Face Scanning Distinguishes Social and Communication Impairments in Autism

Background: How closely related are the social and communicative impairments in Autism Spectrum Disorder (ASD)? Recent findings in typically developing children suggest that both are highly heritable but have only moderate behavioural and genetic overlap. The face transmits both socio-emotional and communicative information. Fixating the eyes is important to detect certain emotions such as fear, while fixating the mouth facilitates language comprehension.

Objectives: The present eye tracking study aimed at testing the hypothesis that social impairment symptoms and communication problems are differentially related to face scanning in ASD. Specifically, we expected children better at socio-emotional behaviors to fixate the eyes more than the mouth, while the opposite was expected for children better at communication.

Methods: The gaze of 15 young children with formal DSM-IV diagnosis within the Autism Spectrum and a typically developing group was recorded with an eye tracker (Tobii 1750) while they looked at several male and female faces. We related the Social Impairment scale and the Communication Impairment scale of the Autism Diagnostic Interview –Revised (ADI-R) to where in the face they were looking (eyes or mouth).

Results: We show that when looking at other people’s faces, children with ASD who are better at social interaction than communication look more at the eyes, while the children better at communication than social interaction look more at the mouth.

Conclusions: This study suggests that the neural systems for social-emotional and communication behaviors are clearly separable in ASD, and that in face observation, they give opposing instructions to the oculomotor system. We believe this finding has important theoretical and clinical implications.