A comparison of cognitive/neuropsychological impairments of nonretarded autistic and schizophrenic children

The performance of children meeting DSM-III criteria for schizophrenic disorder and infantile autism and of normal children (ages 7 years 10 months to 14 years 4 months) was compared on the Wisconsin Card Sorting Test, Rey's Tangled Line Test, Benton Judgment of Line Orientation, Digit Symbol Substitution Test, and Peabody Picture Vocabulary Test. The mean performance IQ of the schizophrenic and autistic children was equal and in the normal range. The normal children were of average intelligence as estimated by the PPVT. As compared to normal children, both autistic and schizophrenic children were impaired on the DSST and RTLT. The autistic children had significantly lower scores on the PPVT than schizophrenic and normal children. The schizophrenic children made significantly more perseverative responses on the WCST than did normal children. They significantly increased their nonperseverative errors on the second half of the WCST, after having been taught the correct sorting principles. It is argued that in schizophrenia a core deficit in momentary processing capacity underlies the above performance pattern. In contrast, in autism the core cognitive deficit involves an inability to use language to regulate and control ongoing behavior.Preparation of this article was supported in part by a John D. and Catherine T. MacArthur Foundation Grant to Robert Asarnow, and NIMH Grant MH 30897 to the UCLA Clinical Research Center for the Study of Childhood Psychoses. We gratefully acknowledge the assistance of Michael J. Goldstein, Ph.D., who acted as reseach advisor to the first author over the course of this study; Delores Adams, who assisted us in data analysis; and Sara Lerner, who enthusiastically helped us in data collection. We also acknowledge the assistance of the staff of the Clinical Research Center for the Study of Childhood Psychosis at UCLA, as well as the many children who participated in this study, and their parents.