首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
A comprehensive test battery, including phonological, speed, motor and cerebellar tasks, was administered to the entire cohort of two schools for children with learning disabilities. Testing was undertaken blind without accessing the psychometric data on the children. Children were then allocated to a discrepancy group on the basis of their IQ, with the majority (n = 29) classified as nondiscrepant (IQ < 90) and a smaller set (n = 7), with IQ of at least 90, classified as discrepant (with dyslexia). Both groups showed significant deficits relative to age-matched controls on almost all the tests. On phonological, speed, and motor tasks, the nondiscrepant group were at least as severely impaired as the discrepant group. By contrast, on the cerebellar tests of postural stability and muscle tone, the nondiscrepant group performed significantly better than the children with dyslexia and close to the level of the controls. The findings indicate that cerebellar tests may prove a valuable method of differentiating between poor readers with and without IQ discrepancy. The findings are interpreted in terms of the cerebellar deficit hypothesis for dyslexia.  相似文献   

2.
There is a consensus that dyslexia is on a continuum with normal reading skill and that dyslexics fall at the low end of the normal range in phonological skills. However, there is still substantial variability in phonological skill among dyslexic children. Recent studies have focused on the high end of the continuum of phonological skills in dyslexics, identifying a “surface” dyslexic, or “delayed” profile in which phonological skills are not out of line with other aspects of word recognition. The present study extended this work to a longitudinal context, and explored differences among subgroups of dyslexics on a battery of component reading skills. Third grade dyslexics (n=72) were classified into two subgroups, phonological dyslexics and delayed dyslexics, based on comparisons to younger normal readers at the same reading level (RL group). The children were tested at two points (in third and fourth grade). The results revealed that the classification of dyslexics produced reliable, stable, and valid groups. About 82 percent of the children remained in the same subgroup category when retested a year later. Phonological dyslexics were lower in phoneme awareness and expressive language. Delayed dyslexics tended to be slower at processing printed letters and words but not at rapid automatic naming of letters, and relied more heavily on phonological recoding in reading for meaning than did phonological dyslexics. A subset of the delayed dyslexics with the traditional “surface dyslexic” pattern (relatively high pseudoword and low exception word reading) was also identified. The surface subgroup resembled the RL group on most measures and was not very stable over one year. The results are discussed in light of current models of dyslexia and recent subgrouping schemes, including the Double-Deficit Hypothesis.  相似文献   

3.
The prevalence of phonological and surface dyslexia subtypes among Swedish university students with dyslexia (n = 40) was examined using both the regression method, developed by Castles and Coltheart, and latent profile analysis. When an academic‐level control group was used as a reference group in a regression, eight students with phonological dyslexia and 15 students with surface dyslexia were identified. In contrast, 17 students with phonological dyslexia and two students with surface dyslexia were identified when the subtypes were defined by reference to a reading‐level control group, indicating a deviant profile among the students with phonological dyslexia and delayed development among those with surface dyslexia. The latent profile analysis was based on five phonological and four orthographic tasks. Seven profiles were obtained, of which none exhibited deficits in orthographic but not in phonological skills or vice versa. Thus, the analysis further supported the phonological deficit hypothesis of dyslexia.  相似文献   

4.
Although there are a number of standardised measures to assess dyslexia in children, there are comparatively fewer instruments suitable for the assessment of dyslexia in adults. Given the growing number of students entering UK higher education institutions, there is a need to develop reliable tools for assessing the additional needs of those with dyslexia and related difficulties. This study reports data from a revised version of the York Adult Assessment: An Assessment Battery for Dyslexia Screening in Higher Education. The current York Adult Assessment‐Revised (YAA‐R) is an assessment battery consisting of tests of reading, spelling, writing and phonological skills. Data from a normative sample of 106 adults without dyslexia and a validation sample of 20 adults with dyslexia illustrate significant group differences on the tests comprising the YAA‐R. Additionally, the YAA‐R has good discriminatory power yielding 80% sensitivity and 97% specificity. Taken together, the YAA‐R is a suitable test battery for the assessment and identification of dyslexia in university students.  相似文献   

