Subjects will have an electroencephalograph (EEG) done before starting kava and again at the end of kava (study day 30). For this procedure, several electrodes (metal cups attached to wires) are secured to the scalp with a glue-like substance. A conductive gel fills the space between the electrode and the scalp to ensure good contact. The electrodes will remain in place for about 2 hours and then removed. The subject lies quietly on a bed during the EEG recording.