Circadian Rhythms in Man

  • Jürgen Aschoff
Part of the Readings from the Encyclopedia of Neuroscience book series (REN)


Like many animals, humans have adjusted to the natural environment so as to be prepared for efficient activity during daytime and to rest at night. As the basis of this program, almost all structures and functions undergo regular changes within 24 hours. Such rhythms have been described in physiological parameters, such as hormone levels in blood plasma, blood pressure and heart rate, body temperature, and sleep propensity, and in behavioral parameters, such as mood, reaction time, computation speed, and performance in learning tasks. These rhythms normally keep distinct phase-relationships with each other, implying a high degree of internal temporal order. In principle, this rhythmicity is maintained when subjects are sleep deprived, when they are starved, or when they receive equal amounts of food at short intervals over the day. The timing of single meals, however, may influence the pattern of some variables, and the sleep-wake cycle can have phase-setting as well as masking effects on the instantaneous value of rhythms as especially known for body temperature and some hormones.


Circadian Rhythm Circadian System Circadian Period Isolation Unit Urinary Cortisol Excretion 
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Further reading

  1. Aschoff J (1985): On the perception of time during prolonged temporal isolation. Human Neurobiol 4: 41–52Google Scholar
  2. Aschoff J, von Goetz Ch, Wildgruber Ch, Wever RA (1986): Meal timing in humans during isolation without time cues. J Biol Rhythms 1: 151–162CrossRefGoogle Scholar
  3. Minors DS, Waterhouse JM (1981): Circadian Rhythms and the Human. Bristol-London-Boston: J. Wright & SonsGoogle Scholar
  4. Moore-Ede MC, Czeisler CA, eds (1984): Mathematical Models of the Circadian Sleep-Wake Cycle. New York: Raven PressGoogle Scholar
  5. Wever R (1979): The Circadian System of Man. New York-Heidelberg-Berlin: Springer-VerlagCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1988

Authors and Affiliations

  • Jürgen Aschoff

There are no affiliations available

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