Hypnosis and sleep: the control of altered states of awareness.

If he had not witnessed the induction procedure, the casual observer might well believe a typical hypnotized subject was asleep. It was this sleeplike appear-ance that led Braid to coin the term "hypnosis" from the Greek hypnos (to sleep) and "somnambulist" from the Latin somnus (sleep) and ambulare (to walk), to describe the deeply hypnotized person. There are indeed many phe-nomenological parallels between sleep and hypnosis. Not only does the deeply hypnotized individual often appear to be asleep; he may subsequently describe the experience as sleeplike. When awaking from either condition, the person often remembers little of what has transpired. Like the sleepwalking somnam-bulist, the hypnotized person may move about and talk, and he/she maintains con-tact with selected aspects of the external world. Vivid dreams may occur in both sleep and hypnosis. The long historical association between hypnosis and sleep is still reflected in many of the standard induction suggestions that subjects should enter into a deep, relaxed, restful sleep.