ASSESSMENT OF FUNCTIONAL ASYMMETRY USING DIFFERENT METHODOLOGICAL APPROACHES

ASSESSMENT OF FUNCTIONAL ASYMMETRY USING DIFFERENT METHODOLOGICAL APPROACHES

Published in 2015, BIOLOGICAL SCIENCES, Issue August 2015 | No comments yet

Anisimova N.V.

Postgraduate student of the Department of Biology and Fundamentals of Medical Knowledge of the Chuvash State Pedagogical University named after I.Ya. Yakovleva, Cheboksary

ASSESSMENT OF FUNCTIONAL ASYMMETRY USING DIFFERENT METHODOLOGICAL APPROACHES

annotation

The purpose of this work is to assess functional asymmetry (FA) using N.N. Bragina and T.A. Dobrokhotova and the Edinburgh questionnaire. The study involved 37 schoolchildren aged 7 to 16 years. According to the results obtained using the methods of N.N. Bragina and T.A. Dobrokhotova to determine manual asymmetry, 30 schoolchildren are right-handed, 4 are left-handed and 3 are ambidextrous. According to the results of the Edinburgh testing, it was revealed that 31 schoolchildren have a leading right hand, 5 schoolchildren are left-handed and 1 is ambidextrous. The results of the correlation analysis show incomplete consistency between the indicators that determine physical activity using different methods.

Key words: functional asymmetry (FA), motor asymmetry, sensory asymmetry, asymmetry coefficient, “handedness”.

Anisimova NV

The graduate of department of biology and basic medical knowledge Chuvash state pedagogical university named by IY Yakovlev, Cheboksary

THE FUNCTIONAL ASYMMETRY ASSESSMENT BY DIFFERENT METHODS

Abstract

The purpose of this research is the functional asymmetry assessment by means of Edinburgh test and Bragina and Dobrohotova tests. Functional asymmetry research was held among 37 schoolchildren in age from 7 to 16. According to the results the padding block questions development by Bragina and Dobrohotova, 30 students are right-handed, 4 are left-handed and 3 are the ambidexters. , we have identified by the Edinburgh questionnaire, that 31 students have the leading right hand, 5 students are left-handed and 1 is the ambidexter. The results of correlation analysis show the partial coherence between FA indexes.

Keywords: functional asymmetry of brain, motor asymmetry, sensory asymmetry, index of asymmetry, handedness.

Relevance of the problem under study. The most important manifestations of FA are structural and functional differences between the left and right hemispheres of the human brain [8]. FA manifests itself in the form of pronounced specificity of information processing, reactivity and cognitive sphere in people with dominance of the right or left hemisphere [7]. To date, science has used two approaches to assess interhemispheric differences: the method of determining “handedness” through a survey (Edinburgh test) [11], and the method of actively identifying motor and sensory asymmetry by N.N. Bragina and T.A. Dobrokhotova [1]. The Edinburgh test is widely used in the world: it is used in the study of behavior [4], emotions [10] and as a preliminary test for selecting participants in neuroimaging studies [3]. Tests to determine the leading limbs and leading eye were used to assess the influence of brain lateralization on intelligence and mathematical abilities [9], to study the adaptive capabilities and physical development of boys and girls, as well as the formation of stress resistance of the body [2], [5]. It follows that both methods are widely represented in modern scientific literature, but we have not found any work that would evaluate the relationship between the results of testing functional asymmetry of the brain using the Edinburgh test and tests for determining motor and sensory asymmetry. Based on this, the purpose of our work is to assess functional asymmetry using N.N. Bragina and T.A. Dobrokhotova and the Edinburgh questionnaire.

Materials and research methods. The study involved schoolchildren from the Municipal Budgetary Educational Institution “Secondary School No. 31 with in-depth study of individual subjects” in Cheboksary, aged from 7 to 16 years, a total of 37 students. The average age was 12±0.4 years.

At the first stage of the study, schoolchildren answered questions from the Edinburgh test [11]. At the same time, their parents were responsible for children under 13 years of age. The Edinburgh questionnaire, adapted by us for schoolchildren, consists of fourteen questions about the preference for using the right or left hand when performing certain actions, such as writing, drawing, sewing, combing hair, brushing teeth, using a spoon or fork, etc. (Table 1).

Table 1 – Questionnaire for students

To determine manual and sensory asymmetry, N.N. tests were used. Bragina and T.A. Dobrokhotova [1].

Functional studies were carried out in the first half of the day, under conditions that meet the hygienic requirements for educational institutions [6]. The study complied with the ethical requirements set out in the Declaration of Helsinki.

The functional asymmetry coefficient was calculated based on answers to the Edinburgh questionnaire using formula (1):

Formula 1),

where H is the coefficient of functional asymmetry, X(i,R) and X(i,L) is the number of “+” signs in the “Right hand” and “Left hand” columns, respectively.

The coefficient of manual asymmetry (CMA) was determined according to formula (2):

formula (2),

where KMA is the coefficient of manual asymmetry, Nп is the number of actions performed by the right hand, Nт is the number of proposed tests.

The sensory asymmetry coefficient was calculated using formula (3):

formula (3),

where Nп is the number of actions performed by the right side of the body, Nт is the number of tests offered.

The total asymmetry is the sum of the KMA and SA coefficients (formula (4)).

formula (4),

where OA is general asymmetry, KMA is the coefficient of manual asymmetry, SA is sensory asymmetry.

Statistical processing of the study results was carried out using the Spearman correlation coefficient.

Research results and discussion. The frequency of occurrence of answer options for Edinburgh test questions is presented in table. 2.

Table 2 - Manual preferences revealed by the results of the Edinburgh test

As follows from the data given in Table 2, students perform most actions with their right hand.

Having analyzed the results obtained during testing using the Edinburgh questionnaire, we came to the conclusion that the majority of children who took part in the study have a pronounced predominance of the right hand: the average value of the asymmetry coefficient is 83.8%, the proportion of schoolchildren with a dominant right hand was 83.8%, with a preference for the left hand when writing and performing various types of work - 13.5%, using both hands with equal success - 2.7%. The distribution of the values ​​of the asymmetry coefficient calculated according to formula 1 is presented in Fig. 1.

Rice. 1 – Individual profiles of “handedness” based on answers to questions in the Edinburgh questionnaire (from left to right – X(i,R), X(i,L), H).

In the course of analyzing tests for motor asymmetry, we found that the majority of students perform tasks with their right hand (83.8% of cases), and the left hand was dominant in only 13.5%. In the course of analyzing the results of tests to identify sensory asymmetry, we found that for the majority of students the leading eye is the right eye (59.5%), and the left is only for 40.5% of students, in 81.1% of cases the leading ear is right.

Based on the coefficient of manual asymmetry, we determined that two children (5.4%) had almost complete left-handedness, the other two schoolchildren had strong left-handedness. The number of ambidextrous people was 3 (8.11%), and the proportion of children who had pronounced right-handedness was 9 (24.32%). In terms of manual asymmetry, the majority of schoolchildren we examined (21 or 56.76%) were strongly right-handed, although we did not find any schoolchildren who performed all tests with their right hand and had a dominant right leg.

The severity of sensory asymmetry was 32.97%. The left sensory fields were dominant in 8 (21.61%) children. The predominance of sensory flows on the right was noted in 29 (77.92%) schoolchildren.

