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Abstract:
Autism is a developmental disorder characterized by profound
social-communicative dysfunction and cognitive abnormalities in
executive functions. Previous neuroimaging studies have indicated
that neocortical and cerebellar system abnormalities in autism may
underlie their deficits in executive function. We performed
behavioral and fMRI studies (3T) in non-mentally retarded autistic
subjects and healthy control volunteers while they performed an
oculomotor spatial working memory task. Behavioral results
indicated a significant deficit in autistic subjects in the
accuracy of a remembered saccade. fMRI results indicated similar
activity in both groups in the frontal eye field, precuneus,
supplementary eye field, pre-supplementary motor area,
intraparietal sulcus, superior temporal sulcus, insula,
supramarginal gyrus, thalamus, and lateral cerebellum. However,
autistic subjects demonstrated significantly less activation than
autistic subjects in dorsolateral prefrontal cortex. These findings
indicate that autistic subjects have intact basic sensorimotor and
attention systems while having abnormalities in prefrontal regions
subserving executive functions.
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