MatsushitaDepartment of Neuropsychiatry, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113, JapanDepartment of Psychology, Senshu University, Kanagawa, JapanDepartment of Psychiatry, University Hospital, Mizonokuchi, Teikyo University School of Medicine, Kanagawa, JapanDepartment of Neuropsychiatry, Faculty of Medicine, University of Ryukyu, Okinawa, JapanDepartment of Psychiatry, Tokyo Metropolitan Matsuzawa Hospital, Tokyo, JapanDepartment of Rehabilitation, National Center Hospital for Mental, Nervous and Muscular Disorders, National Center of Neurology and Psychiatry, Tokyo, JapanThe present study compares the amplitudes and topographic patterns of mismatch negativity (MMN) and N2b in schizophrenic patients and normal controls. Twenty-one schizophrenic outpatients and 19 normal volunteers participated in the study. Event-related potentials (ERPs) were recorded in a selective attention task. During the task, subjects were required to focus on one ear, counting deviant stimuli, those deviating in duration from a sequence of standard stimuli. MMN was significantly attenuated in the schizophrenics as compared with the normals in the frontocentral regions. In addition to MMN, the N2b amplitude was also reduced, which showed a significant correlation with the MMN amplitude in the schizophrenics. The late negativity elicited by the deviant stimuli in the unattended condition showed different topographical features between the groups. Whereas the normals showed a lateralized distribution with an ear-related asymmetry, similar to that of the N2b, the schizophrenics showed a frontal dominance, coinciding with the sustained negativity reported by ä
The present study compares the amplitudes and topographic patterns of mismatch negativity (MMN) and N2b in schizophrenic patients and normal controls. Twenty-one schizophrenic outpatients and 19 normal volunteers participated in the study. Event-related potentials (ERPs) were recorded in a selective attention task. During the task, subjects were required to focus on one ear, counting deviant stimuli,...