It is typical for a person with a developed left hemisphere. The study of types of intelligence

Deglin V.L.

Functional asymmetry is a unique feature of the human brain

40 years ago, the greatest physiologist of our century, IP Pavlov, came to the conclusion that, in principle, all people can be divided into two types - artists and thinkers. The neurophysiology of our days finds an anatomical justification for this.

One of the features of the human brain is the so-called functional specialization of the cerebral hemispheres. Literally in last years it became known that the left hemisphere is the basis of logical abstract thinking, the right one is the basis of concrete figurative thinking, and on which of the hemispheres is most developed in a person (whether due to innate properties, or due to upbringing), his individuality, especially his perception depends.

Candidate of Medical Sciences V. DEGLIN [I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the USSR Academy of Sciences. Leningrad).

In the classification of living beings, man is given the honorary name - homo sapiens (reasonable man). It is natural to assume that our mind is due to a special structure of the brain. What is it? The human brain is large and heavy. But there are animals whose brains are larger and heavier. A person has a large relative brain weight, that is, the proportion of brain weight per kilogram of total body weight. But in this respect, we are inferior to animals - in terms of the relative weight of the brain, cetaceans are in the lead. For a very long time, scientists believed that a person has the largest surface of the cerebral cortex, that it has more convolutions, that it contains more nerve cells, which nerve cells denser in it. But it turned out that animals with a legendary reputation - dolphins - overtook us in these indicators too.

If not the size and weight of the brain, then what is distinctive feature the brain of a "reasonable person"? Today, only one unique feature of our brain can be pointed out - functional asymmetry.

The brain of all animals and the human brain is symmetrical - its right and left halves are built of the same type both in composition and number of individual elements, and in general architecture. In animals, the right and left halves of the brain do the same work. In humans, the right and left hemispheres of the brain have different functions, they control different activities. From time immemorial, it has been known that with focal lesions of the cortex (due to hemorrhages, injuries, tumors, etc.), complete or partial loss of speech - aphaeia - may occur. However, only a little over a hundred years ago it was proved that aphasia develops only with lesions of the left hemisphere.

During the second half of XIX and the beginning of the 20th century, neurological clinics intensively studied those defects in the complex activity of the brain that occur with focal lesions of one of its hemispheres. At the same time, as is often the case, the mass of reliable facts was mixed with data selected to please preconceived views and theories. As a result, neurologists connected not only speech, but also all higher functions with the activity of the left hemisphere. nervous system- intelligence, complex forms of perception and activity. As a result, the left hemisphere was called the "large" or "dominant" hemisphere. The right hemisphere was considered secondary, subordinate to the left, serving it. It was called the "small" or "subdominant" hemisphere. In the textbooks of neuropathology, this hemisphere was called "mute", because it was not known by what symptoms to diagnose its defeat.

Until the middle of our century, neuropathologists were mainly interested in the functional asymmetry of the brain, looking for supporting signs for accurate recognition of focal brain diseases. Along with an in-depth study of the lesion of the left hemisphere, the search for symptoms of the lesion and the "silent" right hemisphere was persistently carried out. And, finally, by the beginning of the fifties, these searches were crowned with success - functions were found that are characteristic only of the right hemisphere. It became clear that the right hemisphere cannot be regarded as a simple appendage of the left, that it makes its own and significant contribution to nervous activity.

There was a breakdown of the traditional concept - the idea of ​​the dominance of one hemisphere was replaced by the idea of ​​the functional specialization of each of them. Since that moment, the problem of asymmetry has gone beyond the exclusive competence of neuropathologists and has attracted the attention of physiologists, psychologists, specialists in age physiology and even representatives of social disciplines. Today, functional asymmetry is becoming almost the paramount problem of the science of the human brain.

WAYS OF OBSERVATION AND STUDY

The earliest source of information about the specialization of the hemispheres were observations of patients with foci of destruction in the right or left hemisphere during their treatment. This classic clinical path of research remains today a source of new facts, although it has its own difficulties.

New ways and methods of studying the functional specialization of the hemispheres were opened up by the development of neurosurgery. To establish the boundaries of the affected area of ​​the brain, surgeons have to irritate the brain with a weak electric current during the operation. Since many brain operations are performed under local anesthesia, the doctor, talking with the patient (the doctor needs to know what condition the patient is in at one time or another during the operation), finds out what sensations he experiences during stimulation of different parts of the operated hemisphere.

When patients are being prepared for brain surgery, in some cases it is necessary to conduct a special test: a sleeping pill is injected into the carotid artery, which supplies blood to one of the hemispheres. The temporarily "sedated" hemisphere ceases to function, and then all complex species nervous activity carried out only by the second hemisphere. Although the "sleep" of one hemisphere lasts about a minute, this minute also revealed new information about the functions of the right and left hemispheres.

