This study investigated the neural basis of the effect of gaze direction on facial expression processing in children with and without ASD, using event-related potential (ERP). Children with ASD (10-17-year olds) and typically developing (TD) children (9-16-year olds) were asked to determine the emotional expressions (anger or fearful) of a facial stimulus with a direct or averted gaze, and the ERPs were recorded concurrently. In TD children, faces with a congruent expression and gaze direction in approach-avoidance motivation, such as an angry face with a direct gaze (i.e., approaching motivation) and a fearful face with an averted gaze (i.e., avoidant motivation), were recognized more accurately and elicited larger N170 amplitudes than motivationally incongruent facial stimuli (an angry face with an averted gaze and a fearful face with a direct gaze). These results demonstrated the neural basis and time course of integration of facial expression and gaze direction in TD children and its impairment in children with ASD.

R. E. Lucas, E. Diener, A. Grob, E. M. Suh, and L. Shao (2000) recently argued that the core of the personality dimension of Extraversion is not sociability but a construct called reward sensitivity. This article accepts their argument that the mere preference for social interaction is not the central element of Extraversion. However, it claims that the real core of the Extraversion factor is the tendency to behave in ways that attract social attention. Data from a sample of 200 respondents were used to test the 2 hypotheses with comparisons of measures of reward sensitivity and social attention in terms of their saturation with the common variance of Extraversion measures. The results clearly showed that social attention, not reward sensitivity, represents the central feature of Extraversion.

Systemizing is the drive to analyse systems or construct systems. A recent model of psychological sex differences suggests that this is a major dimension in which the sexes differ, with males being more drawn to systemize than females. Currently, there are no self-report measures to assess this important dimension. A second major dimension of sex differences is empathizing (the drive to identify mental states and respond to these with an appropriate emotion). Previous studies find females score higher on empathy measures. We report a new self-report questionnaire, the Systemizing Quotient (SQ), for use with adults of normal intelligence. It contains 40 systemizing items and 20 control items. On each systemizing item, a person can score 2, 1 or 0, so the SQ has a maximum score of 80 and a minimum of zero. In Study 1, we measured the SQ of n = 278 adults (114 males, 164 females) from a general population, to test for predicted sex differences (male superiority) in systemizing. All subjects were also given the Empathy Quotient (EQ) to test if previous reports of female superiority would be replicated. In Study 2 we employed the SQ and the EQ with n = 47 adults (33 males, 14 females) with Asperger syndrome (AS) or high-functioning autism (HFA), who are predicted to be either normal or superior at systemizing, but impaired at empathizing. Their scores were compared with n = 47 matched adults from the general population in Study 1. In Study 1, as predicted, normal adult males scored significantly higher than females on the SQ and significantly lower on the EQ. In Study 2, again as predicted, adults with AS/HFA scored significantly higher on the SQ than matched controls, and significantly lower on the EQ than matched controls. The SQ reveals both a sex difference in systemizing in the general population and an unusually strong drive to systemize in AS/HFA. These results are discussed in relation to two linked theories: the 'empathizing-systemizing' (E-S) theory of sex differences and the extreme male brain (EMB) theory of autism.

Eye contact is a crucial social cue constituting a frequent preliminary to interaction. Thus, the perception of others' gaze may be associated with specific processes beginning with asymmetries in the detection of direct versus averted gaze. We tested this hypothesis in two behavioural experiments using realistic eye stimuli in a visual search task. We manipulated the head orientation (frontal or deviated) and the visual field (right or left) in which the target appeared at display onset. We found that direct gaze targets presented among averted gaze distractors were detected faster and better than averted gaze targets among direct gaze distractors, but only when the head was deviated. Moreover, direct gaze targets were detected very quickly and efficiently regardless of head orientation and visual field, whereas the detection of averted gaze was strongly modulated by these factors. These results suggest that gaze contact has precedence over contextual information such as head orientation and visual field.

Pictures of objects have been shown to automatically activate affordances, that is, actions that could be performed with the object. Similarly, pictures of faces are likely to activate social affordances, that is, interactions that would be possible with the person whose face is being presented. Most interestingly, if it is the face of a real person that is shown, one particular type of social interactions can even be carried out while event-related potentials (ERPs) are recorded. Indeed, subtle eye movements can be made to achieve an eye contact with the person with minimal artefacts on the EEG. The present study thus used the face of a real person to explore the electrophysiological correlates of affordances in a situation where some of them (i.e., eye contacts) are actually performed. The ERPs this person elicited were compared to those evoked by another 3D stimulus: a real dummy, and thus by a stimulus that should also automatically activate eye contact affordances but with which such affordances could then be inhibited since they cannot be carried out with an object. The photos of the person and of the dummy were used as matching stimuli that should not activate social affordances as strongly as the two 3D stimuli and for which social affordances cannot be carried out. The fronto-central N300s to the real dummy were found of greater amplitudes than those to the photos and to the real person. We propose that these greater N300s index the greater inhibition needed after the stronger activations of affordances induced by this 3D stimulus than by the photos. Such an inhibition would not have occurred in the case of the real person because eye contacts were carried out.

