Light Modulation of Human Clocks, Wake, and Sleep
Lyon Neuroscience Research Center (CRNL), Integrative Physiology of the Brain Arousal Systems (Waking) Team, Inserm UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, F-69000 Lyon, France
Charité University Medicine Berlin, Institute of Medical Immunology, Group Chronobiology, 10117 Berlin, Germany
St. Hedwig Krankenhaus, 10115 Berlin, Germany
Sleep/Wake Research Centre, Massey University, Wellington 6140, New Zealand
Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center (DLR), 51170 Cologne, Germany
Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, USA
Medical Chronobiology Program, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, USA
Authors to whom correspondence should be addressed.
Shared senior authors.
Clocks & Sleep 2019, 1(1), 193-208; https://doi.org/10.3390/clockssleep1010017
Received: 20 November 2018 / Revised: 2 March 2019 / Accepted: 8 March 2019 / Published: 13 March 2019
(This article belongs to the Section Clocks & Sleep and Zeitgebers (Light))
Light, through its non-imaging forming effects, plays a dominant role on a myriad of physiological functions, including the human sleep–wake cycle. The non-image forming effects of light heavily rely on specific properties such as intensity, duration, timing, pattern, and wavelengths. Here, we address how specific properties of light influence sleep and wakefulness in humans through acute effects, e.g., on alertness, and/or effects on the circadian timing system. Of critical relevance, we discuss how different characteristics of light exposure across the 24-h day can lead to changes in sleep–wake timing, sleep propensity, sleep architecture, and sleep and wake electroencephalogram (EEG) power spectra. Ultimately, knowledge on how light affects sleep and wakefulness can improve light settings at home and at the workplace to improve health and well-being and optimize treatments of chronobiological disorders.