Of all the functions of the brain, consciousness is probably the most difficult to understand.
To figure out how our gray matter copes with this complex function, scientists at the University of Michigan took a closer look at what the brain does when a person goes unconscious.
Everything seems to happen as if at the flick of a switch - click! and you are already unconscious ("passed out"), the main areas of your nervous system are turned off.
Anesthesiologist George Mashour disagrees.
“When I was working as an anesthesiologist, I published a theoretical article in which I suggested that anesthesia does not shut off the brain, but rather isolates processes in certain areas of the brain during anesthesia,” he says.
Like any good scientist, it was not enough for Mashur to simply guess; he wanted to test his hypothesis.
Therefore, together with his colleagues, he conducted a lot of research to find out exactly what happens in the brain when it goes from conscious to unconscious.
In the first study, Mashur and colleagues examined the level of blood flow in certain nerve tissues using magnetic resonance imaging (MRI). They compared the data of 23 patients, some of whom were under anesthesia, others arrived in a vegetative state.
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Scientists have found that in the early stages of unconsciousness, the brain's information processing productivity decreases, with local areas being more connected.
In the second study, scientists took it upon themselves to determine how information is actually inserted into the brain.
Based on the data of the brain encephalogram, the scientists calculated the φ index, which shows the degree of information integration, which is the main condition for the appearance of consciousness in a complex system.
As the brain becomes more and more modular during anesthesia, that is, it “breaks down” into weakly interacting parts, the degree of integration decreases. As a result, in an unconscious state in the central nervous system, effective and active communication is disrupted.
In their final report, the scientists analyzed their findings and summarized their understanding of how our brains work during sleep, general anesthesia, and mental disturbances.
This study may help us gain a better understanding of what patients who do not respond to external stimuli may be aware.
It is becoming more and more obvious that the difference between consciousness and forgetting is much more complex than we thought.
Learning more and more about the processes taking place in the brain, we may one day be able to unravel one of the most mysterious abilities of the brain - namely, the existence of consciousness.
Svetlana Bodrik