5.
In seven experiments, we investigated whether compensated and uncompensated adults with dyslexia show different patterns of deficits in magnocellular visual processing and in language processing tasks. In four visual tasks, we failed to find evidence of magnocellular deficits in either group. However, both groups of adults with dyslexia showed deficits in component language skills, and the degree of reading impairment predicted the nature and extent of these deficits. Uncompensated readers showed deficits in orthographic and especially phonological coding and awareness and were slower on rapid naming. Compensated readers showed word and nonword performance below controls but better than the uncompensated readers. The compensated group was not significantly less accurate than controls on phonological awareness, nor significantly worse overall on rapid naming.  相似文献   

6.
It is now thought that the cerebellum is involved in the acquisition of “language dexterity” in addition to its established role in motor skill acquisition and execution. Mild cerebellar impairment, therefore, provides a possible explanation of a range of problems shown by children with dyslexia. The authors have established suggestive evidence in support of this hypothesis in tests of balance and of time estimation. In a further test of the hypothesis, a battery of clinical tests for cerebellar impairment, including tests of muscle tone and of coordination, was administered to matched groups of children with dyslexia and control children aged 10, 14, and 18 years (55 subjects in all). The children with dyslexia showed highly significant impairments on all the cerebellar tests, and significant impairment compared even with reading age controls on 11 of the 14 tasks. Deficits on the majority of tests were among the largest found in our research program. The findings, therefore, provide further intriguing evidence of cerebellar impairment in dyslexia. We speculate that the well-established phonological deficits in dyslexia may arise initially from inefficient articulatory control attributable to cerebellar impairment.  相似文献   

7.
Children (n = 122) and adults (n = 200) with dyslexia completed rapid automatic naming (RAN) letters, rapid automatic switching (RAS) letters and numbers, executive function (inhibition, verbal fluency), and phonological working memory tasks. Typically developing 3rd (n = 117) and 5th (n = 103) graders completed the RAS task. Instead of analyzing RAN/RAS results the usual way (total time), growth mixture modeling assessed trajectories of successive times for naming 10 symbols in each of five rows. For all three samples and both RAN and RAS, two latent classes were identified. The “faster” class performed slowly on the first row and increased time by small increments on subsequent rows. The “slower” latent class performed more slowly on the first row, and children, but not adults, increased time by larger increments on subsequent rows. For children, both the initial row (automaticity index) and slope (sustained controlled processing index) of the trajectory differentiated the classes. For adults, only the initial row separated the classes. The longest time was on row 3 for RAN and row 4 for RAS. For the typically developing 5th graders, close in age to the children with dyslexia, the trajectories were flatter than for children with dyslexia and only the slower class (4%) showed the peak on row 4. For children with dyslexia, inhibition predicted RAN slope within the slower latent class and phonological working memory predicted RAS slope for both latent classes. For adults with dyslexia, inhibition and phonological working memory differentiated both latent classes on RAN intercept and RAS slope. Taken together, RAN, which may assess the phonological loop of working memory, and RAS, which may assess the central executive in working memory, may explain the timing deficit in dyslexia in sustaining coordinated orthographic-phonological processing over time. This research was supported by Grant Ns. P50 33812 and R01 HD25858 from the National Institute of Child Health and Human Development, Virginia W. Berninger, PI.  相似文献   

8.
Phonology,reading development,and dyslexia: A cross-linguistic perspective   总被引:1,自引:0,他引:1  
In this paper, I present a theoretical overview at the cognitive level of the role of phonological awareness in reading development and developmental dyslexia across languages. My assumption is that the primary deficit in developmental dyslexia in all languages lies in representing speech sounds: a deficit in “phonological representation.” I will argue that this deficit manifests in somewhat different ways, depending on orthography. I will also argue that the phonological deficit in dyslexia is initially at the syllable and onset-rime levels of phonological awareness, with the development of “phonemic” awareness being a consequence rather than a precursor of reading. Finally, I will suggest that some of the processes underpinning language acquisition are disrupted in dyslexia, in particular, the detection of rhythm in speech.  相似文献   

