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THE ROLE OF INFORMATION PROCESSING IN PERCEPTUAL AND READING DISABILITIES
THE ROLE OF INFORMATION PROCESSING IN PERCEPTUAL AND READING DISABILITIES
Pages 405-466
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From page 405... ...
S INGRAM The Nature of Dyslexia In this paper, I shall attempt to describe what has been and is meant by the terms "dyslexia," "specific dyslexia," and "developmental dyslexia"; these are common terms that have become confusing because authors have used them in so many different ways.
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From page 406... ...
Dejerine30 considered that the lesion responsible for "alexia" was in the medial and inferior portions of the left occipital lobe.12-21 At the same time as the first papers on "congenital word deafness" and "developmental aphasia" or "congenital aphasia" were being written, the first inadequate accounts of children who were unable to recognize written words or letters appeared. They were considered to suffer from "congenital word blindness."78'100 Soon, further reports described otherwise healthy children of apparently average intelligence who were "word blind" or "letter blind." Most of the early reports were by ophthalmologists.48'64'66'122'126 It was perhaps inevitable that, just as children who suffered from "congenital aphasia" were assumed to have brain lesions similar to those found in adults suffering from aphasia, so children with "congenital word blindness" or "congenital alexia" were suspected of having lesions similar to those described in adults who had lost the power to read and write.
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From page 407... ...
Hinshelwood's account of the clinical findings in children who suffered from "congenital word blindness" was remarkably complete, although he did not comment on the frequent history of associated retarded speech development or on "crossed laterality," an increased tendency to left-handed ness and ambidexterity already noted by other authors.93-95 McCready postulated that there were common etiologic factors in "word-blindness," "congenital word-deafness," "delay in the acquisition of speech," and "stuttering." All these disorders could be regarded as being the result of "biological variations in the higher cerebral centres causing retardation" of the various functions of language. He thought that they were the result of variations in the degree of cerebral dominance that was also manifest in weakness of lateralization of 407
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From page 408... ...
Hinshelwood's idea that underdevelopment of cerebral dominance was important in determining the disturbance of spoken and written language in his patients probably had a considerable influence on later authors, particularly Orton.103'106 Study of Perceptual Defects After Hinshelwood's work, further studies of patients with difficulties in learning to read and spell were devoted largely to more accurate descriptions and analyses of their difficulties in recognizing, orienting, interpreting, and reproducing written symbols of spoken language. Bronner,15 in The Psychology of Special Abilities and Disabilities, appears to have been the first author to study systematically the nature of the perceptual defects associated with reading disability.
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From page 409... ...
He hypothesized that in his patients there was an intermixture of control in the areas in the two hemispheres of the brain that serve the visual or reading part of the language function and that in normal children are active only in the dominant hemisphere. He suggested that there might be conflict between the mirror images in the two hemispheres when word-blind children attempt to build associations between letters and spoken words.
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From page 410... ...
She found that reversals of numbers in reading and writing to dictation occurred less frequently than she had expected on the basis of the findings of Orton103 and Monroe." She noted the frequency with which psychiatric symptoms were found in children suffering from reading disabilities and speculated about the extent to which these symptoms were the result of reading difficulties and con410
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From page 411... ...
Eustis42 described a family in which four generations showed an excess of ambidexterity, left-handedness, body clumsiness, retarded speech development, or other speech disorders and reading disability. He noted that "these conditions occur together in the individual and in his family tree sufficiently often to constitute a syndrome," but that all the symptoms he had described were found normally in infants and young children, and were to be regarded as abnormal only when they persisted into later childhood and adult life.
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From page 412... ...
Some patients with a history of retarded speech development and poor performance on the Wechsler Verbal Scale had both visuospatial and audiophonic difficulties and were thus severely educationally handicapped. As in other similar surveys, a high proportion of patients had a positive family history of retarded speech development, stammer, and educational difficulties.
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From page 413... ...
They concluded that patients with a history of retarded speech development misspelled words in different ways and for different reasons than did those who had higher scores on the Wechsler Verbal Scale than on the Wechsler Performance Scales and associated difficulties in differentiating fingers. They considered that 413
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From page 414... ...
