Acute Deprivation of the Terminal Four Hours of Sleep Does Not Increase Delta (0–3-Hz) Electroencephalograms: A Replication

Abstract

This experiment evaluated further our previous finding that substitution of waking for the terminal 3-4 hr of sleep produces little or no increase in either visually scored or computer measures of delta sleep. Eleven young adults (mean age 24.5 yr) were studied on a baseline night, a night with sleep limited to an average of 188 min, and a recovery night. Visually scored sleep stages, eye movement activity and computer measures of 0-3 Hz were analyzed by nonrapid eye movement periods (NREMPs) and for all recorded sleep in each condition. In addition, we measured the heights, durations and areas under the curve manifested by the cyclic waxing and waning of 0-3-Hz integrated amplitude across sleep. Acute loss of 3.9 hr of sleep did not increase either visual or computer measures of delta electroencephalograms (EEG) on the recovery night, essentially confirming our previous findings. We hypothesize that augmentation of delta EEG above baseline levels after acute (one night's) sleep loss requires that disruption or loss of sleep from the first two NREMPs (or delta cycles). Rapid eye movement (REM) sleep durations on the recovery night were unaffected by the marked loss of REM sleep caused by partial deprivation. Although eye movements as well as stage REM were lost in the deprivation condition, eye movement density was significantly reduced rather than increased on the recovery night. This reduction is consistent with the hypothesis that REM activity varies inversely with sleep depth (or directly with central arousal level). The observations here, taken in association with previous results, suggest that a threshold for eye movement suppression by sleep deprivation in young adults lies in the range of 3-4 hr of prior sleep loss.

Sleep Patterns in Reading Disabled Children

“…Preadolescent children within this age range, who typically sleep approximately 9 hours per night, have been characterized as not exhibiting daytime sleepiness (59,60) and could, therefore, be said to be sleep satiated. This is an important consideration as sleep deprivation in young adults is commonly associated with an extended REM latency (66,67,(76)(77)(78). The observed variations in sleep architecture in RD children could suggest the presence of some degree of sleep deprivation, and reasons for considering this explanation as the basis for these observations have been previously discussed in the context of laboratory adaptation.…”

“…In addition, sleep deprivation has been shown to result in increases in stage 4 sleep, which occur mainly in the first NREM cycle and effectively extend this interval relative to baseline values (44,53,(63)(64)(65). However, there are studies in both young adults (66,67) and older preadolescents (11-13 years) (68), which indicate that expected increases in delta activity during recovery sleep following a one-night deprivation of3-5 hours of sleep, either visually scored or computer measured, do not occur. These results suggest that the slow wave rebound following shortterm sleep deprivation may require loss of sleep from the first two NREM cycles, which contain nearly all of the stage 4 sleep of the night (44,62,69).…”

“…It is possible that RD children are chronically sleep deprived and the 9 hours total bedtime at home and in the laboratory investigation constitutes an insufficient amount of available time to meet their sleep need. If this were the case, then significant increases in slow wave activity would have been expected later in the night, as well as during the first NREM sleep cycle (53,64,66,67,76).…”

Delta Sleep Response to Metyrapone in Post-Traumatic Stress Disorder

“…Integrated amplitude of 0.3-4.0 Hz activity per 30 s epoch was analyzed by NREM/REM cycles across all recorded sleep following the technique described by Feinberg et al (1987Feinberg et al ( , 1991 and Travis et al (1991). PAA analyses were conducted on all epochs of NREM and REM sleep.…”

Hypothalamic–Pituitary–Adrenal Axis Activity and Sleep in Posttraumatic Stress Disorder

“…Delta sleep activity was analyzed by period amplitude analysis (PAA) using the Pass Plus (Delta Software) analytic software. Integrated amplitude of 0.3-4.0 Hz activity per 30 s epoch was analyzed by NREM cycles on all epochs of NREM sleep across the night following the technique described by Feinberg et al (1987Feinberg et al ( , 1991 and (Travis et al, 1991). Epochs scored as wake were not included in these analyses.…”