This is a non-clinical study to understand the fundamental mechanisms of sleep and wake under high sleep pressure. We use EEG to measure the different brain activity across different times of day and tasks. In particular, we aim to determine whether parts of the brain can selectively fall asleep. To do this, we employ sleep restriction to make you as tired as possible. This involves coming to the lab for 2 nights, staying awake for 24 hours in between, watching a TV series of your choice and conducting cognitive tests.
Participants are screened so that they are very similar among each other, without introducing confounding elements that might bias the results. Furthermore, they must be able to handle the conditions of the experiment, without it being too different from their regular sleep-wake rhythms.
You must be:
- Between the ages of 18 and 25
- Healthy
- An average chronotype
- A good sleeper
You will be excluded if you have or have done any of the following:
- Been diagnosed with or strongly suspected of having a psychiatric or medical condition
- Any learning disorders
- Sensitive skin
- Currently in a period of stress, or generally being vulnerable to stress
- Currently required to wake up more than 2h before preferred wakeup time, or go to sleep 2h later than preferred
- Any sleep disorders, daytime sleepiness, or any other sleep complaints
- Nap regularly
- Pregnant
- Heavy consumer of:
- Caffeine
- Alcohol
- Regular consumer of:
- Drugs (any drug)
- Nicotine
- Currently taking medication
- Any past experience with:
- Frequent drug use
- Severe addiction and/or withdrawal
- Alcoholism
- Substantial experience with:
- Shift work
- Time zone travel
- Sleep deprivation
If you're not sure, or hope that something doesn't apply exactly to your situation, it will become clear with the Screening Questionnaire (provided below) if you are eligibile or not.
Risks
There are no risky procedures involved in this study if you are a healthy young participant without skin problems. Some people react negatively to the conductive gel used for the EEG, but these are individuals who tend to have multiple skin allergies, eczemas, etc. The effects of prolonged wakefulness are well documented in healthy people, but have different, often unknown, effects in patient populations.
Preparation for the Main Experiment:
Controlled sleep week: for 7 days before the experiment, you are asked go to sleep and wake up at the same pre-specified times, and avoid any behaviour that could affect your sleep (for the exact list of do's and don'ts, see Obligations).
Every morning right after waking up, you will be provided a Sleep Report to fill out, which asks you about the quality of your sleep, dreams, mood, and your activities from the day before. During this week, you will be given an actigraphy watch to measure activity levels. If anything happens during this week that could affect your sleep, we will need to reschedule.
Main Experiment:
Here you can see how the day will be organized. The list below explains what each section refers to.
During all EEG recordings, there will be a microphone recording audio, to keep track of everything that happens.
Participation is entirely voluntary. If you decide to withdraw, you do not need to give a reason.
This study was approved by the Kantonale Ethikkommission Zürich (BASEC ID: 2019-01193)
For more information, you can read the Information and Consent document, which is what you will need to sign before participating. You can also refer to the German version. In general, we recommend at least a conversational understanding of English, because experiment instructions and questionnaires will be in English. You will always be able to ask the experimenters for clarifications.
Burdens
There are some aspects of the experiment that you might find too burdensome. Please make sure you’re willing to withstand the following:
- Staying awake for 24 hours after only 4 hours of sleep. You will be monitored by the experimenters to make sure you don’t doze off. You will be tired.
- Wearing an EEG net for 36 hours continuously, also while sleeping. This is uncomfortable.
- Sticking to a strict schedule on when to fall asleep and wake up for a week. This is a burden if you have to reschedule events.
- Abstaining from coffee or other caffeinated beverages while in the lab, and limiting coffee in the week before.
- Abstaining from drugs,alcohol,and partyingthe entire week of the experiment. We’re sorry if participating in this experiment has a negative impact on your social life.
- Conducting boring tasks for extended periods of time.
- Eating the same set of snacks at 3h intervals instead of 3 normal meals during the 24h awake.
The 2 nights in the lab and 24h awake is expected to be conducted on the weekend, but if scheduling allows, it may be possible to run the experiment during the week. All recording sessions will be conducted between January and March 2020.
The experiment will take place at the Irchel campus in Zurich.
We are part of the Child Development Center at the University Children's Hospital of Zurich. We specialize in using high density EEG to study local changes in sleep and sleep pressure.
Prof. Reto Huber is the principal investigator, and Sophia Snipes is the student conducting this study for her PhD thesis, with the help of Elias Meier.
If you have any qustions, you may contact Sophia directly:
sophia.snipes@kispi.uzh.ch
What will I eat?
We will provide dinner when you come to the first night of the experiment, and breakfast the morning of the last day. During the experiment you will get 6 small meals spaced out during the free periods. We will decide together what will make up this meal, but it has to be the same set of foods each time.