Orientation to and processing of social stimuli under normal and competitive conditions in children with autism spectrum disorder

Background: Autism spectrum disorder (ASD) is a complex neurodevelopment disorder characterized by early specific impairments in social attention. However, the abnormality of orientation and processing ability in social attention is still unclear in children with ASD. Method: To address this question, we designed two viewing tasks including a background search task (normal social attention condition) and a paired preference task (competitive social attention condition) to explore the social attention in children with ASD. Eye-tracking technology was applied to measure the ability of ASD children to orient towards and process social stimuli under normal and competitive task conditions. Results: The results indicated that the initial orientation ability of social attention in children with ASD was normal, but the subsequent processing ability was impaired under both normal and competitive conditions. Specifically as follows: ASD groups, compared with controls groups, had similar time to first fixation to social stimuli but less fixation duration to social stimuli. More importantly, severity of symptoms in ASD children was negatively correlated with the fixation duration to social stimuli. Furthermore, both ASD and TD children preferred to orient and process stimuli related to circumscribed interests (CI), but ASD children had difficulty distinguishing between social and non-CI stimuli under competitive condition. Conclusion: These findings suggest that the abnormality in subsequent processing of social stimuli could serve as a key role in social attention impairments, which may provide a new perspective for early identification and intervention training.