Although autism spectrum disorder (ASD) can be diagnosed at any age, symptoms generally appear in the first two years of a child’s life. The earlier ASD is diagnosed, the sooner treatment and access to relevant services can start. A new study has found that checking toddlers’ visual attention to geometric images is a reliable biomarker for the early identification of autism.
Led by Karen Pierce, PhD, from the University of California, San Diego, the study expanded upon Pierce’s previous research, which had examined the disproportionate amount of time toddlers with ASD spent looking at geometric images when given the opportunity.
A large sample of 1,863 toddlers was drawn from the community, with an average age of around two years. After performing an in-depth diagnostic evaluation, the sample was divided into groups: children with ASD, children with ASD features, children with global developmental delay, children with language delay, and typically developing children.
Pierce hypothesized that the preference for geometric images was a valid, measurable biomarker, or biological indicator, for identifying children with autism within their first years of life.
The toddlers were shown a one-minute video with geometric images on one side of the screen and images of children doing yoga on the other. Using eye-tracking technology, researchers measured the time the toddlers spent fixated on the geometric images.
Data showed that toddlers with ASD spent more time looking at geometric images than toddlers in the other subject groups who preferred the social, non-geometric images. Some toddlers with ASD were found to fixate on geometric images more than 90% of the time, and the research found that those toddlers with a strong preference for those images also had higher symptom and lower cognitive ability scores than toddlers with ASD who preferred to look at the images containing children.
Additional data suggested that the preference for geometric images remained stable over the 12 months after the initial eye-tracking session. Analysis using bioinformatics confirmed the statistical robustness of the data collected.
The study’s large sample of diverse, community-based participants that included toddlers with non-ASD developmental delays, combined with the robustness of the data, suggests that eye-tracking has valuable utility as a simple but reliable tool for identifying ASD in young children.
The study was published in Scientific Reports.