Cognitive/neuropsychological studies of children with a schizophrenic disorder.

This article summarizes a series of cognitive/neuropsychological studies of children with schizophrenia. One set of studies, which surveyed a broad range of neuropsychological functions, revealed no evidence that children with schizophrenia are consistently impaired in sensory, perceptual, or language functions. Rather, the studies showed that children with schizophrenia performed poorly on tasks requiring sensory, perceptual, and language processing that made extensive demands on information-processing capacity. A second series of studies, which examined visual information processing by manipulating the processing demands of span of apprehension tasks, yielded similar findings. The key characteristic of tasks that elicit impaired performance in children with schizophrenia is that the task makes extensive demands on processing resources. This suggests that these children have limited information-processing capacity. Three hypotheses are proposed concerning the cognitive processes that are impaired in children with schizophrenia: (1) the cognitive processes that seem to be impaired in these children are part of a more general, hierarchically organized attention system; (2) the component processes of the system are subserved by different brain structures; and (3) the structures are part of a network that includes the frontal lobe and thalamus in interaction with the reticular activating system.