不同LED照明环境下学生的脑电信号变化

摘要

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.%不良的教室照明容易使学生疲劳、降低学习效率.通过实验室模拟教室照明, 让学生在不同照度 (500 lx、1000lx、1500lx、2000lx、2500lx、3000lx) 和色温 (4000K、5000K、 6500K) 组成的LED照明环境下学习3 h, 每0.5 h监测一次脑电信号 (EEG), 测量δ波、θ波、α波和β波节律, 分析频带能量比例R值, 判断脑疲劳程度和精神兴奋性的变化.结果表明:随着照度的提高, 脑疲劳先减小后增大, 2000lx照度组的脑疲劳最低, 说明过高的照度更容易引起脑疲劳;精神兴奋性起初变化不明显, 超过1500lx后显著提高.随着色温的提高, 脑疲劳逐渐增加, 精神兴奋性先增加后减小;光照时间的影响与色温相似, 脑疲劳随着时间的增加而加深, 且速度加快;精神兴奋性随时间的增加先提高后降低.