The relationship between facial expression and gaze processing was investigated with the Garner selective attention paradigm. In Experiment 1, participants performed expression judgments without interference from gaze, but expression interfered with gaze judgments. Experiment 2 replicated these results across different emotions. In both experiments, expression judgments occurred faster than gaze judgments, suggesting that expression was processed before gaze could interfere. In Experiments 3 and 4, the difficulty of the emotion discrimination was increased in two different ways. In both cases, gaze interfered with emotion judgments and vice versa. Furthermore, increasing the difficulty of the emotion discrimination resulted in gaze and expression interactions. Results indicate that expression and gaze interactions are modulated by discriminability. Whereas expression generally interferes with gaze judgments, gaze direction modulates expression processing only when facial emotion is difficult to discriminate.

The face conveys a rich source of non-verbal information used during social communication. While research has revealed how specific facial channels such as emotional expression are processed, little is known about the prioritization and integration of multiple cues in the face during dyadic exchanges. Classic models of face perception have emphasized the segregation of dynamic vs. static facial features along independent information processing pathways. Here we review recent behavioral and neuroscientific evidence suggesting that within the dynamic stream, concurrent changes in eye gaze and emotional expression can yield early independent effects on face judgments and covert shifts of visuospatial attention. These effects are partially segregated within initial visual afferent processing volleys, but are subsequently integrated in limbic regions such as the amygdala or via reentrant visual processing volleys. This spatiotemporal pattern may help to resolve otherwise perplexing discrepancies across behavioral studies of emotional influences on gaze-directed attentional cueing. Theoretical explanations of gaze-expression interactions are discussed, with special consideration of speed-of-processing (discriminability) and contextual (ambiguity) accounts. Future research in this area promises to reveal the mental chronometry of face processing and interpersonal attention, with implications for understanding how social referencing develops in infancy and is impaired in autism and other disorders of social cognition.

Gaze plays a crucial role in social interactions. Social Anxiety Disorder (SAD), which is associated with severe impairment of social interactions, is thus likely to exhibit disturbances of gaze perception. We conducted two experiments with SAD-patients and healthy control participants using a virtual head whose gaze could be interactively manipulated. We determined the subjective area of mutual gaze, the so-called gaze cone, and measured it prior to and after a psychotherapeutic intervention (Exp. 1). Patients exhibited larger gaze cones than control subjects. Exp. 2 varied the emotional expression of the virtual head. These data were validated using a real person (professional actor) as stimulus. Excellent reliability indices were found for our gaze cone measure. After Cognitive Behavioral Therapy, group differences in gaze cone width had disappeared. Emotional expressions were observed to modulate the gaze cone's width. Especially an angry expression caused the gaze cone to widen, possibly mediated by increased arousal. Finally, wider gaze cones in SAD-patients could be demonstrated for virtual and for real human heads confirming the ecological validity of virtual heads. The findings are of relevance for a more fine-grained understanding of perceptual processes in patients with SAD.

Subjects were asked to detect visual, laterally presented reaction signals preceded by head-body cue stimuli in a spatial cueing task. A head rotated towards the reaction signal combined with a front view of a body resulted in shorter reaction times in comparison to the front view of a head and body. In contrast, a cue showing the head and body rotated towards the reaction signal did not result in such a facilitation in reaction times. The results suggest that the brain mechanisms involved in social attention orienting integrate ventrally processed visual information from the head and body orientation. A cue signaling that the other person, in his or her frame of reference, has an averted attention direction shifts the observer's own attention in the same direction.

Gaze direction is known to be an important factor in regulating social interaction. Recent evidence suggests that direct and averted gaze can signal the sender's motivational tendencies of approach and avoidance, respectively. We aimed at determining whether seeing another person's direct vs. averted gaze has an influence on the observer's neural approach-avoidance responses. We also examined whether it would make a difference if the participants were looking at the face of a real person or a picture. Measurements of hemispheric asymmetry in the frontal electroencephalographic activity indicated that another person's direct gaze elicited a relative left-sided frontal EEG activation (indicative of a tendency to approach), whereas averted gaze activated right-sided asymmetry (indicative of avoidance). Skin conductance responses were larger to faces than to control objects and to direct relative to averted gaze, indicating that faces, in general, and faces with direct gaze, in particular, elicited more intense autonomic activation and strength of the motivational tendencies than did control stimuli. Gaze direction also influenced subjective ratings of emotional arousal and valence. However, all these effects were observed only when participants were facing a real person, not when looking at a picture of a face. This finding was suggested to be due to the motivational responses to gaze direction being activated in the context of enhanced self-awareness by the presence of another person. The present results, thus, provide direct evidence that eye contact and gaze aversion between two persons influence the neural mechanisms regulating basic motivational-emotional responses and differentially activate the motivational approach-avoidance brain systems.

