Subjective time runs faster under the influence of bright rather than dim light conditions during the forenoon.
The study investigated if 6 h morning bright light exposure, compared with dim light exposure, could influence time sense (range: 5-15 s). Eight women served as participants. The participant entered a bioclimatic chamber at 10:00 h on the day before the test day, where an ambient temperature and relative humidity were controlled at 25 degrees C and 60%RH. She sat quietly in a sofa in 50 lx until 22:00 h, retired at 22:00 h and then slept in total darkness. She rose at 07:00 h the following morning and again sat quietly in a sofa till 13:00 h, either in bright (2500 lx) or dim light (50 lx), the order of light intensities between the two occasions being randomized. The time-estimation test was performed from 13:00 to 13:10 h in 200 lx. The participant estimated the time that had elapsed between two buzzers, ranging over 5-15 s, and inputting the estimate into a computer. The test was carried out separately upon each individual. Results showed that the participants estimated higher durations of the given time intervals after previous exposure to 6 h of bright rather than dim light. The finding is discussed in terms of different load errors (difference between the actual core temperature and its thermoregulatory set-point) following 6-h exposure to bright or dim light in the morning.
Morita
Takeshi
T
Department of Living Environmental Science, Fukuoka Women's University, Fukuoka 813-8528, Japan. morita@fwu.ac.jp
Fukui
Tomoe
T
Morofushi
Masayo
M
Tokura
Hiromi
H
D000328:Adult; D001831:Body Temperature / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008027:Light; D008183:Luteal Phase / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D013998:Time Perception / Q000502:physiology*