How ubiquitous is the direct-gaze advantage? Evidence for an averted-gaze advantage in a gaze-discrimination task

I prefer what you can see: The role of visual perspective-taking on the gaze-liking effect

Individuals' gaze on an object usually leads others to prefer that object, which is called the gaze-liking effect. However, it is still unclear whether this effect is driven by social factors (i.e., visual perspective-taking) or the domain-general processing (i.e., attention cueing). This research explored the mechanism of the gaze-liking effect by manipulating the objects' visibility to an avatar in six online one-shot experiments. The results showed that participants' affective evaluation for the object was modulated by the avatar's visual perspective. Specifically, the visible object to the avatar received a higher rating of liking degree. However, when the avatar was replaced with a non-social stimulus, the experimental effect was absent. Furthermore, the gaze-liking effect was robust while controlling for confounding factors such as the distance between the object and the avatar or type of stimuli. These findings provided convincing evidence that the gaze-liking effect involves a process of the other's visual experience and is not merely a by-product of the gaze-cueing effect.

The Time Course of Information Processing During Eye Direction Perception

Gaze directed at the observer (direct gaze) is a highly salient social signal. Despite the existence of a preferential orientation toward direct gaze, none of the studies carried out so far seem to have explicitly studied the time course of information processing during gaze direction judgment. In an eye direction judgment task, participants were presented with a sketch of a face. A temporal asynchrony was introduced between the presentation of the eyes and that of the rest of the face. Indeed, the face could be presented before the eyes, the eyes could be presented before the face, or the face and the eyes could be presented simultaneously. In a second time, the face direction was also manipulated. The results suggest that the time course of information processing during eye direction judgment follows a continuum that makes it possible to perceive the eyes first and then to use the facial context to judge the direction of gaze. Furthermore, the congruency between the direction of gaze and that of the face confirms this observation. Although these results are discussed in the light of existing theories about the mechanisms underlying gaze processing, our data provide new information suggesting that, despite their power to capture attention, the eyes probably have to stand out from a more general spatial configuration (i.e., the face) in order for their direction to be adequately processed.

Modulatory Effects of Communicative Gaze on Attentional Orienting Are Driven by Dorsomedial Prefrontal Cortex but Not Right Temporoparietal Junction

Communicative gaze (e.g., mutual or averted) has been shown to affect attentional orienting. However, no study to date has clearly separated the neural basis of the pure social component that modulates attentional orienting in response to communicative gaze from other processes that might be a combination of attentional and social effects. We used TMS to isolate the purely social effects of communicative gaze on attentional orienting. Participants completed a gaze-cueing task with a humanoid robot who engaged either in mutual or in averted gaze before shifting its gaze. Before the task, participants received either sham stimulation (baseline), stimulation of right TPJ (rTPJ), or dorsomedial prefrontal cortex (dmPFC). Results showed, as expected, that communicative gaze affected attentional orienting in baseline condition. This effect was not evident for rTPJ stimulation. Interestingly, stimulation to rTPJ also canceled out attentional orienting altogether. On the other hand, dmPFC stimulation eliminated the socially driven difference in attention orienting between the two gaze conditions while maintaining the basic general attentional orienting effect. Thus, our results allowed for separation of the pure social effect of communicative gaze on attentional orienting from other processes that are a combination of social and generic attentional components.

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

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

The impact of facial expression and communicative gaze of a humanoid robot on individual Sense of Agency

Sense of Agency (SoA) is the feeling of control over one's actions and their outcomes. A well-established implicit measure of SoA is the temporal interval estimation paradigm, in which participants estimate the time interval between a voluntary action and its sensory consequence. In the present study, we aimed to investigate whether the valence of action outcome modulated implicit SoA. The valence was manipulated through interaction partner's (i) positive/negative facial expression, or (ii) type of gaze (gaze contact or averted gaze). The interaction partner was the humanoid robot iCub. In Experiment 1, participants estimated the time interval between the onset of their action (head movement towards the robot), and the robot's facial expression (happy vs. sad face). Experiment 2 was identical, but the outcome of participants' action was the type of robot's gaze (gaze contact vs. averted). In Experiment 3, we assessed-in a within-subject design-the combined effect of robot's type of facial expression and type of gaze. Results showed that, while the robot's facial expression did not affect participants' SoA (Experiment 1), the type of gaze affected SoA in both Experiment 2 and Experiment 3. Overall, our findings showed that the robot's gaze is a more potent factor than facial expression in modulating participants' implicit SoA.

