The disorder of recognition of parts of one's own body is called. Auditory recognition disorders (auditory agnosia). General principles of operation of analyzer systems

agnosia (from Greek a - negative particle + gnosis - knowledge)- violation various kinds perception that occurs when the cerebral cortex and the nearest subcortical structures are damaged. A. is associated with damage to the secondary (projection-associative) sections of the cerebral cortex, which are part of the cortical level of the analyzer systems. The defeat of the primary (projective) sections of the cortex causes only elementary disorders of sensitivity (impairment of sensory visual functions, pain and tactile sensitivity, hearing loss). When defeated secondary departments in the cerebral cortex, elementary sensitivity in humans is retained, but it loses the ability to analyze and synthesize incoming information, which leads to disruption of recognition processes in different modalities.

There are several main types of Agnosia: visual, tactile, auditory.

Spotting Agnosia occur with damage to the secondary sections of the occipital cortex. They manifest themselves in the fact that a person - with sufficient preservation of visual acuity - cannot recognize objects and their images (subject Agnosia), distinguish the spatial features of objects, the main spatial coordinates (spatial A.); the process of identifying faces is disturbed while the perception of objects and their images is preserved (A. on faces, or prosopagnosia), the ability to classify colors is impaired while color vision is preserved (color Agnosia), the ability to distinguish letters is lost (letter Agnosia) (this type of A. lies at the heart of one of the forms of impaired reading, see Alexia), the volume of simultaneously perceived objects is sharply reduced (simultaneous Agnosia). The nature of visual A. is determined by the side of the lesion and the localization of the focus within the secondary cortical fields of the occipital regions of the cerebral hemispheres and the parietal and temporal regions adjacent to them.

Tactile Agnosia arise when the secondary cortical fields of the parietal lobe of the left or right hemisphere are damaged and manifest themselves as a disorder in the recognition of objects by touch (astereognosia) or in a violation of the recognition of parts of one's body, a violation of the body scheme (somatognosia).

Auditory Agnosia occur with damage to the secondary cortical fields of the temporal lobe. With damage to the temporal cortex of the left hemisphere, auditory or auditory-speech A. manifests itself in the form of a violation of phonemic hearing, i.e. impaired ability to distinguish speech sounds, which leads to a speech disorder (see Aphasia); when the temporal cortex of the right hemisphere is damaged (in right-handed people), auditory A. itself occurs - the inability to recognize familiar non-musical sounds and noises (for example: barking dogs, creaking steps, the sound of rain, etc.) or amusia - the inability to recognize familiar melodies, disorder musical ear. (E.D. Khomskaya)

Psychological dictionary. A.V. Petrovsky M.G. Yaroshevsky

agnosia (from Greek a - negative particle and gnosis - knowledge)- a violation of various types of perception that occurs with certain brain lesions. Distinguish:

  1. visual A., manifested in the fact that a person, while maintaining sufficient visual acuity, cannot recognize objects and their images;
  2. tactile A., manifested in the form of disorders of recognition of objects by touch (astereognosia) or in violation of the recognition of parts of one's own body, in violation of the idea of ​​\u200b\u200bthe body scheme (somatognosia);
  3. auditory A., manifested in a violation of phonemic hearing, i.e. the ability to distinguish speech sounds, which leads to its disorder (see Aphasia), or in violations of the ability to recognize familiar melodies, sounds, noises (while maintaining elementary forms of hearing).

Dictionary of psychiatric terms. V.M. Bleikher, I.V. Crook

agnosia (and Greek gnosis - knowledge)- impaired recognition of objects and phenomena in a state of clear consciousness and the preservation of the functions of the organs of perception themselves. Sometimes the correct perception of individual elements of the object being identified is preserved. A. can be complete and partial. It is observed in organic lesions of the brain, capturing the cortical zones of the corresponding analyzers, the zones of their representation in the brain.

  • Agnosia ACOUSTIC- manifested by impaired recognition of sounds, phonemes and objects by their characteristic sounds. Complete A. acoustic is called mental deafness. Syn.: A. auditory.
  • Agnosia PAIN- characterized by impaired perception of pain stimuli.
  • Agnosia VISUAL(OPTICAL) - characterized by impaired recognition of visual images of objects and phenomena. The following forms are distinguished: 1) apperceptive, which is based on a violation of the visual synthesis of individual signs - the patient cannot distinguish the image and combine its elements into one meaningful whole; 2) associative, in which the patient clearly distinguishes the visual structure of the image, but cannot name the corresponding object. Complete A. visual is called mental blindness.
  • Agnosia ON FACE- loss of the ability to recognize familiar faces in direct communication and in photographs. Synonym: prosopagnosia, Bodamer's symptom.
  • Agnosia olfactory- characterized by a violation of the recognition of objects or substances by their typical smell.
  • Agnosia ONE-SIDE SPATIAL- violation of the perception of non-verbal stimuli (visual, tactile, auditory) emanating from the left half of the space. It is observed with damage to the posterior sections of the right hemisphere - the parietal-occipital sections of the cortex and subcortical formations [Korchazhinskaya V.I., Popova L.T., 1977]. Included in the structure of Zangwill and Geken apractagnostic syndromes.
  • Agnosia SPATIAL- a form of optical agnosia, characterized by a loss of the ability to navigate in space, in the location of objects and determine the distance between them. Seen in focal organic lesion brain of parietal-occipital localization. Synonym: geometric-optical agnosia, blindness of space.
  • Agnosia SIMULTANEOUS- characterized by a violation of the recognition of a group of objects as a whole in their totality or the situation as a whole, while individual objects are recognized correctly. It is observed with damage to the anterior part of the occipital lobe of the dominant hemisphere.
  • Agnosia AUDIOUS See A. acoustic.
  • Agnosia TACTILE- characterized by the inability to determine objects by touch, although their individual qualities (shape, mass, surface temperature) are qualified correctly. It differs from other types of astereognosis - anchilognosia (impaired recognition of the texture of an object, its mass, temperature) and amorphognostia (impaired recognition of the shape of an object). Syn.: tactile semantic agnosia.

