We have mentioned in the past certain aspects regarding Rapid Eye Movement (REM) sleep but we have yet to properly explain what REM sleep really is and why it is truly important. Out of the stages of sleep, doctors and scientists agree that REM sleep is the most important. The questions we look to answer are “What is REM sleep”, and “How does it occur?”
Every night when you go to sleep you experience anywhere from 1-2 hours of REM sleep. REM sleep is typically spread out over the night but the majority happens in the early morning hours. The amount you get a night also varies with age. Infants spend a considerably greater amount of time in REM sleep than adults do. This is because REM stimulates the areas of the brain associated with learning so it is a vital part of an infants development.
REM is also the period of sleep in which the vast majority of your dreaming takes place. When you begin to REM sleep the area of the brain called the pons begins to send signals to the thalamus which relays the signals to the cerebral cortex. The cerebral cortex is the area of the brain that is associated with organizing information, thinking, and learning new things. The pons also sends signals to the spinal chord temporarily paralyzing the limbs so you don’t actually move with your dreams. A condition exists called REM sleep behavior disorder where the pons fails to send these paralyzing signals and a person will literally act out their dreams which can have disasterous results. Comedian Mike Birbiglia is one such person with REM sleep behavior disorder and he documents the time he jumped out of a second story window of a hotel in Walla Walla, Washington when he was dreaming a missile was headed for his hotel room. Such is the power of REM sleep. When a person is experiencing REM sleep they demonstrate similar brain patterns to a waking person. This is why REM sleep is often called paradoxical sleep and is the phase of sleep in which you sleep lightest.
REM occurs in mammals and birds but curiously not in cold blooded animals like reptiles. This is why you can see your dog running or whining in his/her sleep. The process of REM sleep is a complex physiological process that interacts with several locations in the brain, but scientists still disagree as to exactly why this happens. Now that we have talked about what REM sleep is, all thats left is why it happens. Come back next week to find out the interesting theories on why it is the body requires REM sleep and the terrible consequences of neglecting those requirements.