Title |
Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness
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Published in |
Proceedings of the National Academy of Sciences of the United States of America, December 2014
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DOI | 10.1073/pnas.1418490112 |
Pubmed ID | |
Authors |
Anne-Marie Chang, Daniel Aeschbach, Jeanne F. Duffy, Charles A. Czeisler |
Abstract |
In the past 50 y, there has been a decline in average sleep duration and quality, with adverse consequences on general health. A representative survey of 1,508 American adults recently revealed that 90% of Americans used some type of electronics at least a few nights per week within 1 h before bedtime. Mounting evidence from countries around the world shows the negative impact of such technology use on sleep. This negative impact on sleep may be due to the short-wavelength-enriched light emitted by these electronic devices, given that artificial-light exposure has been shown experimentally to produce alerting effects, suppress melatonin, and phase-shift the biological clock. A few reports have shown that these devices suppress melatonin levels, but little is known about the effects on circadian phase or the following sleep episode, exposing a substantial gap in our knowledge of how this increasingly popular technology affects sleep. Here we compare the biological effects of reading an electronic book on a light-emitting device (LE-eBook) with reading a printed book in the hours before bedtime. Participants reading an LE-eBook took longer to fall asleep and had reduced evening sleepiness, reduced melatonin secretion, later timing of their circadian clock, and reduced next-morning alertness than when reading a printed book. These results demonstrate that evening exposure to an LE-eBook phase-delays the circadian clock, acutely suppresses melatonin, and has important implications for understanding the impact of such technologies on sleep, performance, health, and safety. |
X Demographics
Geographical breakdown
Country | Count | As % |
---|---|---|
Thailand | 407 | 14% |
United States | 193 | 7% |
United Kingdom | 51 | 2% |
Canada | 31 | 1% |
Spain | 31 | 1% |
Japan | 29 | <1% |
India | 27 | <1% |
Netherlands | 23 | <1% |
Australia | 18 | <1% |
Other | 172 | 6% |
Unknown | 1970 | 67% |
Demographic breakdown
Type | Count | As % |
---|---|---|
Members of the public | 2768 | 94% |
Scientists | 94 | 3% |
Practitioners (doctors, other healthcare professionals) | 55 | 2% |
Science communicators (journalists, bloggers, editors) | 35 | 1% |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
United States | 11 | <1% |
United Kingdom | 6 | <1% |
Spain | 6 | <1% |
Germany | 3 | <1% |
Portugal | 3 | <1% |
Australia | 3 | <1% |
Japan | 3 | <1% |
Sweden | 2 | <1% |
France | 2 | <1% |
Other | 12 | <1% |
Unknown | 1625 | 97% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Student > Bachelor | 335 | 20% |
Student > Master | 196 | 12% |
Researcher | 166 | 10% |
Student > Ph. D. Student | 165 | 10% |
Other | 83 | 5% |
Other | 286 | 17% |
Unknown | 445 | 27% |
Readers by discipline | Count | As % |
---|---|---|
Medicine and Dentistry | 229 | 14% |
Psychology | 182 | 11% |
Agricultural and Biological Sciences | 115 | 7% |
Neuroscience | 94 | 6% |
Nursing and Health Professions | 92 | 5% |
Other | 433 | 26% |
Unknown | 531 | 32% |