Clinical observation suggests that social phobia is characterised by eye avoidance in social interaction, reflecting an exaggerated social sensitivity. These reports are consistent with cognitive models of social phobia that emphasize the role of interpersonal processing biases. Yet, these observations have not been verified empirically, nor has the psychophysiological basis of eye avoidance been examined. This is the first study to use an objective psychophysiological marker of visual attention (the visual scanpath) to examine directly how social phobia subjects process interpersonal (facial expression) stimuli. An infra-red corneal reflection technique was used to record visual scanpaths in response to neutral, happy and sad face stimuli in 15 subjects with social phobia, and 15 age and sex-matched normal controls. The social phobia subjects showed an avoidance of facial features, particularly the eyes, but extensive scanning of non-features, compared with the controls. These findings suggest that attentional strategies for the active avoidance of salient facial features are an important marker of interpersonal cues in social phobia. Visual scanpath evidence may, therefore, have important implications for clinical intervention.

The fear of being scrutinised is a core feature of social anxiety disorder and socially anxious individuals overestimate being 'looked at'. A recent development in the vision sciences is a reliable psychophysical index of the range of eye gaze angles judged as being directed at oneself (Cone of Direct Gaze: CoDG). We tested the CoDG as a measure of

Faces are visual objects in our environment that provide strong social cues, with the eyes assuming particular importance. Here we show that the perceived attractiveness of an unfamiliar face increases brain activity in the ventral striatum of the viewer when meeting the person's eye, and decreases activity when eye gaze is directed away. Depending on the direction of gaze, attractiveness can thus activate dopaminergic regions that are strongly linked to reward prediction, indicating that central reward systems may be engaged during the initiation of social interactions.

Perception and eye movements are affected by culture. Adults from Eastern societies (e.g. China) display a disposition to process information holistically, whereas individuals from Western societies (e.g. Britain) process information analytically. Recently, this pattern of cultural differences has been extended to face processing. Adults from Eastern cultures fixate centrally towards the nose when learning and recognizing faces, whereas adults from Western societies spread fixations across the eye and mouth regions. Although light has been shed on how adults can fixate different areas yet achieve comparable recognition accuracy, the reason why such divergent strategies exist is less certain. Although some argue that culture shapes strategies across development, little direct evidence exists to support this claim. Additionally, it has long been claimed that face recognition in early childhood is largely reliant upon external rather than internal face features, yet recent studies have challenged this theory. To address these issues, we tested children aged 7-12 years of age from the UK and China with an old/new face recognition paradigm while simultaneously recording their eye movements. Both populations displayed patterns of fixations that were consistent with adults from their respective cultural groups, which 'strengthened' across development as qualified by a pattern classifier analysis. Altogether, these observations suggest that cultural forces may indeed be responsible for shaping eye movements from early childhood. Furthermore, fixations made by both cultural groups almost exclusively landed on internal face regions, suggesting that these features, and not external features, are universally used to achieve face recognition in childhood.

In this study, we use separate eye-tracking measurements and functional magnetic resonance imaging to investigate the neuronal and behavioral response to painted portraits with direct versus averted gaze. We further explored modulatory effects of several painting characteristics (premodern vs modern period, influence of style and pictorial context). In the fMRI experiment, we show that the direct versus averted gaze elicited increased activation in lingual and inferior occipital and the fusiform face area, as well as in several areas involved in attentional and social cognitive processes, especially the theory of mind: angular gyrus/temporo-parietal junction, inferior frontal gyrus and dorsolateral prefrontal cortex. The additional eye-tracking experiment showed that participants spent more time viewing the portrait's eyes and mouth when the portrait's gaze was directed towards the observer. These results suggest that static and, in some cases, highly stylized depictions of human beings in artistic portraits elicit brain activation commensurate with the experience of being observed by a watchful intelligent being. They thus involve observers in implicit inferences of the painted subject's mental states and emotions. We further confirm the substantial influence of representational medium on brain activity.

Attractive faces are appealing: We like to look at them, and we like to be looked at by them. We presented attractive and unattractive smiling and neutral faces containing identical eye regions with different gaze directions. Participants judged whether or not a face looked directly at them. Overall, attractive faces increased participants' tendency to perceive eye contact, consistent with a self-referential positivity bias. However, attractiveness effects were modulated by facial expression and gender: For female faces, observers more likely perceived eye contact in attractive than unattractive faces, independent of expression. For male faces, attractiveness effects were limited to neutral expressions and were absent in smiling faces. A signal detection analysis elucidated a systematic pattern in which (a) smiling faces, but not highly attractive faces, reduced sensitivity in gaze perception overall, and (b) attractiveness had a more consistent impact on bias than sensitivity measures. We conclude that combined influences of attractiveness, expression, and gender determine the formation of an overall impression when deciding which individual's interest in oneself may be beneficial and should be reciprocated.

When subjects viewed straight and turned eyes that were isolated singly or in pairs from a head that was straight or turned, they underestimated their true direction of gaze. They also underestimated the direction of head turn when both eyes were closed. However, the judged direction of gaze was improved when the eyes were layered against the heads. Judged direction of averted gaze was primarily based on the abducting eye. The effect that the deviation between an eye's optical axis and its true direction of gaze (angle kappa) has on its judged direction of gaze is discussed.

