Effects of indoor artificial light on visual working memory performance in young college students

With the increasing popularity of artificial light sources, people are exposed to artificial light for longer periods of time. Creating an artificial light with specific illuminance and correlated color temperature (CCT) that enhances cognitive function is an area of great interest to individuals, schools, and corporations. However, research on this topic has shown inconsistencies. As a preliminary exploratory research, this study investigated the cognitive function using working memory performance of young undergraduate students exposed to different indoor artificial lights. The experiment utilized a 2 (illuminance, 100 lx/1000 lx) × 2 (CCT, 3000 K/6500 K) × 2 (gender, men/women) × 2 (Time-of-day, day/evening) mixed group design, and several common individual immediate states (subjective affect, comfort, familiarity) were considered. A significant interaction of illuminance, CCT and gender on visual working memory performance was found. The male exhibited better accuracy in visual working memory tasks when exposed to warm light sources (3000 K) at higher illumination level (1000 lx vs. 100 lx). The results suggested that after controlling for the lighting time-of-day and the immediate state of the subject, gender, illuminance, and color temperature collectively influence performance in visual working memory. This research investigates the effects of illuminance, correlated color temperature, and gender on visual working memory, providing valuable new insights for understanding the impact of artificial light on working memory and optimizing lighting settings in our workplaces. However, the generalizability of the conclusions requires further validation in future studies.