside the foveated visual field. In study 1, we explored whether and how race is categorized extrafoveally in same- and other-race faces normalized for low-level properties by tracking eye movements of Western Caucasian and East Asian observers in a saccadic response task. The results show that not only are people sensitive to race in faces presented outside of central vision, but the speed advantage in categorizing other-race faces occurs astonishingly quickly in as little as 200 ms. Critically, this visual categorization process was approximately 300 ms faster than the typical button press responses on centrally presented foveated faces. Study 2 investigated the genesis of the extrafoveal saccadic response speed advantage by comparing the influences of the response modality (button presses and saccadic responses), as well as the potential contribution of the impoverished low-spatial frequency spectrum characterizing extrafoveal visual information processing. Button press race categorization was not significantly faster with reconstructed retinal-filtered low spatial frequency faces, regardless of the visual field presentation. The speed of race categorization was significantly boosted only by extrafoveal saccades and not centrally foveated faces. Race is a potent, rapid, and effective visual signal transmitted by faces used for the categorization of ingroup/outgroup members. This fast universal visual categorization can occur outside central vision, igniting a cascade of social processes.

Alcohol use severity and the neural correlates of the effects of sleep disturbance on sustained visual attention

Alcohol misuse is associated with sleep disturbance and cognitive dysfunction. However, the neural processes inter-relating the severity of alcohol use, sleep disturbance and cognitive performance remain under-investigated. We addressed this issue with a dataset of 964 subjects (504 women) curated from the Human Connectome Project. Participants were assessed with the Pittsburgh Sleep Quality Index (PSQI) and fMRI while identifying relational dimension pictures and matching dimension pictures (as a control) in alternating blocks. Imaging data were analyzed with published routines and the results were evaluated at a corrected threshold. Subjects showed lower accuracy rate and longer reaction time (RT) in relational than control blocks. The difference in RT between the two blocks (RT_Rel-Con) was driven primarily by the RT and correlated positively with performance accuracy of relational trials, suggesting that a more cautious response (i.e., longer RT_Rel-Con) improved accuracy. The severity of alcohol use, identified from principal component analysis of drinking metrics, was positively correlated with sleep disturbance. Further, whole-brain regression identified activity of the superior colliculus (SC) during relational vs. control blocks in positive and negative correlation with RT_Rel-Con and PSQI score, respectively. Mediation and path analyses demonstrated a significant model: more severe alcohol use → greater sleep disturbance → diminished SC activity → impaired performance. These findings support the influences of alcohol misuse on sleep and suggest neural correlates that mediate the relationship between sleep disturbance and altered sustained attention in young adults.

The roles of gaze and head orientation in face categorization during rapid serial visual presentation

Little is known about how perceived gaze direction and head orientation may influence human categorization of visual stimuli as faces. To address this question, a sequence of unsegmented natural images, each containing a random face or a non-face object, was presented in rapid succession (stimulus duration: 91.7 ms per image) during which human observers were instructed to respond immediately to every face presentation. Faces differed in gaze and head orientation in 7 combinations - full-front views with perceived gaze (1) directed to the observer, (2) averted to the left, or (3) averted to the right, left ¾ side views with (4) direct gaze or (5) averted gaze, and right ¾ side views with (6) direct gaze or (7) averted gaze - were presented randomly throughout the sequence. We found highly accurate and rapid behavioural responses to all kinds of faces. Crucially, both perceived gaze direction and head orientation had comparable, non-interactive effects on response times, where direct gaze was responded faster than averted gaze by 48 ms and full-front view faster than ¾ side view also by 48 ms on average. Presentations of full-front faces with direct gaze led to an additive speed advantage of 96 ms to ¾ faces with averted gaze. The results reveal that the effects of perceived gaze direction and head orientation on the speed of face categorization probably depend on the degree of social relevance of the face to the viewer.

Gaze aversion in conversational settings: An investigation based on mock job interview

We report the results of an empirical study on gaze aversion during dyadic human-to-human conversation in an interview setting. To address various methodological challenges in assessing gaze-to-face contact, we followed an approach where the experiment was conducted twice, each time with a different set of interviewees. In one of them the interviewer’s gaze was tracked with an eye tracker, and in the other the interviewee’s gaze was tracked. The gaze sequences obtained in both experiments were analyzed and modeled as Discrete-Time Markov Chains. The results show that the interviewer made more frequent and longer gaze contacts compared to the interviewee. Also, the interviewer made mostly diagonal gaze aversions, whereas the interviewee made sideways aversions (left or right). We discuss the relevance of this research for Human-Robot Interaction, and discuss some future research problems.