In order to clarify the morphological uniqueness of the human eye and to obtain cues to understanding its adaptive significance, we compared the external morphology of the primate eye by measuring nearly half of all extant primate species. The results clearly showed exceptional features of the human eye: (1) the exposed white sclera is void of any pigmentation, (2) humans possess the largest ratio of exposed sclera in the eye outline, and (3) the eye outline is extraordinarily elongated in the horizontal direction. The close correlation of the parameters reflecting (2) and (3) with habitat type or body size of the species examined suggested that these two features are adaptations for extending the visual field by eyeball movement, especially in the horizontal direction. Comparison of eye coloration and facial coloration around the eye suggested that the dark coloration of exposed sclera of nonhuman primates is an adaptation to camouflage the gaze direction against other individuals and/or predators, and that the white sclera of the human eye is an adaptation to enhance the gaze signal. The uniqueness of human eye morphology among primates illustrates the remarkable difference between human and other primates in the ability to communicate using gaze signals.

For social species such as primates, the recognition of conspecifics is crucial for their survival. As demonstrated by the 'face inversion effect', humans are experts in recognizing faces and unlike objects, recognize their identity by processing it configurally. The human face, with its distinct features such as eye-whites, eyebrows, red lips and cheeks signals emotions, intentions, health and sexual attraction and, as we will show here, shares important features with the primate behind. Chimpanzee females show a swelling and reddening of the anogenital region around the time of ovulation. This provides an important socio-sexual signal for group members, who can identify individuals by their behinds. We hypothesized that chimpanzees process behinds configurally in a way humans process faces. In four different delayed matching-to-sample tasks with upright and inverted body parts, we show that humans demonstrate a face, but not a behind inversion effect and that chimpanzees show a behind, but no clear face inversion effect. The findings suggest an evolutionary shift in socio-sexual signalling function from behinds to faces, two hairless, symmetrical and attractive body parts, which might have attuned the human brain to process faces, and the human face to become more behind-like.

The interpretation of interpersonal gaze behavior requires the use of complex cognitive processes and guides social interactions. Among a variety of different gaze characteristics, gaze direction and gaze duration modulate crucially the meaning of the

Common maxims about beauty suggest that attractiveness is not important in life. In contrast, both fitness-related evolutionary theory and socialization theory suggest that attractiveness influences development and interaction. In 11 meta-analyses, the authors evaluate these contradictory claims, demonstrating that (a) raters agree about who is and is not attractive, both within and across cultures; (b) attractive children and adults are judged more positively than unattractive children and adults, even by those who know them; (c) attractive children and adults are treated more positively than unattractive children and adults, even by those who know them; and (d) attractive children and adults exhibit more positive behaviors and traits than unattractive children and adults. Results are used to evaluate social and fitness-related evolutionary theories and the veracity of maxims about beauty.

We report seven experiments that investigate the influence that head orientation exerts on the perception of eye-gaze direction. In each of these experiments, participants were asked to decide whether the eyes in a brief and masked presentation were looking directly at them or were averted. In each case, the eyes could be presented alone, or in the context of congruent or incongruent stimuli In Experiment 1A, the congruent and incongruent stimuli were provided by the orientation of face features and head outline. Discrimination of gaze direction was found to be better when face and gaze were congruent than in both of the other conditions, an effect that was not eliminated by inversion of the stimuli (Experiment 1B). In Experiment 2A, the internal face features were removed, but the outline of the head profile was found to produce an identical pattern of effects on gaze discrimination, effects that were again insensitive to inversion (Experiment 2B) and which persisted when lateral displacement of the eyes was controlled (Experiment 2C). Finally, in Experiment 3A, nose angle was also found to influence participants' ability to discriminate direct gaze from averted gaze, but here the effect was eliminated by inversion of the stimuli (Experiment 3B). We concluded that an image-based mechanism is responsible for the influence of head profile on gaze perception, whereas the analysis of nose angle involves the configural processing of face features.

Recent research suggests that eye-gaze direction modulates perceived emotional expression. Here we explore the extent to which emotion affects interpretation of attention direction. We captured three-dimensional face models of 8 actors expressing happy, fearful, angry and neutral emotions. From these 3D models 9 views were extracted (0 degrees , 2 degrees , 4 degrees , 6 degrees , 8 degrees to the left and right). These stimuli were randomly presented for 150 ms. Using a forced-choice paradigm 28 participants judged for each face whether or not it was attending to them. Two conditions were tested: either the whole face was visible, or the eyes were covered. In both conditions happy faces elicited most

Gaze perception is an important social skill, as it portrays information about what another person is attending to. Gaze direction has been shown to affect interpretation of emotional expression. Here the authors investigate whether the emotional facial expression has a reciprocal influence on interpretation of gaze direction. In a forced-choice yes-no task, participants were asked to judge whether three faces expressing different emotions (anger, fear, happiness, and neutral) in different viewing angles were looking at them or not. Happy faces were more likely to be judged as looking at the observer than were angry, fearful, or neutral faces. Angry faces were more often judged as looking at the observer than were fearful and neutral expressions. These findings are discussed on the background of approach and avoidance orientation of emotions and of the self-referential positivity bias.

