Conditional reflexes

Conditioned reflexes are complex adaptive reactions of the body, carried out the highest parts of the Central nervous system through the formation of a temporary connection between signal stimulus and supportive to this stimulus is certainly reflex act. Based on the analysis of the formation of conditional reflexes school of I. P. Pavlov was created the doctrine of higher nervous activity (see). Unlike unconditioned reflexes (see), which ensure the adaptation of the organism to constant environmental influences, conditional reflexes allow the body to adapt to changing environmental conditions. Conditioned reflexes are formed on the basis of unconditional reflexes, which requires the coincidence in time of any stimulus from the external environment (conditional stimulus) with the implementation of one or another unconditioned reflex. Conditional stimulus becomes a dangerous signal or a favorable situation, enabling the body to react adaptive reaction.
Conditioned reflexes are unstable and are acquired in the process of individual development of an organism. Conditioned reflexes are divided into natural and artificial. First occur in response to natural stimuli in natural conditions of existence: puppy, first gained meat for a long time sniffs and timidly eats, and this act of eating is accompanied by salivation. In the future, as only the sight and smell of meat cause the puppy licking and secretion of saliva. Artificial conditional reflexes are developed in an experimental setting, when the conditioned stimulus for the animal serves effects, unrelated to unconditional reactions in their natural habitat (eg, flashing lights, the sound of metronome sound clicks).
Conditioned reflexes are divided into food, defensive, sex, estimated depending on reinforcing the conditional stimulus of unconditional reaction. Conditional reflexes can be named depending on the recorded response of the body: motor, secretory, vegetative, excretory and may be indicated by the form of the conditioned stimulus - light, sound and other
For the development of conditioned reflexes in the experiment required number of conditions: 1) the conditional stimulus in time should always be preceded by unconditional stimulus; 2) the conditional stimulus should not be strong enough not to call his own body responses; 3) as the conditional is taken stimulus, usually occurring in the surrounding environment of this animal or person; 4) an animal or person should be healthy, vigorous, and have sufficient forces motivation (see).
There are also conditional reflexes of various generations. With the support of the conditioned stimulus unconditional produced a conditioned reflex of the first order. If the stimulus is reinforced by the conditioned stimulus, which has already produced a conditioned reflex, at first stimulus produces a conditioned reflex of the second order. Conditional reflexes of higher orders are produced with difficulty that depends on the level of organization of a living organism.
The dog can develop conditional reflexes to 5-6 order monkey - up to 10-12 order, and the person to 50-100 order.
The works of I. P. Pavlov and his students found that in the mechanism of occurrence of conditioned reflexes leading role belongs to the formation of functional connections between the centers of excitation from conditional and unconditional stimuli. An important role was given to the cerebral cortex, where conditional and unconditional stimuli, creating pockets of excitement started to interact with each other, creating a temporary connection. In the future, electrophysiological methods study found that the interaction between conditional and unconditional excitations can occur at the level of subcortical structures of the brain, and at the level of the cerebral cortex is the formation of a comprehensive conditioned reflex activity.
However, the cerebral cortex always keeps under control the activities of subcortical formations.
Research activity of single neurons of the Central nervous system microelectrode method it was established that one neuron come both conditional and unconditional excitation (touch-biological convergence). Especially it is clearly expressed in neurons of the cerebral cortex. These data were forced to withdraw from representation of the presence of a bark of a brain lesions conditional and unconditional excitation and to create a theory of convergent circuit of the conditioned reflex. According to this theory the temporal relation between conditional and unconditional excitation occurs in the form of a chain of biochemical reactions in the cytoplasm of the nerve cells of the cerebral cortex.
Modern representations about conditional reflexes has considerably widened and deepened through the study of higher nervous activity of animals in terms of their free natural behaviour. It is established that the environment along with the time factor plays an important role in the behavior of the animal. Any stimulus from the external environment can be conditional, allowing the body to adapt to the environment. As a result of formation of conditional reflexes of the body reacts some time before the impact of unconditional irritation. Hence, conditional reflexes contributed to the success of finding food animals, helps in advance to avoid danger and most completely navigate the changing conditions of existence.