Approach and Avoidance Behavior in Female Patients With Borderline Personality Disorder

Objectives

Borderline personality disorder (BPD) is portrayed by unstable relationships, fears of abandonment and heightened sensitivity to social rejection. Research has shown that these characteristics may lead to inappropriate social behavior including altered approach-avoidance behavior. However, it has remained unclear how social exclusion may affect approach-avoidance behavior in patients with BPD.

Design

We assessed social approach-avoidance behavior and the impact of social exclusion in a sample of 38 patients with BPD and 40 healthy control participants.

Methods

We used an explicit joystick-based approach-avoidance task (AAT) after playing a virtual ball-tossing game (Cyberball), which simulates the exclusion of the participant by two other players. In the AAT, participants were required to push or pull emotional stimuli, more specifically happy and angry facial expressions, with either direct or averted gaze direction.

Results

Patients with BPD approached happy stimuli less and showed overall less differential approach-avoidance behavior toward individuals expressing positive or negative facial emotions compared to healthy participants, who showed more approach behavior for happy compared to angry facial expressions. Moreover, borderline symptom severity correlated inversely with the AAT score for happy facial expressions and positively with subjective unpleasantness during social exclusion as well as rejection sensitivity. However, social exclusion did not influence approach-avoidance tendencies.

Conclusion

Patients with BPD showed altered approach-avoidance behavior, which might affect social interactions in the patient’s everyday lives and may therefore impede social interaction.

Attention neglects a stare-in-the-crowd: Unanticipated consequences of prediction-error coding

Direct gaze - someone looking at you - is an important and subjectively-salient stimulus. Its processing is thought to be enhanced by the brain's internalised predictions - priors - that effectively specify it as the most likely gaze direction. Current consensus holds that, befitting its presumed importance, direct gaze attracts attention more powerfully than other gazes. Conversely, some Predictive Coding (PC) models, in which exogenous attention is drawn to stimuli that violate predictions, may be construed as making the opposite claim - i.e., exogenous attention should be biased away from direct gaze (which conforms to internal predictions), toward averted gaze (which does not). Here, searching displays with salient, 'odd-one-out' gazes, we observed attentional bias (in rapid, initial saccades) toward averted gaze, as would be expected by PC models. However, this pattern obtained only when conditions highlighted gaze-uniqueness. We speculate that, in our experiments, task requirements determined how prediction influenced perception.

Eye contact in active and passive viewing: Event-related brain potential evidence from a combined eye tracking and EEG study

Eye contact is a salient social cue, which is assumed to influence already early neural correlates of face perception. Specifically, the N170 component of the event-related potential (ERP) has often been found to be larger for faces with an averted gaze as compared to faces that directly look at the observer. In most existing ERP studies, effects of eye contact were investigated under comparatively artificial conditions where participants were instructed to maintain a steady fixation while they passively observed gaze changes in the stimulus face. It is therefore unclear to what extent neural correlates of eye contact generalize to more naturalistic situations that involve a continuous interplay between directed and averted gaze between the communication partners. To start bridging this gap, the present study compared the passive viewing of gaze changes to an active condition in which the participant's own gaze (measured online with an eye tracker) interacted with the gaze position of a continuously presented stimulus face. We also investigated whether eye contact effects were modulated by the face's emotional expression. In both the passive and the active viewing condition, N170 amplitudes were larger when the gaze of the stimulus faces was averted rather than directed towards the participant. Furthermore, eye contact decreased P300 amplitudes in both conditions. The emotional expression of the face also modulated the N170, but this effect did not interact with that of gaze direction. We conclude that the neural correlates of gaze perception during active gaze interactions are comparable to those found during passive viewing, encouraging the further study of eye contact effects in more naturalistic settings.

