Abrupt onsets and gaze direction cues trigger independent reflexive attentional effects

A common and specialized neural code for social attention triggered by eye gaze and biological motion

Humans appear to be endowed with the ability to readily share attention with interactive partners through the utilization of social direction cues, such as eye gaze and biological motion (BM). Here, we investigated the specialized brain mechanism underlying this fundamental social attention ability by incorporating different types of social (i.e., BM, gaze) and non-social (arrow) cues and combining functional magnetic resonance imaging (fMRI) with a modified central cueing paradigm. Using multi-voxel pattern analysis (MVPA), we found that although gaze- and BM-mediated attentional orienting could be decoded from neural activity in a wide range of brain areas, only the right anterior and posterior superior temporal sulcus (aSTS and pSTS) could specifically decode attentional orienting triggered by social but not non-social cues. Critically, cross-category MVPA further revealed that social attention could be decoded across BM and gaze cues in the right STS and the right superior temporal gyrus (STG). However, these regions could not decode attentional orienting across social and non-social cues. These findings together provide evidence for the existence of a specialized social attention module in the human brain, with the right STS/STG being the critical neural site dedicated to social attention.

Social cues tip the scales in emotional processing of complex pictures

Perception of a picture is influenced by the social information and emotional value it carries for the viewer. There are still many unanswered questions about how social and emotional processing are related, but it is clear they involve overlapping brain areas and are cognitively interconnected. Yet studies of emotion processing using standardized picture datasets typically leave the social content in the pictures free to vary. In a few studies where the social content has been measured, it correlated with emotional arousal and valence. Here we tested the association between social and emotional content orthogonally, by selecting a similar number of pictures in four categories varying in presence of nonverbal social cues (e.g., gestures, facial expression, body language) and emotional content (neutral, negative). Across two studies, participants (N = 698 in total) provided three ratings for each picture: social relevance (defined as the self-reported use of social cues to understand the picture), valence, and arousal. Despite our best effort to balance the presence of social cues between negative and neutral pictures, ratings of social relevance were strongly associated with ratings of arousal and, to a lesser extent, with valence. These findings likely reflect the intertwined nature of social and emotional processing, which has implications for the neurobiology underlying them, how these systems develop, and how picture databases are used in research.

Visual mental imagery of nonpredictive central social cues triggers automatic attentional orienting

Previous research has demonstrated that social cues (e.g., eye gaze, walking direction of biological motion) can automatically guide people's focus of attention, a well-known phenomenon called social attention. The current research shows that voluntarily generated social cues via visual mental imagery, without being physically presented, can produce robust attentional orienting similar to the classic social attentional orienting effect. Combining a visual imagery task with a dot-probe task, we found that imagining a non-predictive gaze cue could orient attention towards the gazed-at hemifield. Such attentional effect persisted even when the imagery gaze cue was counter-predictive of the target hemifield, and could be generalized to biological motion cue. Besides, this effect could not be simply attributed to low-level motion signal embedded in gaze cues. More importantly, an eye-tracking experiment carefully monitoring potential eye movements demonstrated the imagery-induced attentional orienting effect induced by social cues, but not by non-social cues (i.e., arrows), suggesting that such effect is specialized to visual imagery of social cues. These findings accentuate the demarcation between social and non-social attentional orienting, and may take a preliminary step in conceptualizing voluntary visual imagery as a form of internally directed attention.

The mechanism for the specificity of gaze direction: Inhibiting background location

The experiment combined the spatial Stroop paradigm to examine the effect of background location on the perception of arrow or gaze direction in the vertical dimension by manipulating the congruence between the target direction and background location, and to validate a possible cognitive mechanism for gaze direction specificity - inhibiting background location. The results showed that when subjects were required to identify the target direction in a Stroop task (Experiment 1), the gaze cue failed to induce the Stroop effect. However, when subjects were required to judge the congruence between the target direction and the background location (Experiment 2), the gaze cue and the arrow cue both induced the Stroop effect. This suggests that " inhibiting background location" is responsible for the elimination of the spatial Stroop effect by gaze direction, which may one of the mechanisms for gaze direction specificity.

The Influence of Competing Social and Symbolic Cues on Observers' Gaze Behaviour

The effects of social (eye gaze, pointing gestures) and symbolic (arrows) cues on observers' attention are often studied by presenting such cues in isolation and at fixation. Here, we extend this work by embedding cues in natural scenes. Participants were presented with a single cue (Experiment 1) or a combination of cues (Experiment 2) embedded in natural scenes and were asked to 'simply look at the images' while their eye movements were recorded to assess the effects of the cues on (overt) attention. Single-gaze and pointing cues were fixated for longer than arrows but at the cost of shorter dwell times on the cued object. When presented together, gaze and pointing cues were fixated faster and for longer than simultaneously presented arrows. Attention to the cued object depended on the combination of cues and whether both cues were directed towards or away from the target object. Together, the findings confirm earlier observations that people attract attention more strongly than arrows but that arrows more strongly direct attention.

