Sleep and dream

V. Read the text and say what the difference between Rapid Eye Movement stage and Non Rapid Eye Movement stage.

Sleep is very important to humans; the average person spends 220,000 hours of a lifetime sleeping. Until about thirty years ago, no one knew much about sleep. Then doctors and scientists began doing research in sleep laboratories. They have learned a great deal by studying people as they sleep, but there is still much that they don’t understand.

Scientists study the body characteristics that change during sleep, such as body temperature, brain waves, blood pressure, breathing and heartbeat. They also study rapid eye movement (REM). This stage might last an hour and a half and is the time when you dream. For the rest of the night, REM and NREM stages alternate.

Body movement during sleep occurs just before the REM stage. The average person moves about 30 times during sleep each night. Sleep is a biological need, but your brain never really sleeps. It is never actually blank. The things that were on your mind during the day are still there at night. They appear as dreams, which people have been discussing for centuries. At times people believed that dreams had magical powers or that they could tell the future.

Sometimes dreams are terrifying, but they are usually a collection of confused thoughts. If you dream about something that is worrying you, you may wake up exhausted, sweating, and with a rapid heartbeat. Dreams have a positive effect on our lives. Perhaps during a dream the brain can concentrate on a problem and look for different solutions.

Researchers say that normal people may have four or five REM periods of dreaming at night. The first one may begin only a half-hour after falling asleep. Each period of dreaming is a little longer and the last one lasting up to an hour. Dreams also become more intense as the night continues. Nightmares usually occur toward dawn.

People dream in color, but many don’t remember the colors. Certain people control some of their dreams. Many people talk in their sleep, but it is usually just confused half sentences. They might feel embarrassed when someone tells them they were talking in their sleep, but they probably didn’t give away any secrets.

Sleepwalking is most common among children. They usually grow out of it when they are adolescents. Children don’t remember that they were walking in their sleep, and they don’t usually wake up if the parents lead them back to bed. Researchers don’t know why people talk, walk while they are sleeping.

There are lots of jokes about snoring, but it isn’t really funny. People snore because they have trouble breathing while they are asleep. Some snores have a condition called sleep apnea. They stop breathing up to 30-40 times an hour because the throat muscles relax too much and block the airway. Then they breathe in some air and start snoring. This is a dangerous condition because if the brain is without oxygen for 4 minutes, there will be permanent brain damage. Sleep apnea can also cause irregular heartbeats, a general lack of energy, and high blood pressure.

What should you do if you have trouble sleeping? Lots of people take sleeping pills, but these are dangerous because they are habit-forming. If you take them for several weeks, it is hard to stop taking them.

Doctors say the best thing is to try to relax and to avoid bad habits. If you always go to bed and get up at about the same time, this sets a rhythm in your life. Caffeine keeps people awake, so don’t drink caffeine drinks in the evening. Smoking and alcohol can also keep you awake. You may have trouble sleeping if you have a heavy meal just before you go to bed.

You may also have trouble sleeping if you have a problem or something else on your mind. This is when you need to relax. As you lie in bed, tense the muscles in your feet and then relax them. Continue up the body, tensing and relaxing the muscles until you reach the head. Start with the feet again if you are still tens. Then remember some pleasant experience you had and relive it.

If you are thinking about a problem or about something that is going to happen the next day, get up and write about it. That will help take it off your mind. You can also get up and read or watch television.

Sleep is important to humans. We spend a third of our lives sleeping, so we need to understand everything we can about it.

Дата добавления: 2014-12-27