An Eye-Tracking Study of Visual Attention to Human Faces and Nonhuman Graphics in Children with Autism Spectrum Disorders

Background:    It was reported that typically developing children show preferential attention to social rather than inanimate stimuli, and they also prefer to focus on the more socially revealing features of the face, such as the eyes rather than the mouth; in contrast, individuals with autism seem to lack these early social predispositions.

Objectives:   This study explored the visual fixation patterns of ASD children when viewing human faces and inanimate stimuli by an eye-tracking study. 

Methods:   Fourteen children with ASD (male vs. female=12:2, Mage=5.60, SD=1.63) aged from four to seven and thirteen age-matched TD children (male vs. female=7:6, Mage=5.63, SD=0.55) participated study one in which 30 black and white photographs showing human faces with neutral facial expressions were displayed in sequence interval, and each one was displayed 3s with 1s interval. And then they participated the experiment again a week later. Their gaze behaviours were measured via an integrated Tobii TX300. In study two, sixteen videos of graphic movements and transformations were displayed in sequence interval, and each one was displayed 5s with 1s interval. Eighteen children with ASD (male vs. female=15:3, Mage=8.03, SD=3.05) aged from four to seven and twenty-two age-matched TD children (male vs. female=10:12, Mage=5.87, SD=1.42) participated study two. The proportion of total Fixation time to the region of interest (ROI), such as, left eye, right eye, nose, mouth, the main part of face, the whole face and body were investigated.

Results:  In study one, children with ASD fixed significantly less on the main regions of face than TD group. No differences were found on the fixations of ASD between the first and second week, which showed that memory did not affect their attention, but TD children showed less fixation on the left eye and left face region in the first week than in the second week. In study two, ASD children fixation significantly less on the movements and transformation of inanimate graphics than TD group, which is different from the reported findings that ASD had no impairment on their cognition to inanimate/nonhuman information.

Conclusions:   In summary, ASD showed impairments on social information cognition and graphics cognition.