MOTOR SKILL LEARNING IN AUTISM

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This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Abnormalities on motor examination have often afforded valuable insights into developmental disorders of the brain. Such abnormalities have been well documented in individuals with autism (6, 13, 15, 16, 22, 39, 41, 43, 49, 52) and, in fact, date back to some of the original descriptions of the disorder (23). Increased insight into the brain mechanisms underlying autism can be gained from careful consideration of these motor signs. By using tests of motor function for which the neurologic basis is well mapped out, it is possible to gain an understanding of the neural circuits impaired in autism; motor signs can also serve as markers for deficits in parallel brain systems important for control of the social and communication skill impairments that characterize autism. Among the most consistently observed abnormalities on motor examination of autistic patients are deficits in performance of complex gestures. This includes those involving motor imitation as well as performance of other skilled motor tasks (4-6, 17, 19, 22, 40, 43, 45). Investigators have collectively referred to these deficits as "dyspraxia." In the context of the developmental disorder of autism, these deficits could be secondary to a fundamental problem with acquiring motor skills, i.e. motor skill learning. Asperger (1961) in fact stated that autistic children have movement problems because they do not learn by watching other people in daily life (Asperger H. Heilpadagogik {Therapeutic pedagogy}-cited in Miyahara et al., 1997). More recently, in a 1994 review of "Imitation and Action In Autism," Smith and Bryson cited Wing (1969), noting that, "clumsy children with autism reportedly have particular difficulty with learning organized patterns of movements (e.g., skipping and dancing)" (p. 267). Deficiencies in motor skill learning could also result in development of a limited repertoire of movements and behaviors and might thereby help to explain observations of motor stereotypies and other repetitive behaviors in autism. Further, investigations of motor skill learning might help to elucidate the cause of the core social and communicative deficits that characterize autism. Development of social and communicative gestures, for instance pointing, shaking another person's hand, offering comfort to someone, or engaging in reciprocal play, involves learning complex patterns of movements. Infants as young as newborns engage in imitation of facial expression and manual gestures (9, 31, 32), and it has been hypothesized that intact motor imitation is crucial in developing a sense of "other minds" (30). In other words, development of the ability to perceive and interpret other's social/emotional gestures may also depend upon the ability to learn to execute those gestures.