When it is delayed by waking the dreamer every time the rapid eye movements begin, REM returns more insistently in succeeding sleep episodes.

During his 15-year marriage, near-nightly sleep episodes included once flinging his wife into the air, then dropping her onto a hardwood floor.

Uchiyama et al. had earlier determined that sighted Non-24 patients' minimum core body temperature occurs much earlier in the sleep episode than the normal two hours before awakening.

Automatic behavior means that a person continues to function (talking, putting things away, etc.) during sleep episodes, but awakens with no memory of performing such activities.

It is estimated that up to 40 percent of people with narcolepsy experience automatic behavior during sleep episodes.

In chronobiology, biphasic sleep refers to a nap or siesta in addition to the usual sleep episode at night.

Monophasic sleep means just one sleep episode per day.

Another rare side effect of piribedil is excessive daytime sleepiness and unintended sleep episodes.

Moderate doses of alcohol also increase slow wave sleep (SWS) in the first half of an 8-hour sleep episode.

During abstinence, recovering alcoholics have attenuated melatonin secretion in the beginning of a sleep episode, resulting in prolonged sleep latencies.