He felt that it would be useful to ask whether there were particular types of reading backwardness associated with anomalies of laterality. He thought it likely that such differences would be found, and he wrote139: I have been struck by the frequency of retarded speech development, defects of spatial perception, motor clumsiness, and related indications of defective maturation in cases of dyslexia presenting in ill-lateralised (and some left handed)
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From page 415... ...
Most studies have shown that minor defects of acuity, visual fusion, and strabismus are not major causes of the types of reading disabilities that have been described. Abnormalities of eye movement during reading are almost certainly secondary to an underlying difficulty in visuospatial orientation, rather than primary causes.21'55 A high incidence of emotional disturbances among patients referred to departments of child psychiatry is inevitable.20'75'111 Drew,35 a neurologist, found minor neurologic abnormalities in a father and his two sons who suffered from "familial congenital word-blindness," and suggested that minor neurologic abnormalities might have been found more commonly in more patients if they had been looked for -- especially, perhaps, in series described by pediatricians.
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From page 416... ...
An attempt was made to classify children by the likelihood of their suffering from "brain damage" according to their histories and indications of brain dysfunction ascertained in the course of detailed neurologic examination and electroencephalography. Birth histories were judged arbitrarily in the same way as were those of patients suffering from cerebral palsy in a previous study.71 They were scored for the possible and probable traumatic, hypoxic, and toxic insults that they might have suffered in utero.
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From page 417... ...
The composition of the subgroups differed appreciably only in the sex ratio, the "generals" showing a higher proportion of girls than the "specifics." More than 50% of patients gave a history of slow speech development, the percentage being similar in the two groups. About 40% of the "specifics" and 25% of the "generals" had a family history of reading and spelling difficulties in sibs, parents, or aunts and 417
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From page 418... ...
In 11% of the "specifics" only audiophonic mistakes were made, whereas none of the "generals" made only that primitive type of error. Audiophonic difficulties of this type were very striking in patients in the "specific" group who had a history of retarded speech development, but they were not the only cause of their reading failure.
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From page 419... ...
When there are definite clinical signs of brain abnormality, general educational difficulties are more likely to be found than isolated reading retardation, and the family history is less often positive for reading and spelling disorders. Even in the group of patients with specific reading disability without clinical evidence of brain disease and with a positive family history of reading and writing difficulties, it is possible to discern different groups -- for example, those whose errors in reading and spelling are predominantly visuospatial and those whose errors are predominantly of the audiophonic type, with the latter more often having a history of retarded speech development.74 This survey, being retrospective and dealing with a highly selected population, is not very different from a number of others that have been described previously in this paper, but the findings do indicate that "specific developmental dyslexia" should not be regarded as a single disease entity.
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From page 420... ...
She recognized two major types of disability: "a lack of precision in discrimination of complex visual patterns," shown in the child's reading by his inability to comprehend words as units, although he might be able to recognize them when they were spelled out to him; and "a lack of precision in discrimination of spatial orientation," similar to the tendency to reverse symbols and the order of written symbols described by Orton103 as "strephosymbolia." MacMeeken88 studied 383 children in a large Edinburgh primary school between the ages of 7 years 6 months and 10 years 5 months. In her words, "a cross section would show that the children come from homes fairly far down but not very far up the social scale." MacMeeken gave individual tests of intelligence and reading ability.
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From page 421... ...
. In the independent schools, 82% were two or more grades in advance of their expected reading ability.
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From page 422... ...
. who have no well established laterality and in addition exhibit speech and other motor disorders, temperamental instability and reading disability." Later, she modified her point of view somewhat and appeared to be prepared to admit that "specific dyslexia" may be more important as a cause of reading disability than she had originally thought.128 Daniels25 laid stress on the fact that virtually all children with severe reading retardation could be helped by appropriate remedial teaching and used this as an argument against the existence of any such condition as "congenital word blindness." This argument, however, is not generally accepted as valid by psychologists and remedial teachers who have experience with large numbers of so-called "dyslexic children," most of whom are found to make good progress with appropriate treatment.10'26'27'31'43'44'116 It is difficult not to feel, with Critchley,21 that the picture that has developed in the minds of many educationalists and psychologists -- that 422
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From page 423... ...
