Cited by 1,001Circadian rhythm and melatoninSleep and Wakefulness ResearchSleep and Work-Related Fatigue

Light as a central modulator of circadian rhythms, sleep and affect

Open access
LeGates, Tara A., Fernandez, Diego C., Hattar, Samer·2014·Nature Reviews Neuroscience

Abstract

Light has profoundly influenced the evolution of life on earth. As widely appreciated, light enables us to generate images of our environment. However, light - through intrinsically photosensitive retinal ganglion cells (ipRGCs) - also influences behaviours that are essential for our health and quality of life but are independent of image formation. These include the synchronization of the circadian clock to the solar day, tracking of seasonal changes and the regulation of sleep. Irregular light environments lead to problems in circadian rhythms and sleep, which eventually cause mood and learning deficits. Recently, it was found that irregular light can also directly affect mood and learning without producing major disruptions in circadian rhythms and sleep. In this Review, we discuss the indirect and direct influence of light on mood and learning, and provide a model for how light, the circadian clock and sleep interact to influence mood and cognitive functions.

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Crossref · 10.1038/nrn3743

Cites

171 of 171 references verified0 citation errors · 0 not checkable

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  • Peripheral physiological systems express circadian rhythmicity and their misalignment with the environment can result in interoceptively sensed discomfort that can negatively affect emotion.

    “Peripheral physiological systems also express circadian rhythmicity and their misalignment with the environment (e.g., from jetlag) can result in interoceptively sensed discomfort (e.g., gastrointestinal) that can, in turn, negatively affect emotion (LeGates et al., 2014).”

    From Physiological feelings (2019) · cites this paper as LeGates et al., 2014

    The Perspectives section, “Light effects on central and peripheral clocks” (page unavailable), describes peripheral clocks and proposes that their asynchrony with brain oscillators could contribute to depression. The “Transmeridan travel” section (page unavailable) associates jet lag with general malaise and poor mood. Neither passage says that peripheral misalignment causes interoceptively sensed discomfort, such as gastrointestinal discomfort, which then affects emotion. (LLM, conf=0.86)

    Experimental — accuracy not yet measured
  • Some patients may notice improvements within a few days, while others may take several weeks.

    “Some patients may notice improvements within a few days, while others may take several weeks (Rosenthal et al. 1985; Meesters and Houwelingen 1998; LeGates et al. 2014; Chojnacka et al. 2016; Benedetti 2018; Sit et al. 2018; Zhou et al. 2018; Gottlieb et al. 2019).”

    From Light therapy for bipolar disorders: Clinical recommendations from the international society for bipolar disorders (ISBD) Chronobiology and Chronotherapy Task Force (2025) · cites this paper as LeGates et al. 2014

    The Perspectives section (“Environmental lighting conditions”; page unavailable) says antidepressant treatment usually has a response lag of about two weeks and that adding bright light therapy decreases it. It does not say that some patients improve within a few days while others take several weeks, so the claimed range of patient responses is not established by this source. (LLM, conf=0.76)

    Experimental — accuracy not yet measured
  • Exposure to light at night can directly affect mood through ipRGC projections to brain regions involved in affect.

    “First, exposure to light at night can directly affect mood through ipRGC projections to brain regions involved in affect62,63.”

    From Circadian rhythm disruption and mental health (2020) · cites this paper as [62]

    The Perspectives section, “Circuits involved in aberrant light induced-depression,” says ipRGCs project to the lateral habenula and medial amygdala, highlighting a possible direct role for light in mood regulation. But “Mechanisms underlying the direct effect of light” says the role of ipRGCs in conveying these effects had not been directly established. The claim presents that proposed pathway as the mechanism by which light at night affects mood. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • Light itself has been demonstrated to exert subtle influences on emotion mediated by intrinsically photosensitive retinal ganglion cells expressing melanopsin.

    “Moreover, light itself has been demonstrated to exert subtle influences on emotion mediated by the recently discovered intrinsically photosensitive retinal ganglion cells expressing the photopigment melanopsin (LeGates et al., 2012;LeGates et al., 2014).”

    From Physiological feelings (2019) · cites this paper as LeGates et al., 2014

    Experimental — accuracy not yet measured

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Cites

1 retracted

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Research works printed but not linked: 1

  1. [166]Bedrosian TA Weil ZM Nelson RJ Chronic dim light at night provokes reversible depression-like phenotype: possible role for TNF Mol Psychiatry 18 930 6 2013 22824811

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Authors
LeGates, T. A., Fernandez, D. C., & Hattar, S.
Affiliations
Johns Hopkins University (US)
Corresponding author
Hattar, Samer
Venue
Nature Reviews Neuroscience
Published
2014-06-11
Volume
15
Issue
7
Pages
443-454
ISSN
  • 1471-003X (ISSN-L)
  • 1471-0048
OpenAlex
W2011282592
Cited by
1,001
References
171
Citations by year
2026: 82 · 2025: 98 · 2024: 103 · 2023: 100 · 2022: 100 · 2021: 102 · 2020: 133 · 2019: 83 · 2018: 71 · 2017: 51 · 2016: 39 · 2015: 31 · 2014: 5 · 2013: 2
FWCI
4.72
Type
journal article
Language
en
Open access
Locations
  • Nature reviews. Neuroscience (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
Funders
  • National Eye Institute (R21EY024452)
  • National Institute of General Medical Sciences (T32GM007231, R01GM076430)
Topics
  • Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Sleep and Wakefulness Research
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and Work-Related Fatigue
Keywords
light exposure, circadian rhythm, sleep regulation, intrinsically photosensitive retinal ganglion cells, mood, affect, learning, circadian clock, cognitive function
MeSH terms
Affect, Animals, Circadian Rhythm, Humans, Learning, Light, Nerve Net, Retina, Sleep, Wakefulness

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