Distribution Of REM Sleep Research Articles

Patterns in the distribution of REM sleep in normal human sleep.

Results are reported of four analyses of the distribution of REM sleep across nights of two subjects who slept for 50 consecutive nights on a regimented, but normal, sleep schedule. We found (a) a strong phase-setting effect of sleep onset on the distribution of REM sleep within nights, (b) no systematic change in the phase of the distribution of REM sleep across nights, and (c) a relationship between the nocturnal temperature minimum and the distribution of REM sleep within nights. Our results are consistent with the notion that the nightly distribution of REM sleep may be determined by an oscillatory process, the phase of which is reset at sleep onset, but which may be subject to other influences, such as the circadian temperature rhythm. These results are in general agreement with those found by investigators studying subjects on free-running or other abnormal sleep schedules.

Distribution of REM sleep in time zone shifts : T. Kitahara, M. Sasaki, M. Tamura, A. Mori, and S. Endo (Tokyo, Japan)

Distribution of REM sleep in time zone shifts : T. Kitahara, M. Sasaki, M. Tamura, A. Mori, and S. Endo (Tokyo, Japan)

Distribution of REM Sleep in Entrained 24 Hour and Free-Running Sleep-Wake Cycles

One hundred thirty sleep episodes of 6 subjects, living on a natural 24 hr day, were compared with 116 sleep times of the same subjects living isolated from external time cues. The polygraphic sleep recordings were analyzed for the distribution of REM sleep under both conditions. Additionally, the relationship between body temperature and REM sleep was analyzed by comparing sleep episodes in which the temperature minimum occurred early in the sleep episode with those in which there was a late temperature minimum. The results show that there is more REM sleep in the beginning of sleep in sleep episodes of free-running rhythms as compared to sleep episodes of entrained 24 hr rhythms. This higher amount of REM sleep is due to a longer first REM episode and shorter first NREM episodes. The comparison of the sleep episodes that differ in the position of the temperature minimum shows similar differences, i.e., more REM sleep in the beginning of sleep episodes in which the temperature minimum occurs earlier as compared to episodes in which the temperature minimum occurs later. It was hypothesized that the amount of REM sleep depends on the phase relationship between sleep and the circadian temperature cycle. From this point of view, the difference in the distribution of REM sleep in the entrained 24 hr rhythm, on the one hand, and the free-running rhythm, on the other hand, can be explained by the different courses of body temperature during sleep. That only the first REM episode is influenced by circadian parameters may indicate an exceptional role for this REM episode in contrast to the following episodes.

Sleep stage characteristics of extended sleep in normal Ss.

Although numerous studies have been conducted on sleep deprivation, few have concentrated on sleep extension in normal Ss. The initial invesugauon in this area was concerned with the distribution of REM sleep in Ss instructed to sleep ad lib. (Verdoqe, 1968). However, no control nights were obtained nor was NREM sleep exam~ned In stages. Webb and Agnew (1970) described sleep patterns in Ss who characteristically slept (> 8y2-hr.) and short (< 6%-hr.) periods, but had no values for sleep of more rypical length in these Ss. Therefore, it is unclear whether the values for NREM sleep are characterisuc of long sleepers as a group or extended sleep per se. Ss in the present study were 12 normal male college students who habitually slept 7 or 8 hr. The experiment comprised an adaptation night, two control nights of 7 or 8 hr. habitual sleep ( 1 to 9 a.m.) and two nights of extended sleep (10 p.m. to 9 a.m.), wirh a one-day recovery between the two conditions which were balanced as to order. Standard techniques were followed (Rechtschaffen & Kales. 1968) with the exception that Stages 3 and 4 were scored as one stage (3 -4 ) .