Reduced eye contact with others is a common characteristic of autism spectrum disorder (ASD). Although eye contact is an important aspect of social interactions, scientists have previously been unable to study the neurological basis of live social interaction with eye contact in ASD because it is difficult to image the brains of two people simultaneously.
However, researchers at Yale University have now developed a technology that allows them to image the brains of two individuals during live and natural conditions. Using this technology, they have identified specific brain areas in the dorsal parietal region that are associated with the social symptoms of ASD. This study, published in the journal PLOS ONE, suggests that these neural responses to live face and eye contact may provide a biological index that can be used in the clinical classification and assessment of autism.
“Our brains are hungry for information about other people, and we need to understand how these social mechanisms operate in the context of a real and interactive world in both typically developed individuals as well as individuals with ASD,” said Joy Hirsch, Elizabeth Mears, and House Jameson Professor of Psychiatry, Comparative Medicine, and of Neuroscience at Yale, and co-corresponding author of the study.
The Yale team, led by Hirsch and James McPartland, Harris Professor at the Yale Child Study Center, analyzed brain activity during brief social interactions between pairs of adults — each including a typical participant and one with ASD — using functional near-infrared spectroscopy, a non-invasive optical neuroimaging method. Both participants were fitted with caps with many sensors that emitted light into the brain and also recorded changes in light signals with information about brain activity during face gaze and eye-to-eye contact.
The investigators found that during eye contact, participants with ASD had significantly reduced activity in a brain region called the dorsal parietal cortex compared to those without ASD. Further, social features of ASD, as measured by ADOS (Autism Diagnostic Observation Schedule, 2nd Edition) scores, were associated with activity in this brain region. Neural activity in these regions was synchronous between typical participants during real eye-to-eye contact but not during gaze at a video face. This expected increase in neural coupling was not observed in ASD and is consistent with the differences in social interactions.
“We now not only have a better understanding of the neurobiology of autism and social differences but also of the underlying neural mechanisms that drive typical social connections,” Hirsch said.
Reference: “Neural correlates of eye contact and social function in autism spectrum disorder” by Joy Hirsch, Xian Zhang, J. Adam Noah, Swethasri Dravida, Adam Naples, Mark Tiede, Julie M. Wolf and James C. McPartland, 9 November 2022, PLOS ONE.