Congestive excitation in the cerebral cortex. Characteristics of the main processes in the cerebral cortex

In a number of athletes, the increase in excitability of the cerebral cortex can be so great that responses begin to generalize, excessive muscle tension appears, and a certain degree of disinhibition of the nerve centers occurs. More often, these phenomena occur in unprepared athletes. The figure shows electromyograms of athletes of the 3rd category, which reveal on the 4th day of arrival in the middle mountains the vagueness of “volleys” of excitation impulses, residual impulses in pauses between tensions.

The trainer can control the degree of excitability of the central nervous system through physical exercise and short-term ascents to high altitudes. Training work, performed at a calm pace and at a uniform speed, reduces the excitability of the cerebral cortex in those athletes who are in a state of excessive arousal. Short-term ascents to high altitudes can enhance the positive effect of mountain climate on the functional state of the central nervous system.

Reducing the time when altering the signal value of stimuli, reducing the number of errors during the action of positive and negative stimuli, shortening the latent period during the development of tension and relaxation of skeletal muscles (LVH and LVR), increasing the number of movements per unit of time, i.e. increasing a person’s ability to quickly alternate muscle tension and relaxation, acceleration of the process of adaptation of the visual analyzer to varying degrees of illumination indicates an increase in the mobility of nervous processes. In doing so, we proceeded from the position put forward by B. M. Teplov (1956) that mobility in the broad sense of the word should be understood as all those aspects of the work of the nervous system to which the category of speed is applicable. With proper organization of the motor regime, training sessions enhance the positive effect on the mobility of nervous processes.

The convergence of the values of LBH and LBP, the duration of “volleys” of excitation impulses and pauses between them, and the reduction in the number of errors during the action of positive and negative stimuli indicate an improvement in the balance of inhibitory-excitatory processes. Thus, training sessions in mid-mountain conditions in most cases quickly increase the mobility and balance of nervous processes and have a beneficial effect on the properties of the nervous system, which are the most reliable indicator of nervous activity. However, in some cases, a violation of the ratio of inhibitory-excitatory processes was observed. Athletes complained about poor muscle relaxation and the appearance of muscle rigidity. In these cases, the athletes did not adapt well to muscular activity, and special organization of their motor regime was required.

Electromyograms at arbitrary voltages
biceps brachii muscle of athletes
3rd category I-va and T-va

A - in the city of Frunze; B - at an altitude of 2100 m.

The study of the analyzer activity of the cerebral cortex showed that, in general, mid-mountain conditions do not cause significant disturbances in the functions of the visual, motor and vestibular analyzers. During the initial period of acclimatization, the motor analyzer is most susceptible to adverse effects. At the same time, a significant proportion of athletes with an increase in height exhibit an increase in visual acuity and field of vision, the speed of adaptation to various lighting conditions, proprioceptive sensitivity becomes more acute, and the stability of the vestibular apparatus increases. These changes most often occur after the first 5-7 days of staying in the mountains and may indicate an improvement in the state of the athletes’ higher nervous activity and their readiness to begin performing heavy physical activity.

Thus, the results of our studies on the influence of mid-mountain climate and physical work on the higher nervous activity of athletes confirm the position that the cerebral cortex is sensitive to a relatively small decrease in the partial pressure of oxygen (119-125 mm Hg) in the atmospheric air. The direction of these changes largely determines the development of adaptation to muscular activity in the middle mountains.

“Central mountains and sports training”,
D.A.Alipov, D.O.Omurzakov

See also:

The formation of any conditioned reflex in the form of a coordinated response act requires excitation of some cortical nerve centers and inhibition of others. After repeated reinforcement of some and non-reinforcement of others, a strictly specialized reflex is developed precisely to the stimulus that was reinforced. So, excitation and inhibition are the basis of the activity of the cerebral cortex.

Two types of inhibition can develop in the cerebral cortex: unconditioned reflex (b/u) and conditioned reflex (u/p) inhibition (Fig. 13.2).

Fig. 13.2.

