Lecture
This section briefly describes two other forms of nonspecific acalculia — sensory and acoustic-mnestic. Whereas optic acalculia occurs in the syndrome of an impairment of the process of optic perception, these two forms of impairment of counting occur in the syndrome of an impairment of acoustic perception and speech. One of them can therefore conventionally be called "auditory acalculia," in which only the oral form of counting and counting by ear are impaired, while the other — "amnestic acalculia" — is connected with an impairment of auditory-verbal memory and of the volume of auditory perception.
A lesion of (or, in children, an underdevelopment of) the superior temporal gyrus (area 22, Wernicke's area), as is known, leads to sensory aphasia, which is based on an impairment of phonemic hearing. It might seem that speech and phonemic hearing have no direct relation to counting. And yet a lesion of this area of the brain also leads to a peculiar acalculia. Impairments of counting in this case occur in the syndrome of acoustic agnosia, together with, and against the background of, an impairment of phonemic hearing. Recognition and naming of a digit or number becomes difficult for patients with sensory acalculia, and often impossible.
Impairments of phonemic hearing and of oral expressive and impressive speech in patients with sensory aphasia also lead to an impairment of the understanding of words denoting digits and numbers, and of their recognition. Instead of the spoken number шесть (shest', "six"), patients may hear the word семь (sem', "seven"); instead of шестнадцать ("sixteen") — семнадцать ("seventeen"); instead of девять ("nine") — десять ("ten"), and so on. The same and other difficulties arise in naming as well, and all this leads to great complications in counting operations, in their understanding and realization. These defects are not an impairment of counting as such; they only make it more difficult, and they can be overcome if counting and counting operations are shifted into internal operations — without the participation of speech, or better still, if inner speech too is excluded. As for children, defects of the temporal region and a lack of formation of speech lead in them to gross primary impairments of counting, of counting operations, and of the formation of the concept of number. In this case other methods of examination and of restoring counting are necessary.
Thus, sensory acalculia has the following characteristics:
clinical picture — patients do not understand by ear the meaning of a digit or a number, make many attempts when performing oral arithmetic operations, but all of them are unsuccessful;
neuropsychological picture — sensory acalculia occurs in the syndrome of sensory aphasia, agraphia, alexia (symptoms — an impairment of the understanding of numbers by ear, of the naming of numbers because of speech defects; factor — an impairment of acoustic perception and, above all, of phonemic hearing);
psychological picture — in this case the impairment of counting is caused by the impairment of speech, while counting itself, the concept of number, and counting operations are not primarily impaired.
This form of impairment of counting is likewise nonspecific and secondary, and the defects of counting are connected with impairments of speech and acoustic perception and occur in the syndrome of acoustic-mnestic aphasia, the main mechanisms (factors) of which are defects in the volume of acoustic perception and an impairment of object images-representations. This form of acalculia has been little studied and needs further consideration. The fact is that in this form of acalculia there were often symptoms of failure to recognize numbers presented under increased noise or in a large quantity simultaneously for their successive recognition and naming, i.e., symptoms of a secondary agnosia arose, and, as it were, of an amnesia for the name of the digit or number. Under these sensitized conditions perceptual difficulties arose, defects of perception, recognition, and naming of numbers due to defects of images-representations and of the volume of perception. When given the task of quickly writing down a series of digits or numbers, patients likewise made many errors, performed the task slowly and in a highly voluntary and conscious manner, and made attempts to name what they had written, as if helping themselves with speech.
If, in training these patients, comfortable conditions were created for them — reducing the volume of the task, lowering the pace of presenting the material and of the response — most of the errors disappeared. However, errors remained in the writing of digits, in which the essential features distinguishing them from other, similar digits were sometimes absent (3—5, 7—1, 4—1, etc.). Subsequent identification and naming of these digits was made difficult. Particular difficulties arose when it was necessary to write a great deal and quickly, i.e., in a more automatized and less voluntary mode. These defects fit within the syndrome of an impairment of perceptual images and of images-representations of objects and of the symbolic figures of letters and digits. In the pathology, the lower, involuntary level of the perception and identification of number is affected to a greater extent. The structure of counting, the concept of number, and its place-value structure are not primarily impaired in this case, but all the processes connected with counting are made difficult.
Clinical picture. When given the task of naming a number or performing an arithmetic operation, patients perform everything in a highly conscious and slowed manner, constantly ask for the numbers or the task itself to be repeated, often refuse to perform the task, and become upset.
Neuropsychological picture. This acalculia is of secondary origin and occurs in the syndrome of a highly specific acoustic-mnestic aphasia, which is characterized by an impairment of the volume of acoustic perception, the replacement of simultaneous perception by successive perception, and an impairment of images-representations, which leads to defects of naming. All these symptoms manifest themselves in acalculia as well: the volume of perception of a named number is reduced, patients require the number to be repeated in parts, and the images (perception and representation) of numbers are likewise defective — patients cannot single out the essential features of similar numbers.
Factors — a decrease in the volume of acoustic perception, an impairment of the visual image of a digit due to defects in the speech organization of perception.
As is evident from this description, these impairments of counting are not complex, and they do not require special methods of restorative training. The restoration of counting proceeds in parallel with the restoration of speech. It is therefore recommended to use methods for restoring speech in sensory aphasia, especially those aimed at overcoming defects of phonemic hearing in the one case, and, in the other, methods that restore the volume of acoustic perception and auditory-verbal memory. We recommend the methods that have been developed and described by us. (FOOTNOTE: Tsvetkova, L.S. Neuropsychological Rehabilitation of Patients. Moscow: Moscow University Press; Tsvetkova, L.S. Aphasia and Restorative Training. Moscow: Prosveshchenie, 1988).
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