We studied differences between P300 components of event-related potential (ERP) in patients with schizophrenia and normal control subjects during a standard auditory oddball task using magnetoencephalography (MEG) and electroencephalography (EEG). We measured event-related synchronization (ERS) and event-related desynchronization (ERD) [1]. Investigations using MEG also accurately localized the sources of auditory evoked responses [2], and provided higher spatial stability and a more focal ERD and ERS compared to EEG [3]. MEG and EEG have been used to study neural activity in normal subjects and patients with schizophrenia. P300 and ERD are related such that slow and fast alpha ERD are specifically guided or modified by the internal events indexed by P300 [4, 5]. ERD/ERS study may be as useful as P300 as an electrophysiological index reflecting the pathophysiological processes underlying the onset of schizophrenia [6]. ERD/ERS patterns in schizophrenia patients have already been explored using MEG [7, 8]. It was demonstrated that the temporospatial patterns of brain oscillations can be used as a biometric marker that discriminates schizophrenia patients and healthy controls [9].
