Body image, or body scheme, is a subjective representation, according to which a person makes a judgment about the integrity of his body, evaluates the position of its parts and their movement.

For neurologists of the past, the body schema was a postural model (see: Head 1920). Schilder (1935) in his book Image and Appearance of the Human Body argued that the postural model is only the lowest level of body schema organization and that there are also higher psychological levels based on emotion, personality and social interaction. It is known that in clinical practice there are anomalies in body image that affect much more important points than the quality of posture or movement. These anomalies occur in both neurological and psychiatric disorders; in many cases, organic and psychological factors act in combination. Unfortunately, neither the psychiatric nor neurological disorders that are the causes of body image disorder have yet been fully elucidated. In the following description, we broadly follow the outline proposed by Lishman (1987) and recommend the relevant sections (pp. 59-66) of his book and the review by Lukianowicz (1967) to the reader who needs more information about these disorders. term "phantom limb" It is customary to designate a lingering sensation of a lost part of the body. As such, this is perhaps the most compelling evidence in favor of the body schema concept. This phenomenon usually occurs after amputation of a limb, but similar cases have been described after removal of the mammary gland, genitals or eyes (Lishman 1987, p. 91). Sensation of a phantom limb usually occurs immediately after amputation, it may be painful, but under normal conditions, as a rule, gradually disappears, although in a small proportion of patients it persists for years (see neurological manuals or the review of Frederiks (1969)).

Unilateral lack of self-awareness body And "inattention" to the affected side- the most common neurologically caused disorder of the perception of one's own body. It usually affects the left limbs and most often occurs due to damage to the supramarginal and angular gyri of the right parietal lobe of the brain, in particular after a stroke. With a pronounced disorder, the patient sometimes forgets to wash the affected side of the body, does not notice that he has shaved only one side of his face or that he has put on only one shoe. In the mildest form of this disorder, it can only be detected by special testing using double stimulation (for example, it can be concluded that there is a violation if the examiner touches the patient's wrists with a cotton swab, and the latter registers the touch only on one side, although when he does it itself, sensation is present on both sides.) For more information, see Critchley (1953), whose book contains a detailed description of the syndromes resulting from damage to the parietal lobes of the brain. higher than the disorder The patient reports a sensation of loss of one limb, usually the left The disorder may occur on its own or together with hemiparesis Often it is accompanied by unilateral spatial The degree of awareness of this phenomenon varies: some patients are aware of what is actually limb in place, although I feel they are convinced of its absence, while others are fully or partially convinced that there really is no limb.

Anosognosia is a lack of awareness of the disease, which also usually manifests itself on the left side of the body. Most often, this violation occurs for a short time in the first days after acute hemiplegia, but sometimes it persists steadily for a long period. The patient does not complain about the loss of function of the paralyzed side of the body and denies this fact when anyone points to it. Dysphasia, blindness may also be denied (Anton's syndrome), Or amnesia (most pronounced in Korsakov's syndrome).

Pain asymbolism- a disorder in which the patient feels a painful (for normal perception) stimulus, but does not evaluate it as painful. Although such disorders are clearly associated with cerebral lesions, a psychogenic element is suggested by which the awareness of unpleasant phenomena is suppressed (see, for example, Weinstein and Kahn 1955). Of course, organic damage could hardly act in the absence of psychological reactions, but it is unlikely that the latter are the only cause of the pathological condition, since it occurs much more often on the left side of the body.

Autopagnosia- this is the inability to recognize, name or indicate according to the command of the parts of one's body. This disorder can also manifest itself in relation to another person, but not in relation to inanimate objects. This rare condition occurs due to diffuse lesions, usually affecting both hemispheres of the brain. Almost all cases can be explained by comorbidity, dysphasia, or a disorder of spatial perception (see: Lishman 1987, p. 63). Distorted awareness of size and shape It is expressed in the fact that a person feels as if his limb is increasing, decreasing, or somehow deformed. Unlike the disorders already described, these sensations are not directly related to damage to specific parts of the brain. They can also occur in healthy people, especially when falling asleep or waking up, as well as when they are very tired. Similar phenomena have sometimes been noted during migraine, in acute cerebral syndromes, after LSD ingestion, or as a component of the epileptic aura. Changes in the shape and size of body parts (in the Russian-language literature, the term violation of the body scheme is used) are also described by some patients with schizophrenia. Almost always, with the exception of some cases, the unreality of this sensation is realized.

