Dhaka, July 7 -- Diagnosing neurobiological disorders, such as the autism spectrum disorders, focuses on complex clinical evaluations. But a study published last week (March 6) in eLife shows that an objective measure-how the pupil varies in size while viewing an optical illusion-reveals differences in perceptual styles and correlates with a self-reported score of autistic traits. The findings suggest that tracking fluctuations in pupil size, which is called pupillometry, could be used alongside clinical assessments to help researchers and clinicians understand autism.

"We used to think that the pupil was a simple light reflex or that it just indexed arousal," says Stefan Van der Stigchel, an attention and perception researcher at Utrech...