Encoding Similarities but Recognition Differences in Eye-Movement Behaviour during Face Emotion and Identity Processing in Autism Spectrum Disorder

Background:   Individuals with Autism Spectrum Disorder (ASD) show a number of face processing deficits compared to typically developing controls (TYP). These deficits may result from impaired processing of a number of cognitive domains including basic perceptual processes.

Objectives:   We sought to investigate, using objective measures of eye-movement behaviour, the visual processing strategies of individuals with ASD during different tasks of face processing to determine whether basic perceptual processes are disrupted. 

Methods:  We used eye-tracking technology to measure eye movement behaviour or a group of individuals with ASD (N = 8) and TYP (N = 24) in a) an emotion judgment task, b) an identity judgment task, and c) a picture judgment control task. Participants saw sequential pairs of faces (with a 1000 ms delay) and made same/different judgments on the pairs. We presented the basic emotional expressions in all tasks.

Results:   Our main finings show that a) individuals with ASD rely less on the upper region and more on the lower region of faces, b) both groups show a smaller reliance on the upper region when making emotion judgments than when making identity judgments, c) that face emotion modulates the relative reliance on the upper region for both groups, and d) that ASD and TYP show similar patterns of eye movement behaviour at encoding, but differences at recognition.

Conclusions:  These results further specify the nature of face processing deficits in ASD, and suggest that perceptual processes are preserved at encoding but disrupted at recognition in individuals with ASD.