With the morphological maturation of the central nervous system, the development of the higher nervous activity (GNI) of the child also occurs. Most intensively, these processes occur in infants, as well as in the periods of the first and second childhood. In children, the first signal system develops before itself: sensory organs, analyzers, the motor activity of motor actions increases, and so on. Gradually, the second signal system develops: the speech function is improved, the ability to abstract perception of reality, thinking, etc. appears.
The NIS of a person is based on the ability of the brain to perform analytical and synthetic activities. Analytical processes make it possible to separate individual stimuli, whereas synthetic activity unites, generalizes irritation and is realized by a limited set of response reactions of the organism and external influences.
The material basis of all the neural-regulatory processes is reflexes, which are divided into unconditional and conditional. The organism is born with a definite set of unconditioned reflexes, which, above all, ensure the maintenance of vital activity in relatively constant living conditions. These reflexes take place both at the level of somatic and autonomic nervous systems, and provide digestion processes (chewing, sucking, saliva and gastric juice, etc.), protection (coughing, closing of eyes, avoiding pain), sexual relations, thermoregulation , respiration, work of the heart, etc.
Unconditioned reflexes Is the reaction of the body to external or internal stimulation, carried out with the participation of a reflex arc. Conditional reflexes are also responses of the human body to external or internal stimuli, but they are always carried out with the participation of the cortex of the cerebral hemispheres and are realized on the basis of unconditioned reflexes, that is, on the basis of appropriate reflex arcs.
Conditional reflexes are developed in humans in the process of life and provide a more perfect adaptation to the conditions of life. The recognition of food by smell, the processes of standing, running, walking, speech, writing, labor actions are all examples of conditioned reflexes. Conditional reflexes, unlike unconditioned ones, are always individual, they can arise and disappear, they can be processed, etc. To create a conditioned reflex, for example, the saliva is released into the smell of food, certain conditions are necessary. First, the presence of a conditioned stimulus (for example, the smell of food), secondly - the precedence of this stimulus is at least as long as 1-5 seconds. up to an unconditional factor; thirdly, the presence of an unconditioned stimulus or factor (for example, further ingestion of food into the oral cavity with irritation of the corresponding mechanoreceptors to the company, which always induces unconditioned salivation) and, finally, repeated repetition of the conditioned and reinforcing unconditional irritation.
According to P. Pavlov, the material basis of the conditioned reflex is the establishment of temporary neural connections between the nerve centers that receive the conditioned stimulus and the neurons of the center of the corresponding unconditioned reflex through which the conditioned reflex is realized. For example, launching the function of salivating the food smell has the following nervous path: olfactory receptors that perceive the smell impart excitation impulses to the cortical center of smell, and if the smell delicious signal through the intermediate neurons that form the temporary connection is transmitted to the center of salivation , that is, the center of the unconditioned reflex. From this center, the excitation pulses are in turn transferred to the salivary glands and saliva is released, as is usually the case with the unconditioned reflex path when food enters the mouth. "
An important quality of conditioned reflexes is their ability to inhibit, which is distinguished by two types: external (unconditional) and internal (conditional).
External inhibition occurs at the level of the unconditioned reflex arc. In turn, this kind of inhibition is divided into induction and on the beyond. At the basis of induction inhibition is the phenomenon of negative induction, which arises when the dominant excitation changes. A new strong excitation inhibits the previous center of excitation and, accordingly, inhibits the conditioned reflexes that were realized through this center. This type of inhibition underlies the change in attention, activity, directions of search, etc.
The second type of external inhibition is the supernumerary inhibition that occurs when the conditioned stimulus is excessive or prolonged and has a protective value for neurons and nerve centers against possible overstrain and damage. This type of inhibition has a protective function and is manifested, for example, by processes of mental fatigue, a decrease in the rate of reactions, etc.
Internal inhibition develops at the level of temporal neural connections of the conditioned reflex. There are four types of this inhibition: fading, lagging, differential and conditional1 brake. Unlike unconditioned inhibition, which occurs in response to the first presentation of the stimulus, conditioned inhibition is localized in the cerebral cortex and occurs only after preliminary training!
