IV. Cyclical Fluctuations in Sleep-Depth and Eye-Movement Activity during the Course of Natural Sleep *

Abstract

A series of observations first reported by Aserinsky and Kleitman and by Dement and Kleitman are summarized and discussed. These include the discovery of rapid, conjugate eye-movements during sleep. They include the basic experiments which led Dement and Kleitman to propose the use of the Stage 1 EEG and eye-movement criteria as an objective, operational definition of the dream state, and they include data on the distribution of eye-movements over the course of natural sleep and on the relationship between eye-movements and EEG measures of sleep depth.