From eye to arrow: Attention capture by direct gaze requires more than just the eyes

Human attention is strongly attracted by direct gaze and sudden onset motion. The sudden direct-gaze effect refers to the processing advantage for targets appearing on peripheral faces that suddenly establish eye contact. Here, we investigate the necessity of social information for attention capture by (sudden onset) ostensive cues. Six experiments involving 204 participants applied (1) naturalistic faces, (2) arrows, (3) schematic eyes, (4) naturalistic eyes, or schematic facial configurations (5) without or (6) with head turn to an attention-capture paradigm. Trials started with two stimuli oriented towards the observer and two stimuli pointing into the periphery. Simultaneous to target presentation, one direct stimulus changed to averted and one averted stimulus changed to direct, yielding a 2 × 2 factorial design with direction and motion cues being absent or present. We replicated the (sudden) direct-gaze effect for photographic faces, but found no corresponding effects in Experiments 2-6. Hence, a holistic and socially meaningful facial context seems vital for attention capture by direct gaze. STATEMENT OF SIGNIFICANCE: The present study highlights the significance of context information for social attention. Our findings demonstrate that the direct-gaze effect, that is, the prioritization of direct gaze over averted gaze, critically relies on the presentation of a meaningful holistic and naturalistic facial context. This pattern of results is evidence in favor of early effects of surrounding social information on attention capture by direct gaze.

Eye Direction Detection and Perception as Premises of a Social Brain: A Narrative Review of Behavioral and Neural Data

The eyes and the gaze are important stimuli for social interaction in humans. Impaired recognition of facial identity, facial emotions, and inference of the intentions of others may result from difficulties in extracting information relevant to the eye region, mainly the direction of gaze. Therefore, a review of these data is of interest. Behavioral data demonstrating the importance of the eye region and how humans respond to gaze direction are reviewed narratively, and several theoretical models on how visual information on gaze is processed are discussed to propose a unified hypothesis. Several issues that have not yet been investigated are identified. The authors tentatively suggest experiments that might help progress research in this area. The neural aspects are subsequently reviewed to best describe the low-level and higher-level visual information processing stages in the targeted subcortical and cortical areas. A specific neural network is proposed on the basis of the literature. Various gray areas, such as the temporality of the processing of visual information, the question of salience priority, and the coordination between the two hemispheres, remain unclear and require further investigations. Finally, disordered gaze direction detection mechanisms and their consequences on social cognition and behavior are discussed as key deficiencies in several conditions, such as autism spectrum disorder, 22q11.2 deletion, schizophrenia, and social anxiety disorder. This narrative review provides significant additional data showing that the detection and perception of someone's gaze is an essential part of the development of our social brain.

Meeting another's gaze shortens subjective time by capturing attention

Gaze directed at the observer (direct gaze) is an important and highly salient social signal with multiple effects on cognitive processes and behavior. It is disputed whether the effect of direct gaze is caused by attentional capture or increased arousal. Time estimation may provide an answer because attentional capture predicts an underestimation of time whereas arousal predicts an overestimation. In a temporal bisection task, observers were required to classify the duration of a stimulus as short or long. Stimulus duration was selected randomly between 988 and 1479 ms. When gaze was directed at the observer, participants underestimated stimulus duration, suggesting that effects of direct gaze are caused by attentional capture, not increased arousal. Critically, this effect was limited to dynamic stimuli where gaze appeared to move toward the participant. The underestimation was present with stimuli showing a full face, but also with stimuli showing only the eye region, inverted faces and high-contrast eye-like stimuli. However, it was absent with static pictures of full faces and dynamic nonfigurative stimuli. Because the effect of direct gaze depended on motion, which is common in naturalistic scenes, more consideration needs to be given to the ecological validity of stimuli in the study of social attention.

Sclera and Iris Color Interact to Influence Gaze Perception

The white sclera is important in facilitating gaze perception in humans. Iris color may likewise influence gaze perception but no previous studies have directly assessed its effect. We therefore examined how the interaction between sclera and iris color influences human gaze perception. We recorded the eye movements of human participants as they performed a visual search task with human faces exhibiting directed or averted gaze. The faces either exhibited light or dark irises. In addition, the faces had sclera that were depigmented (white) or pigmented (matched the color of the iris). We found that participants were quick and accurate in evaluating gaze regardless of iris color in faces with depigmented sclera. When the sclera were pigmented, participants were slower to evaluate the gaze of faces with both light and dark irises but these effects were most pronounced in the faces with dark irises. Furthermore, participants were generally less accurate in assessing faces with pigmented sclera when the irises were dark rather than light. Our results suggest that depigmented sclera are especially important for gaze perception in faces with dark irises. Because depigmented sclera likely evolved at a time when ancestral humans exhibited dark irises, the depigmented sclera may have been crucial for efficient and accurate gaze perception in ancestral humans.