The average value of complete asymmetry was 42.48%: 2 (5.4%) schoolchildren with almost complete left-handedness, 2 (5.4%) with strong left-handedness, 2 (5.4%) ambidextrous, 9 (24.32%) with pronounced right-handedness and 22 (59.46%) with strong right-handedness.

The main objective of our work is to study the relationship between the results of testing functional asymmetry of the brain using various methods by calculating the Spearman correlation coefficient.

The results of the analysis of the relationship between the H coefficient of the Edinburgh questionnaire, on the one hand, and the coefficients of motor and sensory asymmetry according to the method of N.N. Bragina and T.A. Dobrokhotova are presented in Fig. 2.

Rice. 2 – Correlation connections between the coefficient N and the coefficient of motor asymmetry (A), the coefficient of sensory asymmetry (B)

From the data in Figure 2 it follows that there is a statistically significant correlation between the H coefficient and the motor asymmetry coefficient (R = 0.58; P <0.05); We did not find such a connection in the case of sensory asymmetry (R=0.18, P>0.05). This indicates that the results of testing using the Edinburgh questionnaire are not sufficient to obtain a complete picture of functional asymmetry of the brain.

Summary.

The data we obtained indicate left hemisphere dominance in schoolchildren, both according to the results of a study using the methods of Bragina and Dobrokhotova, and according to the results of the Edinburgh questionnaire. Although the coefficient of manual asymmetry and the coefficient of handedness are related to each other, the dominance of the right hand, revealed by the results of answers to questions, and the nature of sensory asymmetry are not consistent with each other. In addition, we noted individual cases of discrepancy between answers to the questionnaire and real preference for the right and left hands. Based on this, we consider it necessary to conduct additional research to improve the Edinburgh questionnaire.

Literature

1. Bragina, N. N. Functional asymmetries of man / N. N. Bragina, T. A. Dobrokhotova. – 2nd ed. reworked and additional – M.: Medicine, 1988. – 237 p.
2. Lisova N.A. and others. The role of activation processes of the cerebral cortex in the formation of stress resistance in female students with different temperamental characteristics // Siberian Bulletin of Special Education. – 2015. – No. 2(15). – pp. 52-57.
3. Mikhailov, I.V. The significance of functional asymmetry in teaching complex purposeful bimanual movements / I.V. Mikhailov, P.V. Tkachenko // Modern high technology. – 2009. – No. 9. – P. 59–
4. Pankova N.B., Romanov S.V. Dynamics of behavioral manifestations and quantitative indicators of functional interhemispheric asymmetry in students during the school year // Scientific prospects of the XXI century. Achievements and prospects of the new century // III International Scientific and Practical Conference, Novosibirsk, August 15–16, 2014 – No. 3. Part 5. – Novosibirsk: International Scientific Institute “Educatio”, 2014. – P. 38–42.
5. Pulikov A.S. and others. Individual typological characteristics and features of the lateral phenotype in young men // Modern studies of social problems (electronic scientific journal). – 3013. – No. 1. URL: https://sisp.nkras.ru/e-ru/issues/2013.html.
6. SanPiN 2.4.2.2821-10 “Sanitary and epidemiological requirements for the conditions and organization of training in educational institutions” dated 03.03.2011.
7. Sychev, V. S. Functional asymmetry of the brain. Problems and prospects for solutions / V.S. Sychev // BBK 20 A 437. – P. 197.
8. Fokin, V.F. et al. Guide to functional interhemispheric asymmetry / V.F. Fokin // M.: Scientific world. – 2009. – 836 p.
9. Khokhlov N.A. Lateral signs, structural-level characteristics of intelligence and mathematical abilities / N.A. Khokhlov, M.S. Kovyazina // Magazine “Asymmetry”. Volume. – 2013. – T. 7. – No. 3. – pp. 32–52.
10. Aaron A. et al. Reward, motivation, and emotion systems associated with early-stage intense romantic love // ​​Journal of neurophysiology. – 2005. – T. 94. – No. 1. – pp. 327–337.
11. Oldfield RC: The assessment and analysis of handedness: the Edinburgh Inventory. Neuropsychologia 1971 Mar; 9 (1) – pp. 97–113.

References

1. Bragina, NN Funkcional'nye asimmetrii cheloveka / NN Bragina, TA Dobrohotova. – 2nd ed. pererab. i dop. – M.: Medicina, 1988. – 237 s.
2. Lisova NA i dr. Rol' aktivacionnyh processov kory golovnogo mozga v formirovanii sressoustojchivosti u studentok s razlichnymi temperamental'nymi harakteristikami //Sibirskij vestnik special'nogo obrazovanija. – 2015. – No. 2(15). – S. 52-57.
3. Mihajlov, IV Znachenie funkcional'noj asimmetrii pri obuchenii slozhnym celenapravlennym bimanual'nym ​​dvizhenijam / IV Mihajlov, PV Tkachenko // Sovremennye naukoemkie tehnologii. – 2009. – No. 9. – S. 59–
4. Pankova NB, Romanov SV Dinamika v uchebnom godu povedencheskih projavlenij i kolichestvennyh pokazatelej funkcional'noj mezhpolusharnoj asimmetrii u uchashhihsja // Nauchnye perspektivy XXI veka. Dostizhenija i perspektivy novogo stoletija // III Mezhdunarodnaja scientific-prakticheskaja konferencija, Novosibirsk, 15–16 August 2014. - No. 3. Chast' 5. – Novosibirsk: Mezhdunarodnyj Nauchnyj Institut “Educatio”, 2014. – S. 38–42.
5. Pulikov AS i dr. Individual'no-tipologicheskaja harakteristika i osobennosti lateral'nogo fenotipa u junoshej // Sovremennye issledovanija social'nyh problem (jelektronnyj nauchnyj zhurnal). – 3013. – No. 1. URL: https://sisp.nkras.ru/e-ru/issues/2013.html.
6. SanPiN 2.4.2.2821-10 "Sanitarno-jepidemiologicheskie trebovanija k uslovijam i organizacii obuchenija v obshheobrazovatel'nyh uchrezhdenijah" from 03.03.2011.
7. Sychjov, VS Funkcional'naja asimmetrija mozga. Problemy i perspektivy reshenija / VS Sychev // BBK 20 A 437. – S. 197.
8. Fokin, VF i dr. Rukovodstvo po funkcional'noj mezhpolusharnoj asimmetrii / VF Fokin // M. : Nauchnyj mir. – 2009. – 836 s.
9. Hohlov NA Lateral'nye priznaki, strukturno-urovnevye harakteristiki intellekta i matematicheskie sposobnosti / NA Hohlov, MS Kovjazina // Zhurnal “Asimmetrija”. Tom. – 2013. – T. 7. – No. 3. – S. 32–52.
10. Aaron A. et al. Reward, motivation, and emotion systems associated with early-stage intense romantic love // ​​Journal of neurophysiology. – 2005. – T. 94. – No. 1. – pp. 327–337.
11. Oldfield RC: The assessment and analysis of handedness: the Edinburgh Inventory. Neuropsychologia 1971 Mar; 9 (1) – pp. 97–113.

Interhemispheric asymmetry: learning problems in normal and pathological conditions

The problem of interhemispheric asymmetries is one of the most pressing problems of our time. The study of hemispheric asymmetry plays a big role in solving problems in education. This is due to the fact that in educational institutions it is important to take into account the individual characteristics of each child, including the dominant hemisphere. Various sciences of the modern world study the brain and penetrate into the problem of interhemispheric asymmetry of the brain.

