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1.
Impaired visual attention in children with dyslexia   总被引:2,自引:0,他引:2  
Reading involves the correct and rapid identification of visual stimuli with letters and words. The processing of visual stimuli depends not only on the integrity of the peripheral and central visual system but also on the attentional systems involved. In the present study, a cue-target visual attention task was administered to a population-based sample of 25 children with dyslexia from 10 to 12 years of age. A control group matched for group size, age, and gender was obtained from the same general population. A two-stage screening process involved a spelling task of regular words followed by a battery of five single-word reading tasks. The cue-target task involved both a computer-controlled stimulus presentation and a computer-controlled measurement of reaction time. The data were analyzed by visual field, cue condition (valid, invalid, and no cue), and cue-target interval (CTI). The results showed a general pattern of slower responses in the dyslexia group compared to the control group. The dyslexia group also had longer reaction times in the short CTI condition (covert shift of attention) and in the long CTI condition (overt shift of attention). The findings may reflect a general attentional deficit to visual stimuli in dyslexia, possibly related to problems with the recruitment of necessary cognitive resources for the performance of complex reaction time tasks and for fluent reading.  相似文献   

2.
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   

3.
Early interactive processes of development in reading, spelling and implicit and explicit phonological awareness were assessed in a group of children at four time-points as they progressed through their first three years in school. Exploratory causal path analyses were used to investigate the contribution of each ability to the subsequent growth of skill in reading, spelling and phonological awareness. The resultant structural models demonstrate a role of spelling in the early stages of reading acquisition, as well as differential contributions of implicit and explicit phonological awareness to both reading and spelling. They also suggest a developmental cascade from implicit to explicit phonemic awareness in the normal acquisition of phonological knowledge and associated skills. In the early formulative stages of reading implicit phonemic awareness and reading act reciprocally to build skill in each other. But, as ability in word recognition improves, implicit phonemic awareness plays a diminished role in reading. This pattern of initial reciprocal influence and later dissociation is repeated in the relationship between implicit phoneme awareness and spelling. Explicit phonemic awareness is an important factor in the first stages of spelling development but only emerges later as a significant contributor to reading. The early influence of explicit phoneme awareness on spelling, in conjunction with the major contribution of spelling to beginning reading, indicates that experience in spelling promotes the use of a phonological strategy in reading. Within a developmental context, explicit phoneme awareness initially appears to grow out of an implicit appreciation of the overall sound properties of words. Thereafter, ability to identify and segment phonemes develops independently of implicit phonemic awareness and plays an increasingly important role in the further growth of reading and spelling.  相似文献   

4.
This study examined the patterns of reading and spelling performance of first-grade Greek children who either were facing difficulties in literacy acquisition or were normal achievers. In addition, we studied the relationship between obtained literacy development levels and the children's phonological awareness and ability to retain phonological information in short-term memory. The participants were tested in the reading of single letters, letter clusters, words, and nonwords, as well as in word and nonword spelling. Furthermore, their phonological processing knowledge was assessed via a battery of phonological awareness tasks and short-term memory phonetic-representation tasks. The main findings of the study were as follows: (a) Accurate decoding of Greek was achieved by almost every young child (attributed mainly to the nature of the Greek writing system); (b) the time the children needed to process a written item was the crucial index of their difficulty in literacy acquisition; (c) spelling was performed by deriving the orthographic form of a word on the basis of sound-spelling correspondence knowledge; (d) although the children with difficulties in literacy development had achieved a satisfactory performance in phonological processing, their performance was nevertheless significantly lower than that of the normal achievers; and (e) phonemic awareness and speech rate tasks were among the best predictors of learning to read and spell Greek words.  相似文献   

5.
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   

6.
Is the dual route model of word recognition useful in explaining individual differences in reading behaviors for most developmental dyslexics? Many past case studies of surface and phonological acquired dyslexics and a few similar studies of developmental dyslexia have suggested this might be so. The present study investigated individual differences among a group of 65 dyslexics, age 10 to 13, in reading, phonemic segmentation, and word retrieval. The dyslexics’ performance was compared to that of 65 reading age controls and 17 age-matched good readers. The research questions were: (1) Are there discrete subgroups of developmental dyslexics as suggested by the case studies? (2) How do oral language measures relate to the various reading tasks? The data indicated there were no discrete subgroups within the group of dyslexics; in addition, the variability in performance on reading tasks was quite similar for the dyslexic and reading age-control groups. A few dyslexics resembled phonological dyslexics and surface dyslexics, but these subjects were still part of a continuum. We also report the relationship between phonemic segmentation and word retrieval and various reading tasks. It appears that dyslexics at extreme ends of the continuum may exhibit quite different patterns from each other in their oral language task performance as well as in their reading.  相似文献   