Nevertheless, the operation, and electrical stimulation, and the test with sleeping pills cover, as a rule, one hemisphere. Therefore, it is impossible to compare the functions of the right and left hemispheres in the same person. However, more recently, a new operation technique has been developed, in which all the nerve pathways connecting both hemispheres are cut. Such an operation, called "splitting" the brain, is performed when it is necessary to prevent the spread of pathological excitation from one hemisphere to another. After "splitting" the hemispheres begin to function independently of each other. People with a "split brain" are not much different from healthy people, nevertheless, in the process of treating such patients, it is possible to trace what each hemisphere is capable of separately. But since this operation is very rare, the "split brain" remains an inaccessible object of observation.

At present, experimental methods have been created, the so-called dichotic tests, which make it possible to study the functional specialization of the hemispheres in healthy people as well. These tests are based on taking into account the structural features of the brain. It is known that the right ear and the right visual field are connected by more powerful pathways to the left hemisphere, and the left ear and the left visual field are connected to the right hemisphere. If different material is simultaneously presented to the right and left sense organs, then the hemispheres enter into competitive relations, and according to the characteristics of perception, it is possible to judge hemispheric specialization. Here is a specific example. With the help of special equipment it is possible to simultaneously show different letters in the right and left fields of vision for a moment. It turns out that the letters shown only in the right field of view are recognized. If in the same way to show geometric figures, then they will be recognized only in the left field of view.

As you can see, scientists today have a rather impressive set of techniques and ways to study functional asymmetry. Some of them have been tested by time, others have only recently made themselves known. All these methods and ways do not exclude, but complement each other. As a rule, the facts obtained different ways and on different objects, they coincide. But it happens that the information obtained different ways, contradict each other and negate each other. Obviously, the confirmation of already obtained and the verification of doubtful facts, the resolution of conflicting points of view require new research, require the search for new ways to study the functional asymmetry of the human brain. One of these ways will be discussed further.

This method is associated with one of the therapeutic techniques - electroshock therapy. The shock method of treating psychosis came into psychiatric practice about 40 years ago, when the therapeutic possibilities of psychiatrists were very limited. Physicians, who until then had acted as helpless observers of severe nervous disorders, found a powerful means of influencing the disease. Psychoses, which were considered hopeless, steadily leading patients to chronic insanity, turned out to be curable. Psychiatry today has many highly effective drugs at its disposal. But for some mental illnesses, electric shock is still the only treatment.

What is this treatment? Electrodes are placed on the patient's head, and a precisely dosed electrical effect is performed. It causes a state of shock that lasts a minute. For some time after the shock, patients are in an unconscious state - their brain activity is depressed. But within 1-2 hours the oppression passes and the consciousness completely returns. The course of treatment consists of 8-12 shocks. The therapeutic effect usually appears after 3-5 shocks and gradually increases.

To induce an electric shock, electrodes are usually placed on both sides of the head. But a few years ago, the English psychiatrist S. Kennicott suggested applying electrodes only to one side of the head - the right side (later shocks began to be caused by applying electrodes to the left half as well). Such shocks are called unilateral. They, like traditional bilateral ones, have a high therapeutic effect, but they are milder and more easily tolerated by patients.

Since 1967, the team of the psychiatric clinic of the I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the USSR Academy of Sciences has been studying unilateral electric shocks. Professor N. N. Traugott, Doctor of Medical Sciences L. Ya. Balonov, junior researcher N. N. Nikolaenko and the author of this article are participating in this work. A number of studies are being carried out with the participation of A. V. Baru, senior researcher at the I. L. Pavlov Institute of Physiology of the USSR Academy of Sciences. For 7 years in our clinic, a large number of patients underwent shock treatment, and we were convinced of its high efficiency.

Our observations have shown that one-sided electric shock does not depress the entire brain, but only the hemisphere over which the electrodes were located. The second hemisphere remains active. Schematizing somewhat, we can say that after a one-sided shock, a person feels, acts and thinks with only one active hemisphere. Electroencephalograms recorded after shocks show a striking picture - one hemisphere is "asleep", while the other is active, it is "awake".

Since electrodes are applied to the patient in different treatment sessions either on the right or on the left side of the head, the effects of turning off the right and left hemispheres in the same person are revealed. One can compare a person's normal behavior with his behavior in a "one-hemispheric" state, one can observe how behavior changes after the hemisphere is turned off.

Thus, unilateral electric shock, while performing its direct therapeutic function, simultaneously reveals to scientists the depths of functional specialization of the hemispheres.

Summarizing the facts obtained, we will give a generalized description of a person who has one hemisphere functioning - left or right. But let us remember that our "unihemispheric" man is artificial. It is compiled, synthesized from the observations and studies of many people who have undergone shock treatment. And one more caveat - everything that will be discussed applies to "right-handers", for "left-handers" the situation is different.

"LEFT HEMISPHERE" PERSON

This is the conditional name of a person whose right hemisphere is turned off and mental activity is carried out only by the left.

