Limited attentional bias for faces in toddlers with autism spectrum disorders

Abstract

Context: Toddlers with autism spectrum disorders (ASD) exhibit poor face recognition and atypical scanning patterns in response to faces. It is not clear if face-processing deficits are also expressed on an attentional level. Typical individuals require more effort to shift their attention from faces compared with other objects. This increased disengagement cost is thought to reflect deeper processing of these socially relevant stimuli.

Objective: To examine if attention disengagement from faces is atypical in the early stages of ASD.

Design: Attention disengagement was tested in a variation of the cued attention task in which participants were required to move their visual attention from face or nonface central fixation stimuli and make a reactive saccade to a peripheral target. The design involved diagnosis as a between-group factor and central fixation stimuli type as a within-group factor.

Setting: Participants were taken from a cohort of patients at a university-based specialized clinic or from a pool of subjects participating in a prospective study of social cognition in ASD.

Participants: Toddlers with ASD (mean age, 32 months [n = 42]) were compared with toddlers with nonautistic developmental delays (mean age, 29 months [n = 31]) and with typically developing toddlers (mean age, 29 months [n = 46]).

Main outcome measure: Saccadic reaction time.

Results: Developmentally delayed and typically developing toddlers had more difficulties disengaging visual attention from faces than toddlers with ASD. This effect was not present in response to nonfacial stimuli. These results suggest that toddlers with ASD are not captivated by faces to the same extent as toddlers without ASD and that this effect is not driven by a generalized impairment in disengagement of attention.

Conclusion: The results suggest that face-processing difficulties in toddlers with ASD involve disruption of an attentional mechanism that typically supports deeper processing of these highly socially relevant stimuli.

Figure 1

Examples of a nonsocial trial and direct and averted gaze trials. All participants were first exposed to 10 nonsocial trials (A), then half of the sample viewed 64 direct gaze trials (B), while the other half watched 64 averted gaze trials (C). Trials were equated for total duration across conditions. The asterisks represent a peripheral target; ISI, interstimulus interval (a blank screen).

Figure 2

Mean saccadic reaction time in toddlers with autism spectrum disorder (ASD), typical development (TD), and developmental delay (DD) in the nonsocial, direct gaze, and averted gaze conditions. Error bars represent standard error; *mean difference of at least P<.05.