Inductive (external) inhibition occurs in cases when, in the cerebral cortex, when an already developed conditioned reflex is triggered, a new, sufficiently strong focus of excitation, not associated with the reflex, appears. For example, during breakfast the doorbell rang. As a result of the emerging orientation reaction, food reflexes are inhibited. According to the mechanism of its occurrence, this type of inhibition is classified as congenital. A new strong focus of excitation in the cortex from an extraneous stimulus causes inhibition of the conditioned reflex (inductive inhibition according to Pavlov). Unconditioned inhibition is called external because the reason for its occurrence lies outside the structure of the conditioned reflex itself.

Increasing irritation or prolonging its action will lead to a decrease or complete disappearance of the effect. This effect is based on extreme inhibition, which I.P. Pavlov called it protective, since it protects brain cells from excessive consumption of energy resources. This type of inhibition depends on the functional state of the nervous system, age, typological characteristics, state of the hormonal sphere, etc. The endurance limit of a cell in relation to stimuli of varying intensity is called the limit of its performance, and the higher this limit, the easier the cells tolerate the effects of super-strong stimuli. Moreover, we are talking not only about the physical, but also about the informational power (significance) of conditioned signals.

This must be taken into account, for example, when determining the amount of work and the intensity of its implementation, especially when working with children. A child’s brain cannot always withstand an information attack. Overload can lead to fatigue and neuroses. An extreme case of extreme inhibition is numbness that occurs under the influence of a super-strong stimulus. A person can fall into a state of stupor—complete immobility. Such conditions arise not only as a result of a physically strong stimulus (a bomb explosion, for example), but also as a result of severe mental shocks (for example, an unexpected message about a serious illness or death of a loved one).

Conditioned inhibition occurs when the conditioned stimulus ceases to be reinforced by the unconditioned, i.e. gradually loses its starting signal value. Such inhibition does not occur immediately, but develops gradually, is developed according to all the general laws of the conditioned reflex and is changeable and dynamic. Such developed inhibition occurs within the central nervous structures, therefore it is internal (i.e., not induced from the outside, but formed within a given temporary connection).

I.P. Pavlov divided conditioned inhibition into four types: extinction, differentiation, conditioned inhibition and delay.

Extinction inhibition develops if the conditioned reflex is not repeatedly reinforced by an unconditioned stimulus. Some time after extinction, the conditioned reflex can be restored. This will happen if the action of the conditioned stimulus is again reinforced by the unconditioned one.

Extinction inhibition is a very common phenomenon and has great biological significance. Thanks to it, the body stops responding to signals that have lost their meaning. Extinction can be explained by the temporary loss of labor skills, the skill of playing musical instruments, and the fragility of knowledge of educational material if it is not consolidated by repetition. Extinction is the basis of forgetting.

Differential inhibition develops when stimuli that are similar in properties to the reinforced signal are not reinforced. This type of inhibition underlies the discrimination of stimuli. With the help of differential inhibition, from the mass of similar stimuli, the one that is reinforced is isolated, i.e. biologically significant. For example, a mother feeds her child with a silver spoon. The sight of this spoon causes corresponding food reactions, but for some time the child was given medicine from a plastic spoon of a similar size and shape. The sight of a plastic spoon gradually begins to cause a negative reaction.

Thanks to differential inhibition, they distinguish sounds, noises, colors, shapes, shades of objects, similar houses, people, and choose the one they need from similar objects. Already from the first months of life, the child begins to develop various differentiations. This helps him navigate the outside world and isolate significant signal stimuli from it. Differential inhibition is based on the process of concentration of excitation in nerve centers.

Continuous, more subtle differentiation of the phenomena of the surrounding world is an important part of human thinking and determines the possibility of learning. By differentiating verbal stimuli, their particular features necessary for the formation of new concepts are revealed.

As an independent type of conditioned inhibition I.P. Pavlov identified a conditioned inhibitor, which is formed when a combination of a positive conditioned signal and an indifferent stimulus is not reinforced. The additional stimulus, at the first moment of its application in combination with a positive signal, causes an orienting reflex and inhibition of the conditioned reaction (inductive inhibition), then turns into an indifferent stimulus and, finally, a conditioned inhibition develops. If an additional stimulus has acquired these properties, then being attached to any other positive signal, it inhibits the conditioned reflex corresponding to this signal. So, having seen delicious sandwiches, we want to try them, but, much to our disappointment, we notice that a green fly, a carrier of infection, has landed on one of them. This causes an inhibition reaction of the food reflex.

