Reading aloud It is better to have a look at it than to have heard of it a thousand times, says a Russian proverb. Because then, one could continue, one can make the thing in question, the person, the sight appear again and again in his mind's eye. Scientists at the University of California, Los Angeles, have now found, as "Nature" reports, that in the brain, when imagined, the same neurons work as in real vision.

"Our study shows that the same brain cells firing at the sight of the Mona Lisa image do so when you ask a person to imagine the image of Mona Lisa in their minds, " explains the neurosurgeon and lead author of the Itzhak Fried study. For their analysis, the researchers recorded the activity of 276 individual neurons during several patient examinations.

This was possible because the nine patients suffered from a severe form of epilepsy, which is why they had fine microelectrodes implanted in their brains to detect the centers of their seizures. The electrodes were implanted in those regions responsible for memory performance and social behavior, recording impulses from individual mid-temporal lobe neurons, while asking patients to recall previously viewed images before the mind.

The individual neurons in the different brain regions, it turned out, changed their fire rates depending on the stimulus that the subjects just imagined. After the subjects had been shown a series of images several times - faces, household items, cars, food, animals, and other - and the patients recalled these images from memory, the researchers found that the rate of fire of the brain cells was just mental Imagining was almost as high as when actually viewing the pictures. (Nature of 16.11.00)

Doris Marszk ad

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