The dynamics of social gaze: visual attention and autonomic arousal among individuals with varying levels of autistic traits

The ability to accurately perceive and respond to others' gaze is fundamental to optimal social interactions, and it is impaired in autism spectrum disorder and individuals with higher levels of autistic traits. One potential mechanism is reduced attention to social stimuli in general and to the eyes in particular, but the reasons behind such atypical visual behavior remain debated. This study investigated whether reduced attention to the eyes associated with autistic traits stems from aversion to social stimuli or indifference to them. One hundred and twenty-seven adolescents and young adults with varying levels of autistic traits and social functioning completed a task that required indicating the direction of eye gaze of a stimulus while the participant’s eye position and pupil size were recorded. Higher levels of autistic traits were associated with reduced dwell time on the eye region after, but not before, gaze direction judgments, indicating reduced attention to the eyes when it was not task relevant. Specifically, higher levels of autistic traits were associated with more frequent exits and re-entries of gaze from/to the eye region after the gaze judgement, indicating a less stable social engagement pattern. Additionally, autistic traits were not associated with enlarged pupillary responses, indicating a lack of heightened arousal that would be expected if aversion were present. Together, these findings demonstrate reduced sustained engagement with the eyes among individuals with higher levels of autistic traits, and this pattern is more consistent with indifference than aversion. The temporal specificity of gaze avoidance - emerging primarily after task completion - helps reconcile contradictory findings in the literature and highlights the importance of considering task demands when studying social attention in autism. Results indicate that interventions focusing on enhancing sustained social engagement rather than solely addressing aversion may be beneficial.