Dr. Michael Decker at CWRU is seeking healthy non-smoking adults 18-55 years of age to participate in a study to determine how oxygen delivered at a steady concentration or delivered at a variable concentration may change how a person’s brain processes information. Study participation will last about 7 days and will involve 4 study visits on the CWRU main campus . The first study visit lasts 25 minutes hours and involves gathering baseline data collection. Participants will be given a sleep/activity tracking device (Fitbit watch) to wear for approximately 4 days and nights while completing questionnaires on sleep, activity, diet, and fatigue levels. Participants will breathe oxygen via a face mask for 3 hours during each of the next 3 visits, scheduled on 3 days within the same week, while brain activity is measured using electroencephalography (EEG). Before and after two oxygen exposure sessions, a blood sample will be collected. Participants will be compensated. Persons taking daily medications for asthma or those with heart disease, lung disease, neurological diseases, or who are currently pregnant/attempting pregnancy are not eligible. Please call Elizabeth Damato at 216-368-5634 for more information.