A cross-sectional study of scanning and pupillary responses to various face and nonface stimuli in children with an autism spectrum disorder and typically developing children

Abstract

The current study sought to test for the presence of a developmental trend for children with autism spectrum disorder (ASD) from the age of 2 years to 13 years of age in their attention to, and processing of, social images. Children with ASD were expected to show dysregulated pupillary responses that would be associated with a reduction of attention to social images over the span of childhood. Pupil size was measured for children with ASD and typically-developing (TD) peers at baseline and in response to both social and nonsocial stimuli. To investigate the effect of stimulus detail on processing, three types of stimuli were presented during an eye-tracking task: photographs, pictures of figures, and drawings. Contrary to previous reports, there was no effect of age or diagnosis on baseline pupil size. Children with ASD, however, did not show phasic pupillary responses to different stimulus types that were observed in TD children. Regardless of age, children with ASD looked at all stimuli for less time than TD children, with nonsocial images receiving the least amounts of fixation. The results suggest that dysregulation of pupil size may be a less systemic marker of ASD than had been previously reported. Furthermore, larger pupillary dilations were correlated with longer looking time toward social photos, as well as higher MA and less social and communication impairment.