People with schizophrenia do not show the normal benefits of social versus nonsocial attentional cues

OBJECTIVE

Schizophrenia is associated with impairments in social motivation. Social attention has been proposed as an underlying mechanism for social motivation. However, studies in schizophrenia have rarely examined social attention, and none of these studies examined the effects with rapidly presented stimuli.

METHOD

The current study examined whether individuals with schizophrenia have reduced social attention and whether reduced social attention was related to social motivation deficits (measured with the Clinical Assessment Interview for Negative Symptoms) and decreased social functioning (Role Functioning Scale). Thirty-seven outpatients with schizophrenia and 29 healthy participants completed a gaze cueing task with directional social cues (eye gaze) and nonsocial cues (arrows) at varying stimulus onset asynchronies.

RESULTS

As predicted, schizophrenia participants had reduced social attention relative to nonsocial attention, compared with healthy participants. Healthy participants were quicker to respond to social cues than nonsocial cues, but schizophrenia participants did not exhibit this same pattern. Schizophrenia participants showed higher accuracy when targets appeared in the same location as a directional cue (i.e., congruency) for nonsocial, but not social, cues. Contrary to expectations, reduced social attention was not significantly correlated with clinically rated social motivation deficits or decreased social functioning in the schizophrenia group.

CONCLUSION

These findings provide evidence for social attention deficits in schizophrenia, but without a clear mapping of its influence on social motivation. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Heritability of reflexive social attention triggered by eye gaze and walking direction: common and unique genetic underpinnings

BACKGROUND

Social attention ability is crucial for human adaptive social behaviors and interpersonal communications, and the malfunction of which has been implicated in autism spectrum disorder (ASD), a highly genetic neurodevelopmental disorder marked by striking social deficits.

METHODS

Using a classical twin design, the current study investigated the genetic contribution to individual variation in social and non-social attention abilities, and further probed their potential genetic linkage. Moreover, individual autistic traits were further measured in an independent group of non-twin participants to examine the hypothetical link between the core social attention ability and ASD.

RESULTS

We found reliable genetic influences on the social attentional effects induced by two distinct cues (eye gaze and walking direction), with 91% of their covariance accounted for by common genetic effects. However, no evidence of heritability or shared genetic effects was observed for the attentional effect directed by a non-social cue (i.e. arrow direction) and its correlation with the social attention ability. Remarkably, one's autistic traits could well predict his/her heritable core social attention ability extracted from the conventional social attentional effect.

CONCLUSIONS

These findings together suggest that human social attention ability is supported by unique genetic mechanisms that can be shared across different social, but not non-social, processing. Moreover, they also encourage the identification of 'social attention genes' and highlight the critical role of the core human social attention ability in seeking the endophenotypes of social cognitive disorders including ASD.

Joint attention facilitates observed gaze direction discrimination

Efficiently judging where someone else is looking is important for social interactions, allowing us a window into their mental state by establishing joint attention. Previous work has shown that judging the gaze direction of a non-foveally presented face is facilitated when the eyes of that face are directed towards the centre of the scene. This finding has been interpreted as an example of the human bias for misattributing observed ambiguous gaze signals as self-directed eye-contact. To test this interpretation against an alternative hypothesis that the facilitation is instead driven by the establishment of joint attention, we conducted two experiments in which we varied the participants' fixation location. In both experiments, we replicated the previous finding of facilitated gaze discrimination when the participants fixated centrally. However, this facilitation was abolished when participants fixated peripheral fixation crosses (Experiment 1) and reversed when participants fixated peripheral images of real-world objects (Experiment 2). Based on these data, we propose that the facilitation effect is consistent with the interpretation that gaze discrimination is facilitated when joint attention is established. This finding therefore extends previous work showing that engaging in joint attention facilitates a range of social cognitive processes.

Environmental Learning of Social Cues: Evidence From Enhanced Gaze Cueing in Deaf Children

The susceptibility to gaze cueing in deaf children aged 7-14 years old (N = 16) was tested using a nonlinguistic task. Participants performed a peripheral shape-discrimination task, whereas uninformative central gaze cues validly or invalidly cued the location of the target. To assess the role of sign language experience and bilingualism in deaf participants, three groups of age-matched hearing children were recruited: bimodal bilinguals (vocal and sign-language, N = 19), unimodal bilinguals (two vocal languages, N = 17), and monolinguals (N = 14). Although all groups showed a gaze-cueing effect and were faster to respond to validly than invalidly cued targets, this effect was twice as large in deaf participants. This result shows that atypical sensory experience can tune the saliency of a fundamental social cue.