Each person can have a dominant hemisphere. Identifying the dominant hemisphere is important for every person to know, because this will further affect his socialization, learning, development and will help to understand his abilities. Knowledge of hemispheric dominance is also very important psychologically. Focusing on the dominant hemisphere, a psychologist, speech therapist and teacher can use special methods to correct or teach a child, which will help the child cope with the task more easily [7].

Since ancient times, people have clearly delineated the circle of “us” and “strangers”. Guided by the herd spirit inherent in the human psyche, people at all times united into groups, associations, societies. At first, these were very primitive signs, for example, a person’s belonging to a certain clan. But time passed and as society and man himself developed, the signs became more and more sophisticated.

A person with right-hemisphere asymmetry of the brain, that is, a left-hander, cannot go unnoticed in a society of right-handers. He perceives information, thinks, and performs everyday actions in a completely different way than left-hemisphere or right-handed people, which reveals his special organization of the psyche. The combination of indicators of functional, sensory and motor asymmetries provides a complete picture in determining the individual lateral profile of a particular individual. Based on this, in modern scientific society there are 3 types of brain organization: left hemisphere, right hemisphere and equal hemisphere types [1]. I would like to dwell in detail on the first two, as the most common types of brain organization.

According to statistics, the proportion of the population with right-hemisphere brain asymmetry is not so small and amounts to about 15% of the world's population. But despite this, left-handed people always feel a kind of pressure from society. In childhood, many parents zealously try, at all costs, to retrain the “unhappy” baby, making him a “normal” right-hander. When a child grows up, he will constantly feel interested glances in his direction, and sometimes a rather negative attitude towards his mental characteristics. Unfortunately, due to the lack of sufficient information among citizens, sometimes absolutely ridiculous ideas arise about left-handers as “strangers” to our society, some even attribute mental disorders to them. In fact, right-hemisphere asymmetry of the brain, of course, does not necessarily mean that an individual has deviations from the norm of development, but only creates differences in the cognitive processes of left-handers and right-handers [5].

In a person with a left-hemisphere type of brain organization, the left hemisphere acts as the dominant hemisphere. Such an individual has a tendency to generalize and abstract, and cognitive processes are predominantly verbal and logical in nature. It is the left hemisphere that is designed to carry out operations with symbols, conventional signs and words, which makes it possible to conclude that there are conceptual and abstract types of thinking. A feature of right-handed thinking is the presence of so-called elements of unambiguous context. Left-hemisphere individuals, when organizing material of a symbolic nature, create a text that is strictly unambiguously understood, without the possibility of its interpretation and explanation in other ways. In other words, we can conclude that there is a rather pedantic and one-sided approach to understanding statements in the process of interaction in society. The obvious advantages of right-handed people include their keen sense of duty to the promise they made; they are efficient, responsible, reasonable, rational and principled. Also, individuals of the left-hemisphere type are characterized by a large amount of memory, and the speech of such people is devoid of agrammatisms. But also in their character there are such features as: insufficient manifestation of flexibility, spontaneity, spontaneity. They are used to keeping everything to themselves, not letting their true experiences and emotions out, so they may seem somewhat secretive. Based on the structure of the left-hemisphere asymmetry of the brain, right-handed people are suitable for such professions as: linguist, engineer, philosopher, mathematician. They can also be not only representatives of theoretical disciplines, but also administrative positions [2].

People with a right-hemisphere type of brain organization also have their own characteristic features. To these we can include, for example, not the verbal-logical nature of cognitive processes, but the concrete-figurative one. In addition, left-handers are characterized by the presence of a divergent type of thinking. Such people, as a rule, do not think in a standard way; for them there are no frameworks or restrictions; they see many different options and ways to solve them in solving any problem, unlike narrow-minded right-handers. The right hemisphere of the brain is responsible for orientation in space, operations with images of real and specific objects, and also easily perceives spatial connections between objects. Left-handers have visual-figurative thinking, which helps them see the situation as a whole and predict the changes that this or that action will lead to in relation to a given situation. The right hemisphere of the brain, continuously regulating subconscious processes and control over involuntary behavior, produces spatial and structured transformations of information, assesses the complexity and symmetry of an object. The right-hemisphere type of brain organization gives an individual the opportunity to look deeper into what is happening, helping to see not only the object in front of him, but also the background behind it, to deal not with the center, but with the periphery. Thus, the right hemisphere ensures an even distribution of attention, rather than focusing and concentration. Being an organ of the human unconscious, the right hemisphere makes it possible to simultaneously recognize and analyze a large number of connections, sometimes quite contradictory from a logical point of view. People with right-hemisphere asymmetry use in life more intuitive instincts and emotional impulses than strict and logical arguments. The advantage of this type of thinking is manifested in situations that involve complex information that has a large number of internal contradictions and which at first glance cannot be reduced to an unambiguous meaning. Situations of this nature are a creative process. Left-handers, as a rule, have quite expressively colored speech, rich in gestures and intonations. Such people definitely cannot be called boring and monotonous speaking. Despite the fact that their speech is not structured, confusion, hesitation, as well as unnecessary words and sounds are possible, left-handed people have emotional and rich speech. It is about this category of people that they say with admiration: “He’s tongue-tied!” Left-handers are holistic, creative people, capable of openly expressing feelings. They are open to the world, naive and trusting, sociable and sociable. The right-hemisphere type of organization is also characterized by the ability to subtly feel and experience difficult life situations, to easily become upset and cry, or to become angry, that is, to act according to one’s mood. That is why among left-handers you can find a large number of journalists, writers, organizers and cultural figures [8].

Having identified and analyzed the characteristics of the psyche and the nature of the cognitive processes of left- and right-hemisphere people, we can conclude that different approaches are necessary in the process of mastering the school curriculum. Any learning process begins with a properly built motivation of the child to gain knowledge and further learning itself. An important component in achieving this is the interest of the child, the creation of conditions that will demonstrate to him that the educational process is not a routine and boring phenomenon. Thus, knowing the peculiarities of the thinking of right-hemisphere children, we will place emphasis in their teaching on the aesthetic side of objects. For left-handers, there is a great need for self-realization, getting the highest score and praise from the teacher. On the contrary, the left-hemisphere type of thinking is characterized by an orientation towards the cognitive side of the educational process. They are attracted not by praise, but directly by the acquisition of new knowledge and its depth. School activities themselves are considered by right-handers as a way of self-improvement, development of volitional qualities and thinking. For them, it is not the teacher’s assessment that is important, but the learning result itself. In addition, in the process of mastering the school curriculum, it is important to separate children according to their sensory perception characteristics. So, you can conduct a simple test to determine this fact. It is necessary to trace in which direction the child turns his eyes in the process of thinking. Since cognitive activity primarily occurs in one of the cerebral hemispheres, triggering eye movement, it can be assumed that left-hemisphere children will move their eyes to the right, and right-hemisphere children will move their eyes to the left. For left-hemisphere children, the right hemisphere of the classroom space will be significant for perception, so it is necessary to seat such a child in such a way that the board and teacher are on his right side. For right-hemisphere children, the same principle will apply by analogy, but with the replacement of the side of the class hemisphere [9].

