The initial effects of scopolamine on the electroencephalogram in healthy human subjects

We find that the initial effects of scopolamine on the alpha frequency band (7-13 Hz) part of an electroencephalogram (EEC) in healthy human subjects can be characterized using a first order decay model for the relative power contained in the band. We have studied the effects on EEG immediately after injection of scopolamine (i.v.) using an auditory evoked potential series, where the subjects were instructed to count odd signals in the series. This amplifies the activity in the alpha-band and possibly the effect of scopolamine. Eight young healthy human subjects participated in the study and all showed an initial decrease in the relative power of the alpha-band. In contrast the relative power in the alpha-band increased in all subjects when placebo was administered.