Lecture
Methods of restoring reading in sensory and acoustic-mnestic alexia.
A completely different picture of reading impairment is found in lesions of the temporal parts of the left hemisphere, the result of which is an impairment of phonemic hearing and of the sound analysis of a word. In these cases the reading impairment occurs within the syndrome of sensory aphasia. The process of direct visual recognition of familiar words in this form of reading impairment can remain intact, while the sound analysis and synthesis of the word being read prove to be profoundly impaired, and often impossible. Many words (not well-established in the patient's past experience) turn out for him to be merely a system of signs having no sound basis. The inability to recognize the meaning of words by means of sound-letter analysis turns the whole reading process into guessing, close to that which occurs in children learning to read by the whole-word method (T. G. Egorov, 1953). It is characteristic that in patients for whom reading was a highly automatized skill before the illness, recognition of the word being read can be preserved, whereas in patients whose reading skill was less well-established in past experience it breaks down completely.
"Guessing" reading is explained by the fact that, normally, a highly automatized skill can proceed as a process of direct recognition of the word with secondary correction of its sound composition. Therefore, a patient with temporal aphasia and alexia can often recognize a whole, well-familiar word "by sight", yet is unable to read a single letter, syllable, or little-familiar word, since he lacks a clear perception of its sound-letter structure. Sensory alexia occurs as a result of an impairment of the process of sound discrimination because of a defect of acoustic perception, which is the central mechanism and the central defect of sensory alexia. This explains the appearance, during reading, of literal substitutions and paralexias.
Defects of acoustic perception lead not only to the substitution of some phonemes for others, but also to a complete inability to synthesize sounds into a word, to an inability to understand its meaning. This defect leads either to a complete loss of reading, or to the replacement of adequate reading by "guessing" reading, in which the level of understanding of the meaning of the word is impaired, while the discernment of the general sense of what is read remains intact, which can explain the appearance of verbal paralexias.
Interesting data were obtained by the author and I. M. Ulanovskaya in an experimental study of the structure of the reading impairment that arises in acoustic-mnestic aphasia. The experiment revealed, in this form of alexia, defects not so much at the sensorimotor level of reading as an impairment of the level of understanding. At the basis of these reading defects lie predominantly difficulties in retaining the span of incoming information. Thus, patients were asked to read a sentence and select the corresponding picture for it, choosing it from among several close in content. The process of correlating the sentence read with the picture proved to be considerably difficult for patients of this group, and their understanding was inaccurate, indirect, and expanded, and only as a result of prolonged work did understanding become accessible.
Example. Thus, having read the sentence The squirrel sleeps in a hollow, the patient carries out prolonged orientation, examines all the pictures from among which he must choose the needed one, then returns to the sentence, reads it, says "there's the squirrel", and takes the needed picture. For the sentence The fish swim in the river the patient first takes two pictures, accompanying them with the word "swims". After the experimenter's question "Is that right?" the patient returns to reading the original sentence and only then chooses the needed picture.
Such mediated and expanded understanding was most clearly revealed in the experiments involving reading a text: the patient was presented with a text divided into meaningful parts; for each part he had to select a picture. Understanding of the instruction was preserved, and the patient correctly oriented himself in the task, maintaining control over his actions. However, the way in which he selected the picture allows us to speak of an impairment of the direct understanding of what was read, although the sensorimotor level of reading was affected only slightly. Most likely, at the basis of this defect of understanding of sentences and texts lies a narrowing of the span of perception of verbal information. An additional experiment on repeating the sentence read confirmed this assumption and showed that the patient cannot correctly perceive, retain, and reproduce the whole sentence. He selects a picture for the text by its main elements, either by the actions, or by the characters, whose names he has read, i.e., understanding of the text is mediated by singling out the notional words and understanding their meanings.
The two levels of reading — the sensorimotor and understanding — are at first, as it were, disjoined: the patient first reads the text and only then, after corresponding additional actions, understands what is read, i.e., works consciously on understanding. This, however, does not mean that intellectual activity as a whole is impaired in a patient with acoustic-mnestic defects, that he cannot understand the content, or evaluate its meaning and sense. Experiments on understanding the content of pictures, which were conducted not in verbal form, showed complete preservation of this process. The completeness and directness of understanding are impaired only in the process of reading, i.e., when working with verbal material.
Interesting data were also obtained in studying the influence of context and its level on the process of reading, its speed, and the completeness of understanding. The experiments showed that context has a differing influence on the speed and accuracy of reading, as well as on the ability to understand what is read, in different forms of alexia. In the motor forms of alexia, the external and internal contexts are equally important, but understanding is influenced more by the level of the text, then by the speed and accuracy of reading, and only then — by the level of the sentence.
