A psychophysiological study of nightmares and night terrors. I. Physiological aspects of the stage 4 night terror.

Anxious arousals originate from all sleep stages and can be classified as: a) stage 4 night terrors; b) rapid eye movement (REM) nightmares; c) stage 2 awakenings; and d) hypnagogic nightmares. We have confirmed Broughton's finding that the night terror, the most severe type of episode, does not occ