Neurology. Full dictionary. Nikiforov A.S.

agnosia (a - negation of gnosis - knowledge)- a disorder of recognition with the preservation of sensitivity, perception and consciousness, arising in connection with a disorder in the functions of higher gnostic (cognitive) processes. At the same time, the patient may have impaired recognition of objects when they are felt (tactile agnosia, astereognosis), which indicates damage to the cortex of the anterior parts of the parietal lobe on the left (in right-handed people) - field 40. Unrecognition of speech sounds (phonemes) and inability to recognize objects by characteristic them to sounds - auditory (acoustic) agnosia - usually occurs when the pathological focus is localized in the superior temporal gyrus. If the patient loses orientation in space and the ability to recognize objects he sees, then they speak of visual agnosia, which is observed when the function of the cortex of the left parieto-occipital region is impaired - cortical fields 18, 19, 33. With visual spatial agnosia, patients cannot navigate in terms of terrain , on a map, in a familiar area.

The term "agnosia" was introduced in 1881. German physiologist Munk (H. Munk, 1839–1912).

  • Agnosia acoustic- see Agnosia auditory.
  • depth agnosia- a variant of visual spatial agnosia (see). It manifests itself as a violation of the ability to correctly localize objects in three-dimensional space. Despite the fact that the patient sees and recognizes objects, he cannot correctly assess the distance to them and their relative position (it is difficult to assess the absolute and relative distance), it is difficult to determine the relative magnitude of several objects located at different distances from him. With significantly pronounced manifestations of depth agnosia, the patient may miss when trying to pick up a nearby object. He has difficulty walking: he often stumbles, dodges obstacles at the wrong time. According to most researchers, depth agnosia usually occurs when the parieto-occipital region is affected on the left. R. Brain (1965) noted that especially severe manifestations of violation of deep perception occur in bilateral lesions of the parieto-occipital regions of the cerebral hemispheres.
  • Agnosia visual- syn.: Optical agnosia. A disorder in the synthesis of visual sensations, difficulties in comparing them with information stored in memory. In this regard, the impossibility of recognizing and recognizing objects or their images with intact vision. A consequence of damage to the secondary visual cortex (fields, according to Brodmann, 18, 19), adjacent associative cortical zones of the lower parietal region (fields 39, 40) and temporo-occipital region (fields 37 and 21), as well as their connections with subcortical structures and limbic reticular system of the brain. Domestic neuropsychologist A.R. Luria (1973) interpreted visual agnosia as "the disintegration of the higher organization of the visual process." Agnosia visual object. Impossibility or difficulty in recognizing familiar objects and their images: realistic - with severe agnosia; if the degree of severity of agnosia is moderate - a disorder of recognition of abstract, incomplete, dotted, partial images of familiar objects. With object agnosia, the patient can usually characterize the individual properties of an unrecognized object: thus, examining a comb, he says that this object is narrow, flat, long, rough, sometimes he can name its color, but does not know what kind of object it is, and cannot determine its purpose. In 1898, the German neurologist H. Lissauer proposed to differentiate object visual agnosia into apperceptive, associative, and mixed.
  • Agnosia visual constructive- synonym: Poppelreiter-Volpert syndrome. Loss of the ability to synthesize fragments of an object and its image, to understand the meaning of a thematic drawing. Described by the German doctor Poppelreiter and the American doctor Wolpert.
  • Agnosia visual objective associative Lissauer- the patient perceives objects or their images with the help of vision, but is not able to correlate them with his previous experience, recognize and determine their purpose. It is especially difficult for the patient to recognize silhouette, stylized or contour drawings, especially in cases of "noise" of the latter and their imposition on each other (Poppelreiter's drawings, see). All these defects in visual perception are more clearly manifested if the examination is carried out under conditions of time deficit (0.25–0.5 sec), recorded using a tachistoscope. In cases And. n.a. there is a difficulty in extracting ideas, images of memories from the annals of memory. This form of agnosia usually occurs (in right-handers) with damage to the parieto-occipital region of the right hemisphere of the brain. N. Lissauer called it associative mental blindness.
  • visuo-spatial agnosia- the patient experiences difficulties of various degrees of severity and nature in compiling an idea of ​​the spatial relationships between objects. Among various types of visuo-spatial agnosia, depth agnosia (see), disorientation in space and unilateral spatial agnosia are distinguished. Violations of orientation in space, or topographic orientation, lead to the fact that the patient loses the ability to navigate in the spatial coordinate system. He can get lost, leaving the hospital room into the corridor. It is difficult for him to understand the hands on the clock face. He is unable to orientate himself on a contour geographical map, he cannot repeat, on assignment, the changing position in space of the hands of the doctor sitting opposite (Head's test). Patients with this form of pathology are not able to plan their apartment, room, hospital room. At the same time, violations of the right left orientation and signs of autotopagnosia are possible (see).
  • Agnosia for faces- synonym: Hoff-Petzl symptom. Prosopagnosia. Visual agnosia, manifested by the inability to recognize faces or portrait images (drawing, photograph, etc.) familiar or widely famous people(Pushkin, Tolstoy, Gagarin, etc.), a disorder of differentiation of male and female faces is possible. Sometimes the patient cannot even recognize his own face in a photograph or in a mirror. However, in the presence of prosopagnosia, he usually recognizes certain parts of the face - eyebrows, eyes, nose, mouth, bridge of the nose, chin, etc. Without differentiating faces, such a patient often recognizes familiar people by their gait, clothing, and voice. The cause of agnosia on faces is more often a lesion of the associative cortex of the right occipital-parietal region. He described this form of visual agnosia in 1932. G. Milian, he called it morphological blindness, and in 1937. H. Hoff and O. Petzl described this clinical phenomenon in more detail, designating it as a memory disorder for faces - prosopagnosia.
  • Agnosia for colors- Syn.: Achromatopsia. Violation of the ability to distinguish colors and differentiate them, select the same colors or shades of the same color, and also determine whether a particular color belongs to a particular object. At the same time, patients with impaired color perception sometimes retain elementary forms of color vision, which may enable them to recognize primary colors, but deprive them of the ability to differentiate their shades. In cases of complete color agnosia, there is an absolute absence of color perception. Agnosia for colors is often combined with object agnosia, in particular with agnosia for faces, and sometimes with visual alexia. He described color agnosia, highlighting it as a separate sign of cortical pathology, in 1908. M. Lewandowsky. Most authors (K. Kleist, 1932, Kok E.P., 1967) associate color agnosia (achromatopsia) with damage to the occipital region of the subdominant, therefore, more often the right hemisphere of the brain with a predominant lesion of the 19th cortical field, according to Brodmann, and adjacent association zones to it. Agnosia on colors in some cases is combined with agnosia on faces (see).
  • Agnosia olfactory and gustatory- loss of the ability to identify olfactory and gustatory sensations. It may be a consequence of dysfunction of the cortical end of the corresponding analyzers.
  • Optical agnosia- see Visual agnosia.
  • Agnosia digital- synonym: Gerstmann's syndrome. One of the forms of autotopagnosia (see). Violation of recognition and differentiated display of fingers, both one's own and fingers of other people. It is a sign of damage to the angular gyrus, more often the left hemisphere. Described by the Austrian neurologist J. Gerstmann (born in 1887).
  • Agnosia parietal- syn.: Petzl's syndrome is agnostic. One of the manifestations of visual agnosia (see) in patients with damage to the cortex of the posterior part of the angular gyrus of the left parietal lobe and adjacent parts of the occipital lobe. In this case, the patient, when reading and writing, does not recognize letters or makes mistakes in differentiating similar letters, which leads to impaired reading and writing. Usually combined with a disorder of visual perception of numbers, musical signs, etc. Described in 1919. Austrian psychiatrist O. Potzl (1877–1962).
  • Anton's syndrome- a variant of anosognosia (see), in which a patient with severe visual impairment caused by damage to the cortex of the posterior parts of the cerebral hemispheres, sometimes stubbornly denies the existing visual defects. A patient with Anton's syndrome is usually verbose, prone to fiction, fantasy, and is uncritical about his condition. In such cases, the presence of a disorder in the connections of the occipital cortex with the structures of the diencephalon is assumed. It is more common in vascular pathology in elderly men. It was described in 1899 by the German psychoneurologist Anton (1858–1933). He called this rare clinical phenomenon cortical blindness.
  • Spatial agnosia, unilateral- ignoring part of the surrounding space, usually its left half, with a pathological focus in the parieto-occipital region of the subdominant and, therefore, more often the right hemisphere of the brain. The patient seems to lose sight of left half space and your own body. He reads the text only on the right half of the page, sketches only the right side of the image, etc. When drawing objects from memory, a tendency is revealed to draw only the right half of it. The syndrome of unilateral spatial agnosia is rare.
  • Agnosia Simultana Volperta- the impossibility of covering the whole with the availability of perception of details. With it, it is possible to recognize individual objects, but it is impossible to perceive a group of objects as a single whole, there is no ability to generalize the visible. The patient usually recognizes most of the objects depicted in the thematic drawing, but cannot find a logical relationship between them. As a result, he is unable to understand the meaning of the plot picture. At the same time, verbal information, a story about the plot of the drawing, is perceived by patients correctly and with understanding. Simultaneous agnosia is sometimes combined with verbal alexia, in which individual letters are read correctly, but the patient cannot compose a word from them or at the same time has difficulty. The concept of simultaneous (from Latin simul - together, simultaneously) agnosia was formulated in 1924. I. Wolpert.
  • Auditory agnosia- syn.: Acoustic agnosia. Disorder of recognition of audible sounds that occurs when the superior temporal gyrus is damaged. At the same time, its defeat in the left hemisphere leads to the development of a violation of phonemic hearing characteristic of sensory aphasia. If the pathological focus is located in the right hemisphere of the brain, there is amusia (see) and disorders in the recognition of object sounds (the rustle of leaves, the murmur of a stream, etc.).
  • Agnosia tactile- see astereognosis.

