Effect of correlated color temperature and illuminance on sustained attention collected via electroencephalography signals

Abstract

This study aimed to explore the differences in the subjects' sustained attention under the impact of nine lighting conditions consisting of the combination of three commonly used correlated color temperature (CCT) (3300 K, 4300 K, and 5300 K) and illuminance levels (300 lx, 500 lx, and 750 lx) to provide guidance on the adjustment of CCT and illuminance level parameters for indoor lighting. We selected 24 physically and mentally healthy university students (12 male and 12 female) as the experimental subjects. The subjects were required to perform sustained attention to response task (SART) activities under the nine different lighting conditions and collected the alpha (α) waves (8–12 Hz) from the electroencephalography signals. Subsequently, the mean power spectral density of the α waves and various SART parameters were analyzed and tested. Finally, the effects of different CCT and illuminance levels on the subjects' attention were compared. With the increase in CCT, the attention level tended to increase linearly, whereas the attention level was the lowest at 300 lx and the highest at 500 lx and appeared as an inverted “U” shape. The subjects' attention level was the highest at the combination of CCT of 5300 K and illuminance level of 500 lx and the lowest at the combination of CCT of 3300 K and illuminance level of 500 lx. These results provide important data to elucidate the impact of lighting condition on attention.