Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance
-
- Christian Cajochen
- Centres for 1Chronobiology and
-
- Sylvia Frey
- Centres for 1Chronobiology and
-
- Doreen Anders
- Centres for 1Chronobiology and
-
- Jakub Späti
- Centres for 1Chronobiology and
-
- Matthias Bues
- Competence Team Visual Technologies, Fraunhofer IAO/University Stuttgart IAT, Stuttgart, Germany
-
- Achim Pross
- Competence Team Visual Technologies, Fraunhofer IAO/University Stuttgart IAT, Stuttgart, Germany
-
- Ralph Mager
- Applied Technologies in Neuroscience, Psychiatric Hospitals of the University of Basel, Basel, Switzerland; and
-
- Anna Wirz-Justice
- Centres for 1Chronobiology and
-
- Oliver Stefani
- Competence Team Visual Technologies, Fraunhofer IAO/University Stuttgart IAT, Stuttgart, Germany
Description
<jats:p>Many people spend an increasing amount of time in front of computer screens equipped with light-emitting diodes (LED) with a short wavelength (blue range). Thus we investigated the repercussions on melatonin (a marker of the circadian clock), alertness, and cognitive performance levels in 13 young male volunteers under controlled laboratory conditions in a balanced crossover design. A 5-h evening exposure to a white LED-backlit screen with more than twice as much 464 nm light emission {irradiance of 0,241 Watt/(steradian × m<jats:sup>2</jats:sup>) [W/(sr × m<jats:sup>2</jats:sup>)], 2.1 × 10<jats:sup>13</jats:sup>photons/(cm<jats:sup>2</jats:sup>× s), in the wavelength range of 454 and 474 nm} than a white non-LED-backlit screen [irradiance of 0,099 W/(sr × m<jats:sup>2</jats:sup>), 0.7 × 10<jats:sup>13</jats:sup>photons/(cm<jats:sup>2</jats:sup>× s), in the wavelength range of 454 and 474 nm] elicited a significant suppression of the evening rise in endogenous melatonin and subjective as well as objective sleepiness, as indexed by a reduced incidence of slow eye movements and EEG low-frequency activity (1–7 Hz) in frontal brain regions. Concomitantly, sustained attention, as determined by the GO/NOGO task; working memory/attention, as assessed by “explicit timing”; and declarative memory performance in a word-learning paradigm were significantly enhanced in the LED-backlit screen compared with the non-LED condition. Screen quality and visual comfort were rated the same in both screen conditions, whereas the non-LED screen tended to be considered brighter. Our data indicate that the spectral profile of light emitted by computer screens impacts on circadian physiology, alertness, and cognitive performance levels. The challenge will be to design a computer screen with a spectral profile that can be individually programmed to add timed, essential light information to the circadian system in humans.</jats:p>
Journal
-
- Journal of Applied Physiology
-
Journal of Applied Physiology 110 (5), 1432-1438, 2011-05
American Physiological Society
- Tweet
Details 詳細情報について
-
- CRID
- 1362544419977184256
-
- ISSN
- 15221601
- 87507587
-
- Data Source
-
- Crossref