REM(Rapid Eye Movement)
Let’s come back to REM which I mention in my previous post. As we sleep, the electrical activity of the brain exhibits a series of changes. Much of our memorable dreaming takes place during what is known as Rapid Eye movement (REM) sleep, a stage marked by movement of the eye behind the closed lids, accompanied by rhythms in the brain’s electrical activity. The first episode of RAM sleep usually takes place approximately an hour and a quarter after the onset on sleep, and last some 5 minutes. Three or four further periods of REM sleep occur during the night at intervals of about 90 minutes, each lasting longer than the previous one. The final period, which usually ends during the last hour of sleep, is typically between 20 and 50 minutes long. REM sleep is important to our psychological health .If we are deprived of it we suffer from daytime memory loss, poor concentration, fatigue, irritability and trying to make up the deficit by increasing the time spent in REM sleep. Total sleep depravation can even lead to episodes of REM brain activity while we are still awake. Research shows that we normally experience the vivid dreams associated with REM sleep for a total of around 2 hours each night. Dreams are not, however, confined to this type of sleep. Heavier sleepers dream less during non-REM sleep, and the dreams they do have are less visual and active than REM dreams.For many of us there are few, if any periods during sleep when our minds are not active. Dreaming affects the body as well as the brain. Even during apparently tranquil dreams the nervous system responds by increasing heart rate, breathing and gastric secretion. We also show signs of sexual arousal even when erotic dream content is absent. At the same time, as we recognize the dangers that could arise from any attempt to act our dream events physically. We lose muscle tone, resulting in effective paralysis of the major muscle groups except those involved in eye movement. While scientist generally agree that, the process of dreaming is important, many of them believe that the content is valueless-mass of material that has bombarded us during the day. However the existence of recurring dreams, which repeated themselves over many years, would suggest otherwise. Overall ignoring our dreams then may be to ignore a large part of our mental lives.