Decreased spontaneous attention to social scenes in 6-month-old infants later diagnosed with autism spectrum disorders

Abstract

Background: The ability to spontaneously attend to the social overtures and activities of others is essential for the development of social cognition and communication. This ability is critically impaired in toddlers with autism spectrum disorders (ASD); however, it is not clear if prodromal symptoms in this area are already present in the first year of life of those affected by the disorder.

Methods: To examine whether 6-month-old infants later diagnosed with ASD exhibit atypical spontaneous social monitoring skills, visual responses of 67 infants at high-risk and 50 at low-risk for ASD were studied using an eye-tracking task. Based on their clinical presentation in the third year, infants were divided into those with ASD, those exhibiting atypical development, and those developing typically.

Results: Compared with the control groups, 6-month-old infants later diagnosed with ASD attended less to the social scene, and when they did look at the scene, they spent less time monitoring the actress in general and her face in particular. Limited attention to the actress and her activities was not accompanied by enhanced attention to objects.

Conclusions: Prodromal symptoms of ASD at 6 months include a diminished ability to attend spontaneously to people and their activities. A limited attentional bias toward people early in development is likely to have a detrimental impact on the specialization of social brain networks and the emergence of social interaction patterns. Further investigation into its underlying mechanisms and role in psychopathology of ASD in the first year is warranted.

Keywords: Autism; eye-tracking; infants at risk; social development; spontaneous monitoring; visual attention.

Figure 1

(A) Frame from video stimulus with (B) regions of interest (ROIs) used in analysis. The ROIs: Scene (Person + Toys + Background), Person (Face + Body), Toys, Eyes, and Mouth.

Figure 2

Looking time ratios for the four groups (marginal means, +/− 1 standard error) for the Scene, Person, Toys, Face, Eyes and Mouth Regions of Interest across all conditions. P values for planned contrasts are reported with Tukey-Kramer correction for multiple comparisons. † p < .065 * p < .05 ** p < .01 *** p < .001

Figure 3

Looking time ratios for four conditions (marginal means, +/− 1 standard error) for each of the Regions of Interest. P values for post-hoc tests are reported with Tukey-Kramer correction for multiple comparisons. * p < .05 ** p < .01 *** p < .001 JA = Joint Attention; S = Sandwich; DB = Dyadic Bid; MT = Moving Toys