Two biases in perceived gaze direction have been observed when eye and head orientation are not aligned. An overshoot effect indicates that perceived gaze direction is shifted away from head orientation (i.e., a repulsive effect), whereas a towing effect indicates that perceived gaze direction falls in between head and eye orientation (i.e., an attraction effect). In the 60s, three influential papers have been published with respect to the effect of head orientation on perceived gaze direction (Gibson and Pick, 1963; Cline, 1967; Anstis et al., 1969). Throughout the years, the results of two of these (Gibson and Pick, 1963; Cline, 1967) have been interpreted differently by a number of authors. In this paper, we critically discuss potential sources of confusion that have led to differential interpretations of both studies. At first sight, the results of Cline (1967), despite having been a major topic of discussion, unambiguously seem to indicate a towing effect whereas Gibson and Pick's (1963) results seem to be the most ambiguous, although they have never been questioned in the literature. To shed further light on this apparent inconsistency, we repeated the critical experiments reported in both studies. Our results indicate an overshoot effect in both studies.

Previous research has shown that physiological arousal and attentional responses to eye contact are modulated by one's knowledge of whether they are seen by another person. Recently it was shown that this 'eye contact effect' can be elicited without seeing another person's eyes at all. We aimed to investigate whether the eye contact effect is actually triggered by the mere knowledge of being seen by another individual, i.e. even in a condition when the perceiver does not see the other person at all. We measured experienced self-awareness and both autonomic and brain activity responses while participants were facing another person (a model) sitting behind a window. We manipulated the visibility of the model and the participants' belief of whether or not the model could see them. When participants did not see the model but believed they were seen by the model, physiological responses were attenuated in comparison to when both parties saw each other. However, self-assessed public self-awareness was not attenuated in this condition. Thus, two requirements must be met for physiological responses to occur in response to eye contact: an experience of being seen by another individual and an experience of seeing the other individual.

Progress in our understanding of autism spectrum disorder (ASD) has recently been sought by characterising how systematic differences in canonical neural computations employed across the sensory cortex might contribute to clinical symptoms in diverse sensory, cognitive, and social domains. A key proposal is that ASD is characterised by reduced divisive normalisation of sensory responses. This provides a bridge between genetic and molecular evidence for an increased ratio of cortical excitation to inhibition in ASD and the functional characteristics of sensory coding that are relevant for understanding perception and behaviour. Here we tested this hypothesis in the context of gaze processing (i.e., the perception of other people's direction of gaze), a domain with direct relevance to the core diagnostic features of ASD. We show that reduced divisive normalisation in gaze processing is associated with specific predictions regarding the psychophysical effects of sensory adaptation to gaze direction, and test these predictions in adults with ASD. We report compelling evidence that both divisive normalisation and sensory adaptation occur robustly in adults with ASD in the context of gaze processing. These results have important theoretical implications for defining the types of divisive computations that are likely to be intact or compromised in this condition (e.g., relating to local vs distal control of cortical gain). These results are also a strong testament to the typical sensory coding of gaze direction in ASD, despite the atypical responses to others' gaze that are a hallmark feature of this diagnosis.

Perceptual mechanisms are generally flexible or

An explication of the neural substrates for social perception is an important component in the emerging field of social cognitive neuroscience and is relevant to the field of cognitive neuroscience as a whole. Prior studies from our laboratory have demonstrated that passive viewing of biological motion (Pelphrey, Mitchell, et al., 2003; Puce et al., 1998) activates the posterior superior temporal sulcus (STS ) region. Furthermore, recent evidence has shown that the perceived context of observed gaze shifts (Pelphrey, Singerman, et al., 2003; Pelphrey et al., 2004) modulates STS activity. Here, using event-related functional magnetic resonance imaging at 4 T, we investigated brain activity in response to passive viewing of goal- and nongoal-directed reaching-to-grasp movements. Participants viewed an animated character making reaching-to-grasp movements either toward (correct) or away (incorrect) from a blinking dial. Both conditions evoked significant posterior STS activity that was strongly right lateralized. By examining the time course of the blood oxygenation level-dependent response from areas of activation, we observed a functional dissociation. Incorrect trials evoked significantly greater activity in the STS than did correct trials, while an area posterior and inferior to the STS (likely corresponding to the MT/ V5 complex) responded equally to correct and incorrect movements. Parietal cortical regions, including the superior parietal lobule and the anterior intraparietal sulcus, also responded equally to correct and incorrect movements, but showed evidence for differential responding based on the hand and arm (left or right) of the animated character used to make the reaching-to-grasp movement. The results of this study further suggest that a region of the right posterior STS is involved in analyzing the intentions of other people's actions and that activity in this region is sensitive to the context of observed biological motions.

