In total darkness, the brain mobilizes its own previous life and visual experience

In complete darkness, the brain informs the visual system of the situation, which, in his opinion, should be here. In this case, the brain mobilizes its own previous life and visual experience.

How does our brain react to total darkness? Intuitively, it can be assumed that the visual cortex, in the absence of stimuli, will remain silent. In extreme cases, its neurons will become very weak. When researchers first attempted to record the spontaneous activity of brain neurons in the absence of any visual stimuli, they found a strong and coordinated response of the visual centers. This has put them at a dead end. Why does the brain spend time and energy on analyzing the "empty picture" that comes to it from the outside? After some time, neurophysiologists came to the conclusion that the brain at that moment processes not what is in front of the eyes, but what could be.

Work on the analysis of visual information is based on some imaginary models of the surrounding world, which the brain creates all life, based on visual experience. If, for example, we look at a city-type photo, we immediately understand that people in the foreground are much smaller than a bridge or high-rise buildings in the back, although the picture looks the other way around. And if we see in the picture of an elephant standing behind a tree, both its halves will form in our consciousness into one animal; it will never enter our head to accept him for two independent "objects". The brain constantly supplements the missing information and interprets the resulting image on the basis of the previous "pictures of reality".

Several researchers from Cambridge University (Great Britain) suggested that in the dark the brain does not really rest, but gives us some image that we could see, if it were not so dark. The experiment was conducted with several differently aged ferrets and was as follows. The animals were either put in a dark room, or showed them a film, or demonstrated on the screen some unfamiliar objects. All this was accompanied by a recording of the activity of the prefrontal cortex.

As the researchers write in the journal Science, in young animals, brain activity in the dark and activity in response to some visual stimuli sharply differed. But with age, the activity of the brain in the dark increasingly resembled that in response to visual stimuli. Moreover, the spontaneous ("dark") activity of neurons was more like the one that the brain demonstrated in response to the film, rather than the sequence of unfamiliar images.

In other words, when the information is insufficient, the brain tries to fill it with the most natural elements, which, in his understanding, should be present here. And these missing elements he takes, roughly speaking, from the "image bank", which is formed throughout life. It is obvious that the adult ferret fills the surrounding darkness with familiar images, and not with any geometric figures. But the young and inexperienced animals draw the surrounding darkness from nothing: they do not have the necessary vital and visual experience.

The same thing happens with the person: for lack of information, the brain resorts to the models of the surrounding reality that have formed during the lifetime. This, of course, should help in the therapy of various mental disorders like schizophrenia, in which such an internal "world order" is being violated. But at the same time, do many and many social, cultural, and political phenomena of our daily life explain such results? After all, such models can be built not only for the visual system.

[1], [2], [3]