The Impact of Different Movement Types on Motor Planning and Execution in Individuals With Autism Spectrum Disorder.

Although there are consistent reports that motor skills are affected in individuals with autism, the details are still debated; specifically, why individuals spend more time preparing movements and whether or not movement execution takes longer. The present study investigated if the conflicting reports were related to: (a) differences in movement type and (b) if longer reaction times were related to the time for motor planning or for force-generation processes. Participants performed three different movement types. People with autism had longer premotor reaction times and movement times for the three-dimensional movements only. We suggest individuals with autism have difficulty planning and executing unconstrained reaching movements specifically. The present results are consistent with evidence that autistic individuals have more difficulty effectively using visual feedback but can use tactile feedback to execute reaching movements efficiently and accurately.