Oxford Dictionary of Psychology

agnosia- literally "not knowing". Disruption of the recognition process. A person suffering from agnosia can perceive objects and forms, but is not able to consciously recognize them and understand their purpose. Agnosia is the result of neurological pathology and can manifest itself in almost any perceptual/cognitive system. Exist various forms agnosia, some of which are described below, others in the corresponding articles, arranged alphabetically (for example, prosopagnosia).

subject area of ​​the term

AGNOSIA visual subject associative Lissauer- The patient perceives objects or their images with the help of vision, but is not able to correlate them with his previous experience, recognize and determine their purpose. It is especially difficult for the patient to recognize silhouette, stylized or contour drawings, especially in cases of "noise" of the latter and their imposition on each other (Poppelreiter's drawings, see). All these defects in visual perception are more clearly manifested if the examination is carried out under conditions of time deficit (0.25–0.5 sec), recorded using a tachistoscope. In cases And. n. a, there is a difficulty in extracting representations, images-memories from the annals of memory. This form of agnosia usually occurs (in right-handers) with damage to the parieto-occipital region of the right hemisphere of the brain. N. Lissauer called it associative mental blindness.

COLOR AGNOSIA- the ability to classify colors is lost, to select the same colors or shades of the same color (especially brown, purple, orange, pastel colors). They are manifested by difficulties in differentiating mixed. In addition, one can note a violation of color recognition in a real object - difficulties in tasks to correlate one or another color with a specific object (say what color the grass, tomato, snow is). At the same time, elementary forms of color vision are not violated - patients can distinguish the primary colors presented on individual cards. Occurs mainly with damage to the left occipital lobe and adjacent areas. However, there is evidence of involvement in the process in this form of agnosia of the left parietotemporal region.

IDEATOR AGNOSIA- see agnosia, ideational.

APPERCEPTIVE AGNOSIA See agnosia, apperceptive.

Gnostic auditory disorders (auditory agnosias) are observed with right-sided lesions of 41, 42 and 22 fields of the cerebral cortex (secondary projection zones of the auditory cortex). The defeat of similar areas of the left hemisphere is accompanied by speech disorders, which is commonly called aphasia.

auditory agnosia subdivided into subdominant and dominant .

Subdominant auditory agnosia manifests itself in the inability to master the meaning of non-speech noises, namely: a) natural, i.e., emitted by objects of nature; b) subject, i.e., emitted by sounding objects.

Non-speech auditory agnosia occurs when the right temporal lobe is affected. In this case, children do not distinguish between sounds such as squeaks, knocks, pops, rustles, beeps, wind, rain, etc. In a certain category of children, and more often in adult patients, defects in impressive musical hearing (amusia) are noted. It manifests itself in the inability to remember the melody or recognize it. Sometimes patients have hypersensitivity to noises (hyperacusia), as well as cases of changes in the intonation-melodic side of speech, voice, elements of dysarthria. With damage to the right hemisphere, such non-verbal auditory functions as distinguishing the duration of sounds, perception of the timbre of a sound, the ability to localize sounds in space, as well as the ability to recognize the voices of familiar people, especially on the telephone, on the radio, are impaired.

