Variability of cortical evoked responses in man related to slow wave activity

Acoustically evoked responses were recorded from subdural and intracerebral electrodes chronically implanted in man. It was found that during slow wave activity especially the negative component at about 100 ms latency varies in form and amplitude. If the stimuli were presented during increasing cortical negativity, the amplitude of the 100 ms component of the evoked responses was generally larger than in the case of stimuli presented during decreasing negativity.