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1.
One hundred five participants from a random sample of elementary and middle school children completed measures of reading achievement and cognitive abilities presumed, based on a synthesis of current dyslexia research, to underlie reading. Factor analyses of these cognitive variables (including auditory processing, phonological awareness, short-term auditory memory, visual memory, rapid automatized naming, and visual processing speed) produced three empirically and theoretically derived factors (auditory processing, visual processing/speed, and memory), each of which contributed to the prediction of reading and spelling skills. Factor scores from the three factors combined predicted 85% of the variance associated with letter/sight word naming, 70% of the variance associated with reading comprehension, 73% for spelling, and 61% for phonetic decoding. The auditory processing factor was the strongest predictor, accounting for 27% to 43% of the variance across the different achievement areas. The results provide practitioner and researcher with theoretical and empirical support for the inclusion of measures of the three factors, in addition to specific measures of reading achievement, in a standardized assessment of dyslexia. Guidelines for a thorough, research-based assessment are provided.  相似文献   

2.
The present study sought to identify cognitive abilities that might distinguish Hong Kong Chinese adolescents with dyslexia and to assess how these abilities were associated with Chinese word reading, word dictation, and reading comprehension. The cognitive skills of interest were morphological awareness, visual-orthographic knowledge, rapid naming, and verbal working memory. A total of 90 junior secondary school students, 30 dyslexic, 30 chronological age controls, and 30 reading level controls was tested on a range of cognitive and literacy tasks. Dyslexic students were less competent than the control students in all cognitive and literacy measures. The regression analyses also showed that verbal working memory, rapid naming, morphological awareness, and visual-orthographic knowledge were significantly associated with literacy performance. Findings underscore the importance of these cognitive skills for Chinese literacy acquisition. Overall, this study highlights the persistent difficulties of Chinese dyslexic adolescents who seem to have multiple causes for reading and spelling difficulties.  相似文献   

3.
Dyslexia is a developmental disability affecting the acquisition of reading and writing skills, and its developmental nature makes longitudinal research of great importance. This study therefore investigated the cognitive-linguistic profiles of the typical-functioning dyslexics and high-functioning dyslexics with longitudinal cohorts of Chinese-speaking adolescents diagnosed with childhood dyslexia. These two dyslexic groups of fifty students (with 25 typical-functioning dyslexics) were assessed in Grade 2 (Time 1) and in Grade 8 (Time 2), whereas 25 typically developing controls were assessed at Time 2. Students were administered measures of phonological awareness, morphological skills, visual-orthographic knowledge, rapid naming, verbal working memory, and literacy skills. Results showed that, at Time 2, both dyslexic groups performed less well than the control group on most of the measures. Deficits in rapid naming were particularly salient in both dyslexic groups. Comparing the two dyslexic groups, the typical-functioning dyslexics had more multiple deficits than the high-functioning dyslexics. Findings highlight the importance of rapid naming deficits as potential universal causes of dyslexia and the utility of targeting visual-orthographic knowledge and morphological skills in supporting the development of dyslexic adolescents.  相似文献   

4.
The present study was designed to examine the question of whether developmental dyslexia in 12-year-old students at the beginning of secondary education in the Netherlands is confined to problems in the domain of reading and spelling or also is related to difficulties in other areas. In particular, hypotheses derived from theories on phonological processing, rapid automatized naming, working memory, and automatization of skills were tested. To overcome the definition and selection problems of many previous studies, we included in our study all students in the first year of secondary special education in a Dutch school district. Participants were classified as either dyslexic, garden-variety, or hyperlexic poor readers, according to the degree of discrepancy between their word recognition and listening comprehension scores. In addition, groups of normal readers were formed, matching the poor readers in either reading age or chronological age. A large test battery was administered to each student, including phonological, naming, working memory, speed of processing, and motor tests. The findings indicate that dyslexia is associated with deficits in (1) phonological recoding, word recognition (both in their native Dutch and in English as a second language), and spelling skills; and (2) naming speed for letters and digits. Dyslexia was not associated with deficits in other areas. The results suggest that developmental dyslexia, at the age of 12, might be (or might have become) a difficulty rather isolated from deficiencies in other cognitive and motor skills.  相似文献   

