We examined the relationship between contingent negative variation (CN
V) amplitude and digastric muscle activity in jaw-opening motor task.
Subjects were instructed to open their jaws in response to a sound sti
mulus following a visual warning stimulus. Electroencephalograms were
averaged by using the visual stimulus pulse as a trigger. Bilateral CN
Vs were clearly recorded at several cortical locations, with a tendenc
y for larger amplitudes at temporal placements.