Sleep is a phenomenon that has always aroused the interest of human beings, as it is a phenomenon as curious as it is disturbing. At first it was believed that it was an almost supernatural state in which man could come into contact with the divinities, and even visualize future events. The rulers had sages who interpreted their dreams to guide them on the best way to lead their nations.
The development of science has made much of this thought disappear and, in turn, has made it possible to know part of the processes that occur during sleep. Still, we are still far from fully understanding them.
The mystery of dreams
Sigmund Freud found in the content of dreams (the dreamlike) a luxurious way to access the human unconscious. Thus he was able to establish that the mind symbolically represented his fears, memories and desires while he slept. He postulated then that the dream content is a kind of puzzle, which can be deciphered.
In the field of psychoneurology, sleep has been approached in a different way. Scientists have studied the changes that occur in the brain when we are asleep. This has allowed them to understand the physiology of sleep and establish some of the processes that occur during it. For this they have used various experiments.
Researchers have found evidence that during sleep the brain processes the information it has acquired during wakefulness. Not only does it reinforce memories, but it also purifies them by taking what is essential and detaching itself from the most irrelevant elements.
But the matter does not end there. It was also found that the brain manages to establish relationships between data and makes an effort to solve problems that may have seemed insoluble to us when we were awake. The case of Friedrich Kekulé is famous , who was able to find the structure of Benzene while he was asleep, although he had not been able to do so while awake.
These findings about sleep seem the product of fiction. But in reality they are the result of hundreds of studies that have been carried out at different times and in various places in the world. First it was Aserinsky and Kleitman, two physiologists at the University of Chicago, who found sleep cycles.
The two researchers were able to verify that during sleep there are phases of 90 minutes each. In REM, or rapid eye movement, brain activity is very similar to what occurs during wakefulness. Between one of these phases there is a “slow wave” activity. This corroborated that the brain is not passive while we are asleep.
These checks were followed by various studies. In 1994 two Israeli neurobiologists discovered that certain intellectual tasks could be performed better if a subject had slept at least six hours. In the years 2000 and 2006, new evidence appeared that allowed us to conclude that memories were fixed and refined during sleep.
The most interesting data appeared in 2007, when it was found that the brain learns while we are asleep. In several experiments that were done first with rats and then with humans, it was concluded that the brain continues to process data during sleep and that it is capable of performing analytical processes to establish patterns. That is why it is possible to solve sleep problems.
Memory is the function of the brain that seems most closely linked to sleep. It is not that while we are asleep there is a greater willingness to learn or memorize. Rather, it is that the brain continues to process what it has learned during the day, polishes it and organizes it. However, there are still many questions that have not been resolved.
The important thing is that, in one way or another, ancient cultures were right in assigning to sleep a more important role than that of simple rest. Perhaps dreams do not put us in conversation with the divinities, but they are a door to the infinite possibilities of the human brain.