Dominant auditory agnosia occurs with lesions located in the left hemisphere of the brain. It is speech and manifests itself in the difficulties of understanding speech. At the same time, partial understanding of speech is sometimes possible, which is achieved by relying on the length of the phrase, intonation, the situation of communication, i.e., on what, according to modern ideas, is included in the “competence” of the right hemisphere of the brain. With foci located in the right temporal region, the patient, trying to understand the utterance perceived by ear, first of all relies on the sound, phonemic composition of the word and, as a result of the phonological analysis, understands the objective meanings of words. Difficulties in decoding the prosodic characteristics of an utterance, characteristic of the pathology of the right hemisphere of the brain, limit the amount of understanding of the text perceived by ear, but do not completely eliminate it. Only bilateral foci lead to gross speech auditory agnosia.

Speech auditory agnosia is the most complex manifestation of auditory agnosia. Speech perception is carried out due to the joint activity of two temporal zones of the brain (right and left). Unilateral lesions of the temporal lobe, as a rule, do not cause complete auditory agnosia.

- the patient hears sounds: the creak of doors, the noise of steps, pouring water, etc. (i.e., hearing is preserved), but does not recognize them;

- in mild cases auditory memory disorders. The patient does not remember sound complexes of varying complexity. For example, it cannot reproduce successive sounds of different pitches;

–amusia- impaired ability to recognize (sensory amusia) and reproduce (motor amusia) a familiar or just heard melody, to distinguish one melody from another. Music loses its meaning and can cause unpleasant painful experiences (“unpleasant to hear”). Amusia often occurs when the right hemisphere is affected. With sensory amusia, the lesion is located in the temporal region, and with motor amusia, in the posterior parts of the middle frontal gyrus;

- at intonation disorder of speech the patient does not distinguish speech intonations. His own speech is devoid of intonational diversity. Sometimes the patient does not distinguish between male and female voices, loses the ability to distinguish between interrogative, affirmative and exclamatory statements. Violation of intonational hearing manifests itself as a difficulty in the ability to identify emotional state speaker (joy, anger, sadness).

It is generally accepted that a violation of the perception of rhythms, their retention in memory and reproduction in a pattern ( arrhythmia) can occur with both right-sided and left-sided lesions. At the same time, patients experience difficulty in reproducing the rhythmic structures that they present “by ear”. When the left temporal region is affected, acoustic analysis and synthesis of the internal structure of the rhythm suffer first of all, therefore, the more complex (accented, doubled) a series is to be memorized and reproduced, the greater the likelihood of errors in its execution. With right hemispheric foci in more the perception of the structural arrangement of the rhythmic cycle as a whole is disturbed: structurally formed packs of rhythms are better reproduced in comparison with simple ones.

Diagnosis of Gnostic Auditory Disorders[H6] .

1. Playing sound rhythms. The patient is asked, following the experimenter, to reproduce a series of strikes on the table, separated by long and short pauses. The series gradually lengthen and become more complex in structure.

Rhythm samples: ½½ ½ …½ ½½ …

2. Localization of sound in space. The subject is asked to determine from which side the sound comes.

3. Recognition of familiar sounds. The subject is asked after listening to identify familiar sounds (for example, the rustle of paper).

  • Violation of orientation in the area, impaired ability to understand the location of places on the map.
  • Denial of having a disease or defect (eg, blindness, weakness in the limbs), despite the obvious impairment.
  • Indifference to an existing defect: for example, a person is not worried about suddenly developed blindness in both eyes, lack of muscle strength in the legs.
  • Violation to recognize objects by touch: they present difficulties in determining the shape, texture of the object.
  • Sound recognition disorder: for example, a person cannot understand the nature of the sound and where it comes from when they hear an entrance call at home, or hear the voice of a relative
  • Violation of the perception of his body: the patient cannot accurately determine the length of his limbs, their number.
  • Violation of the ability to recognize the faces of acquaintances: in this case, a person can name gender, approximate age, but is not able to recognize the face.
  • Impaired recognition of complex visual images: despite the preserved ability to recognize individual elements, a person, looking at a picture, recognizes a glass on the table, but does not realize that the presence of a glass on the table, as well as jugs, food and many people at the table, indicates what is depicted holiday/feast
  • Ignoring half of the visible space: for example, while eating, a person eats porridge only from the left half of the plate, when walking, a person touches the door frame with his right shoulder (because he does not see the obstacle on the right).

Forms

Depending on the characteristics of agnosia, the following forms are distinguished.

  • visual agnosia:
    • object agnosia - a person does not recognize objects previously known to him. For example, he cannot say what he sees in front of him when he is shown a book or a telephone, but if he is told what it is, he can indicate the use of this object (a book for reading, a telephone for making calls);
    • facial agnosia (prosopagnosia): impaired ability to recognize the faces of acquaintances. At the same time, a person can name gender, approximate age, but is not able to recognize the face;
    • color agnosia - the person does not recognize colors. For example, if you ask a patient to look at a green cucumber and name its color, the person will not be able to do this. However, if asked to remember what color the cucumber is, a person can easily say that the cucumber is green;
    • simultaneous agnosia (simultagnosia) - a violation of the recognition of complex visual images despite the preserved ability to recognize individual elements (for example, a person, looking at a picture, recognizes a glass on the table, but does not realize that the presence of a glass on the table, as well as jugs, food and many people at the table says that a holiday / feast is depicted);
    • ignoring half of the space (neglekt) - while a person, having no vision problems, ignores half of the space visible to him. For example, while eating, he eats porridge only from the left half of the plate, while walking he touches the door jamb with his right shoulder (since he does not see the obstacle on the right);
    • letter agnosia - a person does not recognize the letters in the text or separately written letters (all or only part of them). He can confuse letters, have difficulty reading, but if asked to write any letter, then most often he completes this task without difficulty.
  • auditory agnosia - impaired perception of sounds. A person may not recognize the voices of long-known people, relatives, the noise of cars on the street, the singing of birds.
  • Topographic agnosia - impaired orientation in the area, impaired ability to understand the location of places on the map, as well as impaired orientation in a familiar space: patients forget the way home, get lost in their own apartment, cannot remember, while in the hospital, the way to the dining room, ward, toilet. In this case, the memory remains intact.
  • Somatognosia - violation of the perception of one's body (the size and number of limbs, the location of the hands). It may seem to a person that there are more than five fingers on the hand, that they have become very long, etc.
  • Astereognosis - impaired ability to recognize objects by touch. For example, a patient with closed eyes cannot recognize obvious objects with the help of touch - a pin, a key, a pen, etc. At the same time, by opening the eyes, the patient recognizes the object.
  • Anosognosia - denial of having a disease or defect (eg, blindness, weakness in the limbs). If you tell the patient that he is ill, he will be surprised, will deny it: he does not notice obvious violations.
  • Anosodiaphoria - the patient's awareness of his defect while maintaining indifference to him. For example, a person is not worried about suddenly developing blindness in both eyes.

