Pupillary responses during a joint attention task are associated with nonverbal cognitive abilities and sub-clinical symptoms of autism.

Measures of pupillary dilation provide a temporally sensitive, quantitative indicator of cognitive resource allocation. The current study included 39 typically developing children between 3 and 9 years of age. Children completed a free-viewing task designed to elicit gaze following, a core deficit of Autism Spectrum Disorders (ASD). Results revealed a negative association between children's pupil dilation and a standardized measure of nonverbal intelligence, suggesting that children with lower intelligence allocated more cognitive resources than children with higher intelligence. In addition, the results revealed a negative association between pupil dilation and a parent-report measure of sub-clinical symptoms of ASD, suggesting that children with fewer ASD-related symptoms allocated more cognitive resources than children who showed more sub-clinical symptoms of ASD. Both associations were independent of each other and could not be explained by variation in chronological age. These findings extend previous research demonstrating associations between basic aspects of visual processing and intelligence. In addition, these findings comport with recent theories of ASD that emphasize reduced sensitivity to the reward value of social situations. When confronted with social ambiguity, children with more ASD-related symptoms allocated fewer cognitive resources to resolving this ambiguity than children who showed fewer sub-clinical symptoms of ASD.