Automatic classification of the cats vigilance state.

A special purpose hardware system has been interfaced with a minicomputer for determining the vigilance state in the cat and for quantifying delta and sigma spindle activity in the sleep EEG. The computer agreement with manual scoring is 93.8% when the state is classified as awake. non-REM, or REM sleep. The system identifies six distinct vigilance states: REM sleep, slow-wave sleep 1 or 2 (distinguished by differences in EMG level), light sleep, resting and movement. Five day averages of vigilance state and EEG activity are presented for three animals, and the effects of 5 HTP and L-dopa on delta activity and sleep spindles have been quantified for one cat in order to demonstrate the system utility.