Abstract
A new set of decision rules for identification of brain dysfunction among schizophrenic or schizoaffective disorder patients were tested with the Luria-Nebraska Neuropsychological Battery. In a sample of 100 patients from these categories with normal neurological examination findings, three groups of patients were identified. These patients respectively were identified as cognitively normal, borderline, or abnormal. These groups were subjected to a series of multivariate and univariate analyses that showed them to be associated with significantly different profiles on the Luria-Nebraska Neuropsychological Battery. Different functional systems were postulated to account for the differences in impaired scores across normal, borderline, and abnormal cognitive functioning groups. Further research with external validation criteria was encouraged.