Gaze-cueing and endogenous attention operate in parallel

The present research assessed the nature of endogenous shifts of attention based on internally generated expectations (i.e., target location probability) and involuntary attention shifts following eye-gaze cues from line-drawings of schematic faces (Experiment 1) and photographs of real neutral faces (Experiment 2) and fearful faces (Experiment 3). The time-course of these two forms of attention was explored by manipulating the gaze-target SOA (i.e., 100 ms, 200 ms, 300 ms). In all three experiments, target location probability influenced responding at each SOA with faster responses to high probability than low probability targets. However, the time-course of involuntary attention shifts was dependent on the gaze-cueing stimulus employed. For photographs of neutral gaze, endogenous orienting of attention was most efficient at the briefest SOA with involuntary attention shifts emerging later. However, both schematic and fearful gaze-cues influenced responding across all SOAs, which is indicative of stronger gaze-cueing effects from these cues. At 200 ms there was an additive effect as responses were slowest when the target had been invalidly cued by neutral gaze and also appeared in the low probability location. Taken together these findings suggest that these forms of involuntary and endogenous attention can operate in parallel and relatively independently, but can show potentially differing levels of influence, dependent on the time course in which they take to operate.

Studying "natural" eye movements in an "unnatural" social environment: The influence of social activity, framing, and sub-clinical traits on gaze aversion

Experimental psychologists frequently present participants with social stimuli (videos or pictures) and measure behavioural responses. Such designs are problematic in that they remove the potential for social interaction and inadvertently restrict our eyes multifaceted nature as a tool to both perceive and communicate with others. The aim of this study was to develop a new paradigm within which we can easily and reliably measure the influence of top-down processes (belief), social activity (talking and listening), and possible clinical traits (gaze anxiety, and social interaction difficulties) onto gaze behaviours. Participants were engaged in a "real" or pre-recorded Skype conversation. Findings suggest that participants who believed they were engaging in a real conversation spent less time looking at the speaker's eyes, but no differences were found for dwell time onto the whole face. Within our non-clinical sample, higher levels of gaze anxiety resulted in reduced dwell time onto the whole face but not eyes, whereas social interaction difficulties produced reduced dwell time onto the eyes only. Finally, talking consistently produced reduced dwell time onto the whole face and eyes regardless of any other conditions.

Joint attention is intact even when visuospatial working memory is occupied

The gaze of another modulates and shifts an observer's spatial attention toward this gaze direction. This phenomenon is termed joint attention. Although previous studies found joint attention was induced during a spatial working memory task, it remains an open question whether spatial working memory interferes with joint attention. To address this question, we conducted a dual task paradigm consisting of gaze cuing and spatial working memory tasks. The gaze cuing task requires that participants respond to the location of an abrupt onset of a target while ignoring the gaze of a facial image located at the center of the display. In the spatial working memory task, participants memorized two or three locations of small dots and judged whether these locations changed in the probe screen. In the dual task condition, while participants were maintaining spatial information of the spatial working memory task, they performed the gaze cuing task. In Experiment 1, maintaining spatial information did not impair the magnitude of joint attention. In Experiment 2, we increased load of spatial working memory task, and still observed results similar to Experiment 1. In Experiment 3, we replicated the findings in Experiment 1 when an identification task was conducted. In addition, we measured electrooculographic signals to investigate eye movements of participants during the task. The study provides that joint attention is intact even if spatial working memory is occupied.

Can Monetary Reward Modulate Social Attention?

Selective visual attention is a primary cognitive function, which allows the selection of the most relevant stimuli in the environment by prioritizing their processing. Several studies showed that this process can be influenced by both social signals, such as gaze direction (i.e., the Gaze Cueing Effect, GCE) and by the motivational valence of gratifying stimuli, such as monetary rewards. The aim of this study was to explore whether GCE could be modulated by a monetary reward. To this end, we created an experiment in which participants performed a gaze cuing task before and after an implicit learning task aiming to induce an association between gaze direction and monetary reward (experimental condition), or after a perceptual task (control condition). Statistical analyses were conducted following both a frequentist and a Bayesian approach. Results supported previous findings showing the presence of the GCE, i.e., faster responses in congruent trials when the target appeared in the gazed-at location. Interestingly, our results did not reveal significant differences among the conditions. Therefore, contrary to what was reported by previous attentional orienting studies with non-social stimuli, monetary reward does not seem to be able to modulate (or interfere with) the orienting of attention mediated by gaze direction as measured by the GCE. Taken together our results suggest that social signals such as gaze direction have a greater impact than monetary reward in orienting selective attention.

