REM = Rapid Eye Movement
REM betecknar tillståndet hos en person som drömmer. Under drömsömnen rycker ögonen fram och tillbaka (från höger till vänster till höger, osv). Detta används i sömnlaboratorier för att registrera när en person drömmer. Mätningen görs genom att fästa elektroder vid ögonen som mäter den elektriska aktiviteten då ögonmusklerna är aktiva.
Det är vanligt att kombinera en mätning av REM med EEG.
REM-sleep, the "fast" sleep
The brain awakens and starts to send out the passive alertness kind of waves, the alpha-waves. Despite the alpha-waves, the body stays in deep sleep, even deeper than the one in the fourth stadium. The person is actually sunken in his bed as if he were dead.
During this fifth stadium the person's whole body is paralysed, except for some small muscles in the face, fingers and toes. The sleep during this stadium is called fast, because the brain waves are just as fast as when you are awake.
Now another strange physiological thing takes place; the pupils start to move. First horizontally, from side to side, just like when you are watching a game of Ping-Pong. Then they move vertically, up and down. It is called rapid eye movements, REM.
This stadium, which lasts ten to fifteen minutes, is the one in which we dream. Because the brain's activity during the REM-periods is very large, it can affect the pictures in our dreams, and make them hallucinatory. That makes it easy to tell if the dream you remember is from stadium two or five(REM-stadium).
We need our REM-sleep
Dr Milton Kramer, at the Veterans Administration Hospital in Cincinnati, claims that a certain function in our dreams can be determining for our state of mind the following day. After he had studied several persons for twenty nights he came to the conclusion that they were less unhappy, less aggressive and less hostile the next morning than the previous evening, due to sleeping. The more people involved in their dreams, the happier they were.
One thing that is assured, is that we need our REM-sleep. If you wake someone up every time he is entering his REM-sleep and depriving him of it, his body will react and produce more REM-sleep than usually just to recover. We need our REM-sleep to be able to live a normal life.
- Sova Gott - Richard Trubo. Tryckning Schmidts Boktryckeri AB, Helsingborg, 1980, p.156-157
REM-sömn kallas också parasömn. Den omfattas av de perioder som ortosömnen bryts av drömverksamhet, maximalt 30 minuter. Man räknar med att parasömnen upptar c:a 25% av den totala sömntiden.