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Author Hanifin, J.P.; Lockley, S.W.; Cecil, K.; West, K.; Jablonski, M.; Warfield, B.; James, M.; Ayers, M.; Byrne, B.; Gerner, E.; Pineda, C.; Rollag, M.; Brainard, G.C. url  doi
  Title Randomized trial of polychromatic blue-enriched light for circadian phase shifting, melatonin suppression, and alerting responses Type Journal Article
  Year 2018 Publication Physiology & Behavior Abbreviated Journal Physiol Behav  
  Volume in press Issue Pages  
  Keywords Human Health  
  Abstract Wavelength comparisons have indicated that circadian phase-shifting and enhancement of subjective and EEG-correlates of alertness have a higher sensitivity to short wavelength visible light. The aim of the current study was to test whether polychromatic light enriched in the blue portion of the spectrum (17,000K) has increased efficacy for melatonin suppression, circadian phase-shifting, and alertness as compared to an equal photon density exposure to a standard white polychromatic light (4000K). Twenty healthy participants were studied in a time-free environment for 7days. The protocol included two baseline days followed by a 26-h constant routine (CR1) to assess initial circadian phase. Following CR1, participants were exposed to a full-field fluorescent light (1x10(14) photons/cm(2)/s, 4000K or 17,000K, n=10/condition) for 6.5h during the biological night. Following an 8h recovery sleep, a second 30-h CR was performed. Melatonin suppression was assessed from the difference during the light exposure and the corresponding clock time 24h earlier during CR1. Phase-shifts were calculated from the clock time difference in dim light melatonin onset time (DLMO) between CR1 and CR2. Blue-enriched light caused significantly greater suppression of melatonin than standard light ((mean+/-SD) 70.9+/-19.6% and 42.8+/-29.1%, respectively, p<0.05). There was no significant difference in the magnitude of phase delay shifts. Blue-enriched light significantly improved subjective alertness (p<0.05) but no differences were found for objective alertness. These data contribute to the optimization of the short wavelength-enriched spectra and intensities needed for circadian, neuroendocrine and neurobehavioral regulation.  
  Address Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, USA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue (down) Edition  
  ISSN 0031-9384 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:30296404 Approved no  
  Call Number GFZ @ kyba @ Serial 2025  
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