The first and main feature of a “left hemisphere” person is that he has preserved speech. This was to be expected, because the left hemisphere is speech. Another thing is unexpected: he enters into a conversation more willingly and more easily, seizes the initiative in a conversation, his vocabulary becomes richer and more diverse, his answers more detailed and detailed. He is overly verbose, even talkative. Along with this, he also improves the perception of someone else's speech.

Speech audiometry is used to study speech perception. Specially selected groups of words recorded on magnetic tape are fed through headphones separately to each ear. First, the threshold for detecting speech sounds is measured - the minimum intensity of the speech signal at which a person already hears speech, but still cannot make out the words. The volume is then gradually increased and the person should repeat the words they hear. Speech intelligibility is measured - the number of correctly repeated words in% of all heard.

In a "left-lobular" person, the threshold for detecting speech sounds decreases - he catches quieter speech than he could do in the usual "bihemispheric" state, He repeats the words he hears faster and much more accurately. In general, in a “left lobe” person, speech activity is increased, and speech hearing is facilitated.

Are these facts sufficient to state that speech activity improves in the absence of the right hemisphere? Let's listen carefully to the "left-brained" person. Although he has become more talkative, his speech is losing its intonational expressiveness - it is monotonous, colorless, dull. Moreover, not only is the expressiveness imparted to speech by the voice lost, the voice itself changes: it acquires a nasal, somewhat nasal tone or becomes unnatural, as if barking. Such a speech defect is called dysprosody, since the intonation-voice components of speech are called prosodic (“prosody” - “melody”).

Along with dysprosody, the perception of the prosodic components of the interlocutor's speech is disturbed in a “left-brained” person.

Two series of experiments were carried out. In the first, a person was asked to listen through headphones to short phrases made up of meaningless syllables, but pronounced with an exaggerated intonation - interrogative, angry, plaintive, enthusiastic, etc. It was necessary to determine the meaning of intonation, to say with what expression the phrase was uttered. In the second series of experiments, it was proposed to listen to vowel sounds uttered by a man and a woman through headphones. It was necessary to repeat the sound and say in what voice it was pronounced.

It turned out that the “left hemispheric” person loses the ability to understand the meaning of speech intonations. He listens attentively, tries to decipher the meaningless syllables, repeats them very accurately, but cannot say with what expression (interrogative, angry, etc.) they are pronounced. He cannot distinguish male voice from female.

Everyone knows that the same words spoken with different intonations mean far from the same thing. Similarly, the same words spoken different people(that is, in different voices) can have completely different meanings. Often what is said means more than what is said. Prosodic components give speech concreteness, figurativeness, sensual coloring. A speech message devoid of these components sounds vague, formal, and often incomprehensible.

Thus, along with the preservation of the formal richness of speech, vocabulary and grammar, along with an increase in speech activity, along with an exacerbation of verbal hearing, the “left-brained” person has lost that imagery and concreteness of speech, which is given to it by intonation-voice expressiveness.

So, we are faced with a paradoxical situation: on the one hand, some characteristics of speech hearing are improving, while others are deteriorating. What happened to hearing? Is it only the perception of speech sounds or the auditory function as a whole that has changed? Let's see how a "left hemispheric" person perceives non-speech sounds, sound images.

Coughing, laughter, snoring, animal voices - barking, neighing, grunting - sounds found in nature - thunderstorm noise, roar of the surf - industrial and transport noises were recorded on magnetic tape.

In a "left hemisphere" person, the recognition of such sound images deteriorates sharply - many well-known sounds now cause only bewilderment. In those cases when he does recognize them, this recognition requires much more time from him. Essentially, a "left-brained" person develops auditory agnosia, a disturbance in the perception of complex sounds. A similar disorder can be identified in relation to musical images.

A “left-brained” person not only ceases to recognize familiar melodies, but also cannot sing them, even if he hears music: he begins to be out of tune and, in the end, prefers to count the rhythm without a melody.

Unable to cope with the recognition of sound images, the “left-hemispheric” person tries to get around the difficulties in a very peculiar way: he begins to classify them. Instead of saying: “this is barking”, “this is laughter”, etc., he says: “this is a beast ”,“ this is a person ”,“ this is a folk song ”,“ this is a romance ”. As a rule, he is mistaken, but the very desire to classify, to put everything into a scheme, is symptomatic. Later we will see that such a desire is by no means accidental.

How to interpret the results of the study of the perception of sound images? Maybe a “left-hemispheric” person simply forgets familiar sounds, but the perception itself is not disturbed? This assumption can be tested.

Pairs of short musical phrases are recorded on magnetic tape. Each phrase consists of four notes. In some pairs, the phrases are the same, in others they are slightly different from each other. It is necessary to determine whether the phrases in the pair are the same or they are different. In this task, the ability to distinguish close musical images is studied. Remembering what a person knew in the past is not required. And with this task, the “left-hemispheric” person copes worse than the “two-hemispheric” one.

