Improved Quality of Awakening by Simulating Dawn Lighting with an Ordinary Ceiling Light

Abstract

The effects of simulating dawn lighting with an ordinary ceiling light on the quality of awakening were investigated. The subjects were healthy men, aged 24-27. After sleep for about 7 hours with polysomnographic recordings in a climatic chamber kept at a temperature of 25t and a relative humidity of 50%, each subject was awakened by an alarm. For the 30 minutes immediately before the subject was awakened, the illumination in the chamber was gradually increased, simulating the condition of waking up as the sun rises. Alpha attenuation test, measuring blood pressure and awakening feelings were conducted after awakening.
The time of sleep stage 2 appearing during the 30-minute simulating dawn lighting was significantly less (p<0.05; Wilcoxon test) than during typical waking conditions (i. e., waking up in the dark), while the time of stage W was higher (p=0.0796). The mood after awakening in the simulatig dawn lighting condition was significantly better (p<0.05). There were no significant differences in the alpha attenuation coefficients and blood pressures after awakening between the two conditions.
These results suggest that simulating dawn lighting arouses subjects to light sleep, which makes awakening less sudden and more pleasant. There was no evidence that the light sleep immediately before awakening decreased the subjects' cerebral cortex activity or sympathetic nervous activity after awakening.