This type of inhibition also provides more flexible behavior depending on the action of various environmental factors and the needs of the body; it underlies the ability to stop or not carry out actions in response to prohibitions. An example of stimuli that evoke a conditioned inhibitory reaction are the words “no”, “you can’t”, “stop”, “don’t do something”, etc. Hence it is clear that the development of a conditioned brake plays an important role in the formation of discipline, human behavior, and the ability to obey requirements and laws.

Delay inhibition. When developing this type of inhibition, reinforcement by the corresponding unconditioned reflex is not canceled as in previous types of inhibition, but is significantly delayed from the beginning of the action of the conditioned stimulus. Only the last period of action of the conditioned signal is reinforced, and the long period of its action preceding it is deprived of reinforcement. It is this period that is accompanied by inhibition of retardation. After its expiration, inhibition stops and is replaced by excitation - the so-called reflex phase. So, for athletes with the commands “Attention!”, “To the start!” all body functions are activated, as during the load itself, however, due to delayed braking, the athlete remains motionless at the start. When this inhibition is underdeveloped, he often makes false starts.

In children, delay is developed with great difficulty. The first grader impatiently reaches out his hand, waves it, and gets up from his desk. He knows the answer and wants the teacher to notice him. Only by high school age do children develop such qualities as endurance, the ability to restrain their desires, and willpower. The basis of these qualities is inhibition of delay.

Despite the apparent difference, all types of internal conditioned reflex inhibition have a common similarity, which lies in the fact that they are all developed through repeated exposure to a conditioned reflex stimulus without reinforcement. Inhibitory and excitatory reflexes also have similarities. It lies in the fact that both conditioned reflexes are developed and are signal ones, but with some, excitation develops in the cerebral cortex - these reflexes are called positive; while others are based on inhibition, and they are called negative.

So, inhibition as one of the types of nervous processes is important in the life of the organism. It performs two important functions: protective and corrective.

The protective (protective) role of inhibition is to change the excitatory process to another, more economical one - inhibition. When exposed to extremely strong stimuli, inhibition protects nerve cells from overstrain and exhaustion. Extreme inhibition is of great importance in protecting cells.

The corrective role of inhibition is to bring the reactions and reflexes performed by the body adequately in time and space into accordance with environmental conditions. So, if the developed conditioned reflex has ceased to be reinforced by the unconditioned one, and the conditioned stimulus continues to turn on and cause a significant reaction, in this case the body seems to be making a mistake. Its activities do not correspond to environmental conditions and are therefore uneconomical. This will continue until the conditioned reflex fades away, and the conditioned stimulus causes inhibition. Extinction inhibition corrects the activity of the cerebral cortex in accordance with changed environmental conditions.

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Cerebral cortex is the highest division of the central nervous system , providing, on the basis of innate and acquired functions in ontogenesis, the most perfect organization of the organism’s behavior.

The cerebral cortex has a number of morphofunctional features:

multilayer arrangement of neurons;
modular principle of organization;
somatotopic localization of receptor systems;
screenability - distribution of external reception on the plane of the neuronal field of the cortical end of the analyzer;
dependence of the activity level on the influence of subcortical structures and reticular formation;
the presence of representation of all functions of the underlying structures of the central nervous system;
cytoarchitectonic distribution into fields;
the presence in specific projection sensory and motor systems of the cortex of secondary and tertiary fields with a predominance of associative functions;
the presence of specialized association areas of the cortex;
dynamic localization of functions, expressed in the possibility of compensation for the functions of lost cortical structures;
overlap of zones of neighboring peripheral receptive fields in the cortex;
the possibility of long-term preservation of traces of irritation;
reciprocal functional relationship between excitatory and inhibitory states of the cortex;
ability to irradiate a state;
the presence of specific electrical activity.

