In recent decades, it has discovered that the intercellular connections of braincells changes the whole life ahead of repetitive activities. Previously it was believed that structural changes in the brain happens in the first three years of life, now they know that the brain structure of a child is very different from the teenager and that the practice of the different activities developed some structures such as the hippocampus.

The hippocampus means sea horse and has a purpose and it is memory and spatial learning belonging to the limbic system (limbic means ring).

The limbic system controls the regulation of motivated behavior, such as fear, hunger, aggression and sexual behavior. The hippocampus has a membrane that consists of three layers and is located in the median all cortex. The hippocampus is one of the structures around the thalamic circuit.

Two-based research on the hippocampus was recorded in London, England. The researches have proved that the hippocampus can grow with the activity.

The first research was undertaken with a group of taxi drivers. A taxi driver in London must memorize more than 25 000 routes, and thus they have developed a huge spatial memory. Their hippocampus has grown, that is, they have a bigger structure than the rest of us. They have a huge spatial memory.

The second group was made by musicians who were pianists and violinists, also in London. It was discovered that they have developed highly specific intercellular contacts at the auditory cortex and sensorimotor cortex, and this has happened because they memorize notes, and the cells present in the motor system also has kept pace and f?rb?ttrats.

In adolescence the brain is changing dramatically and not only because of the hormones, which we previously believed, but because it changes in real life because it is a sensitive Transition Period for the brain. Brain plasticity included the ability to adapt and learn at the repetition of activities. That is, while we are practicing or working out or repeat something several times, we become more skilled and there is no change in our brains. There is another type of plasticity, and it's about every time, as we look at a new face or that we do something new, changed our minds and it happens all the time.

There is research in the United States to prove that we have a social brain. The researches were made with a baby and they learned quickly from one voice of a man than the voice of a computer. We have social brains learn faster when we are in a group and it is thanks to mirror neurons and cerebral cortex. Mirror neurons were discovered by Giacomo Rizzolatti, Leonardo Fogassi and Vittorio Gallese, Universities of Parma in Italy. The cerebral cortex is the outermost part of hj?rnar closest kraniumet, which is stored uppleverser and they are related to each other, such as when a child learns how a chair looks like it may relate to other chairs in the first chair. These social interactions in hj?ran is there from birth. We know that in Sweden the number utnivestitetstudenter each year who are studying via the network. It has nackelar and advantages.

Another research has been done by David Hubel and Wiesel Nils who examined the sensory processing in visual cortex. It was made with cats and small cats lost sight but if the kitten is subjected to an intense training could regain nearly normal vision.

Another important research was carried out with rat pups by Dong Liu in 1997 and it was about a man who kept a rat pup in his hand every day, when the rat mother regained its rat pup, she began to lick it and the intense massage lowered the amount of glucocortikoider of the pup . Glucocortikoider is a hormone produced in the kidney and affects the hippocampal much. Stress increases the hormone and weakens the memory.