Gaze and Arrows: The Effect of Element Orientation on Apparent Motion is Modulated by Attention

In two experiments we investigated whether stimuli that elicit automatic orienting of attention (i.e., arrow or averted gaze) could drive apparent motion perception in one of two possible directions, modulating the effect of a low-level property (the orientation of elements along the motion direction). To this end, the competing motion paradigm was used, in which at time 1, a stimulus appears in the center of the display, and at time 2, two other stimuli appear in different spatial locations. Three kinds of stimuli with eight possible orientations were used in separate blocks; (1) a line; (2) an arrow; and, (3) an averted gaze. First, since the three stimuli present in the display at time 2 should be perceived to be located at the same distance (i.e., equidistant), the threshold for perceived equidistance was calculated for each participant and then used as the customized inter-stimulus distance. Participants were asked to press the button corresponding to the direction of the perceived motion. Results show a preference for collinear motion (motions between elements oriented along the motion direction), with a higher percentage of responses for gaze and arrow stimuli. In Experiment 1, a difference between gaze- and arrow-stimuli was observed. Apparent motion was seen towards the collinear position more often for gaze than for arrow when the stimulus was pointing to the vertical directions, while the opposite was true when the stimulus was pointing to the horizontal directions. In Experiment 2, where the lightness contrast between the gaze and the background was reduced, no difference between gaze- and arrow-stimuli emerged. We interpret our results as due to the social and biological value of gaze, which solved a possible ambiguity between gaze direction and the directions conveyed by the figural properties of the contrasted background in Experiment 1. These findings are consistent with the idea that stimuli known to automatically orient visual attention modulate motion perception.

Target Type Modulates the Effect of Task Demand on Reflexive Focal Attention

Focusing attention on a limited space within the environment allows us to concentrate our resources selectively on that location while ignoring the rest of the space. In this study we investigated how the deployment of the focal attention in foveal vision can be affected by task and stimuli specificity. In particular, we measured the cue-size effect in four experiments: shape detection (Experiment 1), shape discrimination (Experiment 2), letter detection (Experiment 3), and letter discrimination (Experiment 4). Our results highlight that, although the focal component can be elicited by different tasks (i.e., detection or discrimination) and by using different types of stimuli (i.e., shapes or letters), those effects interact with each other. Specifically, the effect of focal attention is more noticeable when letter stimuli are used in the case of a detection task, while no difference between letters and geometrical shapes is observed in the discrimination task. Furthermore, the analysis of the cue-size effect across the four experiments confirmed that the deployment of focal attention in foveal vision is mainly reflexive.

Is Inhibition of Return Modulated by Involuntary Orienting of Spatial Attention: An ERP Study

Inhibition of return (IOR) is a mechanism that indicates individuals’ faster responses or higher accuracy to targets appearing in the novel location relative to the cued location. According to the “reorienting hypothesis,” disengagement from the cued location is necessary for the generation of IOR. However, more and more studies have questioned this theory because of dissociation between voluntary or involuntary spatial orienting and the IOR effect. To further explore the “reorienting hypothesis” of IOR, the present experiment employed an atypical cue-target paradigm which combined a spatially non-predictive peripheral cue that was presumed to trigger IOR with a spatially non-predictive central cue that was used to reflexively trigger a shift of attention. The results showed that a significant IOR effect did not interact with automatic spatial orienting as measured in mean RTs and accuracy as well as the Nd component. These findings suggested that the IOR effect triggered by peripheral cue was independent of automatic orienting generated by a central cue. Therefore, the present study provided evidence from location task and neural aspects, which again challenged the “reorienting hypothesis” of IOR.

Social orienting in gaze leading: a mechanism for shared attention

Here, we report a novel social orienting response that occurs after viewing averted gaze. We show, in three experiments, that when a person looks from one location to an object, attention then shifts towards the face of an individual who has subsequently followed the person's gaze to that same object. That is, contrary to 'gaze following', attention instead orients in the opposite direction to observed gaze and towards the gazing face. The magnitude of attentional orienting towards a face that 'follows' the participant's gaze is also associated with self-reported autism-like traits. We propose that this gaze leading phenomenon implies the existence of a mechanism in the human social cognitive system for detecting when one's gaze has been followed, in order to establish 'shared attention' and maintain the ongoing interaction.