Causes

Agnosia develops when the parietal and occipital lobes of the cerebral cortex are affected. This can happen during the following processes:

  • acute violation of cerebral circulation (stroke);
  • brain tumors;
  • chronic circulatory disorders of the brain with a transition to dementia (also manifested by tearfulness, difficulties in mastering new skills, orientation in everyday situations, memory impairment);
  • consequences of traumatic brain injuries - for example, in traffic accidents, falls from a height, blows to the head;
  • consequences of inflammation of the brain (encephalitis);
  • Alzheimer's disease associated with the accumulation of amyloid in the brain (a special protein that normally quickly decomposes in the brain). Manifested by progressive memory impairment;
  • Parkinson's disease is a disease characterized by the development of progressive muscle stiffness, tremor (trembling) and neuropsychological disorders (including apraxia).

Diagnostics

  • Analysis of complaints and anamnesis of the disease:
    • how long ago the signs of agnosia appeared (denial of an existing defect, difficulties in orienting on a map);
    • what event immediately preceded the appearance of these signs (traumatic brain injury, cerebrovascular accident);
    • how quickly the disorders progress (whether they developed gradually or appeared acutely).
  • Neurological examination: assessment of human mental functions, visual fields, visual acuity, hearing. Search for other neurological disorders that may accompany agnosia (impaired skin sensitivity, inability to read, count).
  • Examination by a neuropsychologist: assessment of the patient's condition using special questionnaires and questionnaires, conversations.
  • CT ( CT scan) and MRI (magnetic resonance imaging) of the head allow you to study the structure of the brain in layers and identify possible reasons agnosia (foci of circulatory disorders, tumors, consequences of traumatic brain injury).
  • Consultation is also possible
    • Rejection bad habits(smoking, alcohol).
    • Doing healthy lifestyle life (regular walks for at least 2 hours, physical education, adherence to the regime of day and night ( night sleep at least 8 hours.
    • Compliance with the diet and diet (regular meals at least 2 times a day, the inclusion in the diet of foods rich in vitamins: fruits, vegetables).
    • Timely contacting a doctor in case of health problems.
    • Control of arterial (blood) pressure.

Gnosis (Greek gnosis - cognition, knowledge) - the ability to cognize, recognize objects, phenomena, their meaning and symbolic meaning from sensory perceptions. Violation of recognition with the relative preservation of elementary sensations and intellect is called agnosia. Primary agnosia develops when the secondary cortical zones of the corresponding sensory analyzer (the second block) are affected and, therefore, are characterized by modal specificity, i.e., they are noted in one sensory modality. Secondary agnosia develops when the third block is affected - the block of programming, regulation and control of voluntary activity associated with the pathology of the frontal lobes or as a result of a decrease in the level of attention. In secondary agnosia, all sensory modalities are affected. A characteristic feature of agnosia is the difficulty or inability to recognize a holistic sensory image while maintaining the ability to distinguish and describe its individual features.

Agnosia is multivariate in its manifestations. Agnosia of external space is distinguished: visual, auditory, tactile, olfactory and gustatory, and agnosia of internal space or somatoagnosia: autotopagnosia, anosognosia, fingeragnosia.

Consider the characteristic certain types agnosia and methods of their research.

visual agnosia.

Visual agnosia occurs when the 18th and 19th cytoarchitectonic fields, which are the secondary fields of the visual analyzer, are affected, as well as the tertiary fields adjacent to them and the nearest subcortical zones.

One general rule applies to all forms of visual agnosia:

elementary sensory visual functions remain relatively preserved, patients see well enough, they have normal color perception, normal visual fields.

There are 6 main forms of visual gnosis disorders:

object agnosia

Facial agnosia (prosopagnosia)

color agnosia

opto-spatial agnosia

Letter agnosia

Digital agnosia

Simultaneous agnosia.

The form of violation of visual gnosis is associated both with the side of the lesion and the location of the lesion in the occipital and parietal regions of the brain.

subject agnosia. In patients with object agnosia, the recognition of individual objects and their images is impaired due to the impairment of the ability to combine individual visual impressions into single whole images. In typical cases, patients find it difficult to recognize well-known objects, describing individual features of the object, they cannot say what it is. When examining a pen or a comb, they say that it is a narrow, long object, but do not recognize it. Feeling an object often helps to correctly recognize it. Unlike patients with amnestic aphasia, patients with visual agnosia not only cannot correctly name an object, but also cannot explain its purpose.

Especially gross violations of the ability to recognize an object occur with bilateral lesions of the occipital lobes or parietal-occipital regions, which is often observed in vascular pathology.

In everyday life, patients behave almost like blind people, and although they do not stumble upon objects, they constantly feel them or navigate by sounds.

In milder cases of object agnosia, recognition disorders are detected mainly upon presentation of real objects, their images (Fig. 1-11). Schematic contour images are especially difficult to recognize, with contours of the object superimposed on each other, missing parts of the object, object images against the background of "visual fields", the so-called "noisy drawings" - Poppelreiter's drawings (Fig. 12, 13).

With visual agnosia, the patient is not able to draw a given object, since he has a disturbed holistic perception of his image.

Facial agnosia or prosopagnosia characterized by impaired recognition of familiar faces with the relative preservation of objective gnosis. Patients recognize individual parts of the face (nose, eyebrows, eyes, ears) and the face as an object as a whole, but cannot recognize its individual affiliation, do not recognize the faces of relatives and friends.

In the most severe cases, patients do not recognize their own face in the mirror, do not recognize the features of facial expressions, and do not distinguish between the faces of men and women. Recognition of people in such cases is carried out by voice, clothing, gait. Facial agnosia often coexists with other forms of agnosia. Facial agnosia is associated with damage to the posterior parts of the right hemisphere in right-handers, the lower "visual sphere" - the occipital region, extending in some cases to the parietal and temporal regions.

This symptom is very common in Alzheimer's disease.

To diagnose prosopagnosia, the patient is presented with portraits of well-known people, some figures (Fig. 14) or photographs of relatives and close acquaintances of the patient, distinguishing them from strangers.