The visual scanpaths of five high-functioning adult autistic males and five adult male controls were recorded using an infrared corneal reflection technique as they viewed photographs of human faces. Analyses of the scanpath data revealed marked differences in the scanpaths of the two groups. The autistic participants viewed nonfeature areas of the faces significantly more often and core feature areas of the faces (i.e., eyes, nose, and mouth) significantly less often than did control participants. Across both groups of participants, scanpaths generally did not differ as a function of the instructions given to the participants (i.e.,

Cells selectively responsive to the face have been found in several visual sub-areas of temporal cortex in the macaque brain. These include the lateral and ventral surfaces of inferior temporal cortex and the upper bank, lower bank and fundus of the superior temporal sulcus (STS). Cells in the different regions may contribute in different ways to the processing of the facial image. Within the upper bank of the STS different populations of cells are selective for different views of the face and head. These cells occur in functionally discrete patches (3-5 mm across) within the STS cortex. Studies of output connections from the STS also reveal a modular anatomical organization of repeating 3-5 mm patches connected to the parietal cortex, an area thought to be involved in spatial awareness and in the control of attention. The properties of some cells suggest a role in the discrimination of heads from other objects, and in the recognition of familiar individuals. The selectivity for view suggests that the neural operations underlying face or head recognition rely on parallel analyses of different characteristic views of the head, the outputs of these view-specific analyses being subsequently combined to support view-independent (object-centred) recognition. An alternative functional interpretation of the sensitivity to head view is that the cells enable an analysis of 'social attention', i.e. they signal where other individuals are directing their attention. A cell maximally responsive to the left profile thus provides a signal that the attention (of another individual) is directed to the observer's left. Such information is useful for analysing social interactions between other individuals.(ABSTRACT TRUNCATED AT 250 WORDS)

Several recent studies have begun to examine the neurocognitive mechanisms involved in perceiving and responding to eye contact, a salient social signal of interest and readiness for interaction. Laboratory experiments measuring observers' responses to pictorial instead of live eye gaze cues may, however, only vaguely approximate the real-life affective significance of gaze direction cues. To take this into account, we measured event-related brain potentials and subjective affective responses in healthy adults while viewing live faces with a neutral expression through an electronic shutter and faces as pictures on a computer screen. Direct gaze elicited greater face-sensitive N170 amplitudes and early posterior negativity potentials than averted gaze or closed eyes, but only in the live condition. The results show that early-stage processing of facial information is enhanced by another person's direct gaze when the person is faced live. We propose that seeing a live face with a direct gaze is processed more intensely than a face with averted gaze or closed eyes, as the direct gaze is capable of intensifying the feeling of being the target of the other's interest and intentions. These results may have implications for the use of pictorial stimuli in the social cognition studies.

The neuro-developmental disorders of Williams syndrome (WS) and autism can reveal key components of social cognition. Eye-tracking techniques were applied in two tasks exploring attention to pictures containing faces. Images were (i) scrambled pictures containing faces or (ii) pictures of scenes with embedded faces. Compared to individuals who were developing typically, participants with WS and autism showed atypicalities of gaze behaviour. Individuals with WS showed prolonged face gaze across tasks, relating to the typical WS social phenotype. Participants with autism exhibited reduced face gaze, linking to a lack of interest in socially relevant information. The findings are interpreted in terms of wider issues regarding socio-cognition and attention mechanisms.

Judging where others look is crucial for many social and cognitive functions. Past accounts of gaze perception emphasize geometrical cues from the seen eye. Human eyes have a unique morphology, with a large white surround (sclera) to the dark iris that may have evolved to enhance gaze processing. Here we show that the contrast polarity of seen eyes has a powerful influence on gaze perception. Adult observers are highly inaccurate in judging gaze direction for images of human eyes with negative contrast polarity (regardless of whether the surrounding face is positive or negative), even though negative images of eyes preserve the geometric properties of positives that are judged accurately. The detrimental effect of negative contrast polarity is much larger for gaze perception than for other directional judgements (e.g. judging which way a head is turned). These results suggest an 'expert' system for gaze perception, which always treats the darker region of a seen eye as the part that does the looking.

Eye gaze direction and facial expression are important social cues. Recent studies have shown that emotional expression affects interpretation of gaze direction in such a way that positive emotions are more favorably interpreted as making eye contact than negative or neutral expressions. Here we examine whether stress affects this positivity bias in gaze perception. Stress was induced in 25 healthy young adults by means of the cold pressure stress test (CPS), 24 participants serving as controls. Stimuli were created from three-dimensional face models of 8 actors expressing happy, fearful, angry and neutral emotions. From each of these 3D models we extracted 9 different views (0 degrees , 2 degrees , 4 degrees , 6 degrees and 8 degrees to the left and to the right). This resulted in 288 stimuli, which were randomly presented for 700 ms. Using a forced choice paradigm participants judged whether or not each face was looking at them. The results show that the CPS group falsely interpreted faces with averted gaze direction as making eye contact more often than did controls, independent of the expressed emotion. These results suggest that a stress-induced raise in cortisol level increases the sense of being looked at.

