{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,31]],"date-time":"2026-10-31T22:22:09Z","timestamp":1793485329127,"version":"4.5.0"},"reference-count":52,"publisher":"American Physiological Society","issue":"5","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["American Journal of Physiology-Regulatory, Integrative and Comparative Physiology"],"published-print":{"date-parts":[[2006,5]]},"abstract":"<jats:p>Bright light can influence human psychophysiology instantaneously by inducing endocrine (suppression of melatonin, increasing cortisol levels), other physiological changes (enhancement of core body temperature), and psychological changes (reduction of sleepiness, increase of alertness). Its broad range of action is reflected in the wide field of applications, ranging from optimizing a work environment to treating depressed patients. For optimally applying bright light and understanding its mechanism, it is crucial to know whether its effects depend on the time of day. In this paper, we report the effects of bright light given at two different times of day on psychological and physiological parameters. Twenty-four subjects participated in two experiments ( n = 12 each). All subjects were nonsmoking, healthy young males (18\u201330 yr). In both experiments, subjects were exposed to either bright light (5,000 lux) or dim light &lt;10 lux (control condition) either between 12:00 P.M. and 4:00 P.M. ( experiment A) or between midnight and 4:00 A.M. ( experiment B). Hourly measurements included salivary cortisol concentrations, electrocardiogram, sleepiness (Karolinska Sleepiness Scale), fatigue, and energy ratings (Visual Analog Scale). Core body temperature was measured continuously throughout the experiments. Bright light had a time-dependent effect on heart rate and core body temperature; i.e., bright light exposure at night, but not in daytime, increased heart rate and enhanced core body temperature. It had no significant effect at all on cortisol. The effect of bright light on the psychological variables was time independent, since nighttime and daytime bright light reduced sleepiness and fatigue significantly and similarly.<\/jats:p>","DOI":"10.1152\/ajpregu.00121.2005","type":"journal-article","created":{"date-parts":[[2005,12,22]],"date-time":"2005-12-22T20:48:39Z","timestamp":1135284519000},"page":"R1413-R1420","source":"Crossref","is-referenced-by-count":241,"title":["Time-of-day-dependent effects of bright light exposure on human psychophysiology: comparison of daytime and nighttime exposure"],"prefix":"10.1152","volume":"290","author":[{"given":"Melanie","family":"R\u00fcger","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marijke C. M.","family":"Gordijn","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Domien G. M.","family":"Beersma","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bonnie","family":"de Vries","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Serge","family":"Daan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"24","reference":[{"key":"R1","doi-asserted-by":"publisher","DOI":"10.3109\/00207459008994241"},{"key":"R2","doi-asserted-by":"publisher","DOI":"10.1038\/89522"},{"key":"R3","unstructured":"Badia P\n                      , Culpepper J, Myers B, Boecker M, and Harsh J.\n                      Psychophysiological and behavioral effects of bright and dim light (Abstract).\n                      Sleep\n                      19\n                      : 387, 1990."},{"key":"R4","doi-asserted-by":"publisher","DOI":"10.1016\/0031-9384(91)90549-4"},{"key":"R5","unstructured":"Badia P\n                      , Myers B, and Murphy P.\n                      Melatonin and thermoregulation. In:\n                      Melatonin: Biosynthesis, Physiological Effects, and Clinical Applications\n                      , edited by Reiter R and Yu H-S. Boca Raton, FL: CRC, 1993."},{"key":"R5A","unstructured":"Bakker JO\n                      and Beersma DGM.\n                      A digital 3-channel recorder for long-term registrations (Abstract).\n                      Sleep Res\n                      20A\n                      : 485, 1991."},{"key":"R6","doi-asserted-by":"publisher","DOI":"10.1177\/074873049300800407"},{"key":"R7","doi-asserted-by":"publisher","DOI":"10.1046\/j.1460-9568.1999.00575.x"},{"key":"R8","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.2001.91.3.1214"},{"key":"R9","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2869.1998.00106.x"},{"key":"R10","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2004-0957"},{"key":"R11","doi-asserted-by":"publisher","DOI":"10.1016\/S0166-4328(00)00236-9"},{"key":"R12","doi-asserted-by":"publisher","DOI":"10.1016\/0031-9384(90)90320-4"},{"key":"R13","doi-asserted-by":"publisher","DOI":"10.1177\/074873049501000205"},{"key":"R14","doi-asserted-by":"publisher","DOI":"10.1177\/0748730403258422"},{"key":"R15","doi-asserted-by":"publisher","DOI":"10.1016\/0031-9384(93)90271-G"},{"key":"R16","doi-asserted-by":"publisher","DOI":"10.1016\/0987-7053(96)81529-2"},{"key":"R17","doi-asserted-by":"publisher","DOI":"10.1093\/sleep\/14.6.511"},{"key":"R18","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3940(94)91059-6"},{"key":"R19","doi-asserted-by":"publisher","DOI":"10.1046\/j.1460-9568.2002.02196.x"},{"key":"R20","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuroscience.2004.08.030"},{"key":"R21","unstructured":"Foret J\n                      , Daurat A, and Tirilly G.