New discoveries turned into a collapse of old theories and posed even more difficult tasks for scientists. Researchers at Cornell University in New York were able to prove that when certain parts of the brain are turned off, experimental mice begin to confuse bitter and sweet foods. This means that the tongue is just a sensor that supplies information to the insular cortex of the brain, where true taste detection takes place.
Experiments on mice, and then on humans, have shown that receptors on the tongue only serve to collect data on the chemical composition of food. The cerebral cortex is engaged in the interpretation of these data, and the most difficult thing is that it is not the recognition of tastes according to the simple "bitter-sweet" scheme, but the formation of a complex reaction of the body to what has got into the mouth. When analyzing the MRI images of the brain of the subjects during the tests, the scientists encountered extensive "noise" - one stimulus caused several reactions at once.
For example, when something sour is ingested, there is a reaction to the taste itself, plus a reaction of disgust, which creates a combined nervous system response to food. Sweet food causes a clearly visible activity of a part of the insular cortex, which looks like a kind of "spot" in the photographs. However, when comparing the data of different people, it turned out that its location does not coincide. The spot itself, as a reaction to a sweet taste, is always observed, but its size and position in the brain of different people vary greatly.
Scientists have come to an intermediate conclusion: the brain does not define tastes as such. Instead, it uses patterns formed as a given living individual develops to express its response to the analyte. That is, almost everything depends on personal experience, and the saying “there are no comrades for taste or color” is based on real factors. But how exactly these patterns are formed in the brain, how to learn to control them, remains to be seen.