About a third of one's life is spent in a sleep—in a deep and what appears to be quite useless state of being.
However, sleep is tremendously important for us. We are in need of sleep as much as we are in need of oxygen. Sleep is capable of working wonders: it increases one's work efficiency, extends one's lifespan, cures illnesses. One should not deprive him/herself of sleep.
Interestingly, various cultures had different perceptions of sleep. According to the ancient Chinese belief, for instance, a man acquired unity with the Universe in his sleep. Various European tribes, on the contrary, experienced deadly fear before a state of sleep. In mythology of some cultures it is possible to find references to the god of Sleep as the god of Death’s own brother.
First experiments with people totally deprived of sleep were conducted in the end of past century. Three volunteers participated in the experiment. They have been sleep deprived for 90 hours. In 1920 scientists conducted another experiment, where several people have been deprived of sleep for 60 hours.
American researcher Nathaniel Kleitman can be called “the father of sleep research.” Kleitman's research forms the foundation for many areas of current sleep studies. He examined thirty five volunteers who had been awake for 60 hours. He also conducted an experiment on himself when Kleitman remained awake for a total of 100 hours.
English researcher Oswald described his observations of people who had been sleep deprived for 8 days and nights in the following manner. By the end of the experiment, they began showing signs of mental disturbances, visions and hallucinations. They tried falling asleep in any environment.
An 18-year-old Mexican student set a record by refraining from sleep for a total of 11 days. Afterwards, a 12 hour sleep completely restored the boy's powers and brought him “back to life.”
It is worth mentioning that both Kleitman and Oswald researched continuous sleep deprivation (the experiment has been conducted only once on the same people). Obviously, chronic sleep deprivation can lead to much drastic consequences. The experiments did not prove that humans can function without sleep. On the contrary, they once again reinstated the importance of sleep.
Medics say that modern people do not get enough sleep. Each individual needs a certain amount of hours to completely rehabilitate his/her powers. On the average, an adult requires 8-9 hours of night’s sleep. Many, however, get to sleep 7 hours or less.
Even a slight deprivation of night's sleep can negatively affect one's health. According to the studies conducted by the University of Pennsylvania, those who slept for six hours were later diagnosed with increase of certain chemicals in blood associated with heart diseases and diabetes.
Scientists also note women better adapt to sleep deprivations. On the average, their state of deep sleep lasts for 70 minutes. Men on the other hand remain in the state of deep sleep for 40 minutes.
If we are to compare human beings with animals, the results can turn out to be quite interesting. Ungulate animals for instance require only 3 hours of sleep. Elephants and cows sleep for 4 hours. Dogs, pigs and guinea-pigs just as humans, require 8-9 hours for sleep. Hedgehogs and beavers sleep longer-10-11 hours.
Many people do not think of sleep deprivation as of something serious. Well, they should. White rats that were prevented from sleep eventually died after 10 days.
Sleep deprivation causes emotional disturbances in people. It may also lead to aggressiveness, apathy; result in fluctuations between euphoria and depression and vice versa. One can also experience pain in joints, hallucinations and visions. People also lose their ability to think straight and act quickly.
Those who have been sleep deprived for long, usually find it hard to finish a sentence or find an appropriate word to describe something. His short term memory also tends to fail. Therefore, one should never economize additional time for sleep. A sleep deprived individual does everything twice as slow.
In addition, it should be noted that sleep plays an important part in growth. 80% of the hormone is being produced during the first phase of sleep.
Leonardo DaVinci had one of the most unusual sleeping habits. He divided his time into short sequences and slept only for 15-25 minutes every four hours. It equaled to 2,5 hours per day.