The mean Wechsler IQ of the children was 103.118'136 It was found that specific reading retardation was associated with considerable difficulties in arithmetic, severe problems in spelling, delay in the development of language and immaturity of language still evident on examination to age nine and ten years; inco-ordination; motor impersistence; right/left confusion; (possibly) difficulties in constructional tasks; and a strong family history of reading difficulties.
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From page 424... ...
A more extensive review of the perceptual difficulties of children suffering from cerebral palsy, particularly figure-background relationships, was made by Cruickshank et al.24 They studied 110 nonhandicapped children and 325 children between 6 and 16 years old who suffered from cerebral palsy and had a minimal mental age of 6 years and IQ within average for age. Six tests of tactile and visual perception were given to the children.
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From page 425... ...
It was found that tests most sensitive to lag or disturbance in visuospatial perception tended to be poorly performed by the patients who suffered from cerebral palsy, especially the girls. They had difficulty in visuomotor tasks, such as assembling pieces of form board, block building from memory, copying simple designs on paper, and doing the progressive matrices of Raven.114 Floyer, like many other authors, emphasized that many of the difficulties on psychologic testing that she found in patients suffering from cerebral palsy could be interpreted in terms of immaturity of functioning, rather than permanent disturbance of function that could be attributed to a particular brain lesion.2-33'34'125 The question as to how far the visuospatial difficulties and the associated difficulties in reading and spelling may be regarded as manifestations of developmental lag in concept formation or as specific deficits unlikely to disappear with maturation is fully discussed by Abercrombie,1 who concluded that it would seem that as far as perception is concerned, there is little evidence that cerebral palsied children see things in a distorted manner, though they may see them in a primitive or immature way, that is, they fail to make differentiations at the level of complexity which might be expected from their mental age.
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From page 426... ...
Prechtl and Stemmer were inclined to attribute the learning difficulties of this group of children suffering from the "choreiform syndrome" to difficulties of visual fixation, instability of concentration, and a lag in the development of cerebral dominance and "complex functions." A high proportion of such patients score very poorly on tests of visuospatial perception and, as noted by Birch and Lefford,9 have difficulties in intersensory integration. A positive family history of difficulties in learning to read and spell was not noted in the account given by Prechtl and Stemmer of their studies.110 It is clear from the investigations of visuospatial and intersensory perception in brain-damaged children described above that a variety of handicaps that impair children's ability to learn to read and spell are found frequently.
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From page 427... ...
, and showed no significant sensory defects and no evidence of psychopathology. A wide variety of tests of "behavioural patterning, motility patterning, gross motor patterning, fine motor patterning, laterality, body image perception, visual perception patterning, auditory perceptual patterning, receptive language tests, expressive-language tests and sentence development" were given, in addition to reading-readiness tests, while the children were in kindergarten.
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From page 428... ...
Six of the eight failing children were boys; five were noted to be "markedly hyperactive, distractable, impulsive and disinhibited; they needed many opportunities to move around the room, and became resentful when they were required to sit still." Interestingly, they showed no more ambilateral responses than did the other 45 children, but "the auditory-perceptual and orallanguage tools of the failing readers were decidedly inferior to those of the remaining subjects." Four boys and four girls were categorized as "slow starters." They scored zero on the Gray Oral Reading Test at the end of the first grade, but achieved their expected level at the end of the second grade. Their reading and spelling difficulties appeared to be transient; as they developed and received instruction, their performance improved.
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From page 429... ...
Like MacMeeken,88 Rawson felt that difficulties in the environment contributed to, rather than caused, reading and writing difficulties. New Findings In 1961, the Medical Research Council supported a program of research into the problems of children 2J/2-5 years old with retarded speech development and their later educational problems in the Department of Child Life and Health, University of Edinburgh.
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From page 430... ...
Of the 78 children considered to suffer from developmental dyslexia studied by Ingram and Reid,75 more than half showed retardation of speech development; less formal studies of children in a speech clinic demonstrated that a high proportion of them had later difficulties in learning to read and write.70 To see whether it was possible to isolate one relatively "pure" type of dyslexia, it was decided to investigate what happened to a series of children with significantly retarded speech development once they went to school. The subjects were a group of 73 children in whom a diagnosis of speech retardation was made in the Speech Clinic of the Royal Hospital for Sick Children, Edinburgh, and subsequently confirmed on the basis of tests of articulatory development and language development in the Department of Child Life and Health, University of Edinburgh.