5.
The development of reading skills may depend to a certain extent on the development of basic visual perception. The magnocellular theory of developmental dyslexia assumes that deficits in the magnocellular pathway, indicated by less sensitivity in perceiving dynamic sensory stimuli, are responsible for a proportion of reading difficulties experienced by dyslexics. Using a task that measures coherent motion detection threshold, this study examined the relationship between dynamic visual perception and reading development in Chinese children. Experiment 1 compared the performance of 27 dyslexics and their age- and IQ-matched controls in the coherent motion detection task and in a static pattern perception task. Results showed that only in the former task did the dyslexics have a significantly higher threshold than the controls, suggesting that Chinese dyslexics, like some of their Western counterparts, may have deficits in magnocellular pathway. Experiment 2 examined whether dynamic visual processing affects specific cognitive processes in reading. One hundred fifth-grade children were tested on visual perception and reading-related tasks. Regression analyses found that the motion detection threshold accounted for 11% and 12%, respectively, variance in the speed of orthographic similarity judgment and in the accuracy of picture naming after IQ and vocabulary size were controlled. The static pattern detection threshold could not account for any variance. It is concluded that reading development in Chinese depends to a certain extent on the development of dynamic visual perception and its underlying neural pathway and that the impact of visual development can be specifically related to orthographic processing in reading Chinese.  相似文献   

6.
The present study investigates the performance of persons with reading disabilities (PRD) on a variety of sequential visual-comparison tasks that have different working-memory requirements. In addition, mediating relationships between the sequential comparison process and attention and memory skills were looked for. Our findings suggest that PRD perform worse than normally achieving readers (NAR) when the task requires more than a minimal amount of working memory, unrelated to presentation rate. We also demonstrate high correlations between performance on the task with the most working-memory demands and reading-related skills, suggesting that poor working-memory abilities may be one of the underlying mechanisms of dyslexia. The mediating model analysis indicates that order judgment tasks are mediating to verbal working memory, suggesting that visual sequence memory precedes auditory sequence memory. We further suggest that visual tasks involving sequential comparisons could probe for poor working memory in PRD.  相似文献   

7.
This study aims to investigate the relation of syntactic and discourse skills to morphological skills, rapid naming, and working memory in Chinese adolescent readers with dyslexia and to examine their cognitive–linguistic profiles. Fifty-two dyslexic readers (mean age, 13;42) from grade 7 to 9 in Hong Kong high schools were compared with 52 typically developing readers of the same chronological age (mean age, 13;30) in the measures of word reading, 1-min word reading, reading comprehension, morpheme discrimination, morpheme production, morphosyntactic knowledge, sentence order knowledge, digit rapid naming, letter rapid naming, backward digit span, and non-word repetition. Results showed that dyslexic readers performed significantly worse than their peers on all the cognitive-linguistic tasks. Analyses of individual performance also revealed that over half of the dyslexic readers exhibited deficits in syntactic and discourse skills. Moreover, syntactic skills, morphological skills, and rapid naming best distinguished dyslexic from non-dyslexic readers. Findings underscore the significance of syntactic and discourse skills for understanding reading impairment in Chinese adolescent readers.  相似文献   

8.
This research was aimed at contributing to the current understanding of the underlying factors of naming speed and the causes of naming speed deficits. Forty regular readers and 40 dyslexic university students participated in the study. Electrophysiological (Event-Related Potentials [ERPs]) and behavioral measures were employed. Behavioral baseline tasks assessed general ability, reading skills, reading-related cognitive abilities, and standard Rapid Automatized Naming (RAN) and Rapid Alternating Stimulus tests. ERP tasks included letter and object naming tasks adapted for electrophysiological research presentation. The dyslexics were significantly slower and less accurate than the controls on most of the baseline measures. On all the naming tasks, the peak ERP latencies were elicited later, reaction times were longer, and the P300 latency width was wider among the dyslexics as compared to the regular readers. On the choice reaction time naming tasks, accuracy for both groups was almost perfect. When naming presentation time was controlled by the experiment, the dyslexics were significantly less accurate than the controls. Our data indicated that effective naming speed was related to an earlier P200 latency peak among regular readers and to an earlier P300 latency peak and narrower area component activation in the dyslexic group. The results from this study suggest that effective RAN speed among regular readers might be a result of efficient processing of RAN information at the input stage of stimulis perception and evaluation as well as of updating and processing the information in short-term memory among dyslexics.  相似文献   

9.
This study explores the contribution of cognitive processes to comprehension skills in adults who suffered from childhood developmental dyslexia (CD). The performance of adults with CD (ages 17 to 23), chronological age-matched (CA) adults, and reading level-matched (RL) children was compared on measures of phonological processing, naming speed, working memory (WM), general knowledge, vocabulary, and comprehension. The results showed that adults with CD scored lower on measures of phonological processing, naming speed, WM, general knowledge, and vocabulary when compared to CA readers but were comparable to RL children on the majority of process measures. Phonological processing, naming speed, vocabulary, general knowledge, and listening comprehension contributed independent variance to reading comprehension accuracy, whereas WM, intelligence, phonological processing, and listening comprehension contributed independent variance to comprehension fluency. Adults with CD scored lower than CA adults and higher than RL children on measures of lexical processing, WM, and listening comprehension when word recognition and intelligence were partialed from the analysis. In summary, constraints in phonological processing and naming speed mediate only some of the influence of high-order processes on reading comprehension. Furthermore, adults with CD experience difficulties in WM, listening comprehension, and vocabulary independently of their word recognition problems and intellectual ability.  相似文献   