9.
An unexpected and remarkable preference for second language reading among some dyslexics has been noted, presenting a challenge to accepted theory on dyslexia and the capacity for second language learning. The current study was designed to examine this phenomenon by systematically looking at the differential reading scores in the first and second languages of reading-disabled young Swedish adults who claimed to prefer reading in their second language (English). Three groups were selected for study: a group of 10 reading-disabled young adults who prefer to read English; a second group of 10 reading-disabled with no special preference for second language reading, matched on word recognition efficiency, age group, gender and educational level and a group of 10 normal readers matched on age group and educational level. The test battery was designed to compare overall reading efficiency in English and Swedish and therefore encompassed both speed and accuracy measures. The battery covered seven phonological measures, four orthographic measures,three isolated word reading measures, two continuous text reading measures, a comprehension task and an author recognition task. All tasks were carried out in both English and Swedish. The results showed that two dyslexic groups differed significantly in the degree to which task performance, including reading efficiency, was impeded by the English format. A tentative hypothesis was forwarded as to how the exceptional and unexpected facility with English might be explained.  相似文献   

10.
Here we explore relations between auditory perception of amplitude envelope structure, prosodic sensitivity, and phonological awareness in a sample of 56 typically-developing children and children with developmental dyslexia. We examine whether rise time sensitivity is linked to prosodic sensitivity, and whether prosodic sensitivity is linked to phonological awareness. Prosodic sensitivity was measured by two reiterant speech tasks modelled on Kitzen (2001). The children with developmental dyslexia were significantly impaired in the reiterant speech tasks and in the phonological awareness tasks (onset and rime awareness). There were significant predictive relations between basic auditory processing of amplitude envelope structure (in particular, rise time), prosodic sensitivity, phonological awareness, reading, and spelling. The auditory processing difficulties that characterise children with developmental dyslexia appear to impair their sensitivity to phrase-level prosodic cues such as metrical structure as well as to phonology, but in this study phonological and prosodic sensitivity made largely independent contributions to reading.  相似文献   

11.
The present study explores the relationship between basic auditory processing of sound rise time, frequency, duration and intensity, phonological skills (onset-rime and tone awareness, sound blending, RAN, and phonological memory) and reading disability in Chinese. A series of psychometric, literacy, phonological, auditory, and character processing tasks were given to 73 native speakers of Mandarin with an average age of 9.7 years. Twenty-six children had developmental dyslexia, 29 were chronological age-matched controls (CA controls) and 18 were reading-matched controls (RL controls). Chinese children with dyslexia were significantly poorer than CA controls in almost all phonological tasks, in semantic radical search, and in phonological recoding proficiency. Chinese children with dyslexia also showed significant impairments in most of the basic auditory processing tasks. Regression analyses demonstrated that different auditory measures of rise time discrimination were the strongest predictors of individual differences in Chinese character reading (1 Rise task) and phonological recoding (2 Rise task) respectively, with frequency discrimination also important for nonsense syllable decoding. Our results support the hypothesis that accurate perception of the amplitude envelope of speech is critical for phonological development and consequently reading acquisition across languages.  相似文献   

12.
This study investigated whether children with dyslexia differed in their performance on reading, phonological, rapid naming, motor, and cerebellar-related tasks and automaticity measures compared to reading age (RA)-matched and chronological age (CA)-matched control groups. Participants were 51 children attending mainstream English elementary schools in Quebec. All participants completed measures of IQ, word and nonword reading fluency, elision, nonword decoding, rapid naming, bead threading, peg moving, toe tapping, postural stability, and muscle tone. Results from both group contrasts and analyses at the individual case level did not provide support for claims of motor–cerebellar involvement in either typical or atypical reading acquisition. Results were more consistent with a phonological core process account of both typical reading and reading difficulty. Phonological deficits for children with dyslexia compared to RA-matched controls were, however, only evident in group contrasts. Findings thus also have important implications for identifying at-risk readers among their same-aged peers.  相似文献   

