How the brain encodes thoughts

November 23, 2012 20:39

Clearly, all our thoughts and feelings are accompanied by changes in neuronal activity, but this kind of change? As occurs, for example, switching between two possible answers to the question "to drink or not to drink?" Now we have the data in hand, allowing to present some of the neurons that accompanies the decision: researchers from the Massachusetts Institute of Technology (USA) was able to see what happens in the brain of a change in behavior (although the details and all sorts of special cases of this mechanism still have to work and work.)

Perhaps in the future, doctors will be able to read the thoughts of EEG patient.  (Photo bionerd.)

Perhaps in the future, doctors will be able to read the thoughts of EEG patient. (Photo bionerd.)

The experiment used a monkey trained to respond to objects based on their color or spatial location. Imply a certain cognitive task plasticity: animal had to decide which parameter to give preference to any particular case. That is, it was necessary to focus on one type of information, and to ignore the other. At the same time, researchers recorded the electrical activity of neurons in the cerebral cortex. It turned out that each of the tasks in the brain of monkeys meet the definition of a group of neurons.

Waves, which are produced at the time of the activity of the two groups, although of the same beta rhythms markedly different from each other. Some neurons also applies to the other and to the group, but the pattern of their activity was dependent on the current task.

But, apart from beta-rhythms, scientists recorded more and alpha waves, which are included in a group of neurons at the time the alien problem. That is when I had to take into account the color information, "color" the group worked in the beta rhythm, and the one that was responsible for the analysis of the spatial arrangement of objects, acted in the alpha rhythm. Alpha waves are considered to be inhibitory in other words, to form the correct behavior, it is necessary not only to include the correct group of nerve cells, but also turn off those neurons that are to the task irrelevant.

Figuratively speaking, the researchers were able to make an instant picture of brain activity at the time of the decision. It is possible to determine the basic principles of the brain in such moments. First, for different problems, solutions, units of information — in other words, for different thoughts — in the brain correspond different ensembles of neurons, which have their own pattern of activity, depending on the task. Second, the activation of one group of neurons accompanied by suppression of others. This, incidentally, may explain some limitations of our consciousness — we can not simultaneously keep in mind a few more thoughts, or perform many activities at once, or to experience the sensations immediately fifty. Restrictions are hidden in the device brain is still working, one group of nerve cells, others must be silent.

But this is only the mechanism of change, and now have to find out who runs it. That is, that the structure of one neuron to work orders, and others — to rest. Finally, those who form the working groups? .. According to some assumptions, the coordination of neurons carry the deeper structures of the brain such as the thalamus, but it is, as they say, requires confirmation. As for the fact that the activity of neurons to predict the thoughts, feelings and behavior, then it is unlikely to come soon. Diversity of the world around us corresponds to a variety of combinations of neuronal groups, which also can "flow" into one another, and read the thoughts of a drawing of neural activity and when out, then very soon.

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