Eye contact boosts the reflexive component of overt gaze following

Establishing eye contact with an individual can subsequently lead to a stronger gaze-mediated orienting effect. However, studies exploring this phenomenon have, so far, only assessed manual responses and focused on covert attention - namely, without eye movements. Here, in two experiments, we explored for the first time whether eye contact can also impact on overt attention in an oculomotor task. This approach has two main advantages, in that it relies on more sensitive, online measures of attention allocation and it better mimics real life settings. Participants performed leftwards and rightwards eye movements in response to a central cue. Furthermore, a task-irrelevant central face established - or not - eye contact with the participant, and then averted its gaze either leftwards or rightwards. Hence, eye movement direction was either congruent or incongruent with that of the gaze stimulus. In both experiments, a gaze following behaviour emerged - specifically, smaller saccadic latencies and a greater accuracy emerged on congruent than on incongruent trials - but its magnitude was not modulated by eye contact. However, in Experiment 2 - in which the different eye contact conditions were presented intermixed rather than blocked, thus making eye contact contextually salient - eye contact led to an overall decrement of saccadic latencies and enhanced the reflexive component of gaze following. Taken together, these results provide novel evidence indicating that eye contact can impact on both eye movements programming and overt gaze following mechanisms, at least when eye contact is made contextually salient.

Face detection in 2- to 6-month-old infants is influenced by gaze direction and species

Humans detect faces efficiently from a young age. Face detection is critical for infants to identify and learn from relevant social stimuli in their environments. Faces with eye contact are an especially salient stimulus, and attention to the eyes in infancy is linked to the emergence of later sociality. Despite the importance of both of these early social skills-attending to faces and attending to the eyes-surprisingly little is known about how they interact. We used eye tracking to explore whether eye contact influences infants' face detection. Longitudinally, we examined 2-, 4-, and 6-month-olds' (N = 65) visual scanning of complex image arrays with human and animal faces varying in eye contact and head orientation. Across all ages, infants displayed superior detection of faces with eye contact; however, this effect varied as a function of species and head orientation. Infants were more attentive to human than animal faces and were more sensitive to eye and head orientation for human faces compared to animal faces. Unexpectedly, human faces with both averted heads and eyes received the most attention. This pattern may reflect the early emergence of gaze following-the ability to look where another individual looks-which begins to develop around this age. Infants may be especially interested in averted gaze faces, providing early scaffolding for joint attention. This study represents the first investigation to document infants' attention patterns to faces systematically varying in their attentional states. Together, these findings suggest that infants develop early, specialized functional conspecific face detection.

The influence of top-down modulation on the processing of direct gaze

Gaze or eye contact is one of the most important nonverbal social cues, which is fundamental to human social interactions. To achieve real time and dynamic face-to-face communication, our brain needs to process another person's gaze direction rapidly and without explicit instruction. In order to explain the fast and spontaneous processing of direct gaze, the fast-track modulator model was proposed. Here, we review recent developments in gaze processing research in the last decade to extend the fast-track modulator model. In particular, we propose that task demand or top-down modulation could play a more crucial role at gaze processing than formerly assumed. We suggest that under different task demands, top-down modulation can facilitate or interfere with the direct gaze effects for early visual processing. The proposed modification of the model extends the role of task demand and its implication on the direct gaze effect, as well as the need to better control for top-down processing in order to better disentangle the role of top-down and bottom-up processing on the direct gaze effect. This article is categorized under: Cognitive Biology > Evolutionary Roots of Cognition Psychology > Perception and Psychophysics Neuroscience > Cognition.

Direct Gaze Partially Overcomes Hemispatial Neglect and Captures Spatial Attention

Direct gaze has been shown to be a particularly important social cue, being preferentially processed even when unconsciously perceived. Results from several visual search tasks further suggest that direct gaze modulates attention, showing a faster orientation to faces perceived as looking toward us. The present study aimed to analyze putative modulation of spatial attention by eye gaze direction in patients with unilateral neglect. Eight right hemisphere stroke patients with neglect performed a target cancelation paradigm. Patients were instructed to cross all open-eyed pictures amidst closed eyed distractors. Target images were either in direct or averted gaze. Participants performed significantly better when observing targets with direct gaze supporting the hypothesis that this gaze direction captures attention. These findings further suggest that perception of direct gaze is able to diminish the visuospatial impairment seen in neglect patients.