Two Polarities of Attention in Social Contexts: From Attending-to-Others to Attending-to-Self

Social attention is one special form of attention that involves the allocation of limited processing resources in a social context. Previous studies on social attention often regard how attention is directed toward socially relevant stimuli such as faces and gaze directions of other individuals. In contrast to attending-to-others, a different line of researches has shown that self-related information such as own face and name automatically captures attention and is preferentially processed comparing to other-related information. These contrasting behavioral effects between attending-to-others and attending-to-self prompt me to consider a synthetic viewpoint for understanding social attention. I propose that social attention operates at two polarizing states: In one extreme, individual tends to attend to the self and prioritize self-related information over others', and, in the other extreme, attention is allocated to other individuals to infer their intentions and desires. Attending-to-self and attending-to-others mark the two ends of an otherwise continuum spectrum of social attention. For a given behavioral context, the mechanisms underlying these two polarities will interact and compete with each other in order to determine a saliency map of social attention that guides our behaviors. An imbalanced competition between these two behavioral and cognitive processes will cause cognitive disorders and neurological symptoms such as autism spectrum disorders and Williams syndrome. I have reviewed both behavioral and neural evidence that support the notion of polarized social attention, and have suggested several testable predictions to corroborate this integrative theory for understanding social attention.

Responding to social and symbolic extrafoveal cues: cue shape trumps biological relevance

Social cues presented at visual fixation have been shown to strongly influence an observer’s attention and response selection. Here we ask whether the same holds for cues (initially) presented away from fixation, as cues are commonly perceived in natural vision. In six experiments, we show that extrafoveally presented cues with a distinct outline, such as pointing hands, rotated heads, and arrow cues result in strong cueing of responses (either to the cue itself, or a cued object). In contrast, cues without a clear outline, such as gazing eyes and direction words exert much weaker effects on participants’ responses to a target cue. We also show that distraction effects on response times are relatively weak, but that strong interference effects can be obtained by measuring mouse trajectories. Eye tracking suggests that gaze cues are slower to respond to because their direction cannot easily be perceived in extrafoveal vision. Together, these data suggest that the strength of an extrafoveal cue is determined by the shape of the cue outline, rather than its biological relevance (i.e., whether the cue is provided by another human being), and that this shape effect is due to how easily the direction of a cue can be perceived in extrafoveal vision.

Can we resist another person's gaze?

Adaptive adjustments of strategies are needed to optimize behavior in a dynamic and uncertain world. A key function in implementing flexible behavior and exerting self-control is represented by the ability to stop the execution of an action when it is no longer appropriate for the environmental requests. Importantly, stimuli in our environment are not equally relevant and some are more valuable than others. One example is the gaze of other people, which is known to convey important social information about their direction of attention and their emotional and mental states. Indeed, gaze direction has a significant impact on the execution of voluntary saccades of an observer since it is capable of inducing in the observer an automatic gaze-following behavior: a phenomenon named social or joint attention. Nevertheless, people can exert volitional inhibitory control on saccadic eye movements during their planning. Little is known about the interaction between gaze direction signals and volitional inhibition of saccades. To fill this gap, we administered a countermanding task to 15 healthy participants in which they were asked to observe the eye region of a face with the eyes shut appearing at central fixation. In one condition, participants were required to suppress a saccade, that was previously instructed by a gaze shift toward one of two peripheral targets, when the eyes were suddenly shut down (social condition, SC). In a second condition, participants were asked to inhibit a saccade, that was previously instructed by a change in color of one of the two same targets, when a change of color of a central picture occurred (non-social condition, N-SC). We found that inhibitory control was more impaired in the SC, suggesting that actions initiated and stopped by social cues conveyed by the eyes are more difficult to withhold. This is probably due to the social value intrinsically linked to these cues and the many uses we make of them.

Peripheral cues and gaze direction jointly focus attention and inhibition of return

Centrally presented gaze cues typically elicit a delayed inhibition of return (IOR) effect compared to peripheral exogenous cues. We investigated whether gaze cues elicit early onset IOR when presented peripherally. Faces were presented in the left or right peripheral hemifields, which then gazed upward or downward. A target appeared in one of four oblique spatial locations giving the cue and target horizontal or vertical congruency, both, or neither. After establishing that peripheral movement and gaze direction jointly facilitate target processing at short durations (200 ms: Experiment 1), IOR was evident for peripheral motion at longer time courses (800 and 2400 ms: Experiment 2). Only after 2400 ms did gaze direction additionally contribute to IOR for the specific gazed at location, showing the inverse pattern of response times to Experiment 1. The onset of IOR for gaze cues is independent from peripheral exogenous cueing but nevertheless contributes to the allocation of attention.