The peculiarities of the structural and functional organization of the cerebral cortex are associated with the fact that in evolution there was a corticolization of the functions of the central nervous system, i.e. transferring to it the functions of underlying brain structures. However, this transfer does not mean that the cortex takes over the functions of other structures. Its role comes down to the correction of possible dysfunctions of systems interacting with it, a more advanced, taking into account individual experience, analysis of signals and the organization of an optimal response to these signals, the formation in one’s own and other interested brain structures of memorable traces about the signal, its characteristics, meaning and the nature of the reaction to it. Subsequently, as automation progresses, the reaction begins to be carried out by subcortical structures.

The total area of the human cerebral cortex is about 2200 sq.cm, the number of cortical neurons is more than 10 billion. Pyramidal neurons occupy a significant place in the cellular composition of the cortex. Pyramidal neurons have different sizes, their dendrites carry a large number of spines: an axon (as a rule, it goes through the white matter to other areas of the cortex or to other structures of the central nervous system); stellate cells - have short dendrites and a short axon that provides connections between the neurons of the cortex itself; fusiform neurons - provide vertical or horizontal connections between neurons.

Structure of the cerebral cortex

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The cerebral cortex has a six-layer structure

Upper- molecular layer, is represented predominantly by ascending dendrites of pyramidal neurons; fibers of nonspecific nuclei of the thalamus are also suitable here, regulating the level of excitability of the cortex through the dendrites of this layer.
Second layer - outer grain ty, consists of stellate cells that determine the duration of circulation of excitation in the cerebral cortex and are related to memory.
The third layer is the outer pyramidal, is formed from small pyramidal cells and functionally, together with the second layer, provides cortico-cortical connections of various convolutions of the brain.
The fourth layer is internal granular, contains stellate cells, specific thalamocortical pathways end here, i.e. pathways starting from analyzer receptors.
The fifth layer is the inner pyramidal, a layer of large pyramids, which are output neurons, their axons go to the medulla oblongata and spinal cord.
Sixth layer- polymorphic adhesives current. Most of the neurons in this layer form corticothalamic tracts.

The neuronal composition and its distribution among layers differ in different areas of the cortex, which made it possible to identify in the human brain 53 cytoarchitectonic fields. Moreover, the division into cytoarchitectonic fields is formed as the function of the cortex improves in phylogenesis.

Primary auditory, somatosensory, skin and other fields have adjacent secondary and tertiary fields that provide association of the functions of a given analyzer (sensory system) with the functions of other analyzers. All analyzers are characterized by the somatotopic principle of organizing the projection of peripheral receptor systems onto the cortex. Thus, in the sensory cortex of the second central gyrus there are areas of representation of each point of the skin surface, in the motor cortex each muscle has its own topic, its own place, by irritating which one can obtain the movement of this muscle; in the auditory cortex there is a topical localization of certain tones (tonotopic localization). There is a precise topographic distribution in the projection of the retinal receptors onto the 17th visual field of the cortex. The death of the local zone of the 17th field leads to blindness if the image falls on a section of the retina projecting onto the damaged zone of the cortex.

Features of the cerebral cortex

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Screen operating principle

A special feature of cortical fields is the screen principle of their functioning. This principle lies in the fact that the receptor projects its signal not onto one cortical neuron, but onto their field, which is formed by collaterals and connections of neurons. As a result, the signal is focused not point to point, but on many neurons, which ensures its complete analysis and the possibility of transmission to other structures interested in the process. The screen principle is implemented thanks to a special organization of the interaction of input and output elements of the cortex.

Input(afferent) impulses enter the cortex from below, ascend to the stellate and pyramidal cells of the 3-4-5 layers of the cortex. From the stellate cells of the 4th layer, the signal goes to the pyramidal neurons of the 3rd layer, and from here - along the associative fibers - to other fields, areas of the cerebral cortex. Stellate cells of field 3 switch signals going to the cortex to pyramidal neurons of layer 5, from here the processed signal leaves the cortex to other brain structures.

In the cortex, input and output elements, together with stellate cells, form the so-called « speakers» - functional units of the cortex, organized in a vertical direction. Proof of this is that if the microelectrode is immersed perpendicularly into the cortex, then on its way it encounters neurons that respond to one type of stimulation, but if the microelectrode goes horizontally along the cortex, then it encounters neurons that respond to different types of stimuli.