\n                      Effect of bright light at night on core temperature, subjective alertness and performance as a function of exposure time.\n                      Scand J Work Environ Health\n                      24\n                      ,\n                      Suppl\n                      3: 115\u2013120, 1998."},{"key":"R22","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-7793.1999.905ad.x"},{"key":"R23","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.23-18-07093.2003"},{"key":"R24","unstructured":"Gordijn MCM\n                      , Jansen JHC, Medema HM, Flentge F, and Beersma DGM.\n                      Melatonin in saliva, effect of toothpaste, coffee, smoking and lipstick (Abstract).\n                      Sleep Res\n                      20A\n                      : 493, 1991."},{"key":"R25","unstructured":"Honma K\n                      and Honma S.\n                      A human phase response curve for bright light pulses.\n                      Jpn J Psychiatry Neurol\n                      42\n                      : 167\u2013168, 1988."},{"key":"R26","doi-asserted-by":"crossref","unstructured":"Horne JA\n                      and \u00d6stberg O.\n                      A self-assessment questionnaire to determine morningness-eveningness in human circadian rhythms.\n                      Int J Chronobiol\n                      4\n                      : 97\u2013110, 1976.","DOI":"10.1037\/t02254-000"},{"key":"R27","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2003.040477"},{"key":"R28","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2265.1998.00355.x"},{"key":"R29","unstructured":"Kr\u00e4uchi K\n                      , Cajochen C, and Wirz-Justice A.\n                      Circadian and homeostatic regulation of core body temperature and alertness in humans: what is the role of melatonin? In:\n                      Circadian Clocks and Entrainment\n                      , edited by Honma KI and Honma S. Sapporo, Japan: Hokkaido University, 1998, p. 131\u2013146."},{"key":"R30","doi-asserted-by":"publisher","DOI":"10.1016\/S0893-133X(01)00315-3"},{"key":"R31","doi-asserted-by":"publisher","DOI":"10.1016\/S0306-4530(02)00008-2"},{"key":"R32","doi-asserted-by":"publisher","DOI":"10.1016\/0165-1781(91)90027-M"},{"key":"R33","doi-asserted-by":"crossref","unstructured":"Leproult R\n                      , Colecchia EF, L'Hermite-Baleriaux M, and Van Cauter E.\n                      Transition from dim to bright light in the morning induces an immediate elevation of cortisol levels.\n                      J Clin Endocrinol Metab\n                      86\n                      : 151\u2013157, 2001.","DOI":"10.1210\/jc.86.1.151"},{"key":"R34","doi-asserted-by":"publisher","DOI":"10.1177\/074873049701200306"},{"key":"R35","doi-asserted-by":"publisher","DOI":"10.1126\/science.7434030"},{"key":"R36","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.20-10-03830.2000"},{"key":"R37","doi-asserted-by":"publisher","DOI":"10.1016\/S0306-4522(99)00094-9"},{"key":"R38","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3940(91)90051-T"},{"key":"R39","doi-asserted-by":"publisher","DOI":"10.1016\/0031-9384(93)90067-P"},{"key":"R40","doi-asserted-by":"publisher","DOI":"10.1016\/S0165-0327(99)00063-4"},{"key":"R41","doi-asserted-by":"publisher","DOI":"10.1016\/j.cub.2004.09.082"},{"key":"R42","doi-asserted-by":"publisher","DOI":"10.1093\/sleep\/26.6.695"},{"key":"R43","doi-asserted-by":"publisher","DOI":"10.1177\/0748730403256650"},{"key":"R44","unstructured":"R\u00fcger M\n                      , Gordijn MC, Beersma DG, de Vries B, and Daan S.\n                      Bright light effects at night and day on various measures of sleepiness. 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Maastricht, The Netherlands: Maastricht Dutch Society for Sleep-Wake Research, 2002, p. 95\u201399."},{"key":"R45","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2869.2005.00452.x"},{"key":"R46","doi-asserted-by":"publisher","DOI":"10.1016\/S0304-3940(96)13171-2"},{"key":"R47","doi-asserted-by":"publisher","DOI":"10.1210\/jcem.84.9.6102"},{"key":"R48","doi-asserted-by":"publisher","DOI":"10.1177\/074873099129000614"},{"key":"R49","doi-asserted-by":"publisher","DOI":"10.1016\/j.psyneuen.2003.08.005"},{"key":"R50","doi-asserted-by":"publisher","DOI":"10.1046\/j.1440-1819.2001.00862.x"},{"key":"R51","doi-asserted-by":"publisher","DOI":"10.1081\/CBI-200053536"}],"container-title":["American Journal of Physiology-Regulatory, Integrative and Comparative Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.physiology.org\/doi\/pdf\/10.1152\/ajpregu.00121.2005","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,5,5]],"date-time":"2023-05-05T20:25:29Z","timestamp":1683318329000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.physiology.org\/doi\/10.1152\/ajpregu.00121.2005"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2006,5]]},"references-count":52,"journal-issue":{"issue":"5","published-print":{"date-parts":[[2006,5]]}},"alternative-id":["10.1152\/ajpregu.00121.2005"],"URL":"https:\/\/doi.org\/10.1152\/ajpregu.00121.2005","relation":{},"ISSN":["0363-6119","1522-1490"],"issn-type":[{"value":"0363-6119","type":"print"},{"value":"1522-1490","type":"electronic"}],"subject":[],"published":{"date-parts":[[2006,5]]}}}