Short-term effects of static and dynamic lighting on sleepiness and task performance in simulated enclosed spaces

With the rapid advancement of manned spaceflight and deep-sea exploration and the development of planetary habitats and future underground facilities, research on environmental factors within enclosed spaces has become increasingly important. Beyond visual perception, light exerts significant non-visual effects (NVEs) on human physiology and behavior, such as sleepiness, arousal, and task performance. However, the short-term effects of lighting strategies in enclosed spaces remain underexplored, particularly across static and dynamic illumination patterns. We conducted a controlled experiment analyzing five distinct lighting conditions: two static (300 lx and 500 lx), one dynamic (transitioning from 300 lx to 500 lx), and two combined conditions (integrating static and dynamic elements, transitioning from 300 lx to 500 lx). Participants’ subjective sleepiness was assessed using a visual analog scale at the beginning and end of each lighting condition. Results revealed significant differences in sleepiness scores, with the lowest sleepiness observed under the first combined lighting condition and the highest sleepiness observed under the second combined condition. For task performance, participants exhibited the shortest reaction times under the first combined lighting condition, followed by the second static and dynamic lighting conditions. Notably, 500 lx led to faster responses compared with 300 lx. This finding highlighted the importance of illuminance in improving cognitive efficiency. Electrocardiogram monitoring further revealed increased heart rate and heart rate variability during the first combined lighting condition. These findings indicate that incorporating dynamic lighting elements into static lighting strategies may effectively reduce subjective sleepiness and improve cognitive performance in enclosed spaces. Future work should further explore long-term and circadian-related NVEs to inform intelligent lighting design.