From body shadows to bodily attention: automatic orienting of tactile attention driven by cast shadows

Body shadows orient attention to the body-part casting the shadow. We have investigated the automaticity of this phenomenon, by addressing its time-course and its resistance to contextual manipulations. When targets were tactile stimuli at the hands (Exp.1) or visual stimuli near the body-shadow (Exp.2), cueing effects emerged regardless of the delay between shadow and target onset (100, 600, 1200, 2400ms). This suggests a fast and sustained attention orienting to body-shadows, that involves both the space occupied by shadows (extra-personal space) and the space the shadow refers to (own body). When target type became unpredictable (tactile or visual), shadow-cueing effects remained robust only for tactile targets, as visual stimuli showed no overall reliable effects, regardless of whether they occurred near the shadow (Exp.3) or near the body (Exp.4). We conclude that mandatory attention shifts triggered by body-shadows are limited to tactile targets and, instead, are less automatic for visual stimuli.

Lack of automatic attentional orienting by gaze cues following a bilateral loss of visual cortex

In social interactions, the location of relevant stimuli is often indicated by the orientation of gaze. It has been proposed that the direction of gaze might produce an automatic cueing of attention, similar to what is observed with exogenous cues. However, several reports have challenged this claim by demonstrating that the behavioral gain that arises with gaze cueing could be explained by shifts of attention, which are intentional and not automatic. We reasoned that if cueing by gaze was truly automatic, it should occur without awareness and should be sustained by subcortical circuits, including the amygdalae, independently of the main geniculo-striate visual pathway. We presented a cross-modal version of the Posner cueing paradigm to a patient (TN) with bilateral lesions of occipital cortex (Burra et al., 2013; Pegna, Khateb, Lazeyras, & Seghier, 2005). TN was asked to localize a sound using a key press. The location of the sound was congruent or incongruent with the direction of gaze of a face-cue. In groups of healthy young and age-matched participants, we observed significantly longer response times for incongruent than congruent sounds, suggesting that gaze direction interfered with processing of localized sounds. By contrast, TN׳s performance was not affected by sound-gaze congruence. The results suggest that the processing of gaze orientation cannot occur in the absence of geniculo-striate processing, suggesting that it is not automatic.

Catching eyes: effects of social and nonsocial cues on attention capture

Direct eye contact and motion onset are two powerful cues that capture attention. In the present study, we combined direct gaze with the sudden onset of motion to determine whether these cues have independent or shared influences. Participants identified targets presented randomly on one of four faces. Initially, two faces depicted direct gaze, and two faces depicted averted gaze. Simultaneously with or 900 ms before target presentation, one face with averted gaze switched to direct gaze, and one face with direct gaze switched to averted gaze. When gaze transitions and target presentation were simultaneous, the greatest response-time facilitation occurred at the location of the sudden onset of direct gaze. When target presentation was delayed, direct-gaze cues maintained a facilitatory influence, whereas motion cues induced an inhibitory influence. These findings reveal that gaze cues and motion cues at the same location influence information processing via independent and concurrently acting social and nonsocial attention channels.

The uniqueness of social attention revisited: working memory load interferes with endogenous but not social orienting

It is well known that perceived eye gaze direction influences attentional orienting. However, it still remains unclear whether social orienting involves exogenous or endogenous attentional control. To address this issue, we examined if social orienting and endogenous orienting were differentially modulated by working memory load, which is known to interfere with endogenous but not exogenous attention. To do so, we manipulated eye direction as either spatially counterpredictive in Experiment 1 or spatially predictive in Experiment 2 while participants performed a cueing task either in isolation or under working memory load. We found that when social attention and endogenous attention diverged spatially in Experiment 1, social orienting elicited by gaze direction remained intact while endogenous orienting elicited by the cue's predictive meaning was suppressed under working memory load, suggesting independence between social orienting and endogenous orienting. Indeed, a comparison between the sum of isolated social orienting and endogenous orienting magnitudes from Experiment 1 relative to their combined measure from Experiment 2 confirmed that social attention and endogenous attention operated in parallel. Together, our data show that social orienting is independent from endogenous orienting and further suggest that paying attention to social information might involve either exogenous or unique attentional mechanisms.

