Action performance in children with autism spectrum disorder at preschool age: a pilot study.

Objectives: Motor deficits related to imitation have been observed in autism spectrum disorder (ASD) patients. This pilot investigation focused on motor performances, including daily tool-use actions, performing an action in the absence of the tool, and imitating (copying tool-use action presented visually), in eight children with ASD and eight children with typical development (TD), with all of pre-school age (4-6 years). Methods: Motor performances were compared between the children with ASD and TD. Differences between an actual tool-use action and performing a tool-use action without the tool according to verbal instruction were also assessed between the groups. Results: Children with ASD showed impairments in imitating, but their actual tool-use actions and tool-use actions without tools following verbal instruction were not different from those of TD children. The spatial error rate in the tasks was higher in children with ASD. Conclusions: The present study indicates that disturbance in imitating actions appears by the age of 4-6 years in children with ASD, possibly as a characteristic symptom affecting motor performance at pre-school age. Generalized apraxia might follow by the age of 8 years or older.