An important feature is the process of processing information during a lesson, which occurs differently in left- and right-hemisphere children. Left-brained students may often be called "slow-brained" in the classroom due to their slow processing of information. They slowly and thoughtfully savor every detail; they are not characterized by working on the “question-instant answer” principle. Right-hemisphere children, on the contrary, process information almost instantly, but spontaneously and chaotically. Teachers call such students “in a hurry.”

The speech aspect of the educational process reveals some problems in the use of speech by right- and left-hemisphere children. Students with a dominant right hemisphere are characterized by a weak level of self-control in performing actions. That is why right-hemisphere students have poorly developed control over their pronunciation speech, missing words and problems in word selection and grammar are possible. On the contrary, children with a dominant left hemisphere have developed control over the pronunciation side of speech. Their weak point is summarizing. Problems may also arise with the development of fluent oral speech; it may be necessary to provide assistance in the development of cursive writing in a child. They are successful in applying rules and using words correctly in sentences [1].

We can also observe significant differences in the types of brain organization in the example of the memory process. For right-hemisphere students with visual memory, a characteristic feature is the visualization of information. Such children see words as if through the eyes of the brain. Children of the right hemisphere type have the phenomenon of “innate literacy.” Their fingers and eyes seem to write for them, knowing the correct spelling of a particular word. But, unfortunately, during the process of studying at school, the “innate literacy” of this category of children is destroyed. This is due to the use of an analytical approach to the study of literacy in the curriculum of general education institutions, which is not typical for right-brain students. A child with a dominant left hemisphere can be compared to a tape recorder. Due to the auditory type of memory present in the student, after receiving a question, he, as it were, plays the desired tape in his head. And then the child chooses a piece from it containing the correct answer. During the educational process, a left-hemisphere student often faces the problem of the need to translate remembered information into another modality. This occurs due to the tendency of teachers to change modality in the process of presenting lesson material and conducting an exam. In contrast to this problem, left-hemisphere children make excellent use of the characteristic features of their voluntary memory. Unlike right-hemisphere students, who memorize through practical activities and not through willpower, left-hemisphere children are prone to memorization. To remember, they need repeated repetition and memorization, which is used in the school curriculum [7].

It is also important to choose the right techniques and methods in the process of school teaching. To do this, it is necessary to take into account the peculiarities of thought processes characteristic of children with different types of functional asymmetry of the brain. Thus, it is important to remember the need for different approaches in the learning process using theoretical materials. Reading and evaluating words in a text by left-hemisphere children is comparable to an “attack.” That is why it is important for such students to use a discrete approach to learning, that is, an inductive path “from part to whole.” For right-hemisphere students, on the contrary, it is necessary to use the deductive path of learning “from the general to the specific.” It is for this reason that there are often problems in mastering the school curriculum by right-hemisphere children using the Zaitsev method or the Zankov system, since they are intended for the left-hemisphere type of brain organization [8].

The characteristics of a child’s individual lateral profile often determine the presence of age-related and gender-related manifestations of brain organization. If, for some reason, teachers and parents do not take into account these features of the functional organization of the brain, then this can lead to problems such as hyperactivity, school failure and deficiencies in speech function. The latter is one of the most important problems, since underdevelopment, delay or complete absence of speech will complicate schooling and the future socialization of the child.

When working with children with disabilities, and especially with hearing and speech impairment, one of the most important problems is diagnostic work with the child to predict the characteristics of his speech development. The solution to this problem lies in the analysis of the profile of functional asymmetry [4].

Studies conducted with children with general speech underdevelopment reveal many facts about the relationship between the child’s individual lateral profile and speech disorders. Thus, precisely among children with disabilities, the most common is the left profile of functional sensorimotor asymmetry, rather than the right one. Another interesting fact is that when analyzing children from the group with severe speech impairments, boys mostly have a mixed type of functional sensorimotor asymmetry, while girls have left or symmetrical profiles. If we analyze the intellectual abilities of children with special needs, we will come to an interesting conclusion. The fact is that the highest intelligence indicators are observed in the group of normatively developing boys, as well as boys with minor speech impairments. But at the same time, children from both groups necessarily have a left type of functional asymmetry. If we take a group of preschool children with more pronounced speech impairments, then we will observe the presence of the lowest intellectual indicators in boys with right and mixed types of functional asymmetry. In addition, the results of the study revealed that in groups of preschool children with less severe speech disorders there are approximately the same number of children with a left, right or symmetrical profile. But, if we analyze a group of preschool children with pronounced problems of speech development, then we will see the largest number of children with the left profile of functional sensorimotor asymmetry. Based on the above facts, we can assume that the presence of left profile in preschool children with severe speech impairments indicates paranatal influences on the child, which could lead to a decrease in the level of activity of the right hemisphere [6].

Features of the individual lateral profile, in addition to the speech aspect, leave an imprint on the intelligence and mental health of the child. Thus, according to a study conducted with children with normal development, mental retardation, and mental retardation, we can draw a conclusion about the specificity of the manifestation of brain asymmetry. Based on the percentage results, we see that the percentage of “pure right-handers” and right-handers in groups of children with mental retardation is 1.6-1.8% higher compared to the group of subjects with normal development. But, despite this, in general terms, the percentage of “pure right-handers” and right-handed children in groups of children with mental retardation and mental retardation is the lowest compared to the group with normal development, and ranges from 1.8% to 4% [3].

If we compare left-brain and right-brain people, we can conclude that these people adapt to the world differently using their abilities. The dominant hemisphere will help a person decide on his future profession and make his work activity less difficult. But a person must also develop the hemisphere that does not predominate in his life, because it will help him in various life situations and make a person more self-confident [5].

The dominant hemisphere is important to take into account, especially in the development of children. After all, their training and education depend on this. You can choose various methods and methods, taking into account the dominant hemisphere, which will help the child in further development and learning in kindergarten and school. As is known, school teaching methods mainly train and develop the left hemisphere, ignoring the development of the right hemisphere. With the help of differentiated learning, exploring the specifics of a child’s cognitive development and perception, it is possible to develop pedagogical methods and methods, taking into account the individual and psychophysiological characteristics of children.

Thus, we can conclude that it is necessary to timely determine the child’s individual lateral functional sensorimotor profile for his further successful education at school. After all, each child needs a purely individual approach, which can have a beneficial effect on his mental and mental development in the future.

Interhemispheric asymmetry - interesting facts

Asymmetry is an acquired quality. In addition, it has been proven that it is less pronounced in illiterate people. That is, in the process of learning and acquiring new knowledge, the brain becomes more and more asymmetrical. Those who do not pay due attention to education slow down the development of many important functions.

SPLITTING BRAIN EXPERIMENTS

Functional asymmetry manifests itself in a completely paradoxical way. For example, it turned out that the left hemisphere is responsible for building logical connections and mathematical calculations. It “understands” any complex speech well. The right hemisphere, on the contrary, can recognize only the most general connections. When presented with the most ordinary objects - a spoon or a ball of thread - it can assign them to a certain class. The advantage of the right hemisphere is excellent orientation in space. An experiment was carried out: patients with a split brain for medical reasons were asked to assemble a structure according to a drawing with their right hand. At the same time, they made many mistakes. This was due to the fact that the left hemisphere is responsible for the right side of the body.

