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Short-wavelength sensitivity for the direct effects of light on alertness, vigilance, and the waking electroencephalogram in humans

Lockley, S.W., Evans, E.E., Scheer, F.A.J.L., Brainard, G.C., Czeisler, C.A. and Aeschbach, D. (2006) Short-wavelength sensitivity for the direct effects of light on alertness, vigilance, and the waking electroencephalogram in humans Sleep, 29 (2). pp. 161-168.

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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 � 1013 photons · cm-2 · 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 photo-receptor 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.

Item Type: Article
Authors :
Evans, E.E.
Scheer, F.A.J.L.
Brainard, G.C.
Czeisler, C.A.
Aeschbach, D.
Date : 2006
Uncontrolled Keywords : Alertness, Alpha waves, Auditory performance, Circadian photoreception, Cortisol, Fatigue, Light, Light wave-length, Vigilance, Waking EEG, hydrocortisone, melatonin, hydrocortisone, melatonin, adult, alertness, alpha rhythm, article, attention, auditory stimulation, circadian rhythm, electroencephalogram, fatigue, female, hormone blood level, human, human experiment, hydrocortisone blood level, karolinska sleepiness scale, light exposure, male, normal human, photoreceptor, polysomnography, priority journal, psychomotor activity, radioimmunoassay, rating scale, sleep waking cycle, task performance, arousal, blood, circadian rhythm sleep disorder, electroencephalography, photophobia, physiology, psychomotor performance, somnolence, wakefulness, Adult, Arousal, Disorders of Excessive Somnolence, Electroencephalography, Female, Humans, Hydrocortisone, Male, Melatonin, Photophobia, Psychomotor Performance, Radioimmunoassay, Sleep Disorders, Circadian Rhythm, Wakefulness
Depositing User : Clive Harris
Date Deposited : 17 Jun 2020 01:57
Last Modified : 17 Jun 2020 01:57

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