Larger pupil size found in autism
LSI researchers have added a characteristic to the description of autism – larger “tonic” or resting pupil size. In the March 2009 Developmental Psychobiology, John Colombo, director of LSI, and Christa Anderson, doctoral student in psychology, reported that tonic pupil size of children with Autism Spectrum Disorders (ASD) was larger than those of peers of the same mental and chronological age.
Using only pupil size, researchers were able to correctly identify which children from a group of 22 had ASD with 71 percent accuracy. The researchers believe that pupil size might be used to identify children with ASD earlier than the typical 3 years of age.
People with ASD have differences in heart rate, respiration, blood pressure and sleep that like pupil size are involuntary bodily functions controlled by the same part of the brain. “This is further evidence that the disorder might have its origins in these lower-order brain systems,” Colombo said.