The column has a diameter of about 500 µm and is determined by the distribution zone of collaterals of the ascending afferent thalamocortical fiber. Adjacent columns have relationships that organize sections of multiple columns in the organization of a particular reaction. Excitation of one of the columns leads to inhibition of neighboring ones. Each column can have a number of ensembles that implement any function according to the probabilistic-statistical principle. This principle lies in the fact that not the entire group of neurons, but only part of it, participates in the reaction upon repeated stimulation, and in each case this part of the participating neurons may be different. To perform the function, it is formed group of active neurons, statistically sufficient to provide the required function (static principle).

Areas of the cerebral cortex

The presence of structurally different fields also implies their different functional purposes. Thus, in the cerebral cortex in the occipital lobe there is a visual area that perceives visual signals (field 17), recognizes them (field 18), and evaluates the meaning of what is seen (field 19). Damage to field 18 leads to the fact that a person sees, but does not recognize objects, sees written words, but does not understand them. In the temporal lobe of the cortex there are 22, 41, 42 fields involved in the perception and analysis of auditory stimuli and the organization of auditory control of speech. Damage to field 22 leads to impaired understanding of the meaning of spoken words. The cortical end of the vestibular analyzer is also localized in the temporal lobe. The parietal lobe of the brain is associated with somatic sensitivity related to speech function. Here the effects on skin receptors, deep sensitivity receptors are assessed and the weight, surface properties, shape, and size of the object are assessed. In the frontal region there are centers for coordination of movements, including speech.

The distribution of functions across brain regions is not absolute: almost all brain regions have polysensory neurons, i.e. neurons that respond to various stimuli. Hence, if, for example, field 17 of the visual area is damaged, its function can be performed by fields 18 and 19. In addition, different motor effects of irritation of the same point of the cortex are observed depending on the current activity. If the operation of removing one of the cortical zones is carried out in early childhood, when the distribution of functions is not yet rigidly fixed, the restoration of the function of the lost area occurs almost completely. All of these are manifestations of mechanisms of dynamic localization of functions that make it possible to compensate for functionally and anatomically disturbed structures. The mechanism of dynamic localization of functions is manifested by the fact that in the cortex there is a sequential overlap of peripheral receptive fields.

Preservation of traces of excitation

A feature of the cerebral cortex is its ability to maintain traces of excitement.

In the spinal cord, after irritation, trace processes persist for seconds;
In the subcortical-stem regions - in the form of complex motor-coordinating acts, dominant attitudes, emotional states, these processes last for hours;
In the cerebral cortex, trace processes can persist throughout life.

This property gives the cortex exceptional importance in the mechanisms of processing and storing information and accumulating a knowledge base. The preservation of traces of excitation in the cortex is manifested in fluctuations in cycles of the level of excitability of the cortex, which last in the motor cortex for 3-5 minutes, in the visual cortex - 5-8 minutes.

The main processes occurring in the cortex are realized in two states: excitement Andbraking. These states are always reciprocal. They arise, for example, within the motor analyzer, which is always observed during movements; they can also arise between different analyzers. The inhibitory influence of one analyzer on others ensures narrowing and focusing attention on one process. Reciprocal activity relationships are often observed in neighboring neurons.

The relationship between excitation and inhibition in the cortex manifests itself in the form of the so-called lateral inhibition. During lateral inhibition, a zone of inhibited neurons is formed around the excitation zone, and it is, as a rule, twice as long as the excitation zone. Lateral inhibition provides contrast in perception, which, in turn, makes it possible to identify the perceived object.

In addition to lateral spatial inhibition, inhibition of activity always occurs in the cortex after excitation, and vice versa, after inhibition - excitation (serial induction). In cases where inhibition is unable to restrain the excitatory process in a certain zone, irradiation WHOawakening in the cortex. Irradiation can occur along the cortex from neuron to neuron, along the systems of associative fibers of the 1st layer, then it has a very low speed - 0.5-2.0 m per second. Irradiation of excitation is also possible due to axon connections of pyramidal cells of the 3rd layer of the cortex between neighboring structures, including between different analyzers. Irradiation of excitation ensures the relationship between the states of cortical areas during the organization of conditioned reflex and other forms of behavior.

