Probably the stage of sleep that is most often called by name is the REM sleep stage. One of the reasons that this stage is so often remembered is that it is a descriptive acronym. REM sleep stands for Rapid Eye Movement sleep. REM sleep is the stage during our Sleep Cycles when we usually dream.
Sleeping occurs in stages. Typically, there’s a very wakeful stage as you are falling asleep. Then there are four non REM sleep stages that are simply referred to as numbers one through four. Typically, each of these stages will last from five to fifteen minutes and your body will undergo very subtle changes as these stages progress. After about an hour and a half of sleeping time, the REM sleep stage begins.
Two very helpful Internet sites related to REM sleep, sleep patterns and Sleep Disorders are located at www.sfn.org/content/Publications/BrainBriefings/rem_sleep.html and www.sleepdisorderchannel.net/stages. According to information from these sites, it was apparently in the mid 1950s that scientists discovered the existence of the REM sleep stage. It has typically been accepted since that time that the REM sleep stage is the period during which dreaming occurs and the body is mentally active. It also provides a very obvious marker for scientists and others who perform sleep studies.
One important fact about REM sleep is that this stage gets progressively longer as the sleep period progresses. Have you ever wondered why you tend to wake at a certain time during your sleep period after having a dream? It’s because your body will typically go through the Stages of Sleep at about the same rate, night after night. And because your REM sleep period gets longer each time you hit that stage, your longest periods of REM sleep are near the end of your typical sleep pattern. The first REM stages may last as little as ten minutes with later stages lasting up to an hour.
When you dream about being in a frightening situation and you can’t move, this may very well be your body’s way of protecting itself during REM sleep time. If you had a dream in which you needed to run and you had the ability to run, you could do harm to yourself. Some people manage to overcome the paralysis that keeps most dreamers rooted to the bed. Those people may sleepwalk, talk or perform other acts during their REM sleep time.