doubling phenomenon is the feeling that any part of the body or the whole body is doubled. Thus, the patient may feel as if he has two left arms, or two heads, or as if his whole body has doubled. Such phenomena occasionally occur during migraine, with, as well as with schizophrenia. In an extremely pronounced form, a person has an experience consisting in the consciousness of having a copy of the whole body, a phenomenon already described as autoscopic

Body scheme - an internal representation constructed by the brain, a model of the body that reflects its structural organization and performs such functions as determining the boundaries of the body, forming knowledge about it as a single whole, perceiving the location, lengths and sequences of links, as well as their ranges of mobility and degrees of freedom. The body scheme is based on a set of ordered information about the dynamic organization of the subject's body.

Body scheme - an image of one's own body (not always conscious), which allows the subject to imagine at any time and in any conditions the relative position of body parts in the absence of any external sensory stimulation. This is an internal reference system, thanks to which the relative position of body parts is determined. It plays a decisive role in building coordinated movements when moving in space, in the processes of maintaining and regulating posture.

The sources of ideas about the body scheme were observations from antiquity known and described in the 16th century of the phenomenon of the phantom of an amputated limb, as well as clinical observations of patients with certain types of cerebral pathology, who had distortions in their ideas about their own body and the surrounding space.

In 1911, H. Head and G. Holmes proposed a definition of the body schema, close to the modern one, as a representation of the size, position and interconnection of body parts formed in the cerebral cortex during the synthesis of various sensations. The researchers also suggested that the body schema serves to transform sensory information, which is necessary both for perception and for planning and organizing movements.

Normally, the perception of the body schema seems dim, one might even say vague, but any disorder of the schema is painfully perceived by consciousness as a violation of the vital basis of the organism. The schema of the body is instead a very stable formation, which is proved by the phenomenon of the phantom of amputated limbs, when, despite the absence of a limb, the subject continues to perceive the schema of the whole body, including the removed limb.

The rich experience of clinical observations of the phantom of amputated limbs made it possible to identify the following important features that prove the connection of this phenomenon with the existence of a body schema model in the human central nervous system:

1. after amputation of a limb, phantom pains occur in more than 90% of cases - therefore, they are not pathologies of the psyche, but are a reflection of the presence of a representation of a limb in the body scheme;

2. there are descriptions of phantom pains in the case of a congenital absence of a limb, which indicates the presence of a congenital basis for the body schema;

3. phantom pains are more often the result of amputation of those links that are capable of voluntary movements (that is, with amputation of limbs); in addition, in the phantom, the distal (that is, more distant from the median plane of the body) sections of the remote limb, which have rich sensory and greater mobility, are most clearly perceived;

4. some patients after amputation retain the illusion of the possibility of movement of the amputated limb, and it can also be taken into account when planning actions, which confirms the idea that there is an internal model necessary for organizing movements.

With certain brain lesions, there are disturbances in the perception of space and one's own body, testifying in favor of the existence of an internal model of the body schema. The following manifestations of a violation of the body scheme are observed: changes in the shape, size and severity of individual parts of the body, their disappearance, their separation (the head, arms are felt, but separately from the rest of the body), displacement of parts (the head, shoulders failed, the back is in front, etc. .), increase, decrease, change in the shape and gravity of the whole body, bifurcation of the body (feeling of a double), disappearance of the whole body. Body schema disorders tend to be associated with various other sensory disorders. Most often, we are talking about peculiar visual deceptions of the senses in the form of geometrically optical disorders, when the subject sees objects distorted, turned upside down, reduced or enlarged in volume, etc., polyopia (multiplication of objects in a number), porropsy (violation of vision in depth: objects seem too distant or vice versa). In other cases, body schema disturbances are accompanied by disturbances in general sense and vestibular symptoms. In disorders of the body scheme and in the indicated optical and vestibular symptoms, the main one is a violation of spatial schizoid perceptions concerning both one's own body and the outside world.

With lesions of the right parietal lobe, there are violations of ideas about the belonging of body parts, their size and shape. The following cases can be listed as examples of such distorted ideas about one's body: denial of belonging to the patient of paralyzed limbs, illusory movements of motionless limbs, denial of a defect by the patient, phantom additional limbs. With lesions of the parietotemporal junction, in addition to a violation of the ability to maintain balance, phenomena of the so-called "exit from the body" can be observed. In addition, disturbances in the perception of one's own body and its parts can occur in a person in altered states of consciousness: under the influence of hallucinogens, hypnosis, sensory deprivation, in sleep.

