Sleep And Its Stages

You’re watching TV late at night. While you are sitting there, you take a quick glance at the clock. OMG! It is two hours past your bedtime and you have a huge math test tomorrow! You quickly hurry upstairs and jump right into bed. You then fall asleep almost instantly. Next thing you know, your mother is shaking you and telling you to wake up. What happened during those mysterious eight hours?

People called polysomnographic technologists study this very question.

You first begin your sleep journey with transition/stage N1. After this, the extremely long N2 will come around and use up 45-55% of your night! Following this is the very deep Stage N3! N3 is very hard to wake you up from! Last but not least, REM sleep is the most famous for being the time where you have all memorable dreams!

But let’s start where the whole cycle begins, the under acknowledged stage N1.

There are two kinds of sleep; REM (rapid eye movement) and NREM (non rapid eye movement). When you first lie down, the first stage you will experience is Stage N1, the first stage of NREM. You will lose some muscle tone and most awareness of your environment. This stage is very light and you are quite easily awoken from it. So light, that if someone woke you from it you would say you were only thinking! This stage is actually a transition between a waking mind and sleeping which is why it usually only lasts a few minutes. During this transition, it is common to experience hypnic jerks or an involuntary twitch. Following this is stage N2.

Unlike stage N1, this stage is rather long and takes up 45-55% of all sleep in adults. N2 is the stage where you lose most muscle tone and all awareness of your surrounding environment. There is no eye movement and dreams are extremely rare. Unlike stage N1, this stage is rather long and takes up 45-55% of all sleep in adults. The third and final stage in NREM sleep comes next.

Stage N3, previously stages N3 and N4, became one stage in 2007 when the American Academy of Sleep Medicine (AASM) combined them to make Deep Sleep or SWS (slow wave sleep). This stage is very deep and quite comfortable. Dreaming can happen now, but it is often less clear and vivid than REM dreams. Still, it happens! This is the stage where parasomnias most often occur. They are things that interrupt natural sleep. Some examples of parasomnias are Somnambulism (sleepwalking), Night terrors (AKA sleep terrors), and Bruxism (grinding of teeth). When I was really little, I used to sleepwalk, but I outgrew a long time ago.

The fourth and final stage in the sleep cycle is REM sleep. It is characterized by, well, rapid eye movement! The stage was discovered in 1952 by Eugene Aserinsky and Nathaniel Kleitman with help from William C. Dement. This stage is most famous because of the fact that the most vivid dreams happen now. Some are so vivid that a muscular atonia can happen to prevent the dreamer from acting out their dreams.

Some people claim that they don’t dream. This is not true. All mammals have REM sleep. The people who claim they don’t dream simply don’t remember them. If you wake up during a dream that is the only one you will remember. If you don’t wake up during a dream then you won’t remember anything. This stage usually takes up 20-25% of sleep in all human beings or 90-120 minutes of sleep.

After all this happens, you will keep going through this cycle until you wake up. Then you get out of bed, go to school, come home, do homework, eat dinner, and then watch some TV late at night. While you are sitting there, you take a quick glance at the clock. OMG! It is two hours past your bedtime and you have a huge math test tomorrow! You quickly hurry upstairs and jump right into bed. You then fall asleep almost instantly. Next thing you know, your mother is shaking you and telling you to wake up…

By Simon

Silverstein, Alvin, and Virginia Silverstein. The Mystery of Sleep. 1st ed. Toronto: Little, Brown and Company, 1987. Print.

"Sleep." wikipedia.org. N.p., 3 Mar. 2011. Web. 3 Mar. 2011.

"sleep." 6th. ed. Colombia University Press, 2007. factmonster.com. Web. 18 Feb. 2011.

"Rapid eye movement sleep." wikipedia.org. N.p., 14 Feb. 2011. Web. 3 Mar. 2011.