The effects of wearing a face mask on brain functioning in adults

Participants will come into the laboratory in the Department of Psychology for two visits (each ~60 min) separated by 1 week. Participants will be asked to wear a PPE mask (Safe Plus anti-fog, earloop type, manufactured by BH medical products Co., Ltd.) for one of the visits. Participants will wear the mask for at least 8 hours before commencing the experimental portion, which will last ~60 mins for a total 9 hours of mask wearing. The experimental session involves the following sequence of events: 1. Complete the Mini Mental State Exam, Center for Epidemiological Studies - Depression scale (CES-D) and the Pittsburgh Sleep Quality Index (PSQI). Participants will not be informed of their scores. 2. Completion of simple computer-based cognitive tests (described below). Haemoglobin concentrations and electrical activity will be recorded over the frontal lobe throughout the performance of the cognitive tests (described below). Cognitive Testing Participants will perform a battery of different computer-based cognitive tests. Throughout the performance of the cognitive tests, hemoglobin concentrations and electrical activity will be recorded concurrently. The cognitive tests involve viewing a display on a computer monitor and then pressing a button. The responses involve indicating the location or identifying of a target stimulus. Each response and response latency will be recorded. Button presses will be made on a two-button response box. No visual or audio recordings are involved, and all recordings are completely non-invasive. The experiments are not difficult or stressful and participants will be encouraged to rest as often as they please. Hemoglobin concentrations and electrical activity measures Concentrations of oxygenated and deoxygenated hemoglobin will be measured continuously using near-infrared spectroscopy (NIRS). This method assesses cerebral oxygenation changes. The NIRS technique is based on the relative transparency of human tissue to near-infrared light and on the oxygenation-dependent light absorption changes caused by the chromophores oxyhemoglobin [O2Hb] and deoxyhemoglobin [HHb]. It is completely non-invasive and painless. Concurrently with NIRS, the electrical activity of the brain will be recorded using EEG. EEG refers to recordings from multiple electrodes placed over the scalp, to record underlying electrical activity from the brain over a period of time (commonly referred to as brain waves). The EEG technique measures ionic current-voltage fluctuations which result from within the neurons of the brain. EEG is completely non-invasive and painless. This project was supervised by members of the research team.