Along with the irradiation of excitation, which occurs due to impulse transmission of activity, there is braking irradiation along the bark. The mechanism of irradiation of inhibition is the transfer of neurons into an inhibitory state, due to the inhibition of axons coming to them, their synapses.

Assessing the functional state of the human cerebral cortex is a difficult and still unsolved problem. One of the approaches that indirectly indicates the functional state of the brain and its structures is the registration of oscillations in them electrical potentials.

Each neuron has a membrane charge; when the neuron is activated, this charge is generated in the form of pulse discharges; when braking, the membrane charge often increases and its hyper polarization. The glia of the brain also have a charge on the membranes of their stellate elements. The charge of the membrane of neurons, glia, its dynamics, the processes occurring in synapses, dendrites, axon hillock, in the axon - all these are constantly changing, diverse and multidirectional processes in sign, intensity, and speed. Their integral characteristics depend on the functional state of the nervous structure and determine in total its electrical parameters. These indicators, if they are recorded through microelectrodes, reflect the activity of a local (up to 100 µm in diameter) part of the brain and are called focal activity.

If the recording electrode is located in the subcortical structure, the activity recorded through it is called subcorticogram, if the electrode is located in the cerebral cortex - corticogram.

Basic rhythms of the cerebral cortex

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Finally, when the electrode is located on the surface of the scalp, total activity, in which there is a contribution from both the cortex and subcortical structures. This manifestation of activity is called electroencephalogram(EEG) (Fig. 15.6 Basic rhythms of the electroencephalogram).

All types of brain activity are dynamically subject to intensification and weakening and are accompanied by certain rhythms of electrical oscillations.

At rest in a person, in the absence of external irritations, slow rhythms predominate. This is reflected in the EEG in the form of the so-called alpha rhythm, the oscillation frequency of which is 8-13 oscillations per second, and their amplitude is approximately 50 µV.

A person’s transition to activity leads to a change in the alpha rhythm to a faster one beta rhythm, having a frequency of 14-30 oscillations per second, the amplitude of which reaches 25 µV.

The transition from rest to sleep is accompanied by the development of a slower rhythm - theta rhythm- 4-7 vibrations per second, or delta rhythm- 0.5-3.5 vibrations per second. The amplitude of slow rhythms ranges from 100-300 µV.

In the case when, against the background of rest or another state of the human brain, irritation is presented, for example, light, sound, electric current, then the so-called evoked potentials(VP). The latent period and amplitude of evoked potentials depend on the intensity of the applied stimulation; their components, number and nature of oscillations depend on the adequacy of the stimulus.

Lecture topic: “Neuroleptics, tranquilizers, sedatives.”

Neuroleptics

Currently, the group of antipsychotics includes about 500 drugs.

Classification

A. “Typical” B. “Atypical”

neuroleptics: neuroleptics:

-aminazine - azaleptin

Triftazin

Haloperidol

Droperidol

The ancestor of neuroleptics is aminazine, which was synthesized in 1950 by Charpentier (France), and studied by Courvoisier.

Drugs	Mechanism of action	Application
Aminazin (Aminazinum) etc. 0.025; 0.05; 0.1; amp. 2.5% 1 ml, 2 ml, 5 ml., IM and IV	1. Antipsychotic effect (elimination of delusions, hallucinations) appears after 1-2 weeks. after starting treatment. 2.Sedative effect (elimination of fear, anxiety, restlessness) appears after 15 minutes. after intramuscular injection. 3. Antiemetic effect (eliminates and prevents vomiting and hiccups of central origin). 4. Potentiating effect. 5. Hypotensive effect (BP) 6. Hypothermic effect (t) 7. Reduces skeletal muscle tone	Psychoses (schizophrenia, epilepsy, manic-depressive psychosis, alcoholic psychosis - delirium tremens). Psychoses, neuroses (neurasthenia, hysteria, obsessive-compulsive neurosis). Uncontrollable vomiting of pregnant women, trauma, brain tumors, radiation sickness, vomiting caused by treatment with anticancer drugs. Enhances the effect of anesthesia, sleeping pills, analgesics, etc. Hypertensive crisis (rare). As part of a lytic mixture for hyperthermic syndrome (rarely).

