Psychology & Psychiatry

REM sleep silences the siren of the brain

Upset by something unpleasant? We have all been there. Fortunately, it also passes. A new day, a new beginning. At least: if you have restful REM sleep. Researchers at the Netherlands Institute for Neuroscience discovered ...

Medical research

'Goldilocks' neurons promote REM sleep

Every night while sleeping, we cycle between two very different states of sleep. Upon falling asleep, we enter non-rapid eye movement (non-REM) sleep where our breathing is slow and regular and movement of our limbs or eyes ...

Neuroscience

Same brain cells active during sleep and exploration in mice

Researchers have mapped the activity of individual neurons deep in the brain during sleep and exploration of novel objects in male and female mice. The study, published in JNeurosci, suggests these cells may facilitate memory ...

Neuroscience

Brain marker for angry dreams

Researchers have identified a pattern of brain activity that predicts anger experienced during dreaming, according to a new study of healthy adults published in JNeurosci. The research could potentially inform efforts to ...

Neuroscience

Not all sleep is equal when it comes to cleaning the brain

New research shows how the depth of sleep can impact our brain's ability to efficiently wash away waste and toxic proteins. Because sleep often becomes increasingly lighter and more disrupted as we become older, the study ...

page 1 from 10

Rapid eye movement sleep

Rapid eye movement (REM) sleep is a normal stage of sleep characterized by rapid movements of the eyes. REM sleep is classified into two categories: tonic and phasic. It was identified and defined by Kleitman and Aserinsky in the early 1950s.

Criteria for REM sleep includes not only rapid eye movements, but also low muscle tone and a rapid, low voltage EEG -- these features are easily discernible in a polysomnogram, the sleep study typically done for patients with suspected sleep disorders.

REM sleep in adult humans typically occupies 20-25% of total sleep, about 90-120 minutes of a night's sleep. During a normal night of sleep, humans usually experience about 4 or 5 periods of REM sleep; they are quite short at the beginning of the night and longer toward the end. Many animals and some people tend to wake, or experience a period of very light sleep, for a short time immediately after a bout of REM. The relative amount of REM sleep varies considerably with age. A newborn baby spends more than 80% of total sleep time in REM. During REM, the activity of the brain's neurons is quite similar to that during waking hours; for this reason, the sleep stage may be called paradoxical sleep. This means that there are no dominating brain waves during REM sleep.

REM sleep is physiologically different from the other phases of sleep, which are collectively referred to as non-REM sleep (NREM). Vividly recalled dreams mostly occur during REM sleep.

This text uses material from Wikipedia, licensed under CC BY-SA