What Engages Children with Autism Spectrum Disorders When Viewing Naturalistic Social Scenes?

Background: A central focus of autism research is to understand the experience of individuals with autism as they navigate the social world. Eye-tracking provides a means to ‘see the world through the eyes of others’, demonstrating that people with ASD spend more time looking at bodies and objects than at faces. While these findings indicate altered visual salience in ASD, they fail to capture a critical aspect of a viewers’ experience: how engaged they are with what they’re attending to.  Engagement becomes critical when one considers that not all looks towards a stimulus are equal.  Fixation may reflect active engagement or a passing glance, made without extracting important information. Although children with ASD look less at eyes compared to TD children, they do attend to eyes as much as 30% of the time when viewing movies. What is the experience of children with ASD when focusing on socially relevant stimuli?

Objectives: (1) When children with ASD and TD children fixate on the same region of a scene are children with ASD as engaged as TD children? And (2) What types of stimuli engage children with ASD?

Methods: Engagement was quantified by measuring eye-blink inhibition while children with ASD (n = 49) and TD children (n = 26) viewed movies of social interaction. People spontaneously inhibit blinks when processing salient stimuli to minimize the loss of visual information that occurs when blinking. Exactly when inhibition occurs marks the viewers’ subjective assessment of how engaging a stimulus is (Shultz, Klin, & Jones, in press). Here, we used blink inhibition to measure between-group differences in engagement when both groups fixated on the same part of a scene.  In addition, we examined where children with ASD were fixating when they were highly engaged.

Results: When both groups fixated on eyes and mouths, children with ASD showed reduced blink inhibition relative to TD children, suggesting reduced engagement. However, when both groups fixated on bodies and objects, children with ASD showed significant blink inhibition, suggesting increased engagement. Ongoing analyses are aimed at further exploring the type of stimuli perceived as most engaging by children with ASD.

Conclusions: Measures of eye-blink inhibition indicate that even when children with ASD look at eyes and mouths at the same time as TD children, they are not as engaged, suggesting that their experience of viewing these stimuli may differ fundamentally from that of TD children. This has implications for interventions and clinical assessments, which consider eye contact and gaze towards socially relevant stimuli to be a sign of social ability.  The current results caution against interpreting these behaviors as definitive indicators of social ability by demonstrating that simply fixating on these stimuli does not indicate that they are being processed by children with ASD in the way that we might expect.  Children with ASD may be driven to this stimulus for different reasons than TD children.  What is driving the attention and engagement of children with ASD and the ontogeny of this altered engagement are important questions for future research.