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From page 431... ...
dren who had a history of speech retardation and those with normal speech development. Only nine (18%)
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From page 432... ...
It became increasingly apparent as the study proceeded, however, that many of the difficulties in learning to read suffered by the subjects with slow speech development were not of audiophonic type, but visuospatial. Mason91 made the interesting observation that children with speech retardation, tested before they had reached school age, showed significantly depressed scores on the Goodenough Draw A Man Test, compared with the control group.
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From page 433... ...
Preliminary data suggest that the outlook for overcoming or outgrowing reading and spelling disabilities is most favorable when the difficulties are audiophonic. DISCUSSION The Reading Process What is known about the complex processes by which children learn to read and write with accurate spelling has been fully reviewed by Vernon,127'129 Schonell,120 Burt,16'17 and, from rather different standpoints, Vygotskii,130 Piaget,108 and Luna.87 Luria87 points out that the process of reading begins with the perception of letters and then the analysis of their conventional phonetic value.
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From page 434... ...
The ways in which children learn to correlate visual symbols with sound symbols have been studied extensively, but no major conclusions have been reached. It is obvious, however, that, at some stage in their process of learning to read, children must learn how to correlate written symbols with their spoken equivalents.
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From page 435... ...
Vernon is somewhat cautious in attributing difficulties in learning to read and spell to audiophonic disabilities but admits that "the one universal characteristic of non-readers suffering from specific reading disability is their complete failure to analyse word shapes and sounds systematically and associate them together correctly." Why even quite an intelligent child should fail to realise that there is a complete and invariable correspondence between printed letter shapes and phonetic units remains a mystery which, as we shall see ... , has not been solved.
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From page 436... ...
In 1957, it was possible for Vernon127 to write: Speech defects and slow language development have often been found in backward readers and may have been contributory to the retardation, but in the experimental study of these defects there has been no attempt to determine the frequency with which they appear in severe cases of disability as distinct from their occurrence in the merely backward. To some extent, the preliminary results of the study of children with retarded speech development in Edinburgh have demonstrated that there is a close correlation between the extent to which speech development is retarded and the extent to which the ability to learn to read and to spell is impaired.
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From page 437... ...
The definition of the many syndromes that constitute "specific developmental dyslexia" or "specific dyslexia" is only now becoming possible. Fuller definition is important not only for academic purposes, but also for remedial education, so that teachers may devise appropriate programs of teaching for their pupils.
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From page 438... ...
Research studies from Bellevue Hospital on specific reading disabilities.
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From page 439... ...
The figure background relationship in children with cerebral palsy.
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From page 440... ...
S Chronic brain syndromes in childhood other than cerebral palsy, epilepsy and mental defect, pp.
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From page 441... ...
Barn. A description and classification of common speech disorders associated with cerebral palsy.
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W Follow-up of educational attainments in a group of children with retarded speech development and in a control group.
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From page 443... ...
The concept of dyslexia. Paper presented to the Sixth International Study Group on Child Neurology and Cerebral Palsy organized by the Spastics Society, Oxford, 1968.
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From page 444... ...
The visual perception of cerebral palsied children.
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From page 445... ...
SILVER / ROSA A HAGIN Visual Perception in Children with Reading Disabilities This presentation discusses two questions: What defects in visual perception are associated with delayed acquisition of reading in childhood?
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From page 446... ...
The defects in visual perception that are associated with delayed acquisition of reading include defects in visual discrimination, in visual-motor ability, and in visual memory. Although it may be difficult to isolate them, attempts to do so should be made, because they may reflect different aspects of brain function.
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From page 447... ...
We have further investigated the problem of visual spatial orientation in older children by using the flag figure and the recognition of asymmetric matrices and overlapping forms. The flag figure consists of two crossed diagonal lines with a square drawn at the end of each, having the diagonal line as its base.
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From page 448... ...
Of 60 children with reading disabilities who were involved in a perceptual training project over the last two years, only ten were initially able to recognize and match simple, asymmetric, and complex forms. In our experience, 80% of children with reading disabilities have difficulty with the orientation of visual stimuli in space.
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From page 449... ...