SPERRY'S EXPERIMENTS

Split-brain studies have also shown that people with damage to the right hemisphere have very poor spatial orientation. Often such patients cannot find their way to the house in which they previously lived for decades. R. Sperry proved that when the corpus callosum is dissected, the following occurs: processes in the two hemispheres of the brain begin to occur independently. It's like two different people acting independently of each other. According to many scientists, asymmetry is a phenomenon that man acquired during evolution and is its acquisition.

AGNOSIA IN BRAIN DAMAGE

Brain asymmetry actually manifests itself most clearly when one of the hemispheres is damaged. For example, injuries to the right hemisphere can lead to various types of so-called agnosia. With this disorder, a person is unable to perceive previously familiar information. For example, there is known face agnosia, in which the patient does not recognize the faces of familiar people. And this despite the fact that memory for other objects in the surrounding world and situation remains absolutely intact.

TWO TYPES OF THINKING

So, brain asymmetry involves the division of mental functions into two large spheres - spatial-imaginative thinking and abstract-logical thinking. There are many synonyms for these concepts. For example, the definitions of verbal and nonverbal thinking, as well as discrete and simultaneous, are similar. The right hemisphere is responsible for simultaneous thinking, since it perceives an object in the entirety of its properties. The totality of perception is inaccessible to the logically oriented left hemisphere. It analyzes and studies each object separately.

ANALYSIS AND SYNTHESIS FUNCTIONS

Brain asymmetry is responsible for the distribution of functions between the two hemispheres. The left hemisphere is responsible for analytical information processing. He is characterized by thinking of the “from particular to general” type, that is, induction. It processes the entire flow of information from the outside world according to a logical principle. The right hemisphere is responsible for such a mental operation as synthesis. In this case, the parts of the perceived object are combined into a whole. Thinking is carried out according to the deductive principle - from the general to the specific. The right hemisphere is responsible for metaphorical, figurative thinking.

INTERHEMISPHERE ASYMMETRY: OTHER DIFFERENCES

Perceiving current events in chronological order is a function of the left hemisphere. For the right, on the contrary, all events seem to occur simultaneously. It is not oriented in time: for it there is only “here and now.” The left hemisphere is focused on reading patterns, such as information on geographic maps. The right one, on the contrary, is oriented in a specific space, for example, indoors. There is also a difference between the distribution of emotion control function in the cerebral hemispheres. The left hemisphere is responsible for positive experiences, the right, on the contrary, for negative ones.

ASYMMETRY IN NATURE

It should be noted that the phenomenon under consideration is characteristic of many natural objects. Interhemispheric asymmetry is not only the prerogative of humans. If symmetry is represented in the structure of molecules and crystals, then asymmetry is in the arrangement of internal organs, the structure of the DNA helix. There is also hair asymmetry. Research in this area leaves many mysteries. But the progress of science does not stand still. Perhaps the knowledge that now seems obvious will become completely outdated for future scientists. Perhaps scientists of the future will be able to finally unravel all the secrets of the highest product of evolution - the human brain.

Functional interhemispheric asymmetry in schoolchildren

(Quantitative distribution of students 2003-2008)

The results of our research show a clear change in lateralization trends, both in the form of an increase in right-hemisphere children (36.92% of the surveyed students compared to 25.13% of left-hemisphere children) and the appearance of children with ambidexterity (37.95%).

In addition, several years ago, within the ambidextrous , according to the results of our research, children appeared with balanced right-left laterality in brain processes. The term “ambicerebrality” is more suitable for this phenomenon (the term was first proposed by Khisambeev Sh.R., Moscow, PIRAO, 2008, unpublished). We propose the following working formulation. Ambicerebrality is the ability of a person’s right and left brain to process information alternately, or in parallel and simultaneously. It should be noted that in such children the process of switching information processing in the right and left brain occurs spontaneously. But by the time of maturation, both hemispheres begin to process information in parallel and simultaneously, demonstrating qualitatively new capabilities of brain activity.

Back in the 60-70s, foreign researchers drew attention to a general pattern. Namely, strictly defined eye movements during various cognitive processes. [Day, 1964, 1967a,b; Kinsbourne, 1972]. Both researchers reported that right or left lateral eye movements may indicate a temporary predominance of activity in one or the other brain hemisphere [2].

By us in 1997-2008 436 people were examined. Among them are children aged 5 to 7 years, students from 7 to 17 years old and foreign junior students.

All subjects were examined using our method for studying the involuntary regulation of oculomotor functions using a model of saccadic eye movements in school-age children [5]. The essence of the technique is to divide the spaces of perception into near and far. The subject follows the movement of a light bunny moving horizontally in different perceptual spaces.

Specific irregularities in the trajectory of the pupil were found, which included: nystagmus, saccades, cutting off or distortion of the trajectory of the eye. As well as a sudden slip of the gaze (loss of a line when reading), etc. while the subject is tracking the movement of an image along a smooth trajectory on one of the screens (spaces) of perception while maintaining the immobility of the head of the person being tested. It is possible to register the trajectory of the pupil of the subject watching these images.

As a result of testing, features of eye movements were discovered depending on laterality. In the process of processing both visual and auditory information, the first eye movement with the right laterality of the brain was to the left, with the left - to the right.

A different picture is observed in some children with ambitcerebrality. Some of their information is in the right brain, and some is in the left. The same thing happens with eye movements, which are bilateral in nature. The group of children with ambitcerebrality appears to fall within the ambidextrous group, ranging from approximately 27% to 70% depending on the year of the study, and trending upward. The highest percentage of ambitcerebrality is observed among children 5-12 years old (we did not examine younger children). Perhaps this is a new trend. It is also possible that this is due to the fact that the nerve cells of the cerebral cortex, which are responsible for higher mental functions, do not have an innate specialization [1].

In our opinion, much for understanding the functioning of the brain in ambitcerebral children comes from the classic work of Sperry R, ​​1982, carried out in the 50s on people with a split brain after commissurotomy operations - complete intersection of the corpus callosum and separation of the right and left brain. It turned out that such operations did not change either the personality or behavior of the patients. However, as a result of numerous studies, the impression was created that “in some people, splitting of the brain leads to the emergence of two independent personalities with behavioral characteristics, their own habits, memory for events, their assessment, etc.” [3].

According to our observations, in children with ambitcerebrality, a spontaneous switching of the right and left brain occurs due to the immaturity of interhemispheric interactions. Therefore, we observe polar behavior in such children.

Example: Boy Dima F., born in 1998, 3rd grade student at a comprehensive school, Moscow. When studying laterality options, ambidexterity with a predominance of the right hand was revealed. As well as ambitcerebrality with a predominance of right laterality. The right eye is dominant.

In the evening, my mother checked the poem she had learned in advance. The child recited the poem clearly and with an emotional surge, flawlessly. In the morning I went to school. On this day, the children at the blackboard answered by reciting the assigned poem. Returning from school, the boy cheerfully told his mother that he had “forgot” the poem. And then he told it clearly again. At the same time, when asked what was interesting at school today, he answered: “I don’t remember.” After about 20 minutes, he spontaneously began to talk about what was for lunch in the school cafeteria, however, at that moment he could not remember the ill-fated poem.

In this example, we see the easily recognizable polar behavior of many modern children. It is due to spontaneous switching of the still partially isolated lateral functions of the right and left brain that the coordination of interhemispheric interactions is disrupted. That is, the anatomical features of the immaturity of the corpus callosum, in fact, are not only functional, although they can determine functional differences.