He can hardly tell the difference, everything sounds the same to him. Thus, the point is not in violation of memory, but in the originality of auditory perception.

What is the reason for this peculiarity? Has your hearing sensitivity changed at all? No, the hearing acuity, which was in the "bihemispheric" state, remained the same. But let's remember all the auditory disorders in a "left hemisphere" person - difficulties in recognizing musical and other sound images, difficulties in recognizing male and female voices, a complete misunderstanding of intonations. In other words, all types of figurative auditory perception are violated in him. Undoubtedly, we are faced here with a special state, with a selective, special violation of figurative perception (as already mentioned, the perception of words has even improved).

The inferiority of figurative perception can also be noticed in the visual sphere. If a “left-brained” person is asked to match pairs identical figures- triangles and squares divided into colored or shaded sectors, he will not cope with the task, he cannot immediately cover the location of the sectors, their coloring and shading. He will endlessly shuffle the pieces, repeatedly check them with each other, but he will not be able to pick up the pairs correctly. He will also not be able to notice the missing detail in the unfinished drawings - the absence of a tail in a pig, a bow in glasses, etc. Thus, a “left-brained” person turns out to be helpless when performing tasks that require orientation in a visual, figurative situation, requiring specific features to be taken into account objects.

Of particular interest is the behavior of a “left hemisphere” person in a situation where he is given freedom of choice, the opportunity to operate with visual or abstract signs at his own discretion.

4 cards are placed in front of a person: on one the Arabic numeral “5” is written, on the other the same number in Roman inscription (V), on the third Arabic number “10”, on the fourth the same number in Roman inscription (X) - and they are asked to divide these cards into two groups, putting the "same" together. Obviously, when dividing, one can be guided by an abstract sign of a number (and then fives will fall into one group, and tens into another), or a visual figurative sign - the inscription of numbers (and then Arabic numerals will fall into one group, and Roman numbers into another).

In a normal state, a person, as a rule, experiences doubts and indicates two equally probable ways of classifying. A “left-hemispheric” person does not experience hesitation, he invariably chooses an abstract symbolic sign - he always puts fives in one group, tens in another, regardless of the shape of the numbers.

From what has been said, it is clear that a “left hemisphere” person has a stratification of mental activity - figurative perception is defective, and the perception of words is facilitated; operating with visual concrete features of objects is defective, and operating with concepts is facilitated.

We encounter the same stratification in the study of memory. The “left hemisphere” person has a reserve of school theoretical information, that is, the knowledge acquired through words did not suffer. The ability to memorize new verbal material is also preserved - he can immediately, after hearing, repeat a series of words. And he remembers them for a long time and after 2-3 hours, already in his usual state, he can find among the many words those that he was given to memorize. However, if he is asked to remember not words, but irregular shapes that cannot be called a word, then the images of these figures will not be retained in the memory of a “left-brained” person.

There is another important characteristic of the behavior and psyche of such a person - understanding, or, as neurophysiologists say, understanding the environment, orientation in place and time. A "left-brained" person, based on his answers alone, appears to be well oriented. He correctly names the hospital in which he is located, the number of the department, the date, the day of the week. But it is worth asking him in more detail, and then it turns out that, correctly identifying his location in words, knowing that he is in the hospital, the “left-hemispheric” person does not recognize the room. He looks in bewilderment at the office, where he has been many times, and assures that he came here for the first time. Or, while correctly naming the date, he cannot support his answer with specific observations.

Sometimes, even looking at bare trees and snowdrifts outside the window, a “left-brained” person cannot immediately tell whether it is winter or summer. True, if you seek an answer, then he will report that “January - winter month”, but this is only a formal conclusion, and not the result of direct impressions. Thus, in a “left hemisphere” person, with intact verbal orientation, visual orientation in place and time is grossly violated.

One of the most striking changes mental state The “left hemisphere” person was affected by a shift in the emotional sphere. The mood of such a person improves, he becomes softer, more friendly, more cheerful. This shift is especially striking in patients with depression, that is, with a pathologically low mood. In the "left hemispheric" state, the gloominess and depression characteristic of these patients disappear; focus on painful experiences is replaced by interest in topics not related to the disease; an optimistic assessment of one's own situation appears, faith in recovery, the future is drawn as encouraging, a smile begins to play on the face, a tendency to joke appears.

Let us sum up what we have learned about the "left hemisphere" person, in other words, we summarize the facts that characterize the psyche of a person with the right hemisphere turned off, when only the left hemisphere is active.

What is defective, what is damaged? What has been preserved or enhanced? Those types of mental activity that underlie figurative thinking suffered. Those types of mental activity that underlie abstract theoretical thinking have been preserved or even intensified. Such stratification of the psyche is accompanied by a positive emotional tone.

