The relation of eye movements, body motility, and external stimuli to dream content.

The phenomenon of dreaming has always occupied an important place in the study of human behavior. Questions such as, When do dreams, occur? How long do they last? ]3oes everyone³5aS7 ana many others have beenthe subject of much lively debate. Only recently, how-ever, has it become possible to formulate answers to some of the more fundamental problems of dreaming in objective terms. The first step in answering these questions was made by Aserinsky and Kleitman (1) who observed periods of rapid, conjugate eye move-ments during sleep and tested the possibility that such eye movements were related to dreaming. These investigators found that Ss awakened when rapid eye movements were present showed a high incidence of dream recall, and that awakenings when the eyes were quiescent elicited a very low incidence of dream recall. These findings were subsequently confirmed in both normal and schizo-phrenic Ss (6), and a recent study (7) appears to have conclusively estab-lished rapid eye movements as an objective criterion of dream activity. In the latter study, an 80 % incidence of vivid, detailed dream recall was elicited from 9 Ss after nearly 200 1 Aided by a grant from the Wallace C. and