When are microsleeps common?

• A. During sleep deprivation or monotonous tasks
• B. After a long nap
• C. During high-speed maneuvers
• D. Only during rest periods

Answer: (A)

Microsleeps are ultra-brief, involuntary episodes of actual sleep that sneak in when the brain is extremely fatigued. They’re most common during sleep deprivation or when performing long, monotonous tasks because the brain’s need for sleep overcomes the ability to stay awake, even if you’re trying hard to stay alert. During a microsleep, attention and awareness drop for a few seconds—enough to miss cues or an important change in the cockpit—before you briefly wake up again. A long nap relieves sleep pressure for a while, so microsleeps aren’t typically expected right after waking; high-speed maneuvers require sustained attention, which further reduces the chance of a microsleep in the moment; and microsleeps don’t occur only during rest periods. The takeaway is that fatigue and monotonous tasks create the conditions for microsleeps.