10.
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   

11.
Cross-linguistic studies suggest that the orthographic system determines the reading performance of dyslexic children. In opaque orthographies, the fundamental feature of developmental dyslexia is difficulty in reading accuracy, whereas slower reading speed is more common in transparent orthographies. The aim of the current study was to examine the extent to which different variables of words affect reaction times and articulation times in developmental dyslexics. A group of 19 developmental dyslexics of different ages and an age-matched group of 19 children without reading disabilities completed a word naming task. The children were asked to read 100 nouns that differed in length, frequency, age of acquisition, imageability, and orthographic neighborhood. The stimuli were presented on a laptop computer, and the responses were recorded using DMDX software. We conducted analyses of mixed-effects models to determine which variables influenced reading times in dyslexic children. We found that word naming skills in dyslexic children are affected predominantly by length, while in non-dyslexics children the principal variable is the age of acquisition, a lexical variable. These findings suggest that Spanish-speaking developmental dyslexics use a sublexical procedure for reading words, which is reflected in slower speed when reading long words. In contrast, normal children use a lexical strategy, which is frequently observed in readers of opaque languages.  相似文献   

12.
The contribution of linguistic and cognitive variables to reading processes might vary depending on the particularities of the languages studied. This view is thought to be particularly true for Arabic which is a diglossic language and has particular orthographic and morpho-syntactic systems. This cross-sectional study examined the contribution of phonological, orthographic, morphological, semantic, syntactic, visual perception, rapid automatic naming and phonological working memory abilities to decoding and fluency (the two components of reading). The results, obtained from 1305 native Arabic-speaking children in first–sixth grade, were analyzed using path models. The analysis revealed that memory and orthographic knowledge contributed to both components of reading, while phonological awareness contributed mainly to decoding and rapid automatic naming contributed to fluency. The contribution of morphology to the two components, which appeared already in the first grade, was weak and inconsistent. Finally, the results showed that visual perception, semantics, and syntax predicted neither decoding nor fluency. The data presented here suggest that reading development in Arabic differs from other languages, a finding that might explain certain difficulties in reading acquisition in Arabic. The results are discussed in the light of previous findings in the literature and the specific features of Arabic.  相似文献   

13.
In four carefully selected samples of 8- to 10-year old children with dyslexia (but age adequate arithmetic skills), dyscalculia (but age adequate reading skills), dyslexia/dyscalculia and controls a domain-general deficit in rapid automatized naming (RAN) was found for both dyslexia groups. Dyscalculic children exhibited a domain-specific deficit in rapid naming of quantities. This finding is in line with recent assumptions that dyscalculia is associated with a neurobiological deficit in the processing of numerosities. In the dyslexia/dyscalculia group, RAN deficits were additive, that is, the dyslexia/dyscalculia group exhibited the sum of the deficits found in the dyslexia only and dyscalculia only groups. This finding suggests that the cognitive bases of dyslexia and dyscalculia are independent from each other. Within the naming speed paradigm no differential impact of special demands on the executive functions inhibition and shifting was found for any of the four groups.  相似文献   

14.
Fifteen Portuguese children with dyslexia, aged 9–11 years, were compared with reading and chronological age controls with respect to five indicators related to the phonological deficit hypothesis: the effects of lexicality, regularity, and length, implicit and explicit phonological awareness, and rapid naming. The comparison between groups indicates that Portuguese children with dyslexia have a phonological impairment which is revealed by a developmental deficit in implicit phonological awareness and irregular word reading (where younger reading level controls performed better than dyslexics) and by a developmental delay in decoding ability and explicit phonological awareness (where dyslexics matched reading level controls). These results are discussed in relation to the idea that European Portuguese is written in an orthography of intermediate depth.  相似文献   

15.
Based on the data of the normative study of the Hong Kong test of specific learning difficulties in reading and writing, and the Test of visual‐perceptual skills (non‐motor)—Revised, 99 children aged between 6 and 10½ years were identified as children with dyslexia out of the normative sample of 690 children. By excluding 12 children known to score below average in IQ, 87 children, including 20 children not tested for IQ, could be regarded as children with dyslexia, yielding a prevalence rate of 12.6% and a boy:girl gender ratio of 1.6 to 1. The figures would become 9.7% and 2.0 to 1 if the 20 children were omitted from computation. However, gender imbalance could not be readily explained by gender differences in reading‐related cognitive abilities, as there were only minor and subtle differences. Regression analyses to evaluate the relative contribution of different cognitive abilities to reading and writing suggested that orthographic knowledge and naming speed were most important among children with dyslexia. Implications of the findings and the need for early intervention are discussed.  相似文献   

