The Relationship of "Drowsiness" and "Light Sleep" to the First, Second and Third Stages of Hypnosis

Early investigators often saw a close relationship between "sleep" and "hypnosis." To many of them, it seemed that the only difference between the two "states" was that someone spoke to the subject during "hypnosis" while no one spoke to the subject during "sleep." However, none of these early investigators attempted a controlled experiment to compare the behavior of their subjects during "sleep" and "hypnosis." All relied simply on observation -- usually in a clinical setting.