Light exposure and aspects of cognitive function in everyday life

Summary

Measuring cognitive performance in real world settingsWe aimed to collect cognitive function data in everyday life using an accessible smartphone app, Brightertime39. This app incorporates a Psychomotor Vigilance Task (PVT) to measure sustained attention, an N-back task (NB3; 3-back) to assess working memory, a T vs. L visual search task (VS) to evaluate search accuracy and efficiency, and subjective sleepiness report (KSS) (Fig. 1A). Participants (n = 58) used the app multiple times throughout the day at their discretion (Fig. 1B). (Fig. S2: min = 13, max = 52, median = 23 entries per participant over an 8-day study period; Fig. S3: a representative study design for one participant). Across the 1428 subjective sleepiness reports, we captured the full range of subjective sleepiness, indicating that our methodology appropriately captured real-world variations in ‘tiredness’ throughout the day. The data exhibited minor positive skewness (0.4), with a minimum value of 1, a maximum value of 10, a mean of 4.5, and a standard deviation of 1.9.Fig. 1: Study protocol.A The real-world study setting on light and cognition includes three main components: personal light exposure monitoring using the Spectrawear melanopic equivalent daylight illuminance (EDI) sensor, cognitive performance assessment via the Brightertime mobile app (conducting Psychomotor Vigilance Task (PVT), N-back, and Visual Search tasks), and repeated survey collections on sleep and subjective sleepiness. B The study lasted for eight days. On the first day, a registration meeting was held, and study instructions were provided. Throughout the following week, participants completed a morning diary, cognitive tasks, and surveys at multiple time points during the day. On the final day, a completion meeting was conducted, and optional visual light sensitivity tasks were performed. Abbreviations: MCTQ Munich Chronotype Questionnaire, PSQI Pittsburgh Sleep Quality Index, PIPR Post-Illumination Pupil Response.Object...