Light exposure behaviors predict mood, memory and sleep quality

Abstract Ample research has shown that light influences our emotions, cognition, and sleep quality. However, little research has investigated if different light exposure-related behaviors, such as the use of electric light during daytime, and use of gadgets before sleeping, influence those variables. Three-hundred-and-one Malaysian adults (MeanAge±SD=28 ± 9) completed the Light Exposure Behavior Assessment (LEBA) tool that measured five light exposure behaviors. They also completed the Morningness-Eveningness Questionnaire, Positive and Negative Affect Schedule, Pittsburgh Sleep Quality Index, and single items assessing trouble in memory and concentration. A partial least square structural equation model, showing 61.36% predictive power, revealed that increased use of wearable blue filters indoors and outdoors decreased the morningness affect (Direct effect, DE=-0.16) and sleep quality (Total effect, TE = 0.11). Increased time spent outdoors predicted positive affect (DE = 0.32) and early chronotype (DE: RI = 0.14, PT = 0.15, RT = 0.15). Increased use of gadgets before sleep predicted late chronotype (DE: RT=-0.26; RI=-0.23; PT=-0.24; MA=-0.13), increased negative affect, reduced sleep quality (DE = 0.13), and increased trouble in memory and concentration (TE = 0.20 & 0.23, respectively). Increased use of electric light in the morning and daytime predicted a positive affect (DE = 0.16) and sleep quality (DE=-0.16). The results provide valuable insights into developing a healthy light diet to promote health and wellness.