Zgasalne inhibition occurs if the conditioned reflex is not sustained for a long time by an unconditioned stimulus. With the resumption of this reinforcement, the reflex may reappear. This inhibition is the basis of forgetting. In children, extinction develops more slowly than in adults, so the person from childhood remembers well the facts of his entire life. This is also connected with the phenomenon of severity of weaning children from bad habits, wrong movements (including labor, sports), etc.
The inhibition of inhibition of conditioned reflexes develops if the reinforcement of the conditioned stimulus is attributed unconditionally in time. This inhibition restrains until a certain time the implementation of an action in response to irritation and underlies the behavior of people. The inhibition of inhibition in children is produced slowly, more or less its presence is evident after 12-15 years. The development of this type of inhibition is associated with great functional difficulties and requires a long upbringing and training. Only in the senior schoolchildren (15-17 years) there is a certain endurance, the ability to restrain their desires, willpower. Finally, these qualities are formed up to 25-30 years.
Differential inhibition is done by reinforcing some and not reinforcing other irritations. This type of inhibition makes it possible to isolate the signifi- cantly significant signs of one stimulus from many surrounding stimuli and ensures the recognition of sounds, objects, people, etc., that is, it is the basis for the recognition of external information. In children, differentiation is performed from the first months of life.
A conditional brake is produced by using commands that challenge, which can have the form of gestures or words. For example, by swinging the head or gesturing a finger, the mother may order the child not to touch a dangerous object.
All the considered types of inhibition of conditioned reflexes have a predominantly protective value and, thanks to them, the nervous system is protected from unnecessary actions and exhaustion.
A special form of manifestation of GNI is the formation of dynamic stereotypes, which represent a succession of conditionally unconditioned reflex acts performed in a certain sequence automatically and is the result of a complex systemic reaction of the organism to a complex of conditioned stimuli.
Due to the formation of chains of conditioned reflexes (stereotypes), each current activity of the organism becomes a conditioned stimulus for the subsequent activity, and the most reflexes are carried out easily and quickly.
Stereotypes are difficult to develop, they require considerable efforts of cork activity, but in the future they lead to automatism in many actions. The elaborated stereotype is very difficult to change, so we should strive to ensure that children from the very childhood formed only the right and useful stereotypes, because this is the basis of skills and abilities in any activity. Walking, jogging, jumping, sporting exercises, playing on instruments, writing, using a spoon, fork and knife, labor actions are all stereotypes. The formation of a stereotype underlies the regime of the day, provides a certain dynamics of performance in sports and labor.
Conditioned reflex activity of a person largely depends on the individual properties of the nervous system, in turn due to hereditary features of the course of nervous processes. Such a set of properties of the nervous system is called the type of higher nervous activity. According to IP Pavlov, four main types of GNI are distinguished, based on the correlation of the strength, equilibrium and mobility of the processes of excitation and inhibition. Of these, three are considered strong and one is weak.
• I type - sanguine - characterized as a strong, balanced with great mobility of nervous processes ("living" type). Children of this type are able to quickly switch from one type of activity to another, they are balanced, easy to train, consistent;
• II type - choleric - is characterized as strong, unbalanced with exaggeration of excitement over inhibition ("non-trivial" type). Children of this type are emotional, not restrained, chaotic in desires and actions;
• III type - phlegmatic - is characterized as strong, balanced with low mobility of nervous processes. Children with this type of GNI are active and stable when performing complex tasks, always restrained, consistent, reliable and any business is brought to an end;
• IV type - melancholic, or a weak type is inactive, unbalanced. Children with this type of GNI do not tolerate strong and prolonged loads, easily get tired, subject to monotonous work, they all do it slowly.
It is important to note that in humans, unlike animals, there are two signal systems for perceiving external information. The first signal system is characteristic of many animals and people, based on direct perception of environmental factors with the help of sense organs and corresponding systems analyzing this information. The second signal system is based on the perception of information in an abstract way, with the help of concepts that arise through language or other conceptual substances. The second signal system is peculiar only to man and is the basis of theoretical perception of the laws of the world, the basis of thinking and develops in children gradually, together with the accumulation of information in memory media.
