Acute Shifts in the Sleep-Wakefulness Cycle: Effects on Performance and Mood

Abstract

Ten regular 12-8 a.m. 8-hour sleepers performed a 5-min experimenter-paced calculation task, a 30-min vigilance task and completed an adjective check list to rate their mood following a 12-8 a.m. habitual sleep condition and 8 p.m.-4 a.m., 10 p.m.-6 a.m., 2-10 a.m., and 4 a.m-12 p.m. conditions of shifted sleep. After the shifted sleep conditions compared to the 12-8 a.m. condition performance on the vigilance and calculation tasks was significantly impaired, and negative affect was significantly greater as measured by three scales of the adjective check list. Sleep length did not differ between the various conditions and the decrements in performance and mood were unrelated to any specific changes in the electrophysiological patterns of sleep.

Nocturnal Electrographic Features of Frequently Changing-Irregular Sleep-Wakefulness Rhythms

“…The findings (Table 2) which attained significantly larger nightly variance encompassed: (a) the process of falling asleep; (b) accumulating sleep ; and (c) remaining asleep; these are salient polygraphic features endemic to disturbed sleep generally (Frankel et al, 1976;H a w , Chernik, Hawkins, & Mendels, 1974;Karacan et al, 1973). More specifically, however, a significant variation of the x ultradian (90-min) REM cycle occurred which parallels experimental data reported (Taub & Berger, 1973) on acutely advancing and delaying customary 12:00-8:00 a.m. sleep by 2-4 hr gradations in circadian phase shift studies (Taub & Berger, 1974). A cogent clinical concern raised by the present findings is that irregular rest (sleep)-activity (wakefulness) schedules followed in the everyday environment on a chronic basis may lead to potentially severe 24-hr biological rhythm disorders (e.g., Weitzman, Czeisler, Coleman, Dement, Richardson, & Pollak, 1979, p. 221) such as the delayed sleep phase syndrome, narcolepsy, etc.…”

Who Needs More Sleep? Comparing Undergraduate and Graduate Students' Sleep Habits in a National U.S. Sample

“…Research related to sleep disturbances has long cited that shifts to one's sleep-wake cycle can increase feelings of depression and difficulty concentrating (Taub & Berger, 1974). Likewise, evidence has long suggested that sleep habits, particularly inconsistent wake-up times, can increase irritability and depression among college students (Taub, 1978) as well as significantly influence academic performance (Lack, 1986) and grade point averages (Gaultney, 2010;Taylor et al, 2011;Thacher, 2008;Trockel, Barnes, & Egget, 2000).…”

Sleep Habits and Patterns of College Students: A Preliminary Study

“…Those who report excess daytime sleepiness also report more frequent use of marijuana and alcohol.2 Interestingly, even students who sleep 8 hours nightly but shift their sleep-wake cycle by 2 hours experience increased feelings of depression, reduced affability, and difficulty in concentrating. 3 Students who regularly sleep significantly later on the weekend than they do during the week do not adjust to this changed schedule but develop chronic psychomotor slowing and concentration problems; they also experience increased irritability and depre~sion.~ Although most of these findings have been explored under controlled laboratory conditions, there is support for the belief that sleep difficulties can significantly impair students' academic perf~rmance.~ Unfortunately, students who experience academic difficulties do not realize that poor sleep habits may contribute to their problems. Pilcher and Walters6 found that sleepdeprived students performed significantly worse than students who had a normal night's sleep, but the students inaccurately rated their performance as better than that of students who were not sleep deprived.…”