7.
This study examined differences between adequate and poor readers in phonemic awareness, rapid continuous and confrontation naming, and visual symbol processing. It also investigated which of these skills make independent contributions to word recognition, pseudoword reading, and reading comprehension. Subjects were 170 school referrals of average intelligence, aged 6 to 10 years. The strongest differentiators of adequate and poor readers, with IQ and reading experience controlled, were phonemic awareness, naming speed for letters and pictured objects, and visual symbol processing. Letter naming speed made the largest independent contribution to word recognition, phonemic awareness to pseudoword reading, and object naming speed to reading comprehension. Confrontation picture naming accounted for minimal variance in reading skills, when IQ was controlled. It was concluded that tasks of naming speed, phonemic awareness, and visual symbol processing are valuable components of a diagnostic battery when testing children with possible reading disability.  相似文献   

8.
The present study evaluated the idea that the hemisphere-specific cognitive demands of reading and writing may induce task-specific maladaptive patterns of language lateralization in children with dyslexia. Situation-specific lateralization was examined in a repeated measures design under three dichotic listening conditions: baseline, concurrent reading, and concurrent writing. Twelve males with phonological dyslexia, 8 to 12 years old, were compared to 12 age-matched and 12 younger reading-matched good readers. Lateralization patterns were examined for condition-specific relationships to pseudoword decoding, word recognition, reading comprehension, spelling, and arithmetic. The results show that dyslexia is not related to incomplete lateralization or to a failure to inhibit verbal processing in the right hemisphere during reading and writing. Reading increased the lateralization of the children with dyslexia, which had a negative relation to arithmetic; writing caused a decrease in lateralization, which was linked specifically to deficits in phonological decoding and visual word recognition. The results suggest that children with dyslexia suffer from a selective linguistic vulnerability to left-hemisphere interference from the idiosyncratic attentional and processing demands of particular school tasks. Dyslexia is a much more dynamic and environmentally sensitive disorder than previously thought.  相似文献   

9.
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   

10.
The spelling errors of third graders who fit phonological andsurface profiles of developmental dyslexia were analyzed, alongwith the errors of younger (reading level matched) andchronologically age matched non-dyslexic comparison groups. InStudy 1, errors were analyzed as phonologically constrained,unconstrained, or inaccurate and as either orthographicallyacceptable or unacceptable. Study 2 extended the errorclassification system to nonword spellings. The main finding wasthat different types of dyslexics produced different types oferrors. Both studies found that children produced spelling errorsconsistent with their type of dyslexia. The phonological groupshowed poor knowledge of phoneme-grapheme correspondences,consistent with the existence of a phonological deficit. Thesurface group's spelling error profile differed from thephonological group and closely resembled the younger normalcomparison group. This pattern is consistent with other evidencethat surface dyslexia represents a general delay in acquiringliteracy skills. The studies provide converging evidence, from aspelling task, that developmental dyslexia is a non-homogeneouscategory consisting of at least two major subtypes with distinctetiologies and behavioral sequelae.  相似文献   

11.
Two groups of adolescents with a childhood history of language impairment were compared with a group of developmentally dyslexic young people of the same age and nonverbal ability. The study also included two comparison groups of typically developing children, one of the same age as those in the clinical groups, and a younger comparison group of similar reading level to the dyslexic students. Tests of spoken and written language skills revealed that the adolescents with dyslexia were indistinguishable from those with resolved language impairments on spoken language tasks, and both groups performed at age-expected levels. However, both dyslexic readers and those with resolved specific language impairments showed deficits in phonological awareness. On written language tasks, a different pattern of performance was apparent. In reading and spelling, adolescents with dyslexia performed only as well as those with persistent oral language impairments and younger controls. However, their reading comprehension was better. The theoretical and educational implications of these findings are discussed.  相似文献   

12.
通过对比优、劣汉语阅读者在视觉、听觉时间加工任务中的表现,探讨不同水平的正常阅读者中存在的时间加工能力差异。选择阅读能力正常的小学三年级学生,筛选优秀阅读者18人,拙劣阅读者16人,施以瑞文智力测试及一系列阅读能力测试。采用时间顺序判断的经典范式,分别考察了两组被试的视觉、听觉时间加工能力。数据分析结果表明:优秀汉语阅读者的视、听觉时间加工能力,均显著地高于拙劣汉语阅读者,但当智力因素被控制后,组间差异的显著性消失。  相似文献   

