Social Perception in Autism : An eye tracking and pupillometry study

Typically developing humans innately place subjective value on social information and orient attention to it. This can be shown through eye tracking and pupillometry, a method used to show attentional engagement. Social brain development and social preference is present from infancy, and is thought to rely on a carefully balanced network of neurotransmitters and neural connections. Autism Spectrum Disorder (ASD) presents altered neural systems which cause individuals to perceive and process social information differently, but the neurophysiology of this difference remains unclear. Previous research shows atypical gaze patterns, hyperarousal, and lack of orienting to social stimuli in ASD. Since autism is highly comorbid and shares traits with other neurodevelopmental disorders, it is difficult to distinguish aspects of these social processing differences. This study used a group of 35 neuropsychiatric patients to investigate how individuals with autism process social and non-social scenes. Eye tracking and pupillometry measures were collected while participants observed images of natural scenes with or without a person. Participants with autism did not show a pupillary response to social images and were slower to fixate on the face region than the other participants. Additionally there were correlations between clinical measures of social functioning and the length of time it took to fixate to faces. The results highlight important distinctions of social processing in autism. This thesis proposes a new perspective of looking at the social deficits present in autism spectrum disorder. It suggests reframing the current discussion from two leading hypotheses to a unified approach and formally considering the limitations of differing types of stimuli