This hypothesis may be investigated further by tachistoscopic methods; the emergence of primitive patterns of visual discrimination may be observed in normal children as the exposure time is successively reduced.27 These primitive patterns are similar to those which children with reading disabilities will display with unlimited exposure time. VISUAL-MOTOR FUNCTION Visual-motor function adds the functions of fine motor coordination and of praxis to the capacity for precise visual discrimination.
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From page 450... ...
These findings consistently appear, in greater or lesser degrees, in approximately 90% of children with reading disabilities. The findings agree with those of Keogh.13 There are, of course, many other ways of testing visual-motor function -- for example, the copying of geometric figures other than the Gestalt form8-21; the parallelogram test of Luria,18 in which the patient is to place a circle in the appropriate corner of a parallelogram to reproduce a given parallelogram and circle, all presented in various spatial orientations; the Kohs block test10 or the block-design subtest of the Wechsler Intelligence Scale for Children; and Raven's progressive matrices.25 The latter example, however, may involve cognitive processes other than visual-motor function.
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From page 451... ...
Problems in visual memory in children with reading disabilities may be interpreted primarily as defects in spatial orientation. This defect is also seen in visual discrimination, in visual figure-ground perception, and in visual-motor functioning.
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From page 452... ...
In the area of figure-background perception, those with reading disabilities in childhood made significantly more errors than did controls in reproducing diagonals, in omitting marbles, in displacement of the figures, and in use of tactile or color cues. Twelve years later, significant improvement was noted in only one area: omissions of marbles from the figure.
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From page 453... ...
Of 58 children with reading disabilities treated in our program of perceptual correction, 43 improved in Koppitz scores and 15 did not. Oral reading and reading comprehension improved significantly in the children with improved Koppitz scores; improvement was not significant in the 15 whose Koppitz scores did not improve.
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From page 454... ...
We do not know how to do this, but we have attempted to teach reading to children with reading disabilities by working with the next step in their neurophysiologic maturation -- namely, by improving the accuracy of their perceptual input. The object of this experiment was threefold: to determine whether we can reduce perceptual errors in children of school age by training, to ask what effect this training has on oral reading and on reading comprehension, and to ask what effect this training has on our measures of cerebral dominance.
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From page 455... ...
Predicting Reading Failure: A Preliminary Study of Reading, Writing, and Spelling Disability in Preschool Children. New York: Harper and Row, 1966.
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From page 456... ...
McFie, J Cerebral dominance in cases of reading disability.
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From page 457... ...
He has postulated three points of possible breakdown in this process: a failure of perception, an inadequate language function, and a difficulty (or inability) in associating a visual symbol with the sound that it represents.
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From page 458... ...
I have tried to relate these learning-to-read processes in a neurophysiologic and neuroanatomic model that I think has some value for understanding the complexity of the process with which we are dealing and the various points of weakness at which a breakdown may occur. Anatomic Model In regard to the language function, the indications are that the centers for spoken language develop in the left hemisphere.
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From page 459... ...
Integration Deficit From this experiment, it would appear that under ordinary circumstances in the human there must exist in each hemisphere two conflicting mirror images -- one representing the direct visual input to that 459
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From page 460... ...
In addition, the studies cited above suggest that the most effective integration of complex visual patterns is in the right hemisphere. There must be a consistent reversal whenever images are associated with auditory language symbols mediated in the left hemisphere.
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From page 461... ...
Milner's data2 suggest that, in the adult, although visual pattern recognition is still most effectively mediated in the right hemisphere, the recognition of symbols is most effectively accomplished by the left hemisphere. This suggests that the problem of establishing association between vision and language function is handled by having the center for symbol recognition develop in the left hemisphere, rather than in the right, where pattern recognition is ordinarily most effectively handled.
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From page 462... ...
As to experimental evidence of the value of perceptual training, I know of only one adequately controlled study: that of Rosen.7 He investigated early readers in 25 classrooms; half the children were given a half-hour of perceptual training each day, and the other half were given a half-hour of extra reading instruction. At the end of a semester, they were all tested for perceptual motor skill and reading.
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From page 463... ...
Interhemispheric Relations and Cerebral Dominance. Baltimore: Johns Hopkins Press, 1962.
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From page 464... ...
L An experimental study of visual perceptual training and reading achievement in first grade.
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