13.
Studies of basic (nonspeech) auditory processing in adults thought to have developmental dyslexia have yielded a variety of data. Yet there has been little consensus regarding the explanatory value of auditory processing in accounting for reading difficulties. Recently, however, a number of studies of basic auditory processing in children with developmental dyslexia have suggested that a reduced ability to discriminate the rate of change in amplitude envelope onsets (rise time) may be linked to phonological processing difficulties and thereby to reading difficulties. Here, we select a range of different rise-time tasks used with children, and give them to adults with developmental dyslexia, along with 2 other auditory tasks (intensity discrimination and temporal order judgment). Deficits in both rise-time perception and temporal order judgment were found to predict literacy attainment in adults with developmental dyslexia, but the data were suggestive of different causal pathways.  相似文献   

14.
It has been proposed that the phonological coredeficit that is linked to reading failure hasas its underlying cause a deficit in temporalprocessing. In a multivariate investigationdesigned to examine the temporal processingdeficit hypothesis, thirty reading-disabled(RD) adults, thirty-two normally achievingadults and thirty-one normally achievingchildren (reading-level controls) wereadministered a comprehensive battery thatincluded a wide range of timing tasks, inaddition to reading and phonological measures. Although adults with RD displayed overallperformance that was below that of normallyachieving adults on most of the timing tasks,their performance was not differentiallyinfluenced by rate of stimulus presentation. Although the RD adults displayed the typicalpattern of impaired phonological awareness andpseudoword reading relative to reading-levelmatched children, the reading-disabled adultsoutperformed the children on the timing tasks. Finally, with the exception of continuousnaming, the timing tasks shared little variancewith phonological sensitivity and contributedlittle unique variance to word reading. Although these findings undermine the timingdeficit hypothesis, they do provide evidencefor the involvement of naming deficits inreading disability.  相似文献   

15.
The purpose of this study was to determine whether children with dyslexia, that is, children whose reading levels were significantly lower than would be predicted by their IQ scores, constituted a distinctive group when compared with poor readers, that is, children whose reading scores were consistent with their IQ scores. The performance of children with dyslexia, poor readers, and normally achieving readers was compared on a variety of reading, spelling, phonological processing, language, and memory tasks. Although the children with dyslexia had significantly higher IQ scores than the poor readers, these two groups did not differ in their performance on reading, spelling, phonological processing, or most of the language and memory tasks. In all cases, the performance of both reading disabled groups was significantly below that of nondisabled readers. The findings were similar whether absolute difference or regression scores were used. Reading disabled children, whether or not their reading is significantly below the level predicted by their IQ scores, experience significant problems in phonological processing, short-term and working memory, and syntactic awareness. On the basis of these data, there does not seem to be a need to differentiate between individuals with dyslexia and poor readers. Both of these groups are reading disabled and have deficits in phonological processing, verbal memory, and syntactic awareness.  相似文献   

16.
We report a case study of an acquired dyslexic subject, who on tasks standardly used to assess acquired dyslexia showed no evidence of having any access to sublexical phonological information. However, on a lexical decision task, he showed normal effects of spelling regularity for low-frequency words. Since this effect is typically attributed to the use of sublexical phonological information in word recognition, it appears that sublexical phonological processing is occurring for this subject. The spelling regularity effect is discussed with respect to models of written word recognition and to acquired dyslexia. It is suggested that the reason for the discrepancy in test results may be that the types of explicit tasks previously used in the neuropsychological literature on dyslexia, which require conscious awareness of phonological representations, are not sensitive to implicit processing.  相似文献   

