Work

Heightened gaze responsiveness and mutual gaze instability at close distances characterize dyadic coordination in a marmoset model of autism

Year: 2026

Type: article

Abstract: Autism spectrum disorder (ASD) is associated with differences in social interaction, including alterations in gaze behavior and interpersonal distance. Although most assessments of ASD remain individual-centric, emerging human studies indicate that social difficulties may arise from atypical dyadic coordination rather than from reduced social interest alone. We examined dyadic coordination in a non-human primate model of ASD, focusing on gaze and inter-individual distance during minimally constrained first encounters between prenatal valproic acid-exposed marmosets (VPA) and unexposed conspecifics (UE). Markerless pose estimation quantified frame-by-frame gaze direction and spacing, comparing VPA–UE with UE–UE dyads. VPA–UE pairs exhibited a higher proportion of mutual-gaze events than UE–UE pairs. VPA individuals showed more rapid looks in response to the partner’s gaze, yet exhibited a lower proportion of one-sided looking events. VPA–UE dyads maintained shorter inter-individual distances than UE–UE dyads, and closer spacing was associated with decreased stability of mutual gaze. These findings reveal a dyadic coordination pattern in VPA–UE pairs, with rapid responsiveness coupled with a distance-dependent reduction in time spent in mutual gaze, paralleling features reported in human ASD. Our dyad-centric, markerless framework yields ecologically grounded readouts and potential intervention targets that leverage intact social responsiveness while accommodating altered spatial coordination.

Source: Scientific Reports

DOI: 10.1038/s41598-026-76138-z