Deprivation of Dreaming Sleep by Two Methods

THE rapid-eye-movement (REM) period of sleep has been identified as a distinctive and regularly recurring psychophysiological state within the nightly sleep cycle.²⁻⁴,⁸,²⁰⁻²²REM periods occur during sleep at an interval of about 90 minutes from the onset of one period to the onset of the next in the human adult, and constitute about 20% of total sleep time. The psychologic phenomenon of dreaming occurs during REM periods,²,³,⁸⁻¹⁰and this finding allows investigation of the function of dreaming sleep by reducing REM time. Dement drastically reduced the typical amount of nightly dreaming of experimental subjects by arousing them just after the beginning of each REM period.⁶Subjects showed a progressive increase in dream attempts during a series of deprivation nights and, on recovery nights, a marked elevation in dream time that grossly compensated for the prior REM deficit. Several of Dement's subjects reported an increase