13.
Good and poor readers at the junior high school level and good and poor spellers at the university level were compared on their ability to produce words in response to a semantic cue (a category name), a visual cue (three letters), and an auditory cue (a syllable rime). Kindergarten children were tested on a word-identification task and their retrieval of words in response to the semantic and auditory cues. At all ages, poor readers or spellers produced fewer words on all word-retrieval tasks than did good readers or spellers. Performance on the auditory and visual word-retrieval tasks correlated very highly with pseudoword reading and spelling ability in the two older groups; in the kindergarten children, auditory retrieval correlated with word identification. The results suggest that poor readers have not organized words in long-term memory according to rhyming families but that good readers have. We speculate that failure to retrieve rhyming words during acquisition of reading and spelling skills underlies the failure of poor readers and spellers to abstract the higher-order relationships between orthography and phonology.  相似文献   

14.
Poor readers who met low achievement and IQ‐discrepancy definitions of reading disability were compared with nonimpaired readers on their development of eight precursor and reading‐related skills to evaluate developmental differences prior to students’ identification as reading disabled. Results indicated no evidence for differences between the two groups of poor readers in the development of the eight skills, with three exceptions. Students in the IQ‐discrepant group demonstrated greater growth in letter sound knowledge, greater mean performance in visual‐motor integration at the beginning of first grade, and greater deceleration in rapid naming of letters. When compared to the nonimpaired group, low‐achieving readers demonstrated poorer performance and development in all skills, while the IQ‐discrepant readers demonstrated poorer performance and development in phonemic awareness, rapid naming of letters and objects, spelling, and word reading. The largely null results for comparisons between the two groups of poor readers challenges the validity of the two‐group classification of reading disabilities based on IQ‐discrepancy.  相似文献   

15.
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   

16.
Dyslexic difficulties in lexical stress were compared to difficulties in segmental phonology. Twenty-nine adolescents with dyslexia and 29 typically developing adolescents, matched on age and nonverbal ability, were assessed on reading, spelling, phonological and stress awareness, rapid naming, and short-term memory. Group differences in stress assignment were larger than in segmental phonology in reading and spelling pseudowords but not words, indicating a fragility of explicit processes that manipulate stress representations. Despite impaired stress performance in dyslexia at the group level, individual variability failed to reveal evidence for a stress-specific deficit or for a distinct stress-impaired subgroup.  相似文献   

17.
This study was designed to assess whether the effects of computer-assisted practice on visual word recognition differed for children with reading disabilities (RD) with or without aptitude-achievement discrepancy. A sample of 73 Spanish children with low reading performance was selected using the discrepancy method, based on a standard score comparison (i.e., the difference between IQ and achievement standard scores). The sample was classified into three groups: (1) a group of 14 children with dyslexia (age M = 103.85 months; SD = 8.45) who received computer-based reading practice; (2) a group of 31 "garden-variety" (GV) poor readers (age M = 107.06 months; SD = 6.75) who received the same type of instruction; and (3) a group of 28 children with low reading performance (age M = 103.33 months; SD = 9.04) who did not receive computer-assisted practice. Children were pre- and posttested in word recognition, reading comprehension, phonological awareness, and visual and phonological tasks. The results indicated that both computer-assisted intervention groups showed improved word recognition compared to the control group. Nevertheless, children with dyslexia had more difficulties than GV poor readers during computer-based word reading under conditions that required extensive phonological computation, because their performance was more affected by low-frequency words and long words. In conclusion, we did not find empirical evidence in favor of the IQ-achievement discrepancy definition of reading disability, because IQ did not differentially predict treatment outcomes.  相似文献   

18.
A cohort of 92 children was followed through sixth grade to investigate the relationship of preschool skills and first grade phonological awareness to reading and spelling. In particular, the focus was on the changing roles of letter naming, orthographic awareness, and phonological processing in prediction, as reading experience increased. Preschool letter naming was a consistently significant predictor of reading vocabulary, reading comprehension, and spelling at each grade level, but the preschool orthographic task contributed most to reading comprehension and spelling at the higher grades. Conversely, the contribution of the first grade phonemic awareness measures to reading skills dropped sharply after third grade, although they continued to contribute to spelling prediction. When preschool precursors of phonological processing were examined, letter naming was found to be a predictor of first and third grade phonemic awareness. Findings confirm the importance of letter naming as a predictor and of the role of phonemic awareness in early reading acquisition, but also highlight the contribution of orthographic processing skills to later reading.  相似文献   

19.
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   

20.
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   

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