Oculomotor Behavior in Toddlers with Autism during Naturalistic Viewing of Social Scenes

Background: Previous research has investigated properties of visual saccades and fixations in school-aged children with autism spectrum disorders (ASD) using a natural viewing paradigm. The results confirm findings from two separate bodies of literature, indicating that basic mechanisms of oculomotor function are intact in children with ASD, but that children with ASD differ from their typically-developing peers in terms of the social content on which they preferentially focus. Other research has studied viewing patterns in two-year-olds with ASD during naturalistic viewing and has found that toddlers with ASD also exhibit a preference for different aspects of a social scene than typically-developing toddlers and toddlers with non-autistic developmental delays. However, investigation into the ability to control eye movements during a natural viewing task has not yet been extended to these very young children with ASD. The current study intends to address that topic. 

Objectives: To compare oculomotor properties of visual fixations and saccades during naturalistic viewing of social scenes in toddlers with ASD, typically-developing toddlers and toddlers with non-autistic developmental delays.

Methods: Eye-tracking data were collected while toddlers watched film clips of actresses playing the role of caregiver. From these data, fixations and saccades were identified. Data on the frequency and duration of fixations, and on the frequency, duration, velocity, and amplitude of saccades, were then compared across groups.  

Results: Preliminary analyses suggest that basic properties of saccades and fixations do not differ between two-year-olds with ASD, typically-developing controls and controls with non-autistic developmental delays.

Conclusions: Basic oculomotor circuitry appears to develop normally in individuals with ASD by two years of age. This suggests that discrepancies in viewing patterns between toddlers with ASD and their typically-developing and developmentally-delayed peers are not the result of oculomotor impairments, but rather reflect differences in what aspects of a social scene are most salient to them.