Same object, different uses: prior-intention and action execution in children with high functioning autism

Although motor deficits are not considered to be primary features of autism spectrum disorder (ASD), both experimental evidence and clinical observation suggest that they might have a crucial impact on the core characteristics... [ view full abstract ]

Although motor deficits are not considered to be primary features of autism spectrum disorder (ASD), both experimental evidence and clinical observation suggest that they might have a crucial impact on the core characteristics of autism. Yet, there remain significant gaps in our knowledge of motor dysfunction in ASD, including limited understanding of the relationship between motor planning processes and action execution. The ability to translate a motor plan into the appropriate action can be studied by investigating how movement kinematics vary as a function of action intention. Previous studies indicate that the way an agent grasps an object varies depending on how he/she plans to use it. Capitalizing on this effect, here, we asked 20 children with high functioning ASD and 20 typically developing children (TD) to reach and grasp a bottle with the aim to pour its content into a glass or place it inside a container. Depending on condition, children performed these actions in collaboration with a co-experimenter or on their own. We measured reach-to-grasp kinematics by means of a motion capture system. We found that, although the overall form of the movement was preserved in children with ASD, they exhibited difficulties in modulating their movements to action intentions. In particular, kinematics analysis revealed a delay in scaling movement velocity to the requests embedded in the forthcoming action. Providing further support to the hypothesis that autism is associated with an impairment in anticipatory action control, these findings have important implications in terms of both motor assessment and rehabilitation.