The neuroscientist british Matthew Walker , professor at the University of California at Berkeley, is considered to be a "lover" of the dream. Not only of his own (he says that it gives itself the chance not negotiable to get eight hours of sleep every night) but everything that sleep gives us. Two decades ago, has devoted his entire research career to unraveling the why and what we enter in a state which, as explained, has all the appearance of being the most absurd of biological phenomena and one of the most perplexing human behaviours. When we sleep, we cannot look for food or to socialize, or reproduce ourselves, and, worse still, leaves us helpless, vulnerable to predation. And, however, is indispensable.
In his international bestseller "why we sleep" (Captain Swing), Walker, also director of the Center for the Science of the Human Dream, unravels the mysteries of the complex machinery of the dream, from its evolutionary origins and proposes an intriguing theory: go to sleep in the trees to do it on the floor it was precisely the factor that allowed us to develop all our capacities social, emotional and creative and to reach the apex of the pyramid of evolution.Leave branches
there Was a moment in which we colgarnos of the branches to lie on the floor . It is as well as the rest of the human (or a little more elevated, in beds). However, other primates do it in the trees and rarely come down from them to take a nap on the grass. "The great apes construct a nest that is completely new every night," says the neuroscientist. Fortunately, we don't have to assemble the furniture in the bedroom every day after dinner, but aren't our relatives more cautious? When and why did reason let us sleep in the heights?
As the author explains, the trees provide a safe haven for large predators on land, and the fleas and ticks that haunt the ground and suck blood. It is believed that Homo erectus, ancestor of our own species, Homo sapiens, was the first to sleep in the usual way on the floor. The reason were his short arms and his upright position, which made it very difficult for you to hold on the branches without falling off. How he managed to survive without a hyena, a leopard or a saber-toothed tiger, skilled nocturnal hunters, will rebanaran the neck is due, probably, to the fire .REM sleep
Not without some debate, researchers believe that Homo erectus was the first hominid to use fire, an element that allowed us to get down to firm ground, relax and keep us safe. The flames disuadían large carnivores, at the time that the smoke was an effective fumigation system which away small insects.
of Course, as explained Walker, the fire was not the perfect solution, and sleeping on the floor was still dangerous. "This caused an evolutionary pressure for our way of sleeping is becoming more efficient," he says. In this way, the evolution took care of reduce our sleep time, but increasing your intensity with the increase of the amount of REM sleep every night (when sleeping on the ground, as there was no risk of falling and the dream could be deeper). In this way, our dream is concentrated, is made shorter, with plenty of sleep high-quality.Social and intelligent
As explained by Walker, at least two characteristics differentiate humans from other primates: our degree of complexity socio-cultural and our cognitive intelligence . "And I think that both were molded to form causal and beneficial by the hand of the dream, in particular by our high level of REM sleep, in comparison with other mammals," he says.
The phase REM accelerated the complexity and connectivity of the human brain. For a start, recalibrated and tuned in a precise way the emotional circuits of the human brain, which, according to the researcher, could have accelerated the rational control of our primitive emotions initials. "According to my proposal, this change contributed significantly to the rapid conquest on the part of Homo sapiens dominion over all other species," he says in the book.
This phase, the author adds, increases our ability of recognition and management of socioemotional signals of human culture, such as the facial expressions, the gestures, body and even the group behaviors. This allows us to decide and act in a more intelligent . "From this progress of the emotional intelligence provided by the REM sleep emerged a new and much more sophisticated form of socioecología homínida that allowed the creation of large human communities, emotionally astute, stable, and with an intense social cohesion," says the scientist. In his opinion, "this is the most important advantage is never provided by the dream in the entire history of planetary life". And in the same way, "one of the key elements for the survival and hegemony of our species".Creativity
The second contribution of evolutionary fed by the phase REM is the creativity. REM sleep takes the memories fresh and relate to others more ancient, which promotes birth of new ideas and to build broad networks of association information in the brain. "This way, we can wake up the next day and discover that we have found solutions to problems that before seemed insoluble, or that the dream we have been insufflated radically new ideas and original ", he argues. The use of the language and of the tools also has a relationship with the dream.
In turn, the more intensely we used these emotional circuits, and the creative brain during the day, the greater is our need of repair, and recalibrate, with more REM sleep at night, these neural systems are increasingly demanding.
Walker, who also works com scientific of the dream for Google Life Sciences (Verily), believes that the dream is not usually taken into account, but is convinced that contributed to our "amazingly rapid ascent of evolution to the pinnacle of power, giving rise, for good and for bad, to a new superclass dominant social around the world".Date Of Update: 02 October 2019, 14:00