"RIGHT HEMISPHERE" PERSON

Now let's see what is the antipode of the "left hemispheric" person - the "right hemisphere" person. This is the same person, but now his left hemisphere is turned off and only the right one works.

In contrast to the “left-hemispheric” person, the “right-hemispheric” person’s speech capabilities are sharply limited - the dictionary is poor, words denoting abstract concepts have fallen out of it, it is difficult to remember the names of objects, especially rarely used, although the “right-hemispheric” person can explain the purpose of any object and show how to use it. This suggests that he recognizes the objects. He understands speech poorly, it is necessary to speak with him in very short, simply constructed phrases. His own speech also consists of simple phrases, often individual words. The speech activity of a “right-handed” person is sharply reduced - he is laconic, more willing to respond with facial expressions and gestures than with a word. It is difficult to talk with him, briefly answering one or two questions, he falls silent. Speech attention is also reduced, when he is addressed, he does not notice this, you have to specially attract his attention. The threshold for detecting speech sounds in a "right hemisphere" person is increased - he notices only loud-sounding words. But even quite loudly spoken words, he is far from always able to correctly perceive and repeat, although such a drop in sensitivity to the sounds of speech is not at all associated with any hearing impairment.

At the same time, the voice of a “right hemisphere” person remains the same as it was: despite the stinginess of speech, its intonation pattern is preserved. Hearing for the prosodic components of speech did not suffer either: a “right-brained” person even better than usual, distinguishes between male and female voices, and more accurately and correctly assesses the intonations of the interlocutor.

If attention to words in a “right hemisphere” person is reduced, then when listening to various non-verbal sounds, he is both attentive and active. He recognizes these sounds even easier and faster than in the usual "bihemispheric" state, although, for example, such a sound as the roar of the surf was rarely recognized by people in the normal state and with great difficulty. Listening to the melodies of songs, a “right-brained” person recognizes them much faster than usual. Not only that, he has a need to hum them, he does not even have to be asked about it. Unlike himself in his “left brain” state, he now reproduces melodies very accurately. However, if you ask him to classify sound images, he will refuse, this task is too much for him.

As you can see, the “right hemisphere” person also had a restructuring of perception. But it is opposite to that observed in the "left hemisphere": in the "right hemisphere" person, we are faced with a special condition - a deterioration in verbal perception and a selective improvement in all types of figurative perception.

This is confirmed by other studies. A “right-brained” person easily picks up pairs of triangles and squares, divided into shaded or colored sectors, and does it faster than in the normal state. He has no difficulty in evaluating unfinished drawings and quickly notices the defect in the image. The predominance of figurative perception comes out especially effectively in a situation where the “right hemisphere” person is given the freedom to choose a feature. Classifying four cards with Arabic and Roman numerals, he chooses a visual font feature, and not an abstract numerical one - he combines Roman numerals into one group, Arabic numerals into another. He recognizes all the numbers, but when classifying, he focuses on the way they are drawn, and not on the meaning of the numbers.

The memory of a "right hemisphere" person acquires traits opposite to those observed in a "left hemisphere" person. School theoretical baggage, that is, knowledge acquired through words, has been largely lost. The ability to memorize words is also impaired. A “right-brained” person cannot repeat a series of several words immediately after listening, at best, he will repeat 2-3 from the left out of 10. But even if you manage to keep these words in memory for a while, then after 2 hours he will no longer remember them and will not find among other words. At the same time, he retained his figurative non-verbal-spring memory - he is able to remember figures of a bizarre shape and in a few hours choose them among many others.

Orientation in place and time in the "right hemisphere" person is also changed, but differently than in the "left hemisphere". If you rely only on the answers, then the "right hemisphere" person seems completely disoriented - he cannot say where he is, name the date and even the year. However, he notices the details of the situation and, based on these observations, will say that he is probably in the hospital, although he does not know which one. He recognizes the office in which the research is taking place, although he does not say what the purpose of this office is. Being unable to name either the month or the year, he, looking out the window, will correctly determine the time of year and presumably tell what month it is. Thus, in the absence of verbal orientation, the visual concrete orientation of the "right hemisphere" person is preserved.

Recall that the "left brain" state was accompanied by a change in mood. And in the “right hemispheric” state, an emotional shift occurs, but the opposite in sign - towards negative emotions. The mood worsens, the person becomes gloomy, pessimistically assesses both his current situation and his prospects, complains of feeling unwell. It is difficult to distract him from sad thoughts and complaints.

Let's summarize what we have learned about the "right-brained" person - a person with a turned off left hemisphere. Obviously, here, too, we are dealing with a disorganized psyche, but this disorganization is different from that of a "left lobe" person. In the "right hemisphere" those types of mental activity that underlie abstract theoretical thinking have suffered, and those types of it that are associated with figurative thinking have been preserved or even intensified. This type of stratification of the psyche corresponds to a negative emotional tone.