Orienting in response to gaze and the social use of gaze among children with autism spectrum disorder

Potential relations between gaze cueing, social use of gaze, and ability to follow line of sight were examined in children with autism and typically developing peers. Children with autism (mean age = 10 years) demonstrated intact gaze cueing. However, they preferred to follow arrows instead of eyes to infer mental state, and showed decreased accuracy in following line of sight when several visual distracters were present. Performance across tasks was not correlated for either group. Findings suggest that children with autism are less inclined to prioritize and select eyes, particularly in visually-rich environments. Gaze-following deficits may lie at the level of selective attention, rather than cueing-a possibility that can be explored with more complex and ecologically valid tasks.

The importance of context information for the spatial specificity of gaze cueing

In three experiments, we investigated the spatial allocation of attention in response to central gaze cues. In particular, we examined whether the allocation of attentional resources is influenced by context information-that is, the presence or absence of reference objects (i.e., placeholders) in the periphery. On each trial, gaze cues were followed by a target stimulus to which participants had to respond by keypress or by performing a target-directed saccade. Targets were presented either in an empty visual field (Exps. 1 and 2) or in previewed location placeholders (Exp. 3) and appeared at one of either 18 (Exp. 1) or six (Exps. 2 and 3) possible positions. The spatial distribution of attention was determined by comparing response times as a function of the distance between the cued and target positions. Gaze cueing was not specific to the exact cued position, but instead generalized equally to all positions in the cued hemifield, when no context information was provided. However, gaze direction induced a facilitation effect specific to the exact gazed-at position when reference objects were presented. We concluded that the presence of possible objects in the periphery to which gaze cues could refer is a prerequisite for attention shifts being specific to the gazed-at position.

Is “Inhibition of Return” due to the inhibition of the return of attention?

Inhibition of Return (IOR) is usually explained in terms of orienting–reorienting of attention, emphasizing an underlying mechanism that inhibits the return of attention to previously selected locations. Recent data challenge this explanation to the extent that the IOR effect is observed at the location where attention is oriented to, where no reorienting of attention is needed. To date, these studies have involved endogenous attentional selection of attention and thus indicate a dissociation between the voluntary attention of spatial attention and the IOR effect. The present work demonstrates a dissociation between the involuntary orienting of spatial attention and the IOR effect. We combined nonpredictive peripheral cues with nonpredictive central orienting cues (either arrows or gaze). The IOR effect was observed to operate independent of involuntary spatial orienting. These data speak against the “ reorienting hypothesis” of IOR. We suggest an alternative explanation whereby the IOR effect reflects a cost in detecting a new event (the target) at the location where another event (a cue) was coded before.

Resolving conflicting views: Gaze and arrow cues do not trigger rapid reflexive shifts of attention

It has become widely accepted that the direction of another individual's eye gaze induces rapid, automatic, attentional orienting, due to it being such a vital cue as to where in our environment we should attend. This automatic orienting has also been associated with the directional-arrow cues used in studies of spatial attention. Here, we present evidence that the response-time cueing effects reported for spatially non-predictive gaze and arrow cues are not the result of rapid, automatic shifts of attention. For both cue types, response-time effects were observed only for long-duration cue and target stimuli that overlapped temporally, were largest when the cues were presented simultaneously with the response-relevant target, and were driven by a slowing of responses for invalidly cued targets rather than speeding for validly cued ones. These results argue against automatic attention-orienting accounts and support a novel spatial-incongruency explanation for a whole class of rapid behavioral cueing effects.

Attentional shifts by gaze direction in voluntary orienting: evidence from a microsaccade study

Shifts in spatial attention can be induced by the gaze direction of another. However, it is unclear whether gaze direction influences the allocation of attention by reflexive or voluntary orienting. The present study was designed to examine which type of attentional orienting is elicited by gaze direction. We conducted two experiments to answer this question. In Experiment 1, we used a modified Posner paradigm with gaze cues and measured microsaccades to index the allocation of attention. We found that microsaccade direction followed cue direction between 200 and 400 ms after gaze cues were presented. This is consistent with the latencies observed in other microsaccade studies in which voluntary orienting is manipulated, suggesting that gaze direction elicits voluntary orienting. However, Experiment 1 did not separate voluntary and reflexive orienting directionally, so in Experiment 2, we used an anticue task in which cue direction (direction to allocate attention) was the opposite of gaze direction (direction of gaze in depicted face). The results in Experiment 2 were consistent with those from Experiment 1. Microsaccade direction followed the cue direction, not gaze direction. Taken together, these results indicate that the shift in spatial attention elicited by gaze direction is voluntary orienting.

