Researchers want to better understand how stress affects the brain and body. What they learn may help improve safety and performance during future space missions.

You may be eligible for this study if you meet the following criteria.

Inclusion Criteria:

•   Age between 21-60 years
•   Free of psychological, psychiatric, or physical conditions that preclude participation
•   Free of beliefs, conditions, or circumstances that preclude alcohol consumption, including a history of alcohol abuse
•   BMI between 18.5 and 35
•   Self-reported regular sleep schedule with sleep duration of 6-8.5 h per night
•   Able to read/write English
•   Able to stand unassisted for up to 10 minutes at a time and able to lift arms above head

Exclusion Criteria:

•   Alcohol or drug abuse in the past year
•   Allergies, conditions, or circumstances that preclude alcohol consumption (including cultural beliefs, personal history, or use of prescription or over-the-counter medications or supplements for which alcohol avoidance is advised)
•   Current smoker or tobacco user
•   Excessive caffeine consumption (> 650mg/day, or more than approximately 7 caffeinated drinks per day)
•   Sleep disorders or use within the past month of sleep medication (prescription or over-the-counter) or stimulant medication
•   Acute, chronic, or debilitating medical conditions (including neurological, physical, psychiatric, or other conditions or disorders) that preclude participation, including use of oxygen
•   Unable to get MRIs due to history, implants, contraindications, or severe motion sickness
•   Currently pregnant or breastfeeding
•   Currently working night, swing, split, or rotating shift; or travel across more than one time zone within one week of study start

Overall Duration

Participation includes two screening visits before the study, a short period of at-home tracking, and one continuous 6-day, 5-night stay at the research center.

Screening Visits

You will attend two in-person screening visits that each last about 4 hours.

During these visits, you will:

• Answer questions about your health and medical history
• Have a physical screening
• Provide a blood sample
• Complete a drug screen
• Have an ECG to check your heart

Between the screening visits and your laboratory stay, you will complete a short online survey each morning about the previous night’s sleep. You will also wear a wrist activity monitor every day and night, except while showering or swimming.

In-Lab Activities

If you qualify, you will stay at the research center for 6 days and 5 nights. During this time, you will remain at the research center for the entire study. You will have your own bedroom and bathroom, but you will share common areas, such as the kitchen and dining room, with up to three other participants.

You will follow a schedule created by the research team. All meals and snacks will be provided.

During your stay, you will:

• Complete computer tasks that measure thinking, attention, and reaction time
• Complete simple physical and movement tasks throughout the day
• Wear a heart monitor during the study
• Continue wearing the wrist activity monitor
• Have three MRI scans
• Have six blood draws

You will also complete three different study conditions:

• One day with a normal daily schedule
• One day where you will drink alcohol under medical supervision until you reach the legal driving limit of 0.08% blood alcohol concentration
• One period where you will stay awake for about 27 hours before being allowed to recover with sleep

Researchers will monitor you throughout the study to help keep you safe.

At-Home Activities

Before your laboratory stay, you will:

• Complete a short online sleep survey each morning
• Wear a wrist activity monitor every day and night

No audio or video recordings are collected during these at-home activities.

Additional Details

Because researchers are carefully studying how different conditions affect performance, participants must remain at the research center for the full 6-day stay.

During the laboratory stay:

• Visitors are not allowed
• Personal electronic devices, including cell phones, tablets, laptops, and smartwatches, cannot be used
• Outside communication is limited to emergencies
• Caffeine, tobacco products, and excessive exercise are not allowed
• During free time, you may read, complete puzzles, or enjoy other quiet activities approved by the research team

Yes. Participants who complete the study may receive up to $1,300.

Travel costs for the screening visits and transportation to and from the research center will be reimbursed. All meals and snacks are provided during the laboratory stay.

There is no cost for you to participate in our research study.