TWO HEMISPHERES - TWO DIFFERENT KINDS OF THINKING

So, we got acquainted with people who are very different from each other in terms of mental make-up: a “left hemisphere” person - a person with an exaggerated abstract, but defective figurative thinking, and with a “right hemisphere” human-human with exaggerated figurative, but defective abstract thinking. But this is the same person - only in the first case, his right hemisphere is inactive, and he thinks and feels with one left hemisphere, in the second case, his left hemisphere is inactive, and he thinks and feels with one right hemisphere. Now we can draw a definite conclusion; behind the functional asymmetry of the brain lies a certain principle; the left hemisphere is the base of logical abstract thinking, the right hemisphere is the base of concrete figurative thinking. One can also say this: the functions of each hemisphere represent an integral, complete system - an apparatus that serves a certain type of thinking. Accordingly, each hemisphere, each apparatus has its own set of tools - its own speech, its own memory, its own emotional tone. Let's compare "left hemisphere" and "right hemisphere" instruments.

The starting point of the study of the functional asymmetry of the human brain, as mentioned, was the discovery of the exclusive role of the left hemisphere in speech activity. And today, researchers use the words "left" and "speech" hemisphere as synonyms. However, the "unihemispheric" person showed that the situation is both more complicated and more interesting. Indeed, verbal speech - and the "creation" of words and their perception - is entirely related to the activity of the left hemisphere. And this is understandable. A system of words is a system of symbols, generalizations that have risen above immediate individual phenomena. Only on the basis of such a system of symbols, or, as they say now, on the basis of a sign system, could abstract theoretical thinking develop.

But in speech there is also a non-verbal means of communication, a non-verbal carrier of information - intonation and voice. Both the intonation of one's own speech and the perception of intonations are associated with the activity of the right hemisphere. We have already said that speech intonation carries an extremely important semantic load. Only in a system of intonations does a word or phrase acquire a specific meaning, adequate to the given moment and given circumstances. Likewise, the voice itself is an individual characteristic of speech. The meaning of the message also depends on whether the message belongs to a man or a woman, a friend or a stranger, a friend or a foe. In this case, the connection of the intonation-voice components of speech with the right hemisphere is also understandable; after all, the right hemisphere is in charge of the world of specific individual phenomena.

The intonation-voice side of speech is, in essence, the melodic, musical side, which is reflected in the name itself - the prosodic characteristics of speech. But we already know that musical ability is also under the jurisdiction of the right hemisphere. It follows from this that, by origin, the prosodic characteristics of speech are associated with the activity of the right hemisphere.

"Right hemisphere" speech is older in its evolutionary age, older than "left hemisphere". Highly organized animals leading a herd life transmit each other a danger signal and other signals precisely by intonation modulations of the voice. The great antiquity of this communication channel is also revealed in the study of the formation of speech in a child. The law of biology states that the individual development of an organism (ontogenesis) is a brief repetition of the development of the animal world (phylogenesis). Therefore, the sequence of formation of functions in ontogenesis helps to reveal the evolutionary age of these functions. The research of R. Tonkova-Yampolskaya showed that in the buzz and babble of babies, the intonations characteristic of adults appear long before the formation of verbal speech. It is also known that the child begins to understand intonation earlier than words.

So, in human speech it is necessary to distinguish between two channels of communication: verbal, purely human, evolutionarily young - left hemisphere - and prosodic, common with animals, more ancient - right hemisphere.

On a "one-hemispheric" person, we found that the isolated activity of each hemisphere is associated with a certain range of emotional states: the left - with a positive scale, the right - with a negative one. It is extremely difficult to explain this unexpected fact. One can only assume that behind such a “divergence” of emotions lies an important pattern - a closer connection between abstract thinking and a positive emotional tone and figurative thinking with a negative emotional tone. This pattern has already been noticed by neurophysiologists. A prominent specialist in the field of physiology of emotions P. V. Simonov, based on an analysis of the characteristics of conditioned reflexes formed against the background of negative and positive emotional states, expressed an interesting idea: “Negative emotions tend to operate with specific images .., while positive emotions contribute to the transition to abstract, generalized models.

Perhaps the reason for the connection of different emotional states with different types of thinking, with the activity of different hemispheres, should also be sought in evolution, in the history of the formation of mental activity. N. N. Traugott, studying the patterns of depression and restoration of mental functions in acutely emerging pathological conditions of the brain, showed that evolutionarily older types of mental activity are oppressed later than others and restored earlier than others. At the same time, it turned out that in the process of brain suppression, positive emotions disappear first from emotional reactions and negative ones last. When restoring brain activity, the sequence is reversed. Thus, there are reasons to think that negative emotions have a greater evolutionary age than positive ones. This is indicated by the earlier maturation of negative emotional reactions in infants compared to positive ones.