Spatial orienting of attention simultaneously cued by automatic social and nonsocial cues

The appearance of a stimulus in the periphery and the direction of another person's eye gaze have both been shown to automatically orient attention toward the stimulus and the gazed-at location, respectively. In the present experiment, we examined the effects of viewing both a peripheral stimulus and an eye gaze stimulus simultaneously in order to determine whether one is "more automatic" (i.e., faster, dominates) than the other and whether the two processes interact. Using a spatial cueing paradigm, we measured latency of localization of a target stimulus that was validly or invalidly cued by an uninformative (i.e., nonpredictive) peripheral cue, an uninformative eye gaze cue, or both simultaneously (double cue). We included a short and a long cue-target interval in order to investigate the early and late facilitatory and inhibitory effects of the two processes. Results demonstrated that when the double cues were consistent with each other (indicating the same target location), the effects, both early and late, were the same as when the peripheral cue was presented alone. When the double cues were inconsistent (indicating opposite target locations), the late effect was the same as the peripheral cue, but the early effect was intermediate between the two types of cues. Our results better support an interactive, rather than an additive relationship between social and nonsocial automatic orienting. The double cue conditions that showed similar effects to the peripheral cues suggest that the peripheral cue dominates.

Sequence effects by non-predictive arrow cues

Previous studies have found that attention orienting is influenced by the orienting processes of previous trials in a spatial cueing paradigm. This study mainly investigated whether this sequence effect could happen for a non-predictive arrow cue and whether it was influenced by the cue-target SOAs in previous and current trials. A significant sequence effect was observed for arrow cues even when voluntary control was not required, and it was significantly influenced by the SOAs of previous trials. The present results support the automatic memory check hypothesis and may reflect some temporal characteristics of the memory mechanism in sequential processes. In addition, contrary to the previous findings, we found an overall response facilitation following a catch trial, suggesting that the influence of preceding catch trials may be sensitive to experimental contexts.

Automatic motor activation in the executive control of action

Although executive control and automatic behavior have often been considered separate and distinct processes, there is strong emerging and convergent evidence that they may in fact be intricately interlinked. In this review, we draw together evidence showing that visual stimuli cause automatic and unconscious motor activation, and how this in turn has implications for executive control. We discuss object affordances, alien limb syndrome, the visual grasp reflex, subliminal priming, and subliminal triggering of attentional orienting. Consideration of these findings suggests automatic motor activation might form an intrinsic part of all behavior, rather than being categorically different from voluntary actions.

Neurocognitive mechanisms of gaze-expression interactions in face processing and social attention

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.

Spatio-temporal localisation of attentional orienting to gaze and peripheral cues

Another person's eye gaze often triggers our attention such that we follow their direction of gaze. We investigated how the neural mechanisms for processing eye-gaze and spatial attention interact using magnetoencephalography (MEG) in young adults. In a cueing paradigm, a face was presented centrally with left or right averted eye-gaze serving as the directional cue in the eye-gaze condition. In the peripheral cue condition, the face with a straight gaze was presented with a cue stimulus appearing on the left or right of the face. Cue validity was 50%. MEG was recorded during the two conditions and event-related beamforming was used to determine the timing and location of the brain activity related to the two types of cueing. The MEG data indicated that generally the network of activation in response to our two cue types was similar. In contrast, MEG responses to the targets demonstrated one main peak at 286-306 ms for the eye-gaze cue condition while two peaks were found at 238-258 ms and 286-306 ms for the peripheral cue condition. Activation was also consistently larger for the invalid than valid trials. Source images for the invalid minus valid contrasts for the 238-258 ms window showed significant activation only in the peripheral cueing condition, in the left temporoparietal junction and left inferior frontal gyrus. In the 286-306 ms window, both conditions showed left medial frontal activations. Thus, peripheral cues showed more rapid neural processing than the eye-gaze cues, with the second component being common to both, reflecting in part common processing. We suggest that attentional processing was maximal in the left hemisphere, as the right hemisphere was likely engaged in processing the face information.

Social and non-social cueing of visuospatial attention in autism and typical development

Three experiments explored attention to eye gaze, which is incompletely understood in typical development and is hypothesized to be disrupted in autism. Experiment 1 (n = 26 typical adults) involved covert orienting to box, arrow, and gaze cues at two probabilities and cue-target times to test whether reorienting for gaze is endogenous, exogenous, or unique; experiment 2 (total n = 80: male and female children and adults) studied age and sex effects on gaze cueing. Gaze cueing appears endogenous and may strengthen in typical development. Experiment 3 tested exogenous, endogenous, and gaze-based orienting in 25 typical and 27 Autistic Spectrum Disorder (ASD) children. ASD children made more saccades, slowing their reaction times; however, exogenous and endogenous orienting, including gaze cueing, appear intact in ASD.