To characterize the neural correlates of being personally involved in social interaction as opposed to being a passive observer of social interaction between others we performed an fMRI study in which participants were gazed at by virtual characters (ME) or observed them looking at someone else (OTHER). In dynamic animations virtual characters then showed socially relevant facial expressions as they would appear in greeting and approach situations (SOC) or arbitrary facial movements (ARB). Differential neural activity associated with ME>OTHER was located in anterior medial prefrontal cortex in contrast to the precuneus for OTHER>ME. Perception of socially relevant facial expressions (SOC>ARB) led to differentially increased neural activity in ventral medial prefrontal cortex. Perception of arbitrary facial movements (ARB>SOC) differentially activated the middle temporal gyrus. The results, thus, show that activation of medial prefrontal cortex underlies both the perception of social communication indicated by facial expressions and the feeling of personal involvement indicated by eye gaze. Our data also demonstrate that distinct regions of medial prefrontal cortex contribute differentially to social cognition: whereas the ventral medial prefrontal cortex is recruited during the analysis of social content as accessible in interactionally relevant mimic gestures, differential activation of a more dorsal part of medial prefrontal cortex subserves the detection of self-relevance and may thus establish an intersubjective context in which communicative signals are evaluated.

To date, only little is known about the self-directed perception and processing of subtle gaze cues in social anxiety that might however contribute to excessive feelings of being looked at by others. Using a web-based approach, participants (n=174) were asked whether or not briefly (300 ms) presented facial expressions modulated in gaze direction (0 degrees , 2 degrees , 4 degrees , 6 degrees , 8 degrees ) and valence (angry, fearful, happy, neutral) were directed at them. The results demonstrate a positive, linear relationship between self-reported social anxiety and stronger self-directed perception of others' gaze directions, particularly for negative (angry, fearful) and neutral expressions. Furthermore, faster responding was found for gaze more clearly directed at socially anxious individuals (0 degrees , 2 degrees , and 4 degrees ) suggesting a tendency to avoid direct gaze. In sum, the results illustrate an altered self-directed perception of subtle gaze cues. The possibly amplifying effects of social stress on biased self-directed perception of eye gaze are discussed.

Atypical processing of eye contact is one of the significant characteristics of individuals with autism, but the mechanism underlying atypical direct gaze processing is still unclear. This study used a visual search paradigm to examine whether the facial context would affect direct gaze detection in children with autism. Participants were asked to detect target gazes presented among distracters with different gaze directions. The target gazes were either direct gaze or averted gaze, which were either presented alone (Experiment 1) or within facial context (Experiment 2). As with the typically developing children, the children with autism, were faster and more efficient to detect direct gaze than averted gaze, whether or not the eyes were presented alone or within faces. In addition, face inversion distorted efficient direct gaze detection in typically developing children, but not in children with autism. These results suggest that children with autism use featural information to detect direct gaze, whereas typically developing children use configural information to detect direct gaze.

BACKGROUND: This study investigated whether another person's social attention, specifically the direction of their eye gaze, and a non-social directional cue, an arrow, triggered reflexive orienting in children with and without autism in an experimental situation. METHODS: Children with autism and typically developed children participated in one of two experiments. Both experiments involved the localization of a target that appeared to the left or right of the fixation point. Before the target appeared, the participant's attention was cued to the left or right by either an arrow or the direction of eye gaze on a computerized face. RESULTS: Children with autism were slower to respond, which suggests a slight difference in the general cognitive ability of the groups. In Experiment 1, although the participants were instructed to disregard the cue and the target was correctly cued in only 50% of the trials, both groups of children responded significantly faster to cued targets than to uncued targets, regardless of the cue. In Experiment 2, children were instructed to attend to the direction opposite that of the cues and the target was correctly cued in only 20% of the trials. Typically developed children located targets cued by eye gaze more quickly, while the arrow cue did not trigger such reflexive orienting in these children. However, both social and non-social cues shifted attention to the cued location in children with autism. CONCLUSION: These results indicate that eye gaze attracted attention more effectively than the arrow in typically developed children, while children with autism shifted their attention equally in response to eye gaze and arrow direction, failing to show preferential sensitivity to the social cue. Difficulty in shifting controlled attention to the instructed side was also found in children with autism.

Does movement of the eyes in one or another direction function as an automatic attentional cue to a location of interest? Two experiments explored the directional movement of the eyes in a full face for speed of detection of an aftercoming location target in young people with autism and in control participants. Our aim was to investigate whether a low-level perceptual impairment underlies the delay in gaze following characteristic of autism. The participants' task was to detect a target appearing on the left or right of the screen either 100 ms or 800 ms after a face cue appeared with eyes averting to the left or right. Despite instructions to ignore eye-movement in the face cue, people with autism and control adolescents were quicker to detect targets that had been preceded by an eye movement cue congruent with target location compared with targets preceded by an incongruent eye movement cue. The attention shifts are thought to be reflexive because the cue was to be ignored, and because the effect was found even when cue-target duration was short (100 ms). Because (experiment two) the effect persisted even when the face was inverted, it would seem that the direction of movement of eyes can provide a powerful (involuntary) cue to a location.

