ELECTRICAL BRAIN ACTIVITY IN SCHIZOPHRENIA DESCRIBED BY EQUIVALENT DIPOLES OF FFT-DATA

Since results of conventional FFT-power-analysis are reference-depende nt, only unambiguous neurophysiological data should be used for a func tional physiological interpretation of EEG-data. FFT-approximation wit h successive center-of-gravity-dipole calculation gives unambiguous EE G-data with regard to recording reference. In the present investigatio n 22 medicated schizophrenic patients were compared with 22 healthy ag e- and sex-matched controls with regard to spontaneous resting EEG. Mo re 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 subj ects. With more severe schizophrenic symptoms (higher BPRS-score), the more anterior was the equivalent-dipole localization in the betal-ban d, and the deeper in the theta-band. The different locations of the be ta-band dipoles in schizophrenic patients suggest that different neuro nal populations generate beta-activity in schizophrenia compared to he althy controls. FFT-approximation allows a substantial and meaningful data reduction in multichannel recordings and will hopefully help in u nderstanding pathological brain functions in schizophrenia.