Long latency evoked potential components in human slow wave sleep.

The wave morphology of long latency (more than 200 msec) components of auditory evoked potentials of healthy human adults was analysed in different slow wave sleep stages and at different electrode positions. The results indicated that the marked negative deflection consisted of 2 distinct components with 300 and 550 msec latency and with central and frontal amplitude maxima, respectively. Very long latency components (N1500 and P1900) were observed with monotonously increasing amplitudes parallel to the deepening of sleep. The contribution of the large amplitude, transient evoked slow waves to the SWS EEG and the general role of information processing in the regulation of sleep are briefly discussed.