STUDY OBJECTIVES: To assess the wavelength-dependent sensitivity of the acute effects of ocular light exposure on alertness, performance, waking electroencephalogram (EEG), and cortisol. DESIGN: A between-subjects design was employed to compare the effects of exposure to 460-nm or 555-nm light for 6.5 hours during the biological night. SETTING: Intensive Physiological Monitoring Unit, Brigham and Women's Hospital, Boston, MA. PATIENTS AND PARTICIPANTS: Sixteen healthy adults (8 women; mean age +/- SD = 23.3 +/- 2.4 years). INTERVENTIONS: Subjects were exposed to equal photon densities (2.8 x 10(13) photons x cm(-2) x s(-1)) of either 460-nm (n = 8) or 555-nm (n = 8) monochromatic light for 6.5 hours, 15 minutes after mydriasis. MEASUREMENTS AND RESULTS: Subjects underwent continuous EEG/electrooculogram recordings and completed a performance battery every 30 to 60 minutes. As compared with those exposed to 555-nm light, subjects exposed to 460-nm light had significantly lower subjective sleepiness ratings, decreased auditory reaction time, fewer attentional failures, decreased EEG power density in the delta-theta range (0.5-5.5 Hz), and increased EEG power density in the high-alpha range (9.5-10.5 Hz). Light had no direct effect on cortisol. CONCLUSIONS: Short-wavelength sensitivity to the acute alerting effects of light indicates that the visual photopic system is not the primary photoreceptor system mediating these responses to light. The frequency-specific changes in the waking EEG indicate that short-wavelength light is a powerful agent that immediately attenuates the negative effects of both homeostatic sleep pressure and the circadian drive for sleep on alertness, performance, and the ability to sustain attention.
STUDY OBJECTIVES: To assess the wavelength-dependent sensitivity of the acute effects of ocular light exposure on alertness, performance, waking electroencephalogram (EEG), and cortisol. DESIGN: A between-subjects design was employed to compare the effects of exposure to 460-nm or 555-nm light for 6.5 hours during the biological night. SETTING: Intensive Physiological Monitoring Unit, Brigham and Women's Hospital, Boston, MA. PATIENTS AND PARTICIPANTS: Sixteen healthy adults (8 women; mean age +/- SD = 23.3 +/- 2.4 years). INTERVENTIONS: Subjects were exposed to equal photon densities (2.8 x 10(13) photons x cm(-2) x s(-1)) of either 460-nm (n = 8) or 555-nm (n = 8) monochromatic light for 6.5 hours, 15 minutes after mydriasis. MEASUREMENTS AND RESULTS: Subjects underwent continuous EEG/electrooculogram recordings and completed a performance battery every 30 to 60 minutes. As compared with those exposed to 555-nm light, subjects exposed to 460-nm light had significantly lower subjective sleepiness ratings, decreased auditory reaction time, fewer attentional failures, decreased EEG power density in the delta-theta range (0.5-5.5 Hz), and increased EEG power density in the high-alpha range (9.5-10.5 Hz). Light had no direct effect on cortisol. CONCLUSIONS: Short-wavelength sensitivity to the acute alerting effects of light indicates that the visual photopic system is not the primary photoreceptor system mediating these responses to light. The frequency-specific changes in the waking EEG indicate that short-wavelength light is a powerful agent that immediately attenuates the negative effects of both homeostatic sleep pressure and the circadian drive for sleep on alertness, performance, and the ability to sustain attention.
Authors: S Lehrl; K Gerstmeyer; J H Jacob; H Frieling; A W Henkel; R Meyrer; J Wiltfang; J Kornhuber; S Bleich Journal: J Neural Transm (Vienna) Date: 2007-01-25 Impact factor: 3.575
Authors: Laura K Barger; Steven W Lockley; Shantha M W Rajaratnam; Christopher P Landrigan Journal: Curr Neurol Neurosci Rep Date: 2009-03 Impact factor: 5.081
Authors: Melanie Rüger; Melissa A St Hilaire; George C Brainard; Sat-Bir S Khalsa; Richard E Kronauer; Charles A Czeisler; Steven W Lockley Journal: J Physiol Date: 2012-10-22 Impact factor: 5.182