The Gaze Cueing Effect and Its Enhancement by Facial Expressions Are Impacted by Task Demands: Direct Comparison of Target Localization and Discrimination Tasks

Uncovering the cognitive mechanisms underlying the gaze cueing effect

The gaze cueing effect is the tendency for people to respond faster to targets appearing at locations gazed at by others, compared with locations gazed away from by others. The effect is robust, widely studied, and is an influential finding within social cognition. Formal evidence accumulation models provide the dominant theoretical account of the cognitive processes underlying speeded decision-making, but they have rarely been applied to social cognition research. In this study, using a combination of individual-level and hierarchical computational modelling techniques, we applied evidence accumulation models to gaze cueing data (three data sets total, N = 171, 139,001 trials) for the first time to assess the relative capacity that an attentional orienting mechanism and information processing mechanisms have for explaining the gaze cueing effect. We found that most participants were best described by the attentional orienting mechanism, such that response times were slower at gazed away from locations because they had to reorient to the target before they could process the cue. However, we found evidence for individual differences, whereby the models suggested that some gaze cueing effects were driven by a short allocation of information processing resources to the gazed at location, allowing for a brief period where orienting and processing could occur in parallel. There was exceptionally little evidence to suggest any sustained reallocation of information processing resources neither at the group nor individual level. We discuss how this individual variability might represent credible individual differences in the cognitive mechanisms that subserve behaviourally observed gaze cueing effects.

Gaze-Triggered Communicative Intention Compresses Perceived Temporal Duration

Eye gaze communicates a person's attentional state and intentions toward objects. Here we demonstrate that this important social signal has the potential to distort time perception of gazed-at objects (N = 70 adults). By using a novel gaze-associated learning paradigm combined with the time-discrimination task, we showed that objects previously associated with others' eye gaze were perceived as significantly shorter in duration than the nonassociated counterparts. The time-compression effect cannot be attributed to general attention allocation because it disappeared when objects were associated with nonsocial attention cues (i.e., arrows). Critically, this effect correlated with observers' autistic traits and vanished when the gazing agent's line of sight was blocked by barriers, reflecting the key role of intention processing triggered by gaze in modulating time perception. Our findings support the existence of a special mechanism tuned to social cues, which can shape our perception of the outer world in time domains.

Gazing left, gazing right: exploring a spatial bias in social attention

Faces oriented rightwards are sometimes perceived as more dominant than faces oriented leftwards. In this study, we explored whether faces oriented rightwards can also elicit increased attentional orienting. Participants completed a discrimination task in which they were asked to discriminate, by means of a keypress, a peripheral target. At the same time, a task-irrelevant face oriented leftwards or rightwards appeared at the centre of the screen. The results showed that, while for faces oriented rightwards targets appearing on the right were responded to faster as compared to targets appearing on the left, for faces oriented leftwards no differences emerged between left and right targets. Furthermore, we also found a negative correlation between the magnitude of the orienting response elicited by the faces oriented leftwards and the level of conservatism of the participants. Overall, these findings provide evidence for the existence of a spatial bias reflected in social orienting.

Neural and visual processing of social gaze cueing in typical and ASD adults

Atypical eye gaze in joint attention is a clinical characteristic of autism spectrum disorder (ASD). Despite this documented symptom, neural processing of joint attention tasks in real-life social interactions is not understood. To address this knowledge gap, functional-near infrared spectroscopy (fNIRS) and eye-tracking data were acquired simultaneously as ASD and typically developed (TD) individuals engaged in a gaze-directed joint attention task with a live human and robot partner. We test the hypothesis that face processing deficits in ASD are greater for interactive faces than for simulated (robot) faces. Consistent with prior findings, neural responses during human gaze cueing modulated by face visual dwell time resulted in increased activity of ventral frontal regions in ASD and dorsal parietal systems in TD participants. Hypoactivity of the right dorsal parietal area during live human gaze cueing was correlated with autism spectrum symptom severity: Brief Observations of Symptoms of Autism (BOSA) scores (r = âˆ'0.86). Contrarily, neural activity in response to robot gaze cueing modulated by visual acquisition factors activated dorsal parietal systems in ASD, and this neural activity was not related to autism symptom severity (r = 0.06). These results are consistent with the hypothesis that altered encoding of incoming facial information to the dorsal parietal cortex is specific to live human faces in ASD. These findings open new directions for understanding joint attention difficulties in ASD by providing a connection between superior parietal lobule activity and live interaction with human faces.

Lay Summary

Little is known about why it is so difficult for autistic individuals to make eye contact with other people. We find that in a live face-to-face viewing task with a robot, the brains of autistic participants were similar to typical participants but not when the partner was a live human. Findings suggest that difficulties in real-life social situations for autistic individuals may be specific to difficulties with live social interaction rather than general face gaze.

Does Eye Gaze Uniquely Trigger Spatial Orienting to Socially Relevant Information? A Behavioral and ERP Study

Using behavioral and event-related potential (ERP) measures, the present study examined whether eye gaze triggers a unique form of attentional orienting toward threat-relevant targets. A threatening or neutral target was presented after a non-predictive gaze or an arrow cue. In Experiment 1, reaction times indicated that eye gaze and arrow cues triggered different attention orienting towards threatening targets, which was confirmed by target-elicited P3b latency in Experiment 2. Specifically, for targets preceded by arrow and gaze cues, P3b peak latency was shorter for neutral targets than threatening targets. However, the latency differences were significantly smaller for gaze cues than for arrow cues. Moreover, target-elicited N2 amplitude indicated a significantly stronger cue validity effect of eye gaze than that of arrows. These findings suggest that eye gaze uniquely triggers spatial attention orienting to socially threatening information.

