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Most of the energy consumed by the brain spends unknown what
The brain takes much more energy than other organs. It takes about 20% of the energy consumed by the human body, although the size of the brain - only 2% of total body weight, according to Faktrum. Imaging shows how distributed and enhanced blood flow in different parts of the brain when it is functioning on a variety of tasks. Increased work of a site requires an increased supply of oxygen, and this increases the volume of local blood flow. Normally, an increase in total is 5-10% of normal. It happens that associated with an increase in blood flow increase in energy consumption by the brain is limited by only one per cent compared to the consumption at rest.
It turns out that most of the energy consumed by the brain spends knows what. Maybe he always handles some coming from outside information, which is not realized person? Or the energy goes into some internal processes that do not depend on the outside world? It seems that the second option is closer to the truth. So, in 1994, US psychologists found that only 10% of the connections between neurons in the visual cortex of monkeys (where, in theory, information is processed by the eye) are involved for the perception of visual stimuli. What occupied the remaining 90% - is unknown. And macaques cortex remains active even under general anesthesia. A recent Belgian researchers using positron emission tomography found that the activity of the visual cortex in the blind from birth is not lower than the sighted.
According to one hypothesis, the brain is constantly in dynamic equilibrium, balancing between excitation and inhibition. Here it goes, and the lion's share of energy consumption - to maintain the system in working order, in constant readiness. According to another hypothesis, the brain is busy all the time prediction of the near future in view of past experience, which transforms large amounts of information. especially intrigued researchers that this mysterious brain activity is uneven, it has tides, though externally in the behavior of resting human or animal, nothing changes.
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