Asperger syndrome: how does it relate to non-verbal learning disability?

The syndrome of non-verbal learning disabilities (NLD) is associated with prominent non-verbal deficits such as reduced perceptual and spatial abilities, against a background of relatively intact verbal abilities. Asperger syndrome is one of the several developmental disorders for which Byron Rourke has claimed that almost all the signs and symptoms of NLD are present. This study investigated the claim utilizing a battery of neuropsychological tests that were found to be sensitive to NLD in the original learning disordered populations used to describe the syndrome. Children aged between 8 and 14 were recruited to form two groups: (1) children with Asperger syndrome (N=14) and (2) normal healthy schoolchildren (N=20). By contrast to the main principle outlined in the NLD model, children with Asperger syndrome did not display a relative difficulty with spatial- or problem-solving tasks; indeed, they displayed significantly higher performance on some non-verbal tasks in comparison with verbal tasks. It was only in relation to their high levels of psychosocial and interpersonal difficulties, which are also predicted on the basis of their psychiatric diagnosis, that the children with Asperger syndrome were clearly consistent with the NLD model in this study. These results raise questions about the relevance of the syndrome of NLD for children with Asperger syndrome.