EEG mapping investigations of psychomotor and music perception brain dysfunction in untreated schizophrenic patients.

Twenty-six untreated schizophrenic inpatients and 34 control persons were investigated using 16-channel EEG mapping during resting, manumotor and music perception tasks. Power values of activation tasks were each referenced to a separate, immediately preceding resting condition, using conventional delta, theta, alpha and 2 beta frequency bands. Results in delta and alpha bands, which maximally separated the two groups, are reported only for space reasons. Results indicated a "nonreactivity" (in all frequency bands) on the two activation paradigms in schizophrenic patients as a group. Major gender effects were obtained in normal persons, but not signs of nonreactivity comparable to patients. Subdividing patients exclusively by means of their EEG changes on activation produced meaningful clinical subgroups of "positive/negative" schizophrenics. This latter finding could contribute towards clinical utility of EEG mapping in psychiatry.