Wearing the face mask affects our social attention over space

Recent studies suggest that covering the face inhibits the recognition of identity and emotional expressions. However, it might also make the eyes more salient, since they are a reliable index to orient our social and spatial attention. This study investigates (1) whether the pervasive interaction with people with face masks fostered by the COVID-19 pandemic modulates the processing of spatial information essential to shift attention according to other's eye-gaze direction (i.e., gaze-cueing effect: GCE), and (2) whether this potential modulation interacts with motor responses (i.e., Simon effect). Participants were presented with face cues orienting their gaze to a congruent or incongruent target letter location (gaze-cueing paradigm) while wearing a surgical mask (Mask), a patch (Control), or nothing (No-Mask). The task required to discriminate the identity of the lateralized target letters by pressing one of two lateralized response keys, in a corresponding or a non-corresponding position with respect to the target. Results showed that GCE was not modulated by the presence of the Mask, but it occurred in the No-Mask condition, confirming previous studies. Crucially, the GCE interacted with Simon effect in the Mask and Control conditions, though in different ways. While in the Mask condition the GCE emerged only when target and response positions corresponded (i.e., Simon-corresponding trials), in the Control condition it emerged only when they did not correspond (i.e., Simon-non-corresponding trials). These results indicate that people with face masks induce us to jointly orient our visual attention in the direction of the seen gaze (GCE) in those conditions resembling (or associated with) a general approaching behavior (Simon-corresponding trials). This is likely promoted by the fact that we tend to perceive wearing the mask as a personal safety measure and, thus, someone wearing the face mask is perceived as a trustworthy person. In contrast, people with a patch on their face can be perceived as more threatening, therefore inducing a GCE in those conditions associated with a general avoidance behavior (Simon-non-corresponding trials).

No Influence of Emotional Faces or Autistic Traits on Gaze-Cueing in General Population

The present study addressed the controversial issue of whether autistic traits in the general population are associated with the automatic and fundamental aspects of joint attention through eye gaze. Specifically, we examined whether the degree of autistic traits is associated with the magnitude of reflexive attention orienting in the direction of another's eye gaze embedded in neutral and emotional (angry, fearful, and happy) faces. The cue stimuli changed gaze direction and facial expressions simultaneously. Participants were asked to detect a target that appeared at the left or right of the cue stimuli. The results revealed a robust gaze-cueing effect, such that the reaction time to the target was shorter under the gazed-at-target condition than under the non-gazed-at-target condition. However, emotional expressions did not modulate the gaze-cueing effect. Furthermore, individual differences in autistic traits and emotional characteristics (social anxiety, alexithymia, and emotional disturbances) did not influence the magnitude of the gaze-cueing effect. Although the ability to orient attention in the direction of another's gaze is a fundamental function of social development, the gaze-cueing effect measured in a controlled experiment might not be an elaborate representation of the current social cognitive function, at least in typically developing adults.

Orienting of covert attention by neutral and emotional gaze cues appears to be unaffected by mild to moderate amblyopia

Amblyopia is a developmental disorder of vision associated with higher-order visual attention deficits. We explored whether amblyopia affects the orienting of covert spatial attention by measuring the magnitude of the gaze cueing effect from emotional faces. Gaze and emotion cues are key components of social attention. Participants with normal vision (n = 30), anisometropic (n = 7) or strabismic/mixed (n = 5) amblyopia performed a cued peripheral target detection task under monocular and binocular viewing conditions. The cue consisted of a centrally presented face with left or right gaze (50% validity to target location) and a fearful, happy, or neutral expression. The magnitude of spatial cueing was computed as the reaction time difference between congruent and incongruent trials for each expression. Fearful facial expressions oriented spatial attention significantly more than happy or neutral expressions. The magnitude of the gaze cueing effect in our cohort of mild-to-moderate amblyopia was comparable to that in normal vision and was not correlated with the severity of amblyopia. There were no statistical group or amblyopia subtype differences for reaction time in any viewing condition. These results place constraints on the range of attentional mechanisms affected by amblyopia and possibly suggest normal covert processing of emotional face stimuli in mild and moderate amblyopia.

Investigating facilitatory versus inhibitory effects of dynamic social and non-social cues on attention in a realistic space

This study aimed to investigate the facilitatory versus inhibitory effects of dynamic non-predictive central cues presented in a realistic environment. Realistic human-avatars initiated eye contact and then dynamically looked to the left, right or centre of a table. A moving stick served as a non-social control cue and participants localised (Experiment 1) or discriminated (Experiment 2) a contextually relevant target (teapot/teacup). The cues movement took 500 ms and stimulus onset asynchronies (SOA, 150 ms/300 ms/500 ms/1000 ms) were measured from movement initiation. Similar cuing effects were seen for the social avatar and non-social stick cue across tasks. Results showed facilitatory processes without inhibition, though there was some variation by SOA and task. This is the first time facilitatory versus inhibitory processes have been directly investigated where eye contact is initiated prior to gaze shift. These dynamic stimuli allow a better understanding of how attention might be cued in more realistic environments.