Varying Amount of Social Information in an Image Affects Facial Processing Strategies of Participants with an Autism-Related Phenotype

Abstract

Autism spectrum disorder (ASD) is a developmental condition that presents with a tendency to experience sensory overload as well as deficits in social cognition and communication which may be associated with differences in facial processing strategies. Previous studies have shown that, when viewing a facial image, participants with ASD spend less time on the eyes and lips—which contain more emotional and social information than other areas of the face. This study investigates whether individuals with an autism-related phenotype avoid the eyes of facial images in order to reduce their risk of experiencing sensory overload. Neurotypical participants, either possessing or lacking an autism-related phenotype, viewed images drawn from two stimuli sets: a control set of color images and an experimental set consisting of grayscale and reduced contrast images. Humans have been shown to use color as a source of social information (e.g. relative health, sex, emotion, etc.); the grayscale images in the experimental set thus contained less socially relevant information than the color images in the control set. The color images also contained more brightness and contrast—both of which are potential triggers of sensory overload—than the reduced contrast images. The results revealed that participants with an autism-related phenotype spent more time focusing on the eyes of grayscale images than on the eye region in color images. However, this effect was not observed when reduced contrast images were compared to color images. These results, when extrapolated to a population with a true autism phenotype, suggest that individuals with autism may process grayscale images differently than color images.