A computerized topographic technique that maps brain electrical activity is applied to the investigation of neurophysiological abnormalities in medicated and drug-free schizophrenic patients. This topographic approach uses EEG and evoked potentials to provide functional measures of electrophysiological abnormalities. Neurophysiological differences between schizophrenic patients and controls are delineated which add further evidence that frontal lobe dysfunction may be relevant to our understanding of schizophrenia. An initial investigation employs computed tomography to examine the relationship of structural anatomical pathology in schizophrenia with the functional abnormalities that may be defined using brain electrical activity mapping. When schizophrenic patients with and without frontal cortical atrophy were compared, electrophysiological differences were delineated that overlay frontal cortical regions. This preliminary work suggests that in schizophrenia, abnormal electrophysiological function is associated with definable gross morphological abnormalities of the brain.