Plan
► Physiology of higher nervous activity is scientific trend of Russian physiological school in study of purposive behavior of animals and humans.
► Concept of conditioned and unconditioned reflexes. Classification of conditioned reflexes. Rules of formation of conditioned reflexes.
► Systemic character of brain activity. Concept of dynamic stereotype.
► Theories of formation of temporary connections underlying conditioned reflexes.
► Cortical inhibition: origination, classification, probable mechanisms.
Physiology of Higher Nervous Activity is Scientific Trend of Russian Physiological School
Physiology of higher nervous activity is a scientific trend of Russian physiological school in study of purposive behavior of animals and humans. One of mechanisms of adaptation of animals and humans to the variable environment is nervous activity based on reflex mechanisms. In the process of the evolution, genetically fixed responses (unconditioned reflexes) have been established that integrate and coordinate functions of different organs and provide adaptation of an organism. In individual life humans and higher animals develop qualitatively new reflex responses that were termed ''conditioned reflexes? by I. Pavlov and were regarded by him as the most perfect form of adaptation.
The main dynamically alternating processes in the CNS are excitation and inhibition. Their interrelations, force and localization determine controlling functions of the cortex. According to I. Pavlov, a functional unit of the higher nervous activity (HNA) is a conditioned reflex.
HNA is a complex of conditioned and unconditioned reflexes and of higher mental functions that provides reasonable behavior under variable natural
and social conditions. First suggestions about the reflex nature of the activity of higher divisions of the brain were made by I. Sechenov, and later on this reflex principle was extended to the mental activity of humans. Sechenov's ideas were experimentally confirmed by I. Pavlov who developed a method of objective evaluation of functions of the higher divisions of the brain - a method of conditioned reflexes.