On the basis of the interaction and balance of the first and second signal systems of perception of reality, IP Pavlov singled out also types of GNI that are peculiar only to man:
• an artistic type characterized by an exaggeration of the first signal system over the second. To this type of people are people who primarily perceive reality as a whole, sensitive images, having figurative-objective thinking. In people with this type of GNI, the predominant activity of the right hemisphere is observed (they are called right hemispheres and they mainly include actors, artists, designers, etc.)
• creative type, characterized by exaggeration of the second signal system over the first. Such people perceive reality through an analysis of its constituent components, and then they are combined into a single whole. They have a creative nature, are capable of abstract thinking, forecasting, etc. People with this type of GNI have a predominant activity in the left hemisphere (they are called left hemispheres and they are often writers, scientists, etc
• medium type, characterized by a balanced activity of both signal systems and such people are most.
It should be noted that the innate properties of the nervous system for a certain person are permanent, but in social life on their basis I form and the acquired qualities in training, education, self-improvement, arising with the participation of willpower, motivation, etc.
The development of child GNI is not uniform, the rate of formation of conditioned reflexes in the first months of a child's life is slow, but in Unconditional inhibition of conditioned reflexes is inherent in children from the first days of life, whereas conditioned inhibition begins to manifest itself only in 3-4 months: first a differentiated torus develops dix, etc. zapiznyuvalne and then zgasalne. This type of inhibition, like a conditioned inhibition, occurs with the development of the language.
"The first signs of development of the second signal system appear in children in 6-8 months: the child begins to perceive words. The ability of children to speak begins to form in 1-1.2 years and very intensively occurs in the first 3 years of a child's life.
At 5-7 years, children begin to develop reactivity to verbal stimuli, and from this period the second signaling system begins to exercise a regulating effect on the first signaling system. In this condition, the child becomes fit for school. It is of great pedagogical interest that the generalizing function of a word acquires its full meaning only in adults. From the age of 6 children begin to use concepts abstracted from reality. The formation of this quality of GNI is largely due to the growth of inter-neural connections, with the formation of new synapses.
In children 7-9 years of age, positive and negative conditioned reflex connections are formed relatively quickly, and the reflexes themselves become more stable. During this period, the strength, steadiness and mobility of the nervous processes are intensively improved. At the age of 10-12 years, reflexes to a complex of serially acting stimuli can also be formed in a complex and adequate manner, without unnecessary reactions. This shows that at this age children are already able to perceive and analyze a certain amount of complex information, give it their assessment and choose the appropriate behavioral actions.
In the period of 11-14 years, it is known that the sexual maturation of children begins. At this age, among other things, there are significant changes in both the GNI and the cerebral cortex. In subcortical formations, the processes of excitation are exaggerated, inhibition, especially differential inhibition, worsens. As a result, external reactions become inadequate irritation and pass more violently. The rate of formation of conditioned reflexes to stimuli of the first and second signaling systems decreases. Speech becomes slow, with a small set of words; emotionality is significantly increased (especially among girls). The children significantly increase their motor activity and gestures (additional movements of the hands, legs, trunk and head), even to inadequate irritations. At the same time, functional vegetative disorders may arise: dyspnea, pain in the heart, digestive disorders, circulatory disorders, which are associated with a discrepancy in the growth of the morphological and physiological maturation of individual systems, and with the fact that the activity of the subcortical structures of the brain predominate over the bark. Children of this age also experience mental instability, a critical attitude towards adults (especially parents) is growing, is manifested in a general negative.
From the age of 15 the values of the second signal system begin to grow again, the processes of inhibition of conditioned reflexes increase, and the teenager gradually develops into adolescence with a more harmonious ratio of both signaling systems, cortex and subcortical formations.
Features of GNI of adolescents need close attention of educators and parents, as well as the relevant organization of the educational process, rational mental and physical activity.