Apparently, in further studies it is necessary to pay attention to the phenomenon of trigger switching of lateralization in children with ambitcerebrality.

In other words, we are witnessing qualitatively new processes and changes in both the pace and structural characteristics of the maturation of the central nervous system and the laterality features of modern children.

I'll start with the medical history. During the treatment of schizophrenia with unilateral electroconvulsive shocks, which was carried out in Leningrad by a group led by L.Ya. Balanov, I had to observe such a case in the summer of 1979. A young girl, a gifted artist, does not emerge from severe delirium for months. There are so many different symbols woven into it that one of the psychiatrists, who became acquainted with the history of her illness with me, complained about the almost complete impossibility of identifying the main core in this stream of associations. After a right-sided shock, when the patient’s behavior was controlled mainly by the left (dominant in speech) hemisphere, she, answering questions, began to clearly describe the complex of sexual guilt that tormented her in front of her mother (she fancied that she had lost her innocence, although according to a medical examination, she is a girl). Before the described shock, during shocks from the opposite side, the girl (whose behavior in short intervals after the left-sided shock was controlled predominantly by the right hemisphere, which is in charge of imaginative perception) made several good drawings. After a right-sided shock, in response to a request to draw something, the girl depicted something that I could not have interpreted immediately if I had not previously studied the sexual symbolism of cave paintings of Upper Paleolithic caves (I note that these drawings are from a long period of the history of Homo sapiens characterized by schematization and focus on detail, presented as if in “close-up”, which is typical of the left hemisphere, which apparently played a special role in various types of sign activity after the victory of sound language as the main means of communication). Psychiatrists, who did not have cultural and anthropological training, did not understand the image and began to question the patient. She explained to them: “These are my genitals.” For several tens of minutes after the right-sided shock, the patient’s left hemisphere was intently engaged in introspection, the results of which we observed both in her verbal explanations and in such symbolic drawings. Then, with increasing activation of the right hemisphere, the guilt complex began to appear again in rather transformed forms of delirium, which could again seem mysterious to a new observer. While drawing, the patient said: “Paper, forgive me! Pencil, forgive me! And background, forgive me!” and fell to her knees (knocked off by the fact that she was constantly thumping on them). Concluding the story about this patient, I will add that among her schematized drawings there was also a drawing of a hand with the meaning of the symbol of God, which is characteristic of primitive art and the art of schizophrenics. I would like to emphasize that metalinguistic operations are very typical for the first hour after a right-sided shock, when the left hemisphere demonstrates all its capabilities related to language, including its metalinguistic use, in which language, turning on itself, serves as a means for its own research. Language can be used for a person to understand not only linguistic activity (normally unconscious in relation to the native language), but also for awareness of other aspects of behavior that remain unconscious without verbalization.

I will go straight to the formulation of the proposed hypothesis. Several authors in different countries dealing with functional asymmetry of the brain have independently come to the assumption that the unconscious is associated primarily with the right hemisphere, which is normally mute. In particular, many have drawn attention to the possibility of the participation of the right hemisphere in the formation of dreams (in this sense, treatment of depression through sleep deprivation in the REM phase is similar to the treatment of depression with right-sided shock). Let me add one more thing to this assumption: the conscious understanding of the sphere of gender, characteristic of an adult, belongs to the speech-dominant (left) hemisphere (and to the subcortical areas controlled by it). Penfield, when stimulating certain areas of the right hemisphere with electrodes during brain surgery, was able to evoke various unconscious memories, but they were never related to the sexual sphere. The right hemisphere is a non-speech (in certain respects “pre-speech”) repository of visual images, but images that are already transformed or infantile and do not usually contain their obvious “adult” sexual interpretation (even in those cases, it is very likely). It is advisable to proceed from the opposition of the speech hemisphere, which includes the areas of sexual life of an adult that are conscious through words, and the non-speech hemisphere, which, by the nature of its sexuality, can be infantile and reflect the pre-speech (unconscious) period of development of sexuality. The period of verbal learning about sex (normally quite long) follows the period when the child is learning his native language. It seems possible to show this in such extreme cases as “wolf” children (like Mowgli), who not only do not speak language, but also turn out to be “sexually untrained” and therefore incapable of sexual activity, and as deaf-blind people who, in the absence of special communication, for a long time (after adulthood) remain at a very infantile stage of sexual development. At the same time, the normally non-speech right hemisphere can be a source of images based on infantile and transformed (and sublimated) sexuality. It is associated with figurative creativity and with love as creativity and a source of creativity (it is enough to recall at least the circle of images that underlie the introductory stanzas to “The Knight in the Skin of a Leopard” and similar ideas in other works of medieval literature). The right hemisphere is responsible for the imagery of Pushkin’s “I Remember a Wonderful Moment,” but not for the well-known left-hemisphere author’s prose commentary on the biographical episode reflected in this poem. Blok’s personal drama, as well as the relationship between different genres of poetry (sublime, addressed to Sophia, and obscene) by Vladimir Solovyov, the originals of which, like the letters dictated to himself on behalf of Sophia, were written in different handwritings, perhaps by different hands, and this may be explained by the same difference between the figurative (infantile or sublimated suprasexual) content of emotions of the right hemisphere and the verbalized (including in cynical or erotic statements) sexual activity of the left hemisphere and the subcortical areas controlled by it. Love and creativity are normal, as well as delirium (like the case of the guilt complex with which I began), in pathology they can be correlated precisely with the right hemisphere, and sex, conscious of the mind, with the left. The left and right hemispheres are opposed as systems for controlling, on the one hand, positive emotions (up to euphoria), on the other hand, depression (which explains the possibility of its treatment with sleep deprivation or right-sided shock) and the tendency to self-destruction. In this sense, a significant danger can be posed by the uncontrolled succession of right and bilateral shocks, which can be confirmed by some examples from American clinical practice of past decades.

In a hypothetical form, one could assume that suicide (or forms of behavior close to it, for example, provoking a duel among Russian poets of the 19th century) and the Freudian “institute of death”, the role of which has received due attention only in recent times, can be linked with the right hemisphere (suicide is an extreme case, which from this point of view can be described as murder by the right hemisphere of the left). Then not only the distinction between the “I” (correlated with the left hemisphere), the “Super-ego” and the “Id” (correlated with the right hemisphere), but also the opposition of Eros (left hemisphere) and Thanatos (right hemisphere) in the late Freud could be interpreted ( in the spirit of his early experience in “Psychology for Neurologists”) from the point of view of functional asymmetry of the hemispheres.

Psychoanalysis is characterized by a focus on the word, taken to the extreme in the school of Lacan, but already embedded in the Freudian analysis of slips of the tongue and puns. If speech activity is left-hemisphere, then it is natural that during verbal comprehension (verbalization) of the unconscious, verbally conscious sexual desires as such come to the fore. But the issues of interaction between the two hemispheres and those lower levels of brain organization that are associated with them remain unresolved. Question one: we know that the subdominant (right) hemisphere uses visual gestural images, largely imprinted (through imprinting) from early childhood (when the differentiation of the functions of the hemispheres is just beginning). It remains to clarify the question posed in Freud’s letters to Fliess about how early the first verbal impressions, not yet fully understood, can be dated. How can early nonverbal impressions be translated into verbal language? It is possible that translation is facilitated by the recording of the first words heard and other early perceived images in each hemisphere even before lateralization is consolidated. But even later, such a translation from the language of non-speech images into natural language is also necessary for a psychoanalytic session. A deep analogy arises with hypnosis, in which, apparently, the left hemisphere is switched off and the right hemisphere is more or less isolated (resembling a left-sided shock). It is necessary to find out whether the sexual interpretation of the symbolism of the right hemisphere is not imposed upon its webralization by the left, which is characterized by an orientation toward conscious sex.

