The classical conditioning of sleep and wakefulness

Using a metronome beat as conditioned stimulus three cases are described in which this stimulus was presented in close temporal contiguity with experimentally-induced sleep or waking. Drugs or fatigue consequent upon sleep deprivation were used as unconditioned stimuli for sleep. One of the subjects was an anxiety neurotic, one had narcolepsy and the third was a student volunteer. No EEG indication of conditioned sleep was obtained but there was evidence of conditioned relaxation in the anxiety neurotic and conditioned arousal in the other two cases.