author={Julie Carrier and Timothy H. Monk},
  journal={Chronobiology International},
  pages={719 - 732}
This brief review is concerned with how human performance efficiency changes as a function of time of day. It presents an overview of some of the research paradigms and conceptual models that have been used to investigate circadian performance rhythms. The influence of homeostatic and circadian processes on performance regulation is discussed. The review also briefly presents recent mathematical models of alertness that have been used to predict cognitive performance. Related topics such as… 

Circadian Rhythms in Cognitive Processes: Implications for School Learning

This review analyses the recent findings on circadian rhythms in cognitive processes, as well as the implications of these rhythms for school learning.


Analysis of circadian and homeostatic influences on the indices of sustained attention suggests that performance at work deteriorates at the end of a shift due to a decrease in general stability, an increase in error runs, decrease of long-hit runs, and decline with time on task.

The daily rhythms of working memory and their methodological constraints: a critical overview

ABSTRACT Working memory (WM) performance is not constant throughout the 24-hour cycle. Daily oscillations in WM performance are modulated by interactions between circadian and homeostatic factors.

Relationship between circadian rhythm and brain cognitive functions

This mini review highlights the recent advances in cognitive functioning in the optical and multimodal neuroimaging fields and discusses the processing of brain cognitive functions during the circadian rhythm phase and the effects of the circadian rhythms on the cognitive component of the brain and the brain circuit supporting cognition.

A time to think: Circadian rhythms in human cognition

The picture that emerges from this assessment is that beyond physiological variables, time-of-day modulations affect performance on a wide range of cognitive tasks measuring attentional capacities, executive functioning, and memory.

Circadian rhythms in executive function during the transition to adolescence: the effect of synchrony between chronotype and time of day.

Significant Chronotype × Time of Day interactions revealed that adolescents testing at their optimal times of day performed better than those tested at their nonoptimal times.

The circadian clock and human athletic performance

The importance of circadian clock in managing of key muscle physiological processes, and therefore the impact on athletic performance is well studied. Specifically chronobiology examines the



The Measurement of Circadian Rhythms in Psychological Functions

There is now a wealth of physiological evidence that man’s internal body chemistry changes predictably as a function of time of day. It is thus hardly surprising that there are equivalent predictable

Circadian performance rhythms: some practical and theoretical implications.

  • S. Folkard
  • Environmental Science
    Philosophical transactions of the Royal Society of London. Series B, Biological sciences
  • 1990
It is suggested that shiftworkers merely 'stay up late' on the night shift, rather than adjust to it, and that this is responsible for the reduced safety at night.

Task variables determine which biological clock controls circadian rhythms in human performance

The results indicate that a simple manual dexterity task is almost entirely under the control of the temperature rhythm oscillator, whereas a more complex cognitive task demonstrates a periodicity which appears to be influenced by those oscillators controlling temperature and the sleep/wake cycle.

Circadian Variation in Sports Performance

Although athletes show all the symptoms of ‘jet lag’ (increased fatigue, disturbed sleep and circadian rhythms), more research work is needed to identify the effects of transmeridian travel on the actual performances of elite sports competitors.

Circadian temperature and melatonin rhythms, sleep, and neurobehavioral function in humans living on a 20-h day.

The interaction of homeostatic and circadian processes in the regulation of waking neurobehavioral functions and sleep was studied in six healthy young subjects, demonstrating the exquisite of many neuro behavioral functions to circadian phase and the accumulation of homeOSTatic drive for sleep.

Circadian and sleep/wake dependent aspects of subjective alertness and cognitive performance

It was revealed that prior wakefulness within a range of 0–18 h significantly reduced alertness and performance and that the circadian rhythm of core body temperature paralleled the circadian Rhythm of alerts and performance.

SCN controlled circadian arousal and the afternoon "nap zone".

It would appear that the circadian arousal process can be modified in phase and in amplitude by a number of normal and pathological conditions.

SCN controlled circadian arousal and the afternoon "nap zone".

This paper outlines a conceptual model for the regulation of the circasemidian sleep propensity process with emphasis on a possible mechanism of the afternoon "nap zone". It is proposed that the

The three-process model of alertness and its extension to performance, sleep latency, and sleep length.

A mathematical/computer model for predicting alterness/performance in daily living that includes an identification of levels at which the risk of performance/ alertness impairment starts, as well as prediction of sleep latency and time of awakening of sleep episodes is summarized.

The Topology of Performance Curves during 72 Hours of Sleep Loss: A Memory and Search Task

  • Harvey BabkoffM. MikulincerTamir CaspyDaniel KempinskiHelen Sing
  • Psychology
    The Quarterly journal of experimental psychology. A, Human experimental psychology
  • 1988
Three levels of working memory load of a visual search task were tested in a 72-hour sleep deprivation paradigm and the implication of potentiated circadian rhythmicity as a function of cumulative sleep loss is discussed.