Sleep and dreaming during sleep as psychological phenomena.
Test your knowledge with these top questions!
What does the "R" in REM sleep stand for?
During REM sleep, breathing becomes more rapid and irregular than in deep non-REM sleep.
Which age group experiences sleepwalking most often?
Most children outgrow sleepwalking without treatment by the time they are teenagers.
Which group spends about half of sleep time in REM sleep?
Adults spend about one-fifth of their sleep in REM, so newborns devote a much larger share to this stage.
In healthy adults, how long after falling asleep does the first REM period usually begin?
REM periods grow longer toward morning, while deep non-REM sleep takes up less of the night.
What do sleepwalkers usually remember the next morning about a sleepwalking episode?
Sleepwalking is a partial awakening from deep sleep, so movement can occur while awareness stays impaired.
Sleepwalking episodes most often happen during which type of sleep?
Sleepwalking happens in deep slow-wave sleep, when the brain is hardest to wake fully.
During REM sleep, most voluntary muscles become what?
This limp state is called atonia and keeps sleepers from acting out the vivid dreams of REM sleep.
About how long is one full cycle of the human circadian rhythm?
The name means "about a day"; without light cues to reset it, the human body clock usually runs slightly longer than 24 hours.
What is the medical term for sleepwalking?
The word joins Latin roots for sleep and walking: "somnus" plus "ambulare".
Which circadian disruption affects travelers crossing several time zones?
Jet lag fades as daylight resets the internal clock, often about a day per time zone and longer flying east.