Changes in EEG order in neuroleptically treated normal volunteers during a voluntary movement task

15 normal volunteers were treated over three weeks with haloperidol (HAL) and in the third week additionally with biperidene (BIP). The order of the EEG spectra at different topographical locations and in different frequency bands during a movement task was analyzed using uncertainty analysis (UA), a multivariate analysis technique based on information-theoretical methods. Different patterns of drug-induced changes were found. HAL decreases the theta and alpha band order at the fronto-central lateral areas but increases it at the fronto-central midline in the theta band and at the parietal areas in the alpha band. With the exception of the fronto-central midline locations, BIP more or less counterbalances the effect of HAL. Volunteers felt unwell and had motor disturbances during HAL and felt well again during HAL + BIP. Reaction time values were increased during HAL and normalized during HAL + BIP.