(ORDO NEWS) — The human brain is the command center of the nervous system. It receives signals from the sense organs and transmits information to the muscles, and in certain areas of the left or right hemisphere, depending on the activity, it forms new neural connections, in other words, it learns.
But what if, as a result of treatment for a serious illness, a person did not just turn off part of the brain, but physically removed one of the hemispheres? Is it possible to live with only half a brain, and what kind of life would that be?
You will not believe it, but it will not be so easy to distinguish such a person from a healthy one. This wrinkled and mysterious organ we carry in our skulls has an almost magical ability to change and adapt.
It contains about 86 billion nerve cells – neurons – the same “gray matter”, and the “white matter” consists of billions of dendrites and axons. All this is intertwined with trillions of connections or synapses, and each cell here has a special account.
In 2019, a team of researchers at the California Institute of Technology analyzed the brains of six adults in their 20s and 30s who had undergone a hemispherectomy, a rare neurosurgical procedure that removes half of the brain.
This procedure is indicated in extreme cases of epilepsy and has been carried out since the end of the 19th century. The authors also analyzed the brains of a control group of six healthy individuals who had both hemispheres. All participants underwent functional magnetic resonance imaging.
The results showed that in unihemispheric patients, the brain networks that are responsible for vision, speech and many other functions were surprisingly intact and work in the same way as in healthy people.
Moreover, the authors found that the connection between parts of different networks and their density is actually higher in those patients who underwent hemispherectomy.
Therefore, the brain is able not only to adapt to the conditions, but also to compensate for the loss of the integrity of the organ without loss of functionality.
In 2014, a seven-year-old boy with severe epilepsy had the right occipital lobe, where the visual center is located, and most of his right temporal lobe, where the sound center is located, removed.
The fact is that our brain uses both hemispheres for image processing: the left is responsible for the right side of our visual field, the right for the left side. When we look straight ahead, our brain combines visual information into one picture.
The boy’s brain, in the absence of the right side of the occipital lobe, adapted. Imagine you are taking a panoramic shot and moving your camera around to capture the entire scene. This is how the boy’s visual system began to work.
Moreover, both of his eyes are absolutely healthy and perceive information, but since there is no processing center on the right side of his brain, this information simply has nowhere to go. This is another example of plasticity: brain cells begin to form new neural connections and take on new tasks.
The brain scan of a 29-year-old woman was puzzling to say the least. It turned out that she lacked certain brain structures that are necessary for the perception of smells, but her sense of smell was even better than that of the average person.
Scientists cannot yet fully decipher this phenomenon, but it is absolutely clear that the brain is able to replace idle or missing centers. It was for this reason that another part of the girl’s brain took over the task of processing smells.
Of course, everything is not so simple, the speed and ability to adapt the brain depends on many factors, including age, so scientists from the California Institute of Technology are working on a new study.
They hope to better understand exactly how the brain reorganizes itself after an injury, surgery, or stroke, and how certain areas of the brain are able to compensate for those that are damaged or lost. But the fact remains that without half of the brain, a person is able to live and lead the same way of life as the one who has brains in place.
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