In acoustic-mnestic alexia we find a completely different regularity, and one that differs according to the degree of severity of this alexia. In the severe form of alexia, a high level of context (i.e., reading a text or a phrase) has a negative influence on the speed and accuracy of reading and of understanding what is read. The word is understood better than the sentence, and the latter better than the text. In the moderate and mild degrees of severity, the influence of context on improving reading already appears, but only the internal context, i.e., that of the sentence. It is evident that the meaning of a word, however familiar it may be, is harder to recognize out of context (because of a deficit of information). Therefore, reading all the words (familiar and unfamiliar) took these patients almost the same amount of time.
These experimental data are extremely important for the correct organization of restorative learning of reading in patients with different forms of alexia. Thus, in cases of motor forms of alexia, teaching of reading, of its technical side, should begin with teaching the reading of the phrase, while understanding — with teaching the reading of the text. In an actual teaching situation, it is necessary to teach the reading of phrases taken only from the same text whose understanding is being worked on, and to teach words from these same phrases.
In acoustic-mnestic alexia restorative work must begin at the level of the word, then including it in the sentence, and the latter — in the text (in the severe degree of alexia), while in the moderate and mild degrees, teaching proceeds from the sentence upward — to the text and downward — to the word. It should also be noted that work on restoring full-fledged reading in cases of literal and verbal alexia (in other words, in primary defects of the sound decoding of letters and in a primary tendency to replace analytic reading with guessing reading) must follow a different sequence.
In cases of a primary breakdown of the sound analysis of letters and words, arising in sensory alexia, teaching should begin with reading familiar words with reliance on a picture. Once the ability to read a certain number of words with reliance on pictures, or to recognize them "by sight", has appeared, one can move on to teaching the naming of individual letters making up an unfamiliar word, i.e., to analytic reading. When "guessing" reading predominates, arising in sensory alexia, the method of teaching is directly opposite to that indicated, i.e., work must begin with disinhibiting the tendency to read by direct recognition of words "by sight", so as gradually to transfer reading onto the analytic-synthetic path. This is precisely the central task of teaching reading in sensory alexia. At this stage, work on correlating the letter with its corresponding sound, on recognizing and naming it within a syllable, and later — within a word, must be made the subject of special exercises. The leading method of teaching in this period is the frame method, in which the word is broken down by means of a frame into elements (first into letters, then into syllables, later — into combinations of syllables, etc.). For more detail see (Tsvetkova L. S. Restorative Learning in Local Brain Lesions. M., 1972). The frame inhibits the guessing of the word and directs the reading process into the channel of conscious analytic-synthetic work on it. After this, one can move on to restoring the merging of letters into syllables, and of syllables into words.
Analysis of the dynamics and methods of restoring reading in sensory alexia
Patient V., 35 years old, higher education. Diagnosis: cerebrovascular accident in the system of the middle cerebral artery. In the neuropsychological syndrome — aphasia, complete impairment of writing and reading. Reading had the character of "guessing" reading; it consisted of recognizing words familiar to the patient "by sight", which relied on associations well established in past experience. The patient could only "read" by recognizing individual words as wholes, with frequent verbal substitutions. Recognition was limited to concrete nouns. Verbs, conjunctions, prepositions, etc. were omitted altogether. Semantic substitutions of the words recognized were frequently encountered. Thus, instead of the word «сом» (som, "catfish") the patient reads «рыба» (ryba, "fish"), and then, after his error is pointed out, reads «щука» (shchuka, "pike"). Instead of «зима» (zima, "winter") he reads «снег» (sneg, "snow").
Teaching was begun with restoring the meaning of the letter and its correlation with the sound. This work on the letter was long and difficult.
In parallel, teaching of reading itself proceeded with the help of the frame. The frame, in a purely external way, disrupted "guessing reading", and forcibly developed the ability to analyze the word, first by letters, then by syllables.
As a result of these exercises, by the end of the fourth month of teaching the patient read simple texts, consisting of 54 words, in an average of 3 min 12 sec, making an average of three errors in the process. Let us give an example of the patient's reading of a complex text (freely, and with the frame).
After the frame was introduced into the reading, the patient read the entire text absolutely correctly and retold it. By the end of the fifth month of teaching, as a result of such training with a focus on speed, the patient could, on average, read 180 words of newspaper text in a whisper in 5 min, with correct understanding of the content.
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