title: The external validity of Asperger disorder: lack of evidence from the domain of neuropsychology.
abstract: The present study compared individuals with high-functioning autism (HFA) and Asperger disorder (AD) in intellectual, motor, visuospatial, and executive function domains. Participants with AD demonstrated significantly higher Verbal and Full Scale IQ scores, significantly larger Verbal-Performance IQ discrepancies, and significantly better visual-perceptual skills than those with HFA. Once the superior intellectual abilities of the AD group were controlled (both statistically through analysis of covariance and by examining IQ-matched subgroups of HFA and AD participants), no significant group differences in motor, visuospatial, or executive functions were evident, save a marginally significant trend toward poorer fine motor performance in the AD group. This suggests that AD may simply be "high-IQ autism" and that separate names for the disorders may not be warranted. The relation of these findings to theories of autism and AD are discussed.
authors.affiliation: Department of Psychology, University of Utah, Salt Lake City 84112, USA.
authors.forename: J N
authors.initials: JN
authors.lastname: Miller
authors.forename: S
authors.initials: S
authors.lastname: Ozonoff
mesh_terms: D020817:Asperger Syndrome / Q000175:diagnosis / Q000523:psychology*; D001321:Autistic Disorder / Q000175:diagnosis / Q000523:psychology*; D002648:Child; D003071:Cognition; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D008959:Models, Neurological; D009483:Neuropsychological Tests; D011597:Psychomotor Performance; D012720:Severity of Illness Index; D014796:Visual Perception