We already know that the most ancient components of speech are associated with the right hemisphere. Now we see that older emotions are also associated with the right hemisphere. One should not only think that emotional mechanisms are embedded in the very cortex of the hemispheres. Emotional reactions are associated with the activity of the deep parts of the brain - the subcortical nuclei. The hemispheres of the brain exert only regulatory influences on these nuclei, and, as we have seen, the influences of the right and left hemispheres are different.

The "one-hemispheric" man showed us that each hemisphere has its own memory, its own archive. Both physiologists and psychologists are well aware that memory is not just a storehouse where obsolete materials are sent for long-term storage. Memory is closely connected with the current mental activity, is an indispensable participant in the processing of information. We have seen that each kind of thinking keeps its working archive on its territory. Obviously, the right hemispheric archive - memory for individual concrete phenomena - is also older than the left hemisphere, verbal archive. After all, memory for specific objects and phenomena is well developed even in animals that are lower than mammals on the evolutionary ladder. Children who do not yet know how to speak already have a figurative memory. With acute inhibition of brain activity, verbal memory is disturbed earlier than figurative memory and is restored later than figurative memory, which also indicates a more respectable evolutionary age of figurative memory.

So, evolutionarily more ancient components of complex mental functions are connected with the right hemisphere: speech, memory, emotions. But after all, figurative thinking itself is older than abstract verbal thinking. Subtle and complex perception of specific phenomena of the surrounding world, of course, makes us related to our younger brothers - animals, while abstract thinking was the evolutionary achievement that put us above all living things. It was the functions of the left hemisphere that lifted man to dizzying heights. With certain reservations, we can say that animals have two "right" hemispheres, although, of course, one cannot put an equal sign between the right hemisphere of a person and the hemispheres of animals, even the most highly organized.

And here we come to one of the most intriguing questions of the doctrine of the functional asymmetry of the human brain; how did it form, how did the anatomically and functionally symmetrical animal brain turn into the functionally asymmetric human brain? Let's say right away: there is no definite answer to this question. The problem of the formation of functional asymmetry still remains an area of ​​conjecture and conjecture. This problem has two aspects.

First. Why are new, specifically human functions associated with the activity of one left hemisphere: verbal speech and abstract thinking? According to the most common point of view, the development of new functions in the left hemisphere is due to the leading role of the right hand (and it is controlled by the left hemisphere) in labor activity. This point of view is based on the observation that already in the higher apes, our closest relatives, the predominance of one of the upper limbs - right or left - is outlined in the process of complex motor acts.

However, this assumption still requires more solid justification and further research. Most recently, the American researcher R. Doty found that even macaque monkeys have a hint of unequal hemispheres when controlling certain complex shapes behavior. If this is so, then we can think that some prerequisites for the future functional specialization of the hemispheres already existed in our distant ape-like ancestor. Whatever the reason for the “chosenness” of the left hemisphere, it can be assumed that already from those early stages of the formation of a person, when verbal speech began to form, this process was associated with the activity of the left hemisphere.

Second aspect of the problem. What consequences could the connection of the left hemisphere with the formation of verbal speech have? It is known that when any part of the brain acquires new and more complex functions, then the old functions characteristic of this department in the past are suppressed, become rudimentary. Obviously, such a process must have taken place as verbal speech was formed. The functions associated with imaginative thinking inherited from animal ancestors in the left hemisphere should have been suppressed in this hemisphere, becoming rudimentary. At the same time, the right hemisphere also evolved. But its evolution was a continuation, improvement of those functions that the right hemisphere inherited from animal ancestors - figurative thinking became more complicated and developed. This is how a "distortion" in the work of the brain arose - a functional asymmetry of the human brain - and two independent apparatuses of thinking were formed.

Interestingly, the process of division of functions between the hemispheres can be observed in early childhood. We have already said that the individual development of an organism is essentially a historical play, a concise repetition of the entire evolution of the animal world. The last act of this play is played out before our eyes after the birth of the child. A child is born with a "bi-right hemisphere", he does not yet have a "verbal" hemisphere. According to W. Penfield and L. Roberts, up to two years, any hemisphere can take on this honorary role. Only with age does a healthy child establish a division of "spheres of influence" between the hemispheres. But this doesn't happen to everyone. In almost a third of people, the hemispheres do not acquire a clear functional specialization. But this is a new and also very interesting problem, which we will not touch on in this article.

