The Stages of Our Sleep Cycle
Friday, March 13th, 2009
Our sleep may seem like “switching off” or being quite a steady state, when our mind and body remain dormant and our brain activity is ceased. However, in the middle of the twentieth century it was discovered that every healthy sleep has its special architecture. When we sleep, our mind goes through a sequence of 5 stages, which can be characterized by different brain wave patterns. In 1953, the invention of a device called the electroencephalograph helped the scientists discover two types of sleep:
1. REM (rapid eye movement) sleep, or dreaming stage, which can be characterized with increased brain activity and rapid movement of our eyes under the eyelids.
2. NREM (non-REM) sleep, when our brain activity slows down during sleep.
Adult people spend about 20% of their sleep in REM phase, and infants spend about 50% of their sleep in this phase. This is the stage when we see the brightest and the most vivid dreams that our brain creates from the pieces of information we know and visuals. NREM sleep lasts longer, and during this phase our body works for restoring our tissues and improving the work of all the body systems, recreating bones and muscles, etc. The stages of our sleep include the following 5 phases:
Stage 1. NREM or Slow Wave Sleep (SWS). It is a period of transition between wakefulness and sleep, so the sleep is very light and a person can be woken up easily. The eye movements slow down. On this stage some people experience sudden abrupt movements (so called hypnic myoclonia), and some people may have a sensation of falling down.
Stage 2. NREM or SWS. This is the longest stage which lasts for about 50% of the whole cycle. In this phase we are still in quite light sleep. At that, our body and mind get prepared for entering a deep sleep. Our eye movements stop, the body temperature decreases, and our heart rate and brain activity slows down.
Stage 3. NREM or SWS. This stage is called deep slow-wave sleep. On this stage, very slow brain waves (delta-waves) are generated. It is quite hard to wake up a person during this stage. There are no eye movements or muscle activities.
Stage 4. NREM or SWS. This is the second stage of deep sleep. The brain goes on producing very slow delta-waves. This stage usually lasts for about 30 minutes and possible sleepwalking or bedwetting occurs on this stage. Stages 3 and 4 are the most important stages of our sleep, and if they do not last long enough, the whole sleep will be not satisfying.
Stage 5. REM sleep. The REM period lasts for about 15 minutes and can be characterized with shallow and rapid breathing, increased heart rate and blood pressure, fast movements of the eyes and certain muscle activity. This is the stage when brain activity maximizes and the waves generated can be compared to the ones generated when a person is awake. That is why dreaming occurs, and, if awoken during the REM sleep, a person can remember the dreams very clearly.
Those are the stages of human sleep cycles, which every person, who does not suffer from sleep disorders, experiences every night. Since the whole cycle usually takes 80-90 minutes, during our night seep we go through 4-5 full cycles. The length of the stages aso changes during the course of the night sleep: for example, the REM stages of the later cycles tend to last a little longer, sometimes even up to 40-50 minutes. Therefore, the most vivid and exciting dreams usually come to our mind closer to the morning!
A great number of people have problems with falling asleep. Many of us got already used to tossing and turning in our beds for long time before getting into sleep mode, however, this is really distressful and sometimes even quite harmful to our body and mind. Lasting stresses, depression and anxiety, a lack of physical activities, various ailments and chronic pains, taking certain medications, as well as other possible reasons of physiological or psychological nature can cause difficulties with falling asleep fast.
2. In order to set yourself on a sleeping mood, do something relaxing and very pleasant before going to bed. Some people recommend writing the events of the day in a dairy, some recommend reading or playing the card game Solitaire. You can watch a light TV show like “Late Night with Conan O’Brien” or a repetition of your favorite sit/com 30-40 minutes before going to bed. Listening to some soft relaxing music can also work well. For example, listening to the albums of Mike Oldfield has been helping me for years to free my mind from all problems and stresses and calm down before going to sleep.
1. Warm milk. A glass of warm milk is a well-known effective natural remedy for good sleep that works especially great for young children. Milk and dairy foods contain tryptophan, an amino acid with strong sedative properties, which gets converted in our body into serotonin and melatonin and improves our sleep quality to a great extent. In addition, milk is a great source of calcium necessary to our body to digest trytophan.
3. Herbal teas with Chamomile, Mint and Melissa. Specialists recommend herbal teas as very effective natural remedies to promote good and restful sleep. Chamomile is a great natural solution, which helps to calm down after stresses, relax, soothe irritations and relieve various chronic aches. Mint is a natural ingredient with excellent calming, relaxing and anti-inflammatory properties, and Melissa has very strong sedative, soothing and calming therapeutic effects. That is why these three medicinal herbs are considered to be the most effective for those who fight with insomnia and other sleep disorders.
4. Bananas. Bananas are sweet and delicious natural remedies for good sleep. Bananas are also rich with tryptophan and help to stimulate synthesis of melatonin and serotonin, natural neurotransmitters which promote sleepiness, relaxation and feelings of calm. Besides, banana is a fruit containing a variety of B-group Vitamins, and Vitamin B12 is supposed to be especially useful when combating insomnia. In addition, bananas help our body to produce endorphins, natural chemicals known as “hormones of happiness”. When you feel happy, you always sleep much better, don’t you?
5. Almonds. Some experts consider almonds and some types of nuts to be the best sleep-indulging food. Just like milk and bananas, almonds are also a great source of tryptophan, which helps to relax and calm down. Besides, almonds contain such element as magnesium, known for its excellent muscle relaxing properties. Therefore, eating a handful of almonds in 1or 2 hours before going to bed can be of a great help to those people, who want to get a good night’s sleep.
What was your most pleasant dream ever? You were Agent Smith fighting with Neo, or you were acting like James Bond trying to save the girl you love from bad guys. No, no, no: you were in the bedroom with Paris Hilton or you were playing bass for Avril Lavigne. Now, what was your most disturbing dream ever? By the way, did you know that there is a special Dreambank, created by the specialists of the University of California more than a hundred years ago? You can give those guys a call and tell them what kind of interesting dream you saw tonight. This valuable information gives Dreambank specialists a great opportunity to analyze and study our dreams in order to have a better idea about the nature and function of the dreams.