title: Effect of color temperature of light sources on slow-wave sleep.
abstract: In order to examine whether the spectral compositions of light source may affect sleep quality, sleep architecture under different color temperatures of light sources was evaluated. Seven healthy males were exposed to the light sources of different color temperatures (3000 K, 5000 K and 6700 K) for 6.5 h before sleep. The horizontal illuminance level was kept at 1000 lux. Subjects slept on a bed in near darkness (< 10 lux) after extinguishing the light, and polysomnograms recorded the sleep parameters. In the early phase of the sleep period, the amount of stage-4 sleep (S4-sleep) was significantly attenuated under the higher color temperature of 6700 K compared with the lower color temperature of 3000 K. Present findings suggest that light sources with higher color temperatures may affect sleep quality in a view that S4-sleep period is important for sleep quality.
authors.affiliation: Department of Physiological Anthropology, Faculty of Design, Kyushu University, Japan. kozaki@design.kyushu-u.ac.jp
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Kozaki
authors.forename: Shingo
authors.initials: S
authors.lastname: Kitamura
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Higashihara
authors.forename: Keita
authors.initials: K
authors.lastname: Ishibashi
authors.forename: Hiroki
authors.initials: H
authors.lastname: Noguchi
authors.forename: Akira
authors.initials: A
authors.lastname: Yasukouchi
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003116:Color; D004569:Electroencephalography; D004576:Electromyography; D004585:Electrooculography; D006801:Humans; D008027:Light; D008297:Male; D012890:Sleep / Q000502:physiology* / Q000528:radiation effects*