16.
Reading fluency beyond decoding is a limitation to many children with developmental reading disorders. In the interest of remediating dysfluency, contributing factors need to be explored and understood in a developmental framework. The focus of this study is orthographic processing in developmental dyslexia, and how it may contribute to reading fluency. We investigated orthographic processing speed and accuracy by children identified with dyslexia that were enrolled in an intensive, fluency-based intervention using a timed visual search task as a tool to measure orthographic recognition. Results indicate both age and treatment effects, and delineate a link between rapid letter naming and efficient orthographic recognition. Orthographic efficiency was related to reading speed for passages, but not spelling performance. The role of orthographic learning in reading fluency and remediation is discussed.  相似文献   

17.
The present article aimed to explore how the development of reading comprehension is affected when its cognitive basis is compromised. The simple view of reading was adopted as the theoretical framework. The study followed 76 children with mild intellectual disabilities (average IQ = 60.38, age 121 months) across a period of 3 years. The children were assessed for level of reading comprehension (outcome variable) and its precursors decoding and listening comprehension, in addition to linguistic skills (foundational literacy skills, rapid naming, phonological short-term memory, verbal working memory, vocabulary, and grammar) and non-linguistic skills (nonverbal reasoning and temporal processing). Reading comprehension was predicted by decoding and listening comprehension but also by foundational literacy skills and nonverbal reasoning. It is concluded that intellectual disabilities can affect the development of reading comprehension indirectly via linguistic skills but also directly via nonlinguistic nonverbal reasoning ability.  相似文献   

18.
The study evaluated a substantially updated version of Orton's (1937) classical idea of a significant relatonship in dyslexic children between cerebral lateralization and their word decoding deficits. Attentional lateralization was examined under the assumption that covert spatial attention when directed contralaterally interacts with ageinvariant cerebral asymmetries for receptive speech. Thirty dysphonetic dyslexic children were compared to 30 younger normal readers who were matched to the dyslexics in reading comprehension. The children were tested in left ear (LE) and right ear (RE) directed attention dichotic listening (DAD), and in pseudoword decoding, word recognition, reading comprehension, spelling, arithmetic, and in general intelligence (IQ). Group comparisons in DAD failed to show any differences, confirming the mounting evidence that dyslexia is not related to incomplete lateralization. Entering the DAD scores of the dyslexics (LE first, LE second, RE first, RE second) as predictors of achievement revealed that, independently of chronological age (CA) and IQ, their ability to recall items from the LE first produced a negative regression which predicted 42 percent of the variance in pseudoword decoding. Selective report from the LE also produced small but significant negative correlations with visual recognition of real words and spelling; but no relationship to reading comprehension. IQ was related to reading comprehension and to the ability to shift attention from the LE to the RE. Eventhough the dyslexics were lateralized normally, weak lateralization was related specifically to phonological word decoding, a core deficit in dyslexia. However, unlike Orton's concept, these findings suggest that dyslexics suffer from exuberant right hemisphere processing in response to spatial attentional demands that, in turn, interferes transcallosally with the development of the sound-symbol representations that are required for fluent reading. Lateralization, per se, is unaffected by the disorder.  相似文献   

19.
Comparing the analyses based on the data of 1,235 Chinese children referred for government services and subsequently diagnosed as children with dyslexia in Hong Kong and those of 690 Chinese children in the sample for the normative study of the Hong Kong Test of Specific Learning Difficulties in Reading and Writing, we explored the reading–writing connection through a series of regression and correlation analyses. Specifically, orthographic knowledge, naming speed, and phonological memory were found to be salient predictors predicting both reading and writing, and when they were controlled and partialed out, the correlations between reading and writing were sizably attenuated, suggesting that these cognitive abilities or skills could act as third-variables contributing to the relationship between reading and writing. Issues related to causal inference, directionality of causality, and implications of the findings for intervention efforts and future research are discussed.  相似文献   

20.
A 3-group reading-level design was used to investigate phonological analysis, verbal working memory, and pseudoword reading performance in less skilled fourth-grade readers. Children were given phonological oddity tasks assessing their sensitivity to subsyllabic and phonemic units, together with standardized tests of verbal working memory and pseudoword reading. Less skilled fourth-grade readers performed lower than both chronological age and reading-level controls on the phonological oddity and pseudoword reading tests. Less skilled fourth-grade readers performed at the same level as skilled second-grade readers on a test of verbal working memory. Skilled fourth-grade readers scored higher than both other groups on this test. Correlational analyses were consistent with the view that phonological analysis skills contribute more strongly than verbal working memory skills to children's decoding abilities.  相似文献   

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