Relationships Between Light Exposure and Aspects of Cognitive Function in Everyday Life

This repository contains the analysis scripts for a study investigating the relationships between light exposure and various aspects of cognitive function in everyday life among UK adults.

RStudio project file. Double-click to open in RStudio. Required for features like relative paths using the here package.

• preprocessing/ – Contains numbered R scripts that must be run in order to preprocess raw data and create required variables.
• functions/ – Custom R functions used in processing and analysis.
• figures/ – Contains figures exported by analysis_light_and_cognition.Rmd.
• figure data/ – Data used to generate plots in GraphPad Prism, exported from the main analysis script.
• tables/ – Tables exported by analysis_light_and_cognition.Rmd.
• analysis_light_and_cognition.Rmd – R Markdown file for analysis and reporting. Knitted to a PDF. Uses and exports data from the data/ folder.

This folder should be downloaded from the Figshare repository: DOI-10.48420/28911977.

• brightertime/ – Cognition, subjective sleepiness, sleep, and baseline survey data collected via the mobile app.
• light_sensitivity/ – Light sensitivity metrics (PIPR, brightness discrimination, subjective brightness), processed by Weolders et al. (2024). Also includes dose-response slopes between melanopic lux and cognitive function.
• spectrawear/ – Light exposure data collected by Spectrawear. Includes calculated light exposure metrics and 2-hour history windows before cognitive tasks.

• Sunrise and sunset times were calculated for:
  latitude = 53.4808, longitude = -2.2426.

• All timestamps were recorded in local time (Europe/London) by both Spectrawear and Brightertime.

• Timestamps in .RData files are stored in POSIXct format ("YYYY-MM-DD HH:MM:SS").
  Although shown in local time, timestamps are labeled as UTC for consistency and ease of comparison.

To reproduce the analysis, install the required R packages using:

install.packages(c("here", "progress", "data.table", "dplyr", "lubridate", "lme4", "lmerTest", "ggplot2", "wesanderson", "moments", "ggpubr", "corrplot", "reshape2", "stats", "caret", "Hmisc", "car", "openxlsx", "suncalc", "parameters", "performance", "effectsize"))