Iskra-Golec Irena, Golonka Krystyna, Wyczesany Miroslaw, Smith Lawrence, Siemiginowska Patrycja, Wątroba Joanna
SWPS University of Social Sciences and Humanities, Faculty in Poznań, Poland.
Institite of Applied Psychology, Jagiellonian University, Kraków, Poland.
Adv Cogn Psychol. 2017 Sep 30;13(3):241-247. doi: 10.5709/acp-0224-0. eCollection 2017.
Growing evidence suggests an alerting effect of monochromatic blue light on brain activity. Little is known about the moderation of those effects by timing and duration of exposure. The present electroencephalography (EEG ) study examined such moderations on delta, theta, alpha1, alpha2, and beta EEG bands. A counterbalanced repeated-measures design was applied. The 16-hr daytime period was divided into three sessions: 07:00-12:20, 12:20-17:40, and 17:40-23:00 (timing of exposure). Two light conditions comparable in luminance but differing in wavelength were applied, namely polychromatic white light and monochromatic blue light (460 nm). There were two durations of exposure-the shorter one lasting 30 min and the longer one lasting 4 hrs. Thirty male students participated in the study. Four factors analyses of variance (ANOV As, for light conditions, timing of exposure, duration of exposure, and brain area) were performed on each EEG band. Results indicated an alerting effect of short exposure to monochromatic blue light at midday and in the evening, which was demonstrated by a decrease in lower frequency bands (alpha1, delta, and theta, respectively). Long exposure to blue light may have a reverse effect, especially in the morning and at midday, when increases in lower frequency bands (theta in the morning and theta and alpha1 at midday) were observed. It can be concluded that the daytime effect of monochromatic blue light on EEG activity depends on timing and duration of exposure.
越来越多的证据表明，单色蓝光对大脑活动具有唤醒作用。关于暴露时间和持续时间对这些作用的调节作用，人们了解甚少。目前的脑电图（EEG）研究考察了在δ、θ、α1、α2和β脑电频段上的这种调节作用。采用了一种平衡的重复测量设计。16小时的白天时段被分为三个时间段：07:00 - 12:20、12:20 - 17:40和17:40 - 23:00（暴露时间）。应用了两种亮度相当但波长不同的光照条件，即多色白光和单色蓝光（460纳米）。有两种暴露持续时间，较短的持续30分钟，较长的持续4小时。30名男学生参与了该研究。对每个脑电频段进行了四项方差分析（分别针对光照条件、暴露时间、暴露持续时间和脑区）。结果表明，中午和晚上短时间暴露于单色蓝光具有唤醒作用，这表现为低频段（分别为α1、δ和θ）的减少。长时间暴露于蓝光可能会产生相反的效果，尤其是在早晨和中午，此时观察到低频段增加（早晨的θ以及中午的θ和α1）。可以得出结论，单色蓝光对脑电图活动的白天效应取决于暴露时间和持续时间。
