Asymmetry is ... Interhemispheric asymmetry

It is known that the left and right hemispheres of the person have different functions, which, however, are complementary. Asymmetry is a phenomenon that is inherent in the brain of not only humans, but also animals. And the left hemisphere is not a mirror image of the right and vice versa. The hemisphere, in which every individual has a center of speech, is dominant. In the overwhelming majority of cases, this role is played by the verbal-logical left hemisphere.

Connections between hemispheres

There are several interesting facts about the interrelationships that exist between the two halves of the brain. First, the left hemisphere is always slightly larger in size than the right hemisphere . Secondly, in the right hemisphere there are long nerve fibers that connect it with the left one. And the left, on the contrary, contains a large number of short fibers, which create connections in limited areas.
Asymmetry of the brain is a process, the formation of which takes an average of ten to fifteen years. Sometimes its speed can be due to genetic characteristics. It is practically not observed in infants. Asymmetry is an acquired quality. In addition, it is proved that in illiterate people it is less expressed. That is, in the process of learning and acquiring new knowledge, the brain becomes more asymmetric. Those who do not pay due attention to education, slow down the development of many important functions.

Discovery of asymmetry

Asymmetry is a feature that has always interested scientists. But up to a certain point it remained a mysterious object, which could only provoke a lot of assumptions even in the brightest minds of mankind. The history of the development of this area began with the discovery by Paul Brock of the relationship between the speech of a person and the use of the right or left hand. This happened in 1861, when the scientist discovered from his patient, who suffered from speech loss, lesions in the left hemisphere of the brain.

Also, the connection between the two parts is carried out by means of a special bundle of neurons - the corpus callosum. Thanks to him they work together as a unit. Some seriously ill patients underwent an operation to dissect the corpus callosum. This made it possible to study in more detail the features of the right and left hemispheres.

Experiments with a split brain

Functional asymmetry manifests itself in a completely paradoxical way. For example, it turned out that the left hemisphere is responsible for constructing logical connections, mathematical calculations. It well "understands" any complex speech. The right hemisphere, on the contrary, can identify only the most common connections. When presenting the most common objects - spoons or a tangle of threads - it can refer them to a certain class. The advantage of the right hemisphere is an excellent orientation in space. An experiment was set up: patients with a medically cleared brain were asked to gather the design according to the drawing with their right hand. At the same time, they made many mistakes. This was due to the fact that the left hemisphere is responsible for the right side of the body.

Sperry's experiments

Studies of the split brain also showed that people with injuries of the right hemisphere are very poorly oriented in space. Often, such patients can not find their way to the house in which they had lived more than a dozen years before.
R. Sperry proved that when the corpus callosum is cut, the following occurs: processes in the two hemispheres of the brain begin to proceed independently. It's like that two different people act independently of each other. According to many scientists, asymmetry is a phenomenon that has been acquired by man in the course of evolution and is its acquisition.

Agognosia in case of brain damage

Asymmetry of the brain actually manifests itself most visually when one of the hemispheres is injured. For example, injuries of the right hemisphere can lead to different types of so-called agnosias. In this disorder, a person is not able to perceive previously known information. For example, an agnosia is known to a person, in which the patient does not recognize the faces of familiar people. And this is despite the fact that the memory of other objects of the surrounding world and the situation remains absolutely safe.

Two types of thinking

So, the asymmetry of the brain suggests the division of mental functions into two large spheres - spatial-figurative thinking and abstract-logical. To these concepts there are many synonyms. For example, definitions of verbal and non-verbal thinking, as well as discrete and simultaneous, are similar. The right hemisphere is responsible for simultaneous thinking, because it perceives the object in the whole integrity of its properties. The aggregate of perception is inaccessible to the logically oriented left hemisphere. It analyzes and studies each object separately.

Analysis and synthesis functions

Asymmetry of the brain is responsible for the distribution of functions between the two hemispheres. The left hemisphere is responsible for the analytical processing of information. It is inherent in thinking of the type "from the particular to the general," that is, induction. It processes the entire flow of information from the outside world in a logical way. The right hemisphere is responsible for such a mental operation as synthesis. At the same time, parts of the perceived object are combined into a whole. Thinking is carried out according to the deductive principle - from the general to the particular. The right hemisphere is responsible for metaphorical, imaginative thinking.

Interhemispheric asymmetry: other differences

The perception of current events in chronological order is a function of the left hemisphere. For the right, on the contrary, all events seem to occur simultaneously. It is not oriented in time: for it there is only "here and now".
The left hemisphere is oriented at reading the diagrams, for example, information on geographic maps. The right, on the contrary, is oriented in a specific space, for example, in a room.

There is also a difference between the distribution of the function of controlling emotions in the cerebral hemispheres. The left hemisphere is responsible for positive experiences, the right, on the contrary, for the negative.

Asymmetry in nature

It should be noted that the phenomenon under consideration is characteristic of many objects of nature. Interhemispheric asymmetry is the prerogative not only of man. If the symmetry is represented in the structure of molecules and crystals, then the asymmetry is in the arrangement of internal organs, the structure of the DNA helix. There is also an asymmetry of the hair.

Studies in this area leave a lot of mysteries. But the progress of science does not stand still. Perhaps the knowledge that now seems obvious will become absolutely outdated for scientists of the future. Perhaps the scientists of the future will be able to unravel all the secrets of the higher product of evolution - the human brain.