So, the professional specialization of the hemispheres is completed in a person after birth, and as he grows up, a demarcation line is established between the apparatuses of figurative and abstract thinking. And then it turns out that the individuality of a person, the peculiarities of his psyche depend on which of the apparatuses acquires leading significance. About 40 years ago, the greatest physiologist of our century, I. P. Pavlov, wrote about two types of people: “Life clearly points to two categories of people: artists and thinkers, there is a sharp difference between them. Some are artists... they capture reality as a whole, completely, completely, living reality, without any fragmentation... Others are thinkers, they crush it..., making some kind of temporary skeleton out of it, and then only gradually, as it were, put it back together again. parts of it and try to revive them in this way ... "

In the era of I.P. Pavlov, the science of the brain did not yet have enough information about the functional specialization of the hemispheres, and the above classification of people remained without anatomical justification. Today we already have the necessary information. "Artists" are people with a predominance of "right hemisphere" figurative thinking, that is, with a more active, stronger right hemisphere. "Thinkers" - people with a predominance of "left hemisphere" abstract thinking, that is, with a more active left hemisphere. The American researcher J. Bogen showed that the predominance of the activity of one of the hemispheres, along with innate factors, may be due to the peculiarities of education and training, that is, training.

TWO HEMISPHERES - ONE BRAIN

So far, we have considered the activity of each hemisphere in isolation, as if a person has two different, unrelated brains. In fact, normal mental activity involves the joint work of both hemispheres. But what does collaboration mean? In neurophysiology, this problem is formulated as the problem of the interaction of the hemispheres.

A "right hemispheric" person perceives the world in all its specific richness and diversity. But since he is deprived of theoretical thinking, he fails to analyze his impressions, establish a logical connection between them, correlate them with certain categories, and therefore his wealth does not bear fruit. The same person, but in the "left hemisphere" state, retains the ability to analyze and generalize, to logical operations, but cannot use them, since he has nothing to analyze and generalize. Obviously, only the simultaneous work of both hemispheres, the unification of the mechanisms of figurative and abstract thinking provide a comprehensive, concrete and theoretical coverage of the phenomena of the external world.

But we also saw something else on the "one-heavy" person. When the right hemisphere is turned off, verbal activity is facilitated, that is, the activity of the left hemisphere increases. When the left hemisphere is turned off, figurative perception is aggravated - the activity of the right hemisphere increases. This means that in the usual "bihemispheric" state, each hemisphere slows down the activity of the other.

Thus, both hemispheres are not independent of each other. There are complex and conflicting relationships between them. On the one hand, they take part in the work of the brain in a friendly manner, complementing the abilities of each, on the other hand, they compete, as if preventing each other from doing their own thing. If the meaning of friendly, so-called complementary, interaction is clear, then the meaning of competitive - in other words, reciprocal - does not lie on the surface. Let's try to figure it out.

In the nervous system, excitation is always accompanied by inhibition. The inhibitory process prevents the spread of excitation to areas that should not participate in this activity; reduces the intensity of excitation, which allows you to accurately dose its strength and, finally, stops excitation when it is no longer needed. Without the inhibitory process, the activity of the nervous system becomes chaotic, uncontrollable, self-destructive. Therefore, the more complex this or that part of the brain is built, the more complex its functions, the more complex its inhibitory apparatus is built. Obviously, such an apparatus is especially important for the higher parts of the brain. Indeed, each hemisphere contains inhibitory mechanisms in itself (chains of special inhibitory neurons), the hemispheres are also under the inhibitory influence of the subcortical nuclei, and, finally, as we have seen, each hemisphere experiences inhibitory influences from its partner.

But the mutually inhibiting influence of the hemispheres has another special mission. In order to adequately respond to changing circumstances and various situations that life confronts a person, it is necessary either to combine the abilities of the right and left hemispheres, or to use the abilities of one of them to the maximum. When a mathematician operates with multidimensional space and imaginary values, his abstract thinking is extremely sharpened. But the same person driving a car in an emergency will be able to avoid a catastrophe, only instantly covering a completely real space and quite real objects, that is, by sharpening the figurative perception to the utmost. Reciprocal interaction allows you to always have reserves ready, allows you to very finely and accurately balance the activity of the hemispheres and thereby observe the most beneficial in this moment correlation of figurative and abstract thinking.

Doesn't the answer to another mysterious question lie here - what is the meaning of functional asymmetry, what "benefits" does it promise the brain? After all, nature ruthlessly eliminates everything that does not benefit the body, but meticulously selects and preserves everything that is useful. We just said that there are situations when you need to make the most of one kind of thinking. Obviously, in order to be able to separately activate the apparatuses of figurative and abstract thinking, they must be separated from each other, located in different parts of the brain, so that the sharpening of some abilities is not accompanied by the sharpening of others.

Complementary interaction is called upon to combine the abilities of the two hemispheres; to maintain a balance between the abilities of each hemisphere, at the right time to raise one scale and lower the other, the reciprocal interaction of the hemispheres is called upon. In general, the complex dual nature of interhemispheric relationships makes it possible to "optimize" mental activity and behavior.

So, we have seen that there is no major and minor, "large" and "small" hemispheres. The right hemisphere, the base of figurative thinking, embraces the world of phenomena in all its richness and diversity. The left hemisphere - the base of abstract thinking - seeks and finds in this world the harmony of causes and effects. A full-fledged psyche implies a coordinated and balanced work of both hemispheres.