A similar question arises: how does the subdominant (right) hemisphere use verbal symbols typical of the dominant (left) hemisphere? Even Jackson, who was the first to discover the contrast between the functions of the two hemispheres more than 100 years ago, noted that aphasics retain the ability to swear. Moreover, removing the censorship of the left hemisphere, which controls the “official” norms of speech behavior, contributes to the freer use of swear words. But uncensored (“unofficial” in the terms of M.M. Bakhtin) speech of the right hemisphere usually does not relate to the sexual sphere as such. The right hemisphere uses the corresponding words not in direct, but in figurative use, corresponding to that carnival right-hemisphere imagery of the “grotesque body”, which in relation to the square language of the crowd was studied by the same M.M. Bakhtin. In this regard, the role of the word for understanding the entire macrocosm through correspondence with the human body among the Dogon is of particular interest. The use of these same words only in the literal sense is characteristic of some special forms of sexual behavior (for example, among homosexuals), where the participation of left-hemisphere mechanisms is likely (the erotic role, in particular, as a type of perversion). More normal (obligatory in the folklore of some peoples) is the use of such words in two senses, reminiscent of the pun mechanism described by Freud.

The right hemisphere normally (when the left hemisphere is censored) is wordless, and this is where the origins of its creative potential lie. The eminent linguist Roman Jakobson drew attention to the peculiarities of Einstein’s thinking, which was based not on words, but on wordless images, undoubtedly right-hemisphere. Of particular interest is the fact that already in adulthood, Einstein wanted to find such musical and color images (clearly related by their very nature to the sphere of the right hemisphere) that would correspond to his physical and geometric ideas; according to L.S. The term, corresponding work in his studio in New York was carried out by Einstein together with Bute, who later gained fame as a film director. It is also interesting to pay attention to the peculiarities of speech development (or more precisely, early underdevelopment) of Einstein. Even at the age of 9, Einstein used the words of a child's language; later he had difficulty learning to read. In retrospect, Einstein himself saw in his slow speech development one of the reasons that facilitated his discovery of the foundations of the theory of relativity: he said that he understood space and time in a new way precisely because he learned to use the words “Raum” and “Zeit” only at that age , when other young people have been saying them for a long time, as a rule, without thinking about their meaning, received in ready-made form when learning the language. As a problem for the psychological and biographical history of linguistics of the 20th century. It should also be noted that there is a probable connection between the early illness of N.S. Trubetskoy, which led to aphasia and agraphia with a subsequent depressive state (indicating the predominance of the right hemisphere), with the geometric orientation of the classification types of phonological systems he later proposed (his continued studies in musicology are also indicative).

The censorship of the left hemisphere in some cases must be removed (inhibited) to enhance or at least ensure creative imaginative activity. Connected with this is a clear negative attitude towards psychoanalysis by major literary artists. Everyone is familiar with Nabokov's oft-repeated attacks on the Viennese school. It would be worth devoting a special psychoanalytic study to clarifying the reasons for this hostility of the author of “Lolita” (a Freudian interpretation of which naturally suggests itself) towards Freud. Let me give you one example from my own memories. Once I asked A.A. Akhmatov, why she is so hostile to psychoanalysis. To this she answered me that if she had undergone a course of psychoanalysis, art would have been impossible for her. I supported her thought by referring to two letters from Rilke written on January 24, 1912. At this time, a friend of Nietzsche, Rilke and Freud, Lou Andreas-Zalome, persuaded the poet to undergo a course of psychoanalysis; He answered her that this would only be possible if he did not write anything else. After listening to my retelling of Rilke’s letter, Akhmatova remarked: “Well, you see, it means I was not mistaken. This happens to me sometimes."

The conflict between stereotypical psychoanalytic therapy and poetic creativity underlies the plot of Salinger's cycle of stories about the poet Shimura. His hero, having undergone a course of psychoanalysis at the insistence of his bourgeois relatives, commits suicide. After the creative imaginative function of the right hemisphere is inhibited due to the inclusion of psychoanalytic verbalization, among the various functions of this hemisphere, the depressive - destructive one - wins. Salinger's plan clearly contrasts psychoanalytic clinical practice in its vulgarized form with poetic creativity, among whose representatives Salinger is inclined to include Freud, but not his epigones. It is curious that in one of the letters to his fiancée, Freud himself wrote that he hoped to achieve in science what he failed to achieve in poetic experiments (Einstein also spoke about himself in a similar way, believing that he could fully use his boundless imagination in physics, not in art). Freud’s “visual curiosity,” noted by Erik Erikson, which allowed the founder of psychoanalysis to penetrate the dreams and memories of his patients even before the introduction of final verbal formulations, undoubtedly indicates the presence of this right-hemisphere component in Freud’s own intuition (for its study, Freud’s introspection in a letter to Fliess about his "both left hands"). This intuition was lacking in many of his followers (of course, Jung stands apart, who did a lot for a deep understanding of visual archetypes, despite the controversial and often fantastic nature of the verbal interpretations he proposed). Freud's greatest achievements (in the study of dreams and wit) are associated precisely with the manifestation of this intuition. It seems to me that Freud’s artistic intuition is also reflected in his judgments about art, such as the remark cited in Reik’s memoirs about Dostoevsky’s excessive fascination with pathological cases.

Among the examples illustrating the complementarity (in Bohr’s sense) of psychoanalytic verbalization and creative figurative processing of complexes censored by the left hemisphere (as the representative of society in the brain), I will cite the biographical background of Herman Hesse’s “Steppenwolf.” Let me remind you of the sequence of basic facts. Hesse, who suffered from severe depression for several years, began undergoing psychoanalysis immediately after the end of the first war. His life situation became increasingly aggravated, relief did not come, and his neurosis intensified. This circle of depressive experiences is expressed in a tragic and artistically crystallized form by Hesse in the later published poem “Steppenwolf.” But only artistic sublimation in the wonderful novel of the same name brought Hesse liberation from suffering. Then that enlightened view of the world arises, which is inherent in the late Hesse. Creativity turned out to be the completion of the healing process begun by psychoanalysis. The clear construction of the entire work as a description of the author’s experiments in verbalization of the past, partially similar to psychoanalytic ones, was the basis of Zoshchenko’s book “Before Sunrise.” After writing it, Zoshchenko said in my presence in 1943 that he managed to get rid of the melancholy that had tormented him all his life; he wanted to use the book to make this method publicly available.

Returning from fiction to science, in conclusion I will quote the words of one prominent physicist who became acquainted with the problems of functional asymmetry. According to him, the essence is to achieve perfect harmony between right and left. I think this is the modern form of E. Sapir’s thought about the normal functioning of the unconscious.

Ivanov V.V. The unconscious, functional asymmetry, language and creativity. Unconscious. Collection. - Novocherkassk, 1994, pp. 168-173

Asymmetry of the human cerebral hemispheres

The left hemisphere becomes dominant in speech function in right-handed people, while the right hemisphere remains subdominant. In the left hemisphere of right-handed people, there are two areas related to speech: Broca's area and Wernicke's area.