Side effects: drowsiness, lethargy, with prolonged use depression, orthostatic collapse, liver damage, hematopoietic disorders, allergic reactions, parkinsonism, dyspeptic disorders are possible. Locally: development of dermatitis, with intramuscular injection - painful infiltrates, with intravenous administration - thrombophlebitis.

Triftazin (Triftazinum), tab., solution in ampoules; i/m. Haloperidol (Haloperidolum); tab., solution in bottle, 10 ml (orally), solution in ampoules; IM and IV Droperidol (Droperidolum); 0.25% solution in amp. 2 ml and 5 ml, in a bottle of 5 ml; s/c, i/m, i/v.	1. Antipsychotic effect 2. Antiemetic effect is more pronounced than that of aminazine. 3. The remaining properties are weakly expressed or absent. 1. Antipsychotic effect, relieves hallucinations faster than delirium (50 times superior to chlorpromazine). 2. Sedative effect 3. Antiemetic effect (50 times superior to aminazine). 4. Potentiating effect. 5. Anticonvulsant effect. Other effects inherent to aminazine are weakly expressed. 1. Antipsychotic effect, 2. Sedative effect 3. Antiemetic effect 4. Potentiating effect, for example fentanyl + droperidol = thalamonal 5. Hypotensive effect. The action develops within 5-15 minutes and lasts 3-5 hours.	See aminazine -//- -//- See aminazine Vomiting of various origins. See aminazine -//- See aminazine In anesthesiology for analgesia in preparation for and after surgical interventions, in preparation for instrumental studies, for injuries, myocardial infarction. Hypertensive crisis
Side effects: depression, parkinsonism phenomenon, hypotension, respiratory depression.
Azaleptin(Asaleptinum); tab.0.025 and 0.1; amp.2.5% - 2ml; i/m	1. Antipsychotic effect is strongly expressed 2. Sedative and hypnotic effect. 3. Strengthens the effect of sleeping pills and analgesics. 4. Relaxes skeletal muscles. Other effects inherent to aminazine are not expressed	See aminazine -//- -//- -//-

The dosage regimen is set individually, starting with small doses, which are gradually increased. The daily dose can be used once before bedtime or 2-3 times a day after meals.

After achieving a therapeutic effect, the dose is reduced and switched to a maintenance course.

Side effect: drowsiness, headache, muscle weakness, tachycardia, hypotension, dry mouth, impaired accommodation, sweating, weight gain, decreased potency, blood depression.

The phenomenon of parkinsonism is not noted.

Contraindications: pregnancy (first 3 months), lactation period, children under 5 years of age, glaucoma, myasthenia gravis, blood depression, driving, etc., epilepsy, alcoholic psychosis.

Tranquilizers

I. Derivatives II. "Daytime" tranquilizers

benzodiazepine - rudotel

Phenazepam - Grandaxin

- sibazon (seduxen,

diazepam,

relanium)

- nozepam (tazepam)

Alzolam

Side effects: drowsiness, headache, dizziness, ataxia (unsteadiness of gait), allergic reactions, menstrual irregularities, decreased potency, in large doses amnesia is possible, with long-term use (up to 6 months) addiction and addiction occurs, withdrawal syndrome.

Contraindications: damage to the liver, kidneys, myasthenia, in the process of work requiring quick reaction and coordination of movements, it is forbidden to combine with alcohol, the first 3 months. pregnancy.

“Daytime” tranquilizers do not have a hypnotic effect and do not cause muscle relaxation.

Side effects of Grandaxin: allergic reactions, increased excitability.

Contraindicated during pregnancy.

Sedatives

The drugs of this group regulate the processes of inhibition and excitation in the cerebral cortex.

is a powerful focus of excitation in the cerebral cortex, causing inhibition in the surrounding areas of the cortex according to the law of negative induction.

