Background: From birth, infants show a preference for the faces, gaze, and voices of others. In individuals with autism spectrum disorders (ASDs) these biases seem to be disturbed. The source of these disturbances is not well-understood, but recent efforts have shown that the spontaneous deployment of attention to social targets might be atypical as early as 6 months of age. The nature of this atypical behavior and the conditions under which it arises are currently unknown.
Methods: We used eye-tracking to examine the gaze patterns of 6-month-old infants (n = 99) at high risk (n = 57) and low risk (n = 42) for developing ASD as they viewed faces that were: 1) still; 2) moving and expressing positive affect; or 3) speaking. Clinical outcomes were determined through a comprehensive assessment at the age of 3 years. The scanning patterns of infants later diagnosed with ASD were compared with infants without an ASD outcome.
Results: Infants who later developed ASD spent less time looking at the presented scenes in general than other infants. When these infants looked at faces, their looking toward the inner features of faces decreased compared with the other groups only when the presented face was speaking.
Conclusions: Our study suggests that infants later diagnosed with ASD have difficulties regulating attention to complex social scenes. It also suggests that the presence of speech might uniquely disturb the attention of infants who later develop ASD at a critical developmental point when other infants are acquiring language and learning about their social world.
Keywords: Autism; eye-tracking; faces; infants; social attention; speech.
Copyright © 2014 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.