17.
Malay is an alphabetic language with transparent orthography. A Malay reading-related assessment battery which was conceptualised based on the International Dyslexia Association definition of dyslexia was developed and validated for the purpose of dyslexia assessment. The battery consisted of ten tests: Letter Naming, Word Reading, Non-word Reading, Spelling, Passage Reading, Reading Comprehension, Listening Comprehension, Elision, Rapid Letter Naming and Digit Span. Content validity was established by expert judgment. Concurrent validity was obtained using the schools' language tests as criterion. Evidence of predictive and construct validity was obtained through regression analyses and factor analyses. Phonological awareness was the most significant predictor of word-level literacy skills in Malay, with rapid naming making independent secondary contributions. Decoding and listening comprehension made separate contributions to reading comprehension, with decoding as the more prominent predictor. Factor analysis revealed four factors: phonological decoding, phonological naming, comprehension and verbal short-term memory. In conclusion, despite differences in orthography, there are striking similarities in the theoretical constructs of reading-related tasks in Malay and in English.  相似文献   

18.
This study investigated the phonological processing skills of university students with dyslexia. Fifty-nine students participated in this study: 28 with reading disabilities based on recent psychological assessments and a history of early and persistent reading problems; and 31 controls. The two groups did not differ on estimates of verbal and nonverbal abilities. The dyslexia group performed significantly less well on standardized measures of reading and spelling. However, the dyslexia group scores on these measures fell within the average range. The main dependent variables were subsumed under three areas of phonological processing: phonological awareness, phonological recoding in lexical access, and phonological recoding in working memory. The control group performed significantly better on all phonological processing measures, particularly those measures involving accuracy and response times. Despite age-appropriate performances on standardized reading and spelling measures, phonological processing deficits persisted in the dyslexia group. These findings support the causal role of phonological awareness in the acquisition of reading skills and indicate that differences in phonological processing skills are still evident in a sample of university students with dyslexia compared a group matched on age and education.  相似文献   

19.
This article examines working memory functioning in children with specific developmental disorders of scholastic skills as defined by ICD-10. Ninety-seven second to fourth graders with a minimum IQ of 80 are compared using a 2 x 2 factorial (dyscalculia vs. no dyscalculia; dyslexia vs. no dyslexia) design. An extensive test battery assesses the three subcomponents of working memory described by Baddeley (1986): phonological loop, visual-spatial sketchpad, and central executive. Children with dyscalculia show deficits in visual-spatial memory; children with dyslexia show deficits in phonological and central executive functioning. When controlling for the influence of the phonological loop on the performance of the central executive, however, the effect is no longer significant. Although children with both reading and arithmetic disorders are consistently outperformed by all other groups, there is no significant interaction between the factors dyscalculia and dyslexia.  相似文献   

20.
Morphological awareness in developmental dyslexia   总被引:5,自引:0,他引:5  
This study examines morphological awareness in developmental dyslexia. While the poor phonological awareness of dyslexic children has been related to their difficulty in handling the alphabetical principle, less is known about their morphological awareness, which also plays an important part in reading development. The aim of this study was to analyze in more detail the implications of the phonological impairments of dyslexics in dealing with larger units of language such as morphemes. First, the performance of dyslexic children in a series of morphological tasks was compared with the performance of children matched on reading-level and chronological age. In all the tasks, the dyslexic group performed below the chronological age control group, suggesting that morphological awareness cannot be developed entirely independently of reading experience and/or phonological skills. Comparisons with the reading-age control group indicated that, while the dyslexic children were poorer in the morphemic segmentation tasks, they performed normally for their reading level in the sentence completion tasks. Furthermore, they produced more derived words in the production task. This suggests that phonological impairments prevent the explicit segmentation of affixes while allowing the development of productive morphological knowledge. A second study compared dyslexic subgroups defined by their degree of phonological impairment. Our results suggest that dyslexics develop a certain type of morphological knowledge, which they use as a compensatory reading strategy.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号