title: Electrical brain activity in schizophrenia described by equivalent dipoles of FFT-data.
abstract: Since results of conventional FFT-power-analysis are reference-dependent, only unambiguous neurophysiological data should be used for a functional physiological interpretation of EEG-data. FFT-approximation with successive center-of-gravity-dipole calculation gives unambiguous EEG-data with regard to recording reference. In the present investigation 22 medicated schizophrenic patients were compared with 22 healthy age- and sex-matched controls with regard to spontaneous resting EEG. More anterior and superficial equivalent-dipoles were found in the beta-bands for schizophrenic patients compared to healthy control subjects. There was a tendency of increased beta-activity in schizophrenic subjects. With more severe schizophrenic symptoms (higher BPRS-score), the more anterior was the equivalent-dipole localization in the beta 1-band, and the deeper in the theta-band. The different locations of the beta-band dipoles in schizophrenic patients suggest that different neuronal populations generate beta-activity in schizophrenia compared to healthy controls. FFT-approximation allows a substantial and meaningful data reduction in multichannel recordings and will hopefully help in understanding pathological brain functions in schizophrenia.
authors.affiliation: Department of Psychiatry I, University of Frankfurt/Main, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Dierks
authors.forename: W K
authors.initials: WK
authors.lastname: Strik
authors.forename: K
authors.initials: K
authors.lastname: Maurer
mesh_terms: D000293:Adolescent; D000328:Adult; D001611:Beta Rhythm; D001931:Brain Mapping / Q000295:instrumentation; D002540:Cerebral Cortex / Q000503:physiopathology; D004569:Electroencephalography / Q000295:instrumentation*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D012016:Reference Values; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*