An interesting feature of the body schema model is its ability to "increase": it can be extended to a tool, an object with which the subject performs an action.

The presence of a body scheme can be verified by conducting a small experiment. To do this, you need to cross the index and middle fingers of one hand so that a sufficiently large gap forms between their “crowns”. After that, close your eyes, bring your fingers to your nose, place your nose in this gap and, focusing on the sensations emanating from your fingers, move them lightly along your nose with light touches. With a successful experiment, two noses will be perceived instead of one. The essence of the phenomenon lies in the fact that with such a position of the fingers, those of their surfaces that in this experiment feel the nose, in the usual position, can simultaneously come into contact with only two objects. The sensations that usually emanate from these finger surfaces are part of the hardened body schema. In this experiment, we are confronting the unusual spatial arrangement of available sensations with the usual body scheme, which determines their interpretation.

When the upper parietal region of the cerebral cortex is affected, which is adjacent to that part of the primary sensory cortex of the skin-kinesthetic analyzer, where information from the whole body is projected, a different clinical picture is observed. In these cases, the most common symptoms violations of the "body schema" or somatoagno-zii(disorder of recognition of body parts, their location in relation to each other).

Usually the patient is poorly oriented in one left half of the body (hemisomatognosia), which accompanies the defeat of the right parietal region of the brain. The patient ignores the left limbs, sometimes as if "losing" them. This creates false somatic images. (somatopa-gnosia) in the form of sensations of a “foreign” hand, an increase or decrease in body parts (hands, heads), doubling of limbs.

It is important to note that there are clear lateral features of tactile function disorders in lesions of the parietal regions of the brain. Both lower and upper parietal syndromes of damage to the left and right hemispheres of the brain manifest themselves in different ways. The syndromes of lesions of the anterior and posterior parts of the parietal region are also different.

The ability to draw a figure, previously identified by touch, suffers to a greater extent with damage to the posterior parts of the parietal cortex adjacent to the occipital lobe, and tactile gnostic disorders are more pronounced when the anterior parts of the parietal cortex are affected. In general, object tactile agnosia (astereognosis) and digital agnosia and somatognosia are more roughly expressed in lesions of the right hemisphere of the brain. Tactile alexia is most often associated with a left-sided lesion of the parietal cortex.

Diagnosis of tactile agnosia

The study of touch requires the active participation of the child, which must be taken into account both when choosing a survey technique and when assessing the reliability of the data obtained. As the patient becomes tired, the number of errors in the answers increases, and therefore the examination should not be carried out for more than a few minutes. It is necessary to make sure that the child correctly understands the

keeping instructions, and be aware of the possibility of suggesting certain disorders when using leading questions.

Surface sensitivity(painful) is examined by a needle prick. Temperature - by touching test tubes filled with hot and cold water. To determine tactile sensitivity, a touch with a cotton swab, brush or strip of paper is used.

Deep Sensitivity is evaluated by the patient's responses and his defensive reaction to intense pressure in certain areas of the body (upper edge of the orbit, sternum, phalanges and small joints of the fingers). Joint-muscular feeling is studied with the help of passive movements in various segments of the body, the direction of which the patient must determine without the help of vision.

The sense of position is also being investigated - the patient's ability to determine the position of parts of his body in space and touch them with his eyes closed. The sense of weight is studied with the help of objects that are the same in shape and size, but have different weights.

Sometimes sensitivity disorders are detected only with the simultaneous application of two stimuli of similar intensity. Usually, tactile and pain stimuli are used, which are applied simultaneously on symmetrical parts of the body on the right and left. In some cases, the phenomenon of sensory inattention is noted.

Complex types of sensitivity are investigated after studying simple species, since knowledge of the state of the latter is necessary for a correct assessment of the results obtained.

stereognostic sense(the ability to recognize familiar objects by touch) is examined with the patient's eyes closed: he must recognize objects that are put into his hand (pen, spoon, watch). 2D spatial sense is determined by drawing numbers or figures on the patient's skin, which he must name with his eyes closed.

