Changes in EEG Signals of Students in Different LED Lighting Environments

YANG Chunyu; WANG Tongyue; LIANG Shuying; XIANG Yiyan; YANG Peiliang; HE Wei

doi:10.3969/j.issn.1004-440X.2019.02.015

Abstract：Poor lighting environment in the classroom can easily lead to fatigue, thus reducing the learning efficiency. Through laboratory simulation of classroom lighting environment, volunteers can study for 3 hours in LED lighting environment with different illumination levels (500 lx, 1 000 lx, 1 500 lx, 2 000 lx, 2 000 lx and 3 000 lx) and color temperature (4 000 K, 5 000 K and 6 500 K). In each half hour, we monitored the brain electrical signal (EEG), and analyzed its frequency band energy proportional R value to determine the degree of brain fatigue and the change of mental excitability. The results showed that, with the improvement of illumination, students' brain fatigue decreased first and then increased, and the brain fatigue was the lowest in the 2 000 lx illumination group, indicating that excessive illumination was more likely to cause brain fatigue. The initial change of mental excitability was not obvious, and it increased significantly after 1 500 lx. With the increase of color temperature, the brain fatigue gradually increased, and the mental excitability increased first and then decreased. The effect of light time was similar to that of color temperature, and the fatigue of brain was increased with time, and the speed was accelerated. With the increase of time, the mental excitability increased first and then decreased.