The Use of Eye Tracking as a Biomarker of Treatment Outcome in a Pilot Randomized Clinical Trial for Young Children with Autism.

There is a pressing need for objective, quantifiable outcome measures in intervention trials for children with autism spectrum disorder (ASD). The current study investigated the use of eye tracking as a biomarker of treatment response in the context of a pilot randomized clinical trial of treatment for young children with ASD. Participants included 28 children with ASD, aged 18-48 months, who were randomized to one of two conditions: Pivotal Response Intervention for Social Motivation (PRISM) or community treatment as usual (TAU). Eye-tracking and behavioral assessment of developmental functioning were administered at Time 1 (prior to randomization) and at Time 2 (after 6 months of intervention). Two well-established eye-tracking paradigms were used to measure social attention: social preference and face scanning. As a context for understanding relationships between social attention and developmental ability, we first examined how scanning patterns at Time 1 were associated with concurrent developmental functioning and compared to those of 23 age-matched typically developing (TD) children. Changes in scanning patterns from Time 1 to Time 2 were then compared between PRISM and TAU groups and associated with behavioral change over time. Results showed that the social preference paradigm differentiated children with ASD from TD children. In addition, attention during face scanning was associated with language and adaptive communication skills at Time 1 and change in language skills from Time 1 to Time 2. These findings highlight the importance of examining targeted biomarkers that measure unique aspects of child functioning and that are well-matched to proposed mechanisms of change. Autism Research 2019, 12: 779-793. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Biomarkers have the potential to provide important information about how and why early interventions effect positive change for young children with ASD. The current study suggests that eye-tracking measures of social attention can be used to track change in specific areas of development, such as language, and points to the need for targeted eye-tracking paradigms designed to measure specific behavioral changes. Such biomarkers could inform the development of optimal, individualized, and adaptive interventions for young children with ASD.