The violation of the VPF with local brain damage

Consider 2 and 3 brain blocks. With traumatic brain injuries, tumors (oncological diseases), cystic changes, bullet wounds and strokes.

Agnosia - (A - denial, gnosis - perception) - a violation of perception with a local brain damage. Agnosia are visual, tactile, auditory. Most of all visual agnosias.

Visual agnosia - occurs when the lesions of the occipital or parietal cortex. The wide visual field - 18, 19 fields - the area of ​​the cortex, which is involved in the processing of pulses from visual analyzers.

Visual Agnosia:

1. Subject agnosia - is expressed in any lesion of the parieto-occipital region of the brain. In rough cases - with bilateral lesion of the occipital region of the brain. The patient cannot recognize the object, as well as the real image of the object in the picture. The patient may describe the subject, but not recognize it. To the touch with eyes closed the patient can feel the handle and say that it is a handle. Behavior is similar to the blind. In less severe cases, the patient does not recognize contour images or superimposed images.

Also, the patient may not recognize the image if an extra detail is added or the image is crossed out.

Outside of rude cases, the threshold of perception increases dramatically. A person spends a lot of time identifying an object. Upon presentation of a more complex subject, recognition takes even longer. In this case, copying the figure may be intact, but the patient will not say that he is drawing, because he did not recognize it.

Subject agnosia is a violation of the perception of objectivity. It distinguishes all agnosias. The main property is objectivity.

2. Color agnosia - occurs when the parietal-occipital region of the brain is affected. It may or may not occur. Depends on the individual characteristics of the brain. In this case, color perception and color distinction are preserved, since the work of the optic tracts is not disturbed. The patient may recognize the color, but the categorization of color suffers. When presenting cards with shades that need to be correlated with these colors - the patient can not do this.

The patient is difficult to correlate the color with a specific object. "What is this color?" Or "What is the color of the tree?".

3. Letter Agnosia - occurs when the occipital-temporal region of the left hemisphere is affected. The patient can copy the letter, then can call it. This breaks the reading, meaningful letter. If you write by touch, without visual control, then the task will be completed.

4. Optical-spatial agnosia - occurs when lesions of the occipital-parietal areas. It appears as a violation of spatial relationships, spatial relationships, both real objects and their images. More often suffers left-, right-coordinate. In rough cases, the perception of the upper-lower coordinates plus the left-, right-coordinate may suffer.

It is expressed in real life in such a way that a person cannot understand, for example, a watch - the inability to correlate hands and dials.

Disturbance of orientation in geographical maps. The patient cannot copy or independently produce depth, three-dimensional, spatial features of the object. One-sided optical-spatial agnosia, sometimes referred to as visual inattention, is distinguished. The patient ignores any side (usually left) of the object. The patient describes the right side of the picture, the tree, and the left does not depict. Images can be on the right side of the picture.

Optical-spatial agnosia often manifests itself in lesions of the right occipital part. The degree of domination of the right hemisphere is different for everyone. Most of the information comes from the right eye to the left hemisphere. With the defeat of the right hemisphere, the degree of dominance of the left hemisphere increases. The functions of the left hemisphere are released. It should work for two. With the defeat of one of the hemispheres, you need to consider the involvement of the other hemisphere.

With the defeat of the right hemisphere euphoria occurs, with the defeat of the left hemisphere - depression, since the center of positive emotions is in the left hemisphere. And with the defeat of the right hemisphere - the left releases its potential, therefore, such a reaction occurs.

In the human visual field, the left hemisphere dominates.

5. Facial agnosia - occurs when the lesion of the right hemisphere, right occipital-parietal zones. In rude cases, the patient does not recognize real faces, their images, or even their face.

The neuropsychological test consists in the presentation of images of famous people.

In less severe cases, the patient recognizes his face, and his relatives, but in reality. And in the image, for example in the photo, it is already more difficult for the patient. The answer is given with a delay or an incorrect answer.

The perception strategy of the right-hemispheric people and the left-hemisphere people is different. For left-hemispheric - perception strategy - successive, i.e. information is processed sequentially elementwise.

Right hemisphere perception strategy - simultaneous. Simultaneously shaped. Generally.

At defeat of the right hemisphere - integrity of perception is broken.

6. Simultaneous agnosia - the inability to perceive simultaneously several objects.

In more severe cases - with bilateral lesions: left and right hemispheres, occipital-parietal region, 18, 19 fields.

Balanta syndrome - gaze atoxia. The look becomes unmanageable. Gaze rushing. When recording eye movements - chaotic movement. A person can not carefully consider the object. Reading is violated.

Tactile agnosias - lesion area - crown. Tactile agnosia is a violation of tactile perception with lesions of the parietal regions of the brain.

1. Subject tactile agnosia - the patient can not identify the object by touch. In milder cases, the patient can feel the object by touch. Give the name can not. Description only. The patient constantly requires visual control. In such patients, many automatisms are destroyed. The tactile image of the object suffers.

2. Finger tactile agnosia - a person ceases to orient himself in his fingers, cannot name them, cannot determine to which finger the researcher touches (with eyes closed).

This is manifested in the hand that is opposite to the focus of the brain lesion.

3. Tactile agnosia of the object's texture - the contralateral (ie, the opposite) to the lesion. Man to the touch can not determine the material of an object.

The most common combination of agnosia.

4. Tactile asymbolia - the impossibility of the simultaneous perception by touch of several objects.

5. Symbolic agnosia - (sign, alphabetic) - a person cannot identify a sign or letter written on the back of the hand. Violation of skin reading (on the hand, you can represent simple signs - a square, a triangle, a circle, the letter X, L, H, etc.).

Skin reading is called dermatolexia.

Auditory agnosia - occurs when the secondary areas of the temporal cortex of the right hemisphere are affected.

Auditory agnosia is the inability to perceive household or object noise. With the defeat involved mid-temporal gyrus.

Other disorders in the lesion of the right temporal region.

Amuzia is the non-perception of music. Music falls into separate elements, notes, they perceive music as noise (unpleasant).

Arrhythmia - lack of perception of rhythm. The inability to play the rhythm. If the defeat is gross, then the patient will not be able to reproduce even the lightest rhythm. Rhythm is simultaneity. Consequently, the right hemisphere does not fulfill its function.

Violation of the intonation of speech and. A person cannot perceive the intonation correctly. Himself speaks in an unmodulated voice. Communication suffers.