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P. Lavie

Bio: P. Lavie is an academic researcher. The author has contributed to research in topics: Sleep (system call). The author has an hindex of 1, co-authored 1 publications receiving 402 citations.

Papers
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01 Jan 1986
TL;DR: The results showed that in spite of the significant between-group differences in total sleep, the temporal structure of sleepiness was very similar in the 3 experiments, which demonstrate structured variations in sleepiness across the nycthemeron.

417 citations


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Journal ArticleDOI
TL;DR: Analyses of the (nonadditive) interaction of the circadian and sleep-dependent components of sleep propensity and sleep structure revealed that the phase relation between the sleep-wake cycle and the circadian pacemaker during entrainment promotes the consolidation of sleep and wakefulness and facilitates the transitions between these vigilance states.
Abstract: The role of the endogenous circadian pacemaker in the timing of the sleep-wake cycle and the regulation of the internal structure of sleep, including REM sleep, EEG slow-wave (0.75-4.5 Hz) and sleep spindle activity (12.75-15.0 Hz) was investigated. Eight men lived in an environment free of time cues for 33-36 d and were scheduled to a 28 hr rest-activity cycle so that sleep episodes (9.33 hr each) occurred at all phases of the endogenous circadian cycle and variations in wakefulness preceding sleep were minimized. The crest of the robust circadian rhythm of REM sleep, which was observed throughout the sleep episode, was positioned shortly after the minimum of the core body temperature rhythm. Furthermore, a sleep-dependent increase of REM sleep was present, which, interacting with the circadian modulation, resulted in highest values of REM sleep when the end of scheduled sleep episodes coincided with habitual wake-time. Slow-wave activity decreased and sleep spindle activity increased in the course of all sleep episodes. Slow-wave activity in non-REM sleep exhibited a low amplitude circadian modulation which did not parallel the circadian rhythm of sleep propensity. Sleep spindle activity showed a marked endogenous circadian rhythm; its crest coincident with the beginning of the habitual sleep episode. Analyses of the (nonadditive) interaction of the circadian and sleep-dependent components of sleep propensity and sleep structure revealed that the phase relation between the sleep-wake cycle and the circadian pacemaker during entrainment promotes the consolidation of sleep and wakefulness and facilitates the transitions between these vigilance states.

1,241 citations

Journal ArticleDOI
TL;DR: The evidence did not support a direct link between circadian-related fatigue influences and performance or safety outcomes and further research is needed to clarify the link.

607 citations

Journal ArticleDOI
TL;DR: Exogenous melatonin can act as soporific agent, a chronohypnotic, and/or a chronobiotic in order to treat sleep or circadian rhythm disorders.
Abstract: The circadian rhythm of pineal melatonin is the best marker of internal time under low ambient light levels. The endogenous melatonin rhythm exhibits a close association with the endogenous circadian component of the sleep propensity rhythm. This has led to the idea that melatonin is an internal sleep ‘facilitator’ in humans, and therefore useful in the treatment of insomnia and the readjustment of circadian rhythms. There is evidence that administration of melatonin is able: (i) to induce sleep when the homeostatic drive to sleep is insufficient; (ii) to inhibit the drive for wakefulness emanating from the circadian pacemaker; and (iii) induce phase shifts in the circadian clock such that the circadian phase of increased sleep propensity occurs at a new, desired time. Therefore, exogenous melatonin can act as soporific agent, a chronohypnotic, and/or a chronobiotic. We describe the role of melatonin in the regulation of sleep, and the use of exogenous melatonin to treat sleep or circadian rhythm disorders.

601 citations

Journal ArticleDOI
TL;DR: Three kindreds with a profound phase advance of the sleep–wake, melatonin and temperature rhythms associated with a very short τ represent a well-characterized familial circadian rhythm variant in humans and provide a unique opportunity for genetic analysis of human circadian physiology.
Abstract: Biological circadian clocks oscillate with an approximately 24-hour period, are ubiquitous, and presumably confer a selective advantage by anticipating the transitions between day and night. The circadian rhythms of sleep, melatonin secretion and body core temperature are thought to be generated by the suprachiasmatic nucleus of the hypothalamus, the anatomic locus of the mammalian circadian clock. Autosomal semi-dominant mutations in rodents with fast or slow biological clocks (that is, short or long endogenous period lengths; tau) are associated with phase-advanced or delayed sleep-wake rhythms, respectively. These models predict the existence of familial human circadian rhythm variants but none of the human circadian rhythm disorders are known to have a familial tendency. Although a slight 'morning lark' tendency is common, individuals with a large and disabling sleep phase-advance are rare. This disorder, advanced sleep-phase syndrome, is characterized by very early sleep onset and offset; only two cases are reported in young adults. Here we describe three kindreds with a profound phase advance of the sleep-wake, melatonin and temperature rhythms associated with a very short tau. The trait segregates as an autosomal dominant with high penetrance. These kindreds represent a well-characterized familial circadian rhythm variant in humans and provide a unique opportunity for genetic analysis of human circadian physiology.

535 citations

Journal ArticleDOI
TL;DR: In this article, the authors examined whether smartphone use depletes employees' regulatory resources and impairs their engagement at work the following day, and they found that smartphone use for work at night increased depletion the next morning via its effects on sleep.

476 citations