Founder of the reflex theory. Development and the principles of reflex theory

In each biology textbook it is said that the founder of the reflex theory is Ivan Pavlov. This is true, but many researchers have studied the nervous system even before the famous Russian physiologist. Among them the greatest contribution was made by Ivan Pavlov's teacher Ivan Sechenov.

Prerequisites of the reflex theory

The term "reflex" means a stereotyped reaction of a living organism to an external stimulus. Surprisingly, this concept has mathematical roots. The term was introduced into science by the physicist René Descartes, who lived in the 17th century. He tried to explain, with the help of mathematics, the laws by which the world of living organisms exists.

Rene Descartes is not the founder of the reflex theory in its modern form. But he discovered much of what later became a part of it. Descartes was helped by William Garvey, an English physician who first described the circulatory system in the human body. He also presented it in the form of a mechanical system. Later this method will use Descartes. If Garvey transferred his principle to the internal structure of the body, then his French colleague used this design on the interaction of the organism with the outside world. He described his theory with the help of the term "reflex", taken from the Latin language.

Importance of Discoveries of Descartes

The physicist believed that the human brain is the center responsible for communication with the outside world. In addition, he suggested that from it go nerve fibers. When external factors affect the ends of these strands, the signal enters the brain. It was Descartes who became the founder of the principle of materialistic determinism in the reflex theory. The principle is that any nervous process occurring in the brain is caused by the action of the stimulus.

Much later, the Russian physiologist Ivan Sechenov (the founder of the reflex theory) rightly called Descartes one of those scientists on which he relied in his studies. At the same time, the Frenchman had many misconceptions. For example, he believed that animals, unlike people, act mechanically. The experiments of another Russian scientist - Ivan Pavlov - have shown that this is not so. The nervous system of animals has the same structure as a human.

Ivan Sechenov

Another person who made an important contribution to the development of the reflex theory is Ivan Sechenov (1829-1905). He was an educator and the creator of domestic physiology. The scientist was the first in world science to suggest that the higher parts of the brain work only on reflexes. Prior to it, neurologists and physiologists did not raise the question that, probably, all the mental processes of the human body have a physiological nature.

During studies in France, Sechenov proved that the brain affects motor activity. He discovered the phenomenon of central inhibition. His research produced a furore in the then physiology.

Formation of the reflex theory

In 1863 Ivan Sechenov published the book "Reflexes of the brain", which removes the question of who is the founder of the reflex theory. In this work, many ideas were formulated, which formed the basis of the modern theory of the higher nervous system. In particular, Sechenov explained to the public what the reflex principle of regulation is. It consists in the fact that any conscious and unconscious activity of living organisms is reduced to a reaction within the nervous system.

Sechenov not only discovered new facts, but also did a great job of generalizing already known information about the physiological processes inside the body. He proved that the influence of the external environment is necessary both for the usual pulling of the hand, and for the appearance of thought or feeling.

Criticism of Sechenov's ideas in Russia

Society (especially Russian) did not immediately adopt the theory of a brilliant physiologist. After the book "Reflexes of the brain" was published, some articles of the scientist stopped printing in Sovremennik. Sechenov boldly attacked theological church ideas. He was a materialist and tried to prove everything from the point of view of physiological processes.

Despite the ambiguous assessment in Russia, the fundamentals of the theory of reflex activity were warmly received by the scientific community of the Old World. Sechenov's books began to be published in Europe in giant editions. The scientist even for a while transferred his basic research activity to Western laboratories. He worked productively with the French physician Claude Bernard.

Receptor theory

In the history of science, you can find many examples of how scientists have been following the wrong path, offering ideas that did not correspond to reality. This case can be called the receptor theory of sensations, which contradicts the views of Sechenov and Pavlov. What is their difference? The receptor and reflex theory of sensations differently explain the nature of the body's reaction to external stimuli.

Both Sechenov and Pavlov believed that the reflex is an active process. This point of view was fixed in modern science and today it is considered definitively proven. The activity of the reflex is that living organisms react more sharply to some stimuli than to other ones. Nature separates the necessary from the unnecessary. Receptor theory, on the other hand, says that the sense organs react passively to the environment.

Ivan Pavlov

Ivan Pavlov - the founder of the reflex theory on a par with Ivan Sechenov. He studied the nervous system all his life and developed the ideas of his predecessor. This phenomenon attracted the scientist by its complexity. The principles of the reflex theory were proved by the physiologist in an experimental way. Even people far from biology and medicine heard the phrase "Pavlov's dog". Of course, we are not talking about one animal. There are hundreds of dogs that Pavlov used for his experiments.

The impetus for unconditioning reflexes and the final formation of the entire reflex theory was simple observation. Pavlov had already studied the digestive system for ten years and had many dogs in his laboratory, which he loved very much. One day the scientist wondered why an animal had saliva before it was given food. Further observations showed an amazing connection. Saliva began to stand out when the dog heard the clatter of dishes or the voice of the person who brought her food. Such a signal was triggered by a mechanism that caused the production of gastric juice.

Unconditional and conditioned reflexes

The above case interested Pavlov, and he began a series of experiments. What conclusions did the founder of the reflex theory come to? Descartes in the XVII century spoke of the reactions of the body to external stimuli. The Russian physiologist took this concept as a basis. In addition, Sechenov's reflex theory helped him. Pavlov was his direct disciple.

Watching the dogs, the scientist came to the idea of unconditional and conditioned reflexes. The first group included the inherent characteristics of the organism, inherited. For example, swallowing, sucking, etc. Pavlov called conditional reflexes those that a living being receives after his birth from personal experience and the characteristics of the environment.

These qualities are not inherited - they are strictly individual. At the same time, the body can lose such a reflex, if, for example, the environmental conditions have changed, and there is no longer any need for it. The most famous example of a conditioned reflex is Pavlov's experiment with one of the laboratory dogs. The animal was taught that the food is brought after the lamp is turned on in the room. Then the physiologist followed the appearance of new reflexes. And really, soon the dog began to stand out by itself saliva, when she saw the included light bulb. At the same time, she was not given food.

Three principles of theory

The universally recognized principles of the Sechenov-Pavlov reflex theory are reduced to three rules. What are they? The first of these is the principle of materialistic determinism formulated by Descartes. According to him, each nervous process is caused by the action of an external stimulus. On this rule, the reflex theory of mental processes is based.

The second is the principle of structurality. This rule states that the structure of the nervous system departments directly depends on the quantity and quality of their functions. In practice, it looks like this. If the body does not have a brain, then its higher nervous activity is distinguished by its primitive nature.

The last principle is the principle of analysis and synthesis. It consists in the fact that in some neurons there is inhibition, and in others - excitement. This process is a physiological analysis. As a result, a living organism can distinguish between surrounding objects and phenomena.