The authors measured observers' ability to determine direction of gaze toward an object in space. In Experiment 1, they determined the difference threshold for determining whether a live

Gaze direction is an important social signal in both human and nonhuman primates, providing information about conspecifics' attention, interests, and intentions. Single-unit recordings in macaques have revealed neurons selective for others' specific gaze direction. A parallel functional organization in the human brain is indicated by gaze-adaptation experiments, in which systematic distortions in gaze perception following prolonged exposure to static face images reveal dynamic interactions in local cortical circuitry. However, our understanding of the influence of high-level social cognition on these processes in monkeys and humans is still rudimentary. Here we show that the attribution of a mental state to another person determines the way in which the human brain codes observed gaze direction. Specifically, we convinced observers that prerecorded video sequences of an experimenter gazing left or right were a live video link to an adjacent room. The experimenter wore mirrored goggles that observers believed were either transparent such that the person could see, or opaque such that the person could not see. The effects of adaptation were enhanced under the former condition relative to the latter, indicating that high-level sociocognitive processes shape and modulate sensory coding of observed gaze direction.

Perception of gaze direction depends not only on the position of the irises within the looker's eyes but also on the orientation of the looker's head. A simple analysis of the geometry of gaze direction predicts this dependence. This analysis is applied to explain the Wollaston effect, the Mona Lisa effect, and the newly presented Mirror gaze effect. In an experiment synthetic faces were used in which the position of the iris and the angle of head rotation were varied. Different groups of subjects judged iris position, head rotation, and gaze direction of the same stimuli. The results illustrate how cues of iris location and head orientation interact to determine perceived gaze direction.

The perception of a looker's gaze direction depends not only on iris eccentricity (the position of the looker's irises within the sclera) but also on the orientation of the lookers' head. One among several potential cues of head orientation is face eccentricity, the position of the inner features of the face (eyes, nose, mouth) within the head contour, as viewed by the observer. For natural faces this cue is confounded with many other head-orientation cues, but in schematic faces it can be studied in isolation. Salient novel illustrations of the effectiveness of face eccentricity are 'Necker faces', which involve equal iris eccentricities but multiple perceived gaze directions. In four experiments, iris and face eccentricity in schematic faces were manipulated, revealing strong and consistent effects of face eccentricity on perceived gaze direction, with different types of tasks. An additional experiment confirmed the 'Mona Lisa' effect with this type of stimuli. Face eccentricity most likely acted as a simple but robust cue of head turn. A simple computational account of combined effects of cues of eye and head turn on perceived gaze direction is presented, including a formal condition for the perception of direct gaze. An account of the 'Mona Lisa' effect is presented.

Accurately perceiving self-referential social signals, particularly eye contact, is critical to social adaptation. Schizophrenia is often accompanied by deficits in social cognition, but it is unclear whether this includes gaze discrimination deficits. This study investigated whether eye-contact perception is preserved or impaired and if it is related to symptoms and broader socioemotional functioning in schizophrenia. Twenty-six participants with schizophrenia (SCZ) and 23 healthy controls (HC) made eye-contact judgments for faces in varying gaze direction (from averted to direct in ten 10% increments), head orientation (forward, 30 degrees averted), and emotion (neutral, fearful). Psychophysical analyses for forward faces showed that SCZ began endorsing eye contact with weaker eye-contact signal and their eye-contact perception was less of a dichotomous function, as compared with HC. SCZ were more likely than HC to endorse eye contact when gaze was ambiguous, and this overperception of eye contact was modulated by head orientation and emotion. Overperception of eye contact was associated with more severe negative symptoms. Decreased categorical gaze perception explained variance of socioemotional deficits in schizophrenia after taking basic neurocognition into consideration, suggesting the relationship was not solely due to a general deficit problem. These results were discussed in relation to the nature of categorical gaze perception and its significance to clinical and functional presentations of schizophrenia.

A visual-search paradigm was used to explore the relative ease with which the direction of gaze can be detected. Straight-gaze stimuli were presented as targets within a variable number of distractors with left-averted or right-averted gaze. Reaction time in this case was compared with that when either the left-averted or right-averted gaze stimuli were the targets among distractors of the two remaining gaze directions. The data were examined for the existence of a search asymmetry favoring the straight-gaze targets. Such an asymmetry was found with stimuli that were realistically drawn renditions of pairs of human eyes, as well as with similar schematic stimuli representing pairs of human eyes. The asymmetry, however, was not found with geometric control stimuli, which also presented the critical feature in the central, the left-lateral, or the right-lateral position within the stimulus, but were not eyelike. It was also not found for schematic stimuli consisting of only one eye. It was concluded that the straight gaze direction is a special stimulus with eyelike stimuli, which the visual system is set up to process faster and with fewer errors than averted gaze directions. The results are discussed in terms of the evolutionary significance of the straight gaze direction.