Agnosiaon colors called a violation of the ability to select the same colors or shades of the same color. Patients cannot determine the belonging of a particular color to a particular object.

Color agnosia is observed against the background of preserved color perception.

Such patients correctly name colors and distinguish them correctly, however, they find it difficult to determine the relationship of color to an object, they cannot say what color a carrot or an orange is. Due to the lack of generalized ideas about color, patients cannot classify colors.

Color agnosia is usually observed together with object agnosia, and occurs when the left occipital region is affected. Often, focal brain damage extends to the temporal region.

Letter agnosia. Patients, correctly copying the letters, cannot name them. Reading skills fall apart. Such a reading disorder occurs in isolation from other visual dysfunctions with damage to the left hemisphere - the lower part of the visual sphere on the border of the occipital and temporal regions in right-handed people.

To diagnose letter agnosia, the patient is asked to name the letters in different fonts, crossed out or upside down, in a mirror image (Fig. 15).

Digital agnosia- a variant of visual agnosia, in which patients cannot name numbers. To diagnose digital agnosia, the patient is asked to name Arabic and Roman numerals and numbers in direct, crossed out, inverted, mirror image form (Fig. 15).

Opto-spatial agnosia. It is characterized by a violation of the possibility of orientation in the spatial features of the environment and images of objects. The ability to correctly localize objects in three coordinates of space, especially in depth, is impaired. It becomes impossible to estimate the distance to the object, the right-left orientation becomes difficult.

Patients forget the way to their home, are poorly oriented in a geographical map, navigate the street by the street name and house number, and cannot independently draw a picture (Fig. 16).

Unilateral spatial agnosia also belongs to this category of agnosia. Patients lose sight of half of the space, more often the left, spatial orientation is difficult due to errors related to one side of the space more often than the left (Fig. 16). Half of the space is ignored. The patient does not notice the presence of stimuli on the one hand; when redrawing the image, he reproduces only half of the picture.

Optical-spatial disorders are associated with foci localized in the parietal region (with bilateral lesions), sometimes to a greater extent in the left hemisphere. Violation of topographic orientation in diagrams, maps is associated with the localization of the focus in the left hemisphere, violation of orientation in real space - in the right. The syndrome of unilateral spatial agnosia is detected when the parietal region of the right hemisphere is affected, more often with ischemic stroke in the basin of the right middle cerebral artery.

Optical-spatial agnosia is usually combined with a violation of constructive praxis. This symptom is called opto-agnostic. The combination of these disorders with agraphia, alexia, amnestic aphasia, acalculia, fingeragnosia is called Gerstmann's syndrome. It occurs when the junction of the parietal, temporal and occipital regions of the dominant hemisphere is affected. To diagnose optical-spatial agnosia, the patient is asked to name the time by the hands of the clock, arrange the hands on a silent dial, name the main images on the contour map (Fig. 17,18), draw a plan of the ward, divide the line into parts.

Simultaneous agnosia characterized by a violation of the complex synthesis of visual images. This form of agnosia is characterized by the impossibility of perceiving two images. Correctly identifying individual objects, patients cannot assess the content of the picture. This form of impaired visual gnosis is called Ballint's syndrome. The occurrence of the syndrome is associated with a narrowing of the volume of visual perception, complex disorders of eye movements, the gaze becomes uncontrollable, which makes visual search difficult. The localization of the focal process in Ballint's syndrome is associated with a bilateral lesion of the occipital-parietal region.

auditory agnosia.

Auditory agnosia is a variant of sensory agnosia in which there is a disorder in the recognition of audible sounds. The patient does not recognize the sound of a car horn, barking dogs and other household noises.

Gnostic auditory disorders are associated with damage to the right hemisphere in the region of the superior temporal gyri, more precisely in the secondary cortical projection zones, fields 41,42,22 of Brodmann's architectonic map. With the defeat of the left hemisphere in the area of ​​similar cortical fields, another variant of auditory agnosia arises - deafness to words. At the same time, phonemic hearing is disturbed, in connection with which the understanding of addressed speech is also impaired. The patient hears the words, but does not understand their meaning. Usually this symptom noted within the sensory aphasia syndrome.

More often there is a more erased form of auditory impairment in the form of defects in auditory memory. The latter are manifested in special experiments, showing that a patient who is able to distinguish between pitch relationships cannot express auditory differentiations, i.e. remember two (or more) sound images.

With damage to the temporal region of the brain, a symptom such as arrhythmia may occur. The manifestation of arrhythmia is that patients cannot correctly assess the rhythmic structures that are presented to them by ear, and cannot reproduce them. One of the well-known defects in nonverbal hearing is called amusia. This is a violation of the ability to recognize and reproduce a familiar melody, or one that a person has just heard, as well as to distinguish one melody from another. Patients with amusia not only cannot recognize the melody, but also evaluate it as a painful and unpleasant experience. Music becomes unpleasant for them, often causing headaches. It is important to note that if the symptom of amusia manifests itself mainly with damage to the right temporal region, then the phenomenon of arrhythmia can be detected not only with right-sided, but also with left-sided temporal foci (in right-handed people). Finally, a symptom of damage to the right temporal region is a violation of the intonational aspect of speech.

Patients with such a defect not only do not distinguish speech intonations, but they themselves are not very expressive in their own speech. Their speech is devoid of modulations, intonation diversity. There are descriptions of patients with damage to the right temporal region, who, while repeating a single phrase well, could not understand the same phrase. Thus, auditory agnosias should include: proper auditory agnosia, auditory memory defects, arrhythmia, amusia, violation of the intonational aspect of speech.

Patients with auditory agnosia complain of hearing loss, auditory deceptions. However, an objective examination of ENT specialists does not reveal pathology.

To diagnose auditory agnosia, the patient is asked to recognize objects by sound, for example, by ringing - a bunch of keys, coins, by ticking - a clock; name famous musical melodies; important in the study of auditory gnosis and disorders of auditory-motor coordination is the assessment and reproduction of rhythms (Fig. 19); the patient is asked to determine the nature of the rhythms (single, double, triple beat, their alternation), to perform the rhythms according to the image with direct, delayed (empty) playback and after interference (II II II III III III); perform rhythms according to the speech instruction: hit 2, 3, 2, 4 hits with direct, delayed (after an empty pause) playback, after interference. At the same time, the decay of rhythmic structures and the presence of perseverations are assessed.

Tactile agnosia.

Tactile agnosia is characterized by the inability to differentiate objects by their texture when touched. Difficulties arise in recognizing such qualities of an object as roughness, softness, hardness, while maintaining superficial and deep sensitivity - the sensory basis of tactile perception.

