The maintenance of wakefulness test (MWT) measures how alert you are during the day. The test will show whether or not you are able to stay awake for a defined period of time by measuring your ability to stay awake in a quiet, dark and non-stimulating room. This test is usually given if you are receiving therapy for conditions causing daytime sleepiness. The MWT consists of four trials with breaks lasting two hours in between them. Falling asleep in an average of less than eight minutes during the test would be considered abnormal. Normal results consist of staying awake for the entire 40 minutes of all four trials.