A completely different type of absent-mindedness is observed in cases where a person is not able to concentrate on anything for a long time, when he constantly moves from one object or phenomenon to another, without stopping at anything. This type of absent-mindedness is called genuine absent-mindedness. The voluntary attention of a person suffering from genuine absent-mindedness is characterized by extreme instability and distractibility. Physiologically, genuine absent-mindedness is explained by insufficient strength of internal inhibition. Excitation arising under the influence of external signals spreads easily, but is difficult to concentrate. As a result, unstable foci of excitation are created in the cerebral cortex of an absent-minded person.

The reasons for genuine absent-mindedness are varied. They may be a general disorder of the nervous system, blood diseases, lack of oxygen, physical or mental fatigue, severe emotional experiences. In addition, one of the reasons for genuine absent-mindedness may be a significant number of impressions received, as well as the disorder of hobbies and interests.

14.4. Development of attention

Attention, like most mental processes, has its own stages of development. In the first months of life, the child has only involuntary attention. The child initially reacts only to external stimuli. Moreover, this only happens if they change abruptly, for example, when moving from darkness to bright light, with sudden loud sounds, with a change in temperature, etc.

Starting from the third month, the child becomes increasingly interested in objects that are closely related to his life, that is, those closest to him. At five to seven months, the child is already able to look at an object for a long time, feel it, and put it in his mouth.

His interest in bright and shiny objects is especially noticeable. This suggests that his involuntary attention is already quite developed.

The rudiments of voluntary attention usually begin to appear towards the end of the first - beginning of the second year of life. It can be assumed that the emergence and formation of voluntary attention is associated with the process of raising a child. The people around the child gradually teach him to do not what he wants, but what he needs to do. According to N. F. Dobrynin, as a result of upbringing, children are forced to pay attention to the action required of them, and gradually, consciousness begins to manifest in them, still in a primitive form.

Play is of great importance for the development of voluntary attention. During the game, the child learns to coordinate his movements in accordance with tasks and; ry and direct their actions in accordance with its rules. Parallel

Chapter 14. Attention 371

with voluntary attention, based on sensory experience, involuntary attention also develops. Acquaintance with more and more objects and phenomena, the gradual formation of the ability to understand the simplest relationships, constant conversations with parents, walks with them, games in which children imitate adults, manipulation of toys and other objects - all this enriches the child’s experience, and together thereby developing his interests and attention.

The main feature of a preschooler is that his voluntary attention is quite unstable. The child is easily distracted by extraneous stimuli. His attention is overly emotional - he still has poor control of his feelings. At the same time, involuntary attention is quite stable, long-lasting and concentrated. Gradually, through exercise and volitional efforts, the child develops the ability to control his attention.

School is of particular importance for the development of voluntary attention. During school, the child learns discipline.

He develops perseverance and the ability to control his behavior. It should be noted that at school age the development of voluntary attention also goes through certain stages. In the first grades, the child cannot yet fully control his behavior in class. He still has involuntary attention. Therefore, experienced teachers strive to make their classes bright and captivating the child’s attention, which is achieved by periodically changing the form of presentation of educational material. It should be remembered that a child at this age thinks mainly visually and figuratively. Therefore, in order to attract the child’s attention, the presentation of educational material must be extremely clear.

In high school, the child's voluntary attention reaches a higher level of development. The student is already able to engage in a certain type of activity for quite a long time and control his behavior. However, it should be borne in mind that the quality of attention is influenced not only by the conditions of upbringing, but also by age characteristics. Thus, physiological changes observed at the age of 13-15 years are accompanied by increased fatigue and irritability and in some cases lead to a decrease in attention characteristics. This phenomenon is due not only to physiological changes in the child’s body, but also to a significant increase in the flow of perceived information and impressions of the student.

L. S. Vygotsky tried, within the framework of his cultural-historical concept, to trace the patterns of age-related development of attention. He wrote that from the first days of a child’s life, the development of his attention occurs in an environment that includes the so-called double row of incentives, causing attention. The first row is the objects surrounding the child, which with their bright, unusual properties attract his attention. On the other hand, this is the speech of an adult, the words he pronounces, which initially appear in the form of stimulus-instructions that direct the child’s involuntary attention. Voluntary attention arises from the fact that people around the child begin, with the help of a number of stimuli and means, to direct the child’s attention, direct his attention, subordinate it to their will, and thereby put into the child’s hands those means, with the help of