Participation in this project will involve having assessments in 3 stages: online surveys, and introductory and experimental laboratory visits. Following the initial phone contact, if you are interested and agreeable to attend an introduction session, you will be asked to complete online surveys (~30 minutes). Then, you will be invited to attend an introductory visit (2 hours). During this session, the goals of the study and all the procedures will be explained to you by one of the researchers and you will have a chance to ask any questions. This session will also be used to provide you with a chance to practice at all the performance tests of the study. Next, about 1 week before the experimental visit, you will receive some wearable devices to measure your daily activity patterns, and you'll be asked to keep a daily diary about your sleep and daytime activities. Finally, you will be asked to arrive to the sleep laboratory at 7:30 pm for the experimental laboratory visit. During this visit, you will be asked to undergo the following set of procedures: (1) polysomnographically measured sleep during the first night, (2) driving performance tests (90 minutes) the next morning and at 1:00 the following night, and (3) 5 sets of tests that measure cognition and vigilance.

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