Tactile agnosia occurs when the secondary zones of the cortex of the parietal region are affected (1, 2, partially 5 fields - the upper parietal region) and tertiary zones (39, 40 fields - the lower parietal region).

With the defeat of the post-central areas of the cortex, which border on the zones

representation of the hand and face in the 3rd field there is a violation complex shapes tactile gnosis, known as astereognosis. This is a violation of the ability to perceive familiar objects by touch with closed eyes. Astereognosis manifests itself against the background of a preserved sensory basis of tactile perception, arises as a result of a violation of the synthesis of elementary sensations, a disorder of three-dimensional spatial perception. There are two forms of this disorder: in some cases, the patient correctly perceives the individual features of the object, but cannot synthesize them into a single whole, in others, the identification of these features is also impaired.

Olfactory and gustatory agnosia.

These types of sensory agnosia are characterized by the loss of the ability to identify olfactory and gustatory sensations due to damage to the mediobasal regions of the temporal cortex.

Somatognosia.

Somatoagnosia - agnosia of the internal space. It arises as a result of a violation of the perception of one's own body, which develops from early childhood on the basis of tactile, kinesthetic, visual and other sensations. There are 3 variants of somatoagnosia: autotopagnosia, anosognosia and fingeragnosia (finger agnosia).

At autopagnosia the perception of the body scheme is disturbed. The patient loses the idea of ​​the localization of body parts, cannot, at the request of the doctor, show parts of his body. There is alienation of parts of your body. Separate parts of the body on the opposite side of the focus may appear to be changed in size and shape. There may be a feeling of a third arm or leg (pseudopolymelia), a doubling of the head, or the absence of any part of the body up to a sensation of the absence of limbs and the entire half of the body, usually the left. In this case, these manifestations can be considered as a variant of unilateral spatial agnosia.

Autopagnosia is observed when the cortex of the parietal lobe is damaged (fields 30.40) and the connections of the parietal cortex with the visual tubercle are more often in the right hemisphere, which usually occurs with tumors, strokes, and injuries. Somatognosia can also be one of the manifestations of derealization and depersonalization in epilepsy or schizophrenia.

At anosognosia(Anton's syndrome), the patient does not realize that he has disorders caused by the pathological process, denies their presence. Anosognosia can refer to paralysis, blindness. The patient claims that the movements of his limbs are not disturbed, that he can get up, but he does not want to get up. This syndrome occurs in cases of extensive damage to the parietal lobe of the subdominant hemisphere.

Fingeragnosia It is manifested by the indistinguishability of the fingers on one's hand while maintaining the muscular-articular feeling. The patient also cannot name the fingers that the doctor shows. Despite the absence of violations of superficial and deep sensitivity, patients are mistaken in recognizing passively moved fingers with their eyes closed. The localization of the process in digital agnosia in the region of the angular gyrus of the left hemisphere is determined.

The study of somatosensory gnosis for the diagnosis of somatognosia is carried out according to the following methods: 1) a test to determine the localization of touch on one, two hands, on the face; 2) discrimination test - determination of the number of touches: one or two; 3) definitions of skin-kinesthetic feeling - definition of figures, numbers, letters written on the skin on the left and right hand; (Ferster's feeling); 4) transfer of the posture of the hand and hand from one hand to another with closed eyes; 5) determination of the right and left sides of oneself and the person sitting opposite (left and right orientation); 6) the name of the fingers of the hand; 7) recognition of objects by touch with the left and right hand.

48.1

Agnosia is pathological condition, arising from damage to the cortex and the nearest subcortical structures of the brain, with an asymmetric lesion, unilateral (spatial) agnosias are possible.

Agnosias are associated with damage to the secondary (projection-associative) sections of the cerebral cortex responsible for the analysis and synthesis of information, which leads to a disruption in the process of recognition of stimulus complexes and, accordingly, recognition of objects and an inadequate response to the presented stimulus complexes.

visual agnosia

visual agnosia- the inability to recognize and determine the information coming through the visual analyzer. In this category there are:

  • object agnosia Lissauer - recognition disorder various items while maintaining visual function. At the same time, patients can describe their individual signs, but cannot say what kind of object is in front of them. Occurs when the convexital surface of the left occipital region is damaged;
  • prosopagnosia(facial agnosia) - impaired recognition of familiar faces with intact subject gnosis. Patients well distinguish parts of the face and the face as an object as a whole, but cannot report on its individual affiliation. In the most severe cases, they cannot recognize themselves in the mirror. The disorder occurs when the lower-occipital region of the right hemisphere is affected;
  • agnosia for colors- the inability to select the same colors or shades, as well as to determine whether a particular color belongs to a particular object. Develops with damage to the occipital region of the left dominant hemisphere;
  • weakness of optical representations- a disorder associated with the inability to imagine any object and describe its characteristics - shape, color, texture, size, etc. Occurs as a result of a bilateral lesion of the occipital-parietal region;
  • simultaneous agnosia- a disorder associated with the functional narrowing of the visual field and its limitation to only one object. Patients can simultaneously perceive only one semantic unit, that is, the patient sees only one object, regardless of its size. Develops with damage to the anterior part of the dominant occipital lobe;
  • agnosia due to opto-motor disorders(Balint's syndrome) - a disorder associated with the inability to direct the gaze in the right direction with a general intact movement function eyeballs. This leads to difficulty in fixing the gaze on a given object; especially difficult is the simultaneous perception of more than one object in the field of view. It is difficult for the patient to read, as he hardly switches from word to word. It develops as a result of bilateral lesions of the occipital-parietal region.

Opto-spatial agnosias

Opto-spatial agnosia- disorder of definition of various parameters of space. In this category there are:

  • depth agnosia- violation of the ability to correctly localize objects in three coordinates of space, especially in depth, that is, in the sagittal (forward) in relation to the diseased direction, to determine the parameters further-closer. It develops as a result of damage to the parieto-occipital region, mainly its middle sections;
  • stereoscopic vision disorder- damage to the left hemisphere;
  • unilateral spatial agnosia- a disorder in which one of the halves of the space falls out, often the left. It develops with damage to the parietal lobe, the contralateral side of the prolapse;
  • disorientation- a violation in which the patient cannot navigate in familiar places, cannot find a house, wanders in his own apartment. In this case, the memory remains intact. Develops with damage to the parieto-occipital region;

Disturbances in the perception of time and movement- disorders associated with a violation of the perception of the speed of the passage of time and the movement of objects. It is rare and only a few cases of such disorders associated with damage to the occipital lobes have been described. Impaired perception of moving objects is called akinetopsia.

