It is known that the left and right hemispheres of a person have different functions, which, however, are complementary. Asymmetry is a phenomenon that is inherent in the brain not only of humans, but also of animals. Moreover, the left hemisphere is not a mirror image of the right and vice versa. The hemisphere in which each individual has a center of speech is dominant. In the vast majority of cases, the verbal-logical left hemisphere plays this role.
Hemisphere Relations
There are some interesting facts about the relationships that exist between the two halves of the brain. First, the left hemisphere is always slightly larger than the right. Secondly, in the right hemisphere are long nerve fibers that connect it to the left. And the left, on the contrary, contains a large number of short fibers, which create bonds 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 may be due to genetic characteristics. It is practically not observed in infants. Asymmetry is an acquired quality. In addition, it is proved that among illiterate people it is less pronounced. That is, in the process of learning and acquiring new knowledge, the brain becomes more and more asymmetric. Those who do not pay due attention to education slow down the development of many important functions.
Asymmetry discovery
Asymmetry is a feature that has always interested scientists. But until a certain point, it remained a mysterious object that could cause only a lot of assumptions even among the brightest minds of mankind. The story of the development of this area began with Paul Brock's discovery of the relationship between human speech and the use of right or left hand. This happened in 1861, when a scientist discovered in 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 using a special bundle of neurons - the corpus callosum. Thanks to him, they work seamlessly as a whole. 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.
Split Brain Experiments
Functional asymmetry is manifested 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 recognize only the most common connections. Upon presentation of the most common items - a spoon or a ball of thread - it can attribute them to a certain class. The advantage of the right hemisphere is its excellent spatial orientation. An experiment was performed: patients with a medically split brain were asked with their right hand to assemble the design according to the drawing. 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 experiences
Studies of a split brain have also shown that people with injuries to the right hemisphere are very poorly oriented in space. Often such patients cannot find their way to the house in which they had lived for more than a dozen years.
R. Sperry proved that the following happens when the corpus callosum is cut: processes in the two hemispheres of the brain begin to proceed independently. This is similar to the fact that two different people act independently of each other. According to many scientists, asymmetry is a phenomenon that a person inherited during evolution and is its acquisition.
Agnosia for brain damage
Asymmetry of the brain actually manifests itself most clearly with damage to one of the hemispheres. For example, injuries of the right hemisphere can lead to various types of so-called agnosia. With this disorder, a person is not able to perceive previously familiar information. For example, agnosia on faces is known 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 world and the situation remains absolutely intact.
Two types of thinking
So, the asymmetry of the brain involves the separation of mental functions into two large areas - spatial-shaped thinking and abstract-logical. To these concepts there are many synonyms. For example, the 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 an object in the whole integrity of its properties. The totality of perception is not available 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. He is inherent in the type of thinking “from particular to general,” that is, induction. It processes the entire flow of information from the outside world according to a logical principle. The right hemisphere is responsible for such a mental operation as synthesis. In this case, the parts of the perceived object are combined into a whole. Thinking is carried out according to the deductive principle - from general to particular. The right hemisphere is responsible for metaphorical, figurative thinking.
Interhemispheric asymmetry: other differences
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 does not orient in time: for it there is only “here and now”.
The left hemisphere is focused on reading diagrams, for example, information on geographical maps. The right, on the contrary, is oriented in a specific space, for example, indoors.
There is also a difference between the distribution of the emotion control function in the cerebral hemispheres. The left hemisphere is responsible for positive experiences, the right, on the contrary, for negative ones.
Asymmetry in nature
It should be noted that the phenomenon under consideration is characteristic of many objects of nature. Hemispheric asymmetry is the prerogative of not only man. If symmetry is represented in the structure of molecules and crystals, then asymmetry is in the arrangement of internal organs, the structure of the DNA helix. There is also an asymmetry of hair.
Research in this area leaves many puzzles. But the progress of science does not stand still. Perhaps the knowledge that now seems obvious will become completely obsolete for scientists of the future. Perhaps scientists of the future will be able to finally unravel all the secrets of the highest product of evolution - the human brain.