In short photoperiods, human sleep is biphasic.
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Results of a photoperiod experiment show that human sleep can be unconsolidated and polyphasic, like the sleep of other animals.Abstract:
Results of a photoperiod experiment show that human sleep can be unconsolidated and polyphasic, like the sleep of other animals. When normal individuals were transferred from a conventional 16-h photoperiod to an experimental 10-h photo-period, their sleep episodes expanded and usually divided into two symmetrical bouts, several hours in duration, with a 1-3 h waking interval between them. The durations of nocturnal melatonin secretion and of the nocturnal phase of rising sleepiness (measured in a constant routine protocol) also expanded, indicating that the timing of internal processes that control sleep and melatonin, such as circadian rhythms, had been modified by the change in photoperiod. Previous work suggests that the experimental results could be simulated with dual-oscillators, entrained separately to dawn and dusk, or with a two-process model, having a lowered threshold for sleep-onset during the scotoperiod.read more
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Mammalian Photoperiodic System: Formal Properties and Neuroendocrine Mechanisms of Photoperiodic Time Measurement
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References
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Journal ArticleDOI
A Functional Analysis of Circadian Pacemakers in Nocturnal Rodents. I. The Stability and Lability of Spontaneous Frequency
Serge Daan,Colin S. Pittendrigh +1 more
TL;DR: In this paper, a model of non-parametric entrainment of circadian pacemakers is tested for the case of nocturnal rodents using 1 or 2 light pulses per cycle, and the model makes use of the available data on freerunning period (τ) in constant darkness and on phase response curves (PRC) for short light pulses.
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A functional analysis of circadian pacemakers in nocturnal rodents
Serge Daan,Colin S. Pittendrigh +1 more
TL;DR: In this article, phase response curves for 15′ bright light pulses of four species of nocturnal rodents are described, and the response to a resetting stimulus at a given phase of the rhythm is correlated with the individual's free-running period.
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Timing of human sleep: recovery process gated by a circadian pacemaker
TL;DR: The model shows that the experimental data are consistent with the concept of a single circadian pacemaker in humans, which has implications for the understanding of sleep as a restorative process and its timing with respect to day and night.
Journal ArticleDOI
Circadian Activity Pattern with Two Peaks
TL;DR: It is concluded that the basic two—peak pattern of locomotor activity is a persistent property of the circadian oscillating system.
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The durations of human melatonin secretion and sleep respond to changes in daylength (photoperiod).
TL;DR: The duration of nocturnal MT secretion in human beings was longer after exposure to the short photoperiod, and whether such changes would lead to significant seasonal changes in human physiology and behavior under natural lighting conditions may be worthy of further investigation.