Speech is the highest achievement of evolution, serving as a unique means of communication. One of the fundamental features of speech is that it is at the same time an instrument of thinking, allowing operations of abstraction and generalization to be carried out.

I. P. Pavlov (1932) identified the speech function as a special category of higher nervous activity, calling it the second signaling system.

In contrast to the first signaling system common to humans and animals, which is associated with the analysis of signals from the external world, the second signaling system operates with words, which serve as signals for specific signals and represent a distraction from reality.

In 1861, the French physician P. Broca established that the posterior third of the inferior frontal gyrus of the left hemisphere (in right-handed people) is related to speech function.

Its damage is accompanied by a violation of expressive speech* (motor aphasia). This was the first indication of the disparity (asymmetry) of the hemispheres of the human brain. It is assumed that in left-handers the speech function is less lateralized.

* In modern psychology, a distinction is made between expressive and impressive speech. The first is the coding of thoughts using inner speech into expanded speech, based on the grammatical structure of the language.

Impressive speech is the reverse process of decoding a speech utterance and extracting the thought contained in it.

Broca's area is located in the lateral prefrontal region (areas 44, 45), bordering the area representing the lower half of the face of the motor cortex. In humans, area 46, directly adjacent to Broca's area, also reaches great development.

It is assumed that its role is to ensure the perception of a rhythmic sequence of sounds - a stage necessary for the formation of speech in ontogenesis.

In 1874, the German psychiatrist K. Wernicke described a case of damage to the posterior third of the superior temporal gyrus, in which speech perception suffered (sensory aphasia).

Modern work, which began with the discoveries of P. Broca and K. Wernicke, and in Russia with the research of L. S. Vygotsky and A. R. Luria, has led to the following ideas. Information about the spoken word from the auditory areas of the cortex enters Wernicke's center.

To reproduce a word, the corresponding response structure (pattern) from Wernicke's center enters Broca's center, from where a command follows to the motor representation of the speech muscles.

When a word is spelled, the acoustic pattern is sent to the angular gyrus, an area located directly behind Wernicke's center, where it is converted into a visual pattern.

When reading a word, information about it is sent from the visual areas to the angular gyrus, and then to Wernicke's center, where the corresponding form of the word is retrieved. For most people, understanding a written word is associated with reproducing its auditory form in the Wernicke's center.

In people who are deaf and mute from birth, the Wernicke center does not appear to be involved in reading.

These ideas about the morphofunctional organization of speech activity allow clinicians to not only determine the location of brain damage based on the nature of the speech disorder, but also extrapolate the nature of previously undescribed forms of aphasia with possible brain damage.

Thus, conduction aphasia was predicted, resulting from a disruption of communication between Broca's and Wernicke's centers.

For normal speech activity, the integrity of the visual and auditory areas, the motor representation of the speech muscles, Broca's and Wernicke's centers and the angular gyrus is necessary.

Recent neurophysiological studies have shown that the brain system for providing speech, along with the cortical centers listed above, also includes a number of subcortical structures and, above all, the associative nuclei of the thalamus.

In addition, speech activity is associated with a certain level of wakefulness and consciousness. Finally, the preservation of interhemispheric connections is necessary.

After damage to the corpus callosum, the largest interhemispheric pathway, the patient is unable to read when words appear in the left visual field, write correctly and carry out commands with the left hand, and also name familiar objects held in the left hand; this occurs as a result of unilateral speech control.

The functional difference between the hemispheres (asymmetry) is reflected in the macrostructures of the human brain. It has been established that the Wernicke area of ​​the left hemisphere (in right-handed people) is significantly larger in area than the symmetrical area of ​​the right hemisphere.

These differences are already present in newborns, which indicates the genetic predetermination of the morphological and functional asymmetry of the human brain. At the same time, children may have better recovery for some types of speech disorders than adults.

This is apparently due to the potential readiness of the right hemisphere in early childhood to participate in the speech function.

Observations conducted by F. Sperry and M. Gazaniga (1967) in children with completely isolated hemispheres as a result of the intersection of the corpus callosum, anterior and posterior commissures of the brain, showed that until the age of four, the speech function is represented quite evenly in both hemispheres.

Subsequently, it gradually lateralizes and in right-handed people it becomes left-sided. The left, dominant, hemisphere is involved not only in speech, but also in the brain organization of all speech-related functions of higher nervous activity: categorical perception, active speech memory, logical thinking, etc.

The overwhelming number of symptoms of disorders of higher mental processes described with local lesions of the human brain relate to symptoms that arise from damage to the secondary and tertiary cortical zones of the left hemisphere (dominant in right-handed people).

The symptoms of damage to the cortical zones of the subdominant right hemisphere have been studied much less (see below for more details).

It should, however, be taken into account that for most people both hemispheres complement each other (complementary) and, thus, the law of lateralization is only relative in this sense.

In recent years, effective and safe methods for studying hemispheric dominance have been developed, based on the morphological features of the human brain.

Thanks to these methods, additional data on the localization of speech function in clinically healthy people was obtained. One of these methods is the Wada test.

This method takes into account the peculiarities of the arterial blood supply to the human brain, thanks to which a drug (for example, sodium amytal) injected into the left common carotid artery reaches the left hemisphere much faster.

The procedure is as follows. The person is in a supine position with his arms raised up; he is asked to count out loud.

When a drug is injected into the left carotid artery, the right arm falls within a few seconds (remember that the pyramidal tract is crossed) and the person stops counting. This means that the drug was blocking the left hemisphere.

Each hemisphere receives information primarily from the opposite half of the body. A partial exception is the auditory system. Due to the incomplete decussation of the auditory pathways, sound signals enter each half of the brain.

Since the number of crossed fibers is greater, the input from the opposite side is more powerful. In this regard, the sound of words on the right will be more effectively perceived by the speech centers located in the left hemisphere.

By comparing the results of separate presentation of different sound material on both sides, it was established that the dominance of the left hemisphere over the right hemisphere for speech perception can be expressed by a ratio of 2:1.

In the same way, it was found that the right hemisphere dominates in assessing the tonal structure of sounds, musical melodies and non-speech sounds.

The use of methodological techniques based on the fact that information in a person’s right visual field enters entirely into the left hemisphere and vice versa, made it possible to establish the dominance of the left hemisphere in the perception of written images of letters and words and the right hemisphere in the localization of objects in space.

Research has shown that face recognition also occurs primarily in the right hemisphere. The experiment consisted of the following. In front of the subject there was a screen with a dot in the center to fix the gaze.

In addition, the subject wore special prismatic glasses. Thanks to these techniques, the image on the right was projected into the left hemisphere, and the image on the left into the right hemisphere.

Composite faces are presented to the test subject on a screen. For example, to the right of the fixation point is half a boy’s face, and to the left is half an old man’s face. The image is presented for a short time (0.1-0.5 s) so that the subject cannot examine the image.

Then he is presented with a set of different photographs and asked to choose the one that was presented. He selects the photograph whose image entered the right hemisphere. However, if the subject was asked to describe the image in words, then he described the one that was projected into the left hemisphere.

In most people, due to the left-sided localization of speech centers, there is a special type of motor dominance in the form of gestures of the right hand while pronouncing words. This type of hemispheric dominance can be expressed in a 3:1 ratio.