Auditory agnosia

Auditory agnosia- Disorders of recognition of sounds and speech, with intact function auditory analyzer. Develop with damage to the temporal region. There are the following types:

  • simple auditory agnosia- the inability to identify certain sounds - knocking, gurgling, ringing of coins, rustling of paper, etc.
  • auditory speech agnosia- the inability to recognize speech, which the patient recognizes as a set of unfamiliar sounds.
  • tonal agnosia- expressive aspects of the voice for these patients do not exist. They do not capture any tone, timbre, or emotional coloring. Words and grammatical constructions they understand flawlessly.

somatognosia

somatognosia- a disorder of recognition of parts of one's own body, assessment of their localization relative to each other. Violation occurs when various parts of the right hemisphere are affected (Brodmann's fields 7). There are two main types:

  • Anosognosia- lack of awareness of the disease. Which include:
    • hemiplegia anosognosia- unawareness and denial of the presence of unilateral paralysis or paresis;
    • anosognosia of blindness- unawareness and denial of the presence of blindness. At the same time, confabulatory visual images are perceived as real;
    • anosognosia aphasia- a disorder in which patients with aphasia do not notice their mistakes, even if their speech is completely unintelligible.
  • Autopagnosia- a disorder in which there is an ignorance of half of the body, but mainly a lack of recognition of its individual parts (for example, patients cannot distinguish and correctly show parts of their own body - parts of the face, fingers), a violation of the assessment of the position of individual parts of the body in space. This group includes:
    • hemicorpus autopagnosia(hemisomatognosia) - ignoring half of the body with partial preservation of its functions. So, with complete or incomplete preservation of movements in the arm and leg, the patient does not use them to carry out various actions. He "forgets" about them, ignores their existence, does not include them in his work. This neglect applies only to the left half of the body. For example, the patient washes only one right hand, puts on slippers only on the right foot. In severe cases, the patient has a feeling of absence of the left half of the body;
    • somatoparagnosia- perception of the affected part of the body as foreign. The patient feels that another person is lying next to him, who owns one of his legs in bed (the left leg of the patient), or it is not his leg, but a stick or other object. In some cases, there is a feeling that the body is sawn into two halves, that the head, arm or leg is separated from the body. Often there may be sensations of an increase or decrease in the left side of the body (macro- or microsomatognosia). The feeling of change in the size of individual parts of the body is usually combined with a feeling of weight or unusual lightness. These sensations are painful for the patient and are hard for them to experience;
    • somatic allosthesia- a disorder associated with a sensation of an increase in the number of limbs (fixed or moving). Most often it affects the left limbs, especially the left hand (pseudopolymelia). The first descriptions of pseudopolymelia belong to V. M. Bekhterev (1894) and P. A. Ostankov (1904). Bulbo-spinal localization was present in both cases. pathological process. In 1904, V. M. Bekhterev first described a patient with a right hemispheric focus and a feeling of an extra left hand. In foreign literature, pseudopolymelia is often called the "multiple phantom" of the limb. (supernumerary phantom limbs), "an extra limb" (spare limb) or "doubling the parts of the body" (reduction of body parts). Most often it occurs in vascular lesions of the brain, less often - after a traumatic brain injury, with brain tumors, with multiple sclerosis. The sensation of an extra limb could be an aura in epileptic seizures. In the overwhelming majority of cases, it was about doubling the arm, much less often there was a doubling of the arm and leg or one leg at the same time. Very rarely, patients felt more than three arms or legs: F. Sellal et al. described a patient with "six arms", P. Vuilleumier et al. - "with four legs." An analysis of the literature describing patients in whom pseudopolymelia developed with brain damage revealed two important moments. Firstly, pseudopolymelia was most often observed with damage to the right hemisphere of the brain. Secondly, in all patients, the localization of lesions was deep. The most frequently affected were the deep parts of the parietal lobe, the thalamus, its connections with the parietal lobe, and the internal capsule. The symptomatology, against which the sensation of extra limbs developed, was similar: there were always gross motor disorders in combination with sensory ones, and the muscular-articular feeling necessarily suffered. To this were added in various combinations of symptoms characteristic of lesions of the right hemisphere: anosognosia, ignoring the left side of space, hemicorpus autopagnosia, etc. A manifestation of the sensation of imaginary limbs is a phantom of amputated limbs, when patients continue to feel their presence. Sometimes pain occurs in the phantom limbs (in a patient with a removed hip, hip sciatica may occur). The most stable phantom sensations occur in the distal limbs - hands and fingers, feet and toes. Often, phantom limbs feel reduced or enlarged in size. One of the main conditions for the development of a phantom is the suddenness of amputation (trauma, surgery). In the case of a long-term development of the disease, which led to the need for amputation, a phantom usually does not occur;
    • posture autopagnosia- a disorder in which the patient cannot determine the position of the parts of his body (his hand is raised or lowered, he lies or stands, etc.). Patients find it difficult to copy the position of the hand in relation to the face, they cannot accurately copy the position of the doctor's index finger in relation to the face. Similar difficulties are observed in the same patients when recognizing and copying different orientations of the positions of the hands in relation to each other, demonstrated by the doctor. In all these tasks, the elements of postural praxis are very closely related to the body schema and its recognition. Postural autopagnosia is more common than digital agnosia. Occurs when the upper parietal region of the left hemisphere and its connections with the visual tubercle are damaged (bilateral disorders);
    • disorientation in right-left- the patient does not know which of his two arms or legs is right and which is left, cannot show his right eye or left ear. Difficulties increase if the patient must determine the right and left sides, show the right or left hand(eye) on the body of the doctor sitting opposite. This task becomes especially difficult if the doctor crosses his arms over his chest. Orientation disorders in the right-left arise when the left parietal lobe is damaged in right-handers (angular gyrus). However, relatively rare cases are described when such defects also occur in right parietal lesions (according to observations after neurosurgical operations);
    • digital agnosia(Gerstman's syndrome) - a disorder in which the patient cannot point the finger on his hand that the doctor shows on his hand, especially if the doctor changes the position of the hand. Most often, recognition errors are noted for the II, III and IV fingers of both the right and left hands. Signs of somatoagnosia for other parts of the body are usually not observed. Occurs with damage to the left parietal lobe (angular gyrus).
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