Discriminatory sensitivity examined using Weber's sliding compass. The ability to separate perception of two simultaneously applied stimuli in different parts of the body ranges from 0.2 to 6 cm.

The ability to localize irritation and determine the direction of displacement of the skin is also being studied.

folds - kinesthetic sensitivity. It is advisable to fix the identified disorders on special body drawings, where the nature and prevalence of changes in sensitivity are noted.

Research on somatosensory gnosis in children includes the study of simple and complex forms of sensitivity using special tests. Touch localization tests are carried out: it is proposed to show the point on the hand that the doctor touched, as well as the corresponding point on the opposite hand. The possibility of distinguishing geometric shapes and numbers that the researcher draws on the child's skin is being explored. The preservation of the stereotactic sense is assessed - with the child's eyes closed, the doctor puts an object in his hand (ball, cube, scoop - for preschool age; pencil, ruler, key, watch - for school age). The subject must recognize it by touch.

When conducting a neuropsychological study, an analysis of somatosensory gnosis is carried out. The patient may have complaints about a decrease or a pathological increase in somatic sensitivity, discomfort, a violation of the body scheme, etc. During the study, the following tests are performed:

on the localization of touches (on one hand, on two, on the face);

discrimination (determine the number of touches: one or two);

skin-kinesthetic sense (on the right and left hand), Foerster's sense (definition of figures, numbers written on the skin);

transferring the posture (position of the arm and hand) from one hand to another with eyes closed;

determination of the right and left sides at oneself and opposite the seated person;

naming fingers;

object recognition (key, comb and etc.) to the touch with the right, and then with the left hand (the nature of the feeling is noted: inactive, active with no synthesis, etc.).

Questions and tasks

What are the main manifestations of tactile agnosia?

Give examples of methods for diagnosing auditory, visual and tactile agnosias.

Test 7

1. The inability to recognize by touch the object put into the hand is:

a) anosognosia;

b) autopagnosia;

c) astereognosis.

2. The lesion in tactile agnosia is located:

a) in the left temporal lobe;

b) left frontal lobe;

c) left cerebellopontine angle;

d) secondary fields of the cortex of the parietal region of the brain;

e) medulla oblongata.

3. "Finger agnosia" - a violation of the ability to recognize fingers with closed eyes is sometimes referred to as:

a) Gershtman's syndrome;

b) Argil-Robertson syndrome;

c) Bernard-Horner syndrome.

4. The phenomenon of violation of tactile recognition of numbers or letters is called:

a) tactile alexia;

b) frontal ataxia;

c) causalgia.

5. Symptoms of violation of the "body scheme" are called:

a) hyperesthesia;

b) somatognosia;

c) autopagnosia.

6. Hemisomatognosia is a violation of:

a) orientation in one half of the body;

b) the ability to draw a figure previously identified by touch;

c) identification of the material from which the object is made.

7. Amnestic aphasia is:

a) forgetting the name of the subject;

b) the impossibility of switching from syllable to syllable;

c) repetition of a consonant in the middle of a syllable.

Violation of the body scheme is a violation of orientation in one's own body, which, apparently, is associated with a violation of the higher synthesis of sensitive perceptions in the parietal region. It may seem to the patient that his head is unreasonably large, his lips are swollen, his nose is stretched forward, his arm is sharply reduced or enlarged and lies somewhere nearby, separately from the body. It is difficult for him to understand the "left" and "right". Violation of the body scheme is especially pronounced in a patient with left-sided hemiplegia with simultaneous hemianesthesia and hemianopsia. He cannot find his hand, shows that it starts from the middle of the chest, notes the presence of a third hand, does not recognize his paralysis and is convinced that he can get up and go, but "does not do it" because he "does not want to." If a patient is shown his paralyzed hand, he does not recognize it as his own. These phenomena of anosognosia (lack of consciousness of one’s illness) and autotopagnosia (unrecognition of parts of one’s own body, see) in the presence of diffuse atherosclerotic lesions of the vessels of the cerebral cortex are sometimes combined with their delusional interpretation, the patient, for example, claims that the sick hand is not his, but was thrown to him in bed, that he put his foot in a corner, etc. Various kinds of paresthesia painfully transform into colorful lush delirium. With right-sided hemiplegia, such disorders of the body schema are observed less frequently, since the body schema is more provided by the parietal region of the right hemisphere.