Autism Pathogenesis: The Superior Colliculus

After been exposed to the visual input, in the first year of life, the brain experiences subtle but massive changes apparently crucial for communicative/emotional and social human development. Its lack could be the explanation of the very high prevalence of autism in children with total congenital blindness. The present theory postulates that the superior colliculus is the key structure for such changes for several reasons: it dominates visual behavior during the first months of life; it is ready at birth for complex visual tasks; it has a significant influence on several hemispheric regions; it is the main brain hub that permanently integrates visual and non-visual, external and internal information (bottom-up and top-down respectively); and it owns the enigmatic ability to take non-conscious decisions about where to focus attention. It is also a sentinel that triggers the subcortical mechanisms which drive social motivation to follow faces from birth and to react automatically to emotional stimuli. Through indirect connections it also activates simultaneously several cortical structures necessary to develop social cognition and to accomplish the multiattentional task required for conscious social interaction in real life settings. Genetic or non-genetic prenatal or early postnatal factors could disrupt the SC functions resulting in autism. The timing of postnatal biological disruption matches the timing of clinical autism manifestations. Astonishing coincidences between etiologies, clinical manifestations, cognitive and pathogenic autism theories on one side and SC functions on the other are disclosed in this review. Although the visual system dependent of the SC is usually considered as accessory of the LGN canonical pathway, its imprinting gives the brain a qualitatively specific functions not supplied by any other brain structure.

How wide is the cone of direct gaze?

The cone of direct gaze refers to the range of gaze deviations an observer accepts as looking directly at them. Previous experiments have calculated the width of the cone of direct gaze using the gaze deviations actually presented to the observer, however, there is considerable evidence that observers actually perceive gaze to be systematically more deviated than actually presented. Here, we examine the width of the cone of direct gaze in units of perceived gaze deviation. In doing so, we are able to disambiguate differences in width both within and between observers that are due to differences in their perception of gaze and due to differences in what observers consider to be looking at them. We suggest that this line of inquiry can offer further insight into the perception of gaze direction, and how this perception may differ in clinical populations.

How attention gates social interactions

Social interactions are at the core of social life. However, humans selectively choose their exchange partners and do not engage in all available opportunities for social encounters. In this review, we argue that attentional systems play an important role in guiding the selection of social interactions. Supported by both classic and emerging literature, we identify and characterize the three core processes-perception, interpretation, and evaluation-that interact with attentional systems to modulate selective responses to social environments. Perceptual processes facilitate attentional prioritization of social cues. Interpretative processes link attention with understanding of cues' social meanings and agents' mental states. Evaluative processes determine the perceived value of the source of social information. The interplay between attention and these three routes of processing places attention in a powerful role to manage the selection of the vast amount of social information that individuals encounter on a daily basis and, in turn, gate the selection of social interactions.

Revealing the neural time-course of direct gaze processing via spatial frequency manipulation of faces

Direct gaze is a powerful social cue signalling the attention of another person toward oneself. Here we investigated the relevance of low spatial frequency (LSF) and high spatial frequency (HSF) in facial cues for direct gaze processing. We identified two distinct peaks in the ERP response, the N170 and N240 components. These two components were related to different stimulus conditions and influenced by different spatial frequencies. In particular, larger N170 and N240 amplitudes were observed for direct gaze than for averted gaze, but only in the N240 component was this effect modulated by spatial frequency, where it was reliant in LSF information. By contrast, larger N170 and N240 components were observed for faces than for non-facial stimuli, but this effect was only modulated by spatial frequency in the N170 component, where it relied on HSF information. The present study highlights the existence of two functionally distinct components related to direct gaze processing.

Face and gaze perception in borderline personality disorder: An electrical neuroimaging study

Humans are sensitive to gaze direction from early life, and gaze has social and affective values. Borderline personality disorder (BPD) is a clinical condition characterized by emotional dysregulation and enhanced sensitivity to affective and social cues. In this study we wanted to investigate the temporal-spatial dynamics of spontaneous gaze processing in BPD. We used a 2-back-working-memory task, in which neutral faces with direct and averted gaze were presented. Gaze was used as an emotional modulator of event-related-potentials to faces. High density EEG data were acquired in 19 females with BPD and 19 healthy women, and analyzed with a spatio-temporal microstates analysis approach. Independently of gaze direction, BPD patients showed altered N170 and P200 topographies for neutral faces. Source localization revealed that the anterior cingulate and other prefrontal regions were abnormally activated during the N170 component related to face encoding, while middle temporal deactivations were observed during the P200 component. Post-task affective ratings showed that BPD patients had difficulty to disambiguate neutral gaze. This study provides first evidence for an early neural bias toward neutral faces in BPD independent of gaze direction and also suggests the importance of considering basic aspects of social cognition in identifying biological risk factors of BPD.