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1.
Olson RK 《Annals of dyslexia》2006,56(2):205-238
This article presents an overview of some methods and results from our continuing studies of genetic and environmental influences
on dyslexia, and on individual differences across the normal range that have been conducted over the past 25 years in the
Colorado Learning Disabilities Research Center (CLDRC) and in related projects. CLDRC investigators compare the similarities
of identical twin pairs who share all their genes and fraternal twins who share half their segregating genes to assess the
balance of genetic, shared family environment, and nonshared environment influences on dyslexia and on individual differences
across the normal range. We have learned that among the children we have studied in Colorado, group deficits in reading (dyslexia)
and individual differences in reading across the normal range are primarily due to genetic influences, and these genetic influences
are often shared with some of the same genetic influences on deficits and individual differences in language and ADHD. We
have also learned from our molecular-genetic linkage studies that there are regions on several chromosomes likely to contain
genes that influence dyslexia. Several specific genes within these regions have been tentatively identified through molecular-genetic
association analyses, but much more research is needed to understand the pathways among specific genes, regions of noncoding
DNA that regulate the activity of those genes, the brain, and dyslexia. I conclude with a discussion of our research on individual
differences in early reading development, on the role of early learning constraints in dyslexia, and on how genetic influences
are expressed through their interaction and correlation with the environment. 相似文献
2.
发展性阅读障碍亚类型的研究 总被引：2，自引：0，他引：2
发展性阅读障碍是关系人类健康和发展的重要课题。多年来研究者试图寻找这个群体中发生困难的真正原因,希望从根本上解决阅读落后问题和消除阅读障碍。但是研究者发现阅读障碍群体内部具有很大的变异性。文章在简介了当今具有代表性的两种流派对阅读障碍原因的解释和相应的研究证据后,着重阐述了阅读障碍的亚类型的发展历史、研究者对亚类型的划分以及不同亚类型在语言技能上、一般感知能力和生理机制方面的差异,并且阐述了亚类型研究对阅读障碍早期预测的作用,为根本消除阅读障碍提供了新的视角。 相似文献
3.
Lexical-decision studies with experienced English and French readers have shown that visual-word identification is not only
affected by pronunciation inconsistency of a word (i.e., multiple ways to pronounce a spelling body), but also by spelling
inconsistency (i.e., multiple ways to spell a pronunciation rime). The aim of this study was to compare the reading behavior
of young Dutch readers with dyslexia to the behavior of readers without dyslexia. All students participated in a lexical-decision
task in which we presented pronunciation-consistent words and pseudowords. Half of the pronunciation-consistent stimuli were
spelling consistent and the other half were spelling inconsistent. All three reader groups, that is, students with dyslexia,
age-match students, and reading-match students, read spelling-consistent words faster than spelling-inconsistent words. Overall
reading speed of students with dyslexia was similar to that of reading-match students, and was substantially slower than that
of age-match students. The results suggest that reading in students with or without dyslexia is similarly affected by spelling
inconsistency. Subtle qualitative differences emerged, however, with respect to pseudoword identification. The conclusion
was that the findings were best interpreted in terms of a recurrent-feedback model. 相似文献
4.
Temporal processing in dyslexia 总被引：1，自引：0，他引：1
The temporal processing capabilities of 15 children with dyslexia versus 15 age-matched and 15 reading-matched controls in a word identification task were examined. The hypothesis underlying the present experiment was that word recognition would be inferior in children with dyslexia, relative to controls, when the task demanded the temporal integration (sequencing) of two-syllable words. Such a hypothesis must predict that one-syllable word recognition does not distinguish between these two populations and that these effects cannot be accounted for in terms of eye movement differences. To test this hypothesis, one- and two-syllable words displayed for 100, 300, and 3,000 msec were required to be identified. The results yielded evidence of decreased accuracy of word identification by the children with dyslexia in the two-syllable, 300-msec condition, as predicted. A second experiment was unable to uncover any differences in eye movement behaviors that could account for the effects observed in the first experiment. The results are discussed in terms of potential sequential processing deficits in individuals with dyslexia. 相似文献
5.
The existing literature on developmental dyslexia (hereafter: dyslexia) often focuses on isolating cognitive skills which differ across dyslexic and control participants. Among potential correlates, previous research has studied group differences between dyslexic and control participants in performance on statistical learning tasks. A statistical learning deficit has been proposed to be a potential cause and/or a marker effect for early detection of dyslexia. It is therefore of practical importance to evaluate the evidence for a group difference. From a theoretical perspective, such a group difference would provide information about the causal chain from statistical learning to reading acquisition. We provide a systematic review of the literature on such a group difference. We conclude that there is insufficient high-quality data to draw conclusions about the presence or absence of an effect. 相似文献
6.
《Australian Journal of Learning Difficulties》2013,18(2):213-224
Dyslexia appears to be the most prevalent disability of students with special educational needs in many mainstream classes, affecting around 9.7% of the school population in Hong Kong. The education of these students is therefore of great concern to the community. In the present paper research into dyslexia in the Chinese language is briefly reviewed, with emphasis on the cognitive characteristics of dyslexia and its manifestations, in the hope that understanding the profiles of students with dyslexia may help to lay a solid foundation for assessment, curriculum development and intervention. Recent progress in the study of the cognitive deficits of Chinese-speaking readers with dyslexia in Hong Kong and the development of assessment and intervention framework for early identification and intervention is presented. These developments shed light on dyslexia in the Chinese language and provide grounds for further work on research and practice. 相似文献
7.
Genetic linkage analysis is a means of localizing genes to specific chromosomal regions. Localization of genes influencing specific reading disability (dyslexia) can lead to characterization of the phenotypic effects of each gene and to early diagnosis of children at risk. Previous studies using the family study LOD score method of linkage analysis have identified two chromosomal regions that may contain genes influencing dyslexia. The present study examines the sib pair method of linkage analysis, which has several advantages over the LOD score method. In particular, the mode of inheritance does not need to be specified and diagnosis of parents is not required, but it is a less powerful technique. Using the same population as the previous studies (with less than 200 sib pairs) and two different means of diagnosis of dyslexia, the sib pair analysis was able to detect the same suggested linkages as the LOD score method, plus a possible third region. This confirms that the sib pair method is an effective means of screening for linkage with reasonable sample sizes. 相似文献
8.
儿童阅读是一个复杂的研究领域,“阅读脑”的研究成为儿童阅读领域一个崭新的研究方向。近年来,随着脑成像技术的迅速发展,涌现出很多儿童阅读的脑科学研究新成果,这些研究成果表明,儿童阅读是一个多系统的复杂认知过程,儿童阅读学习过程是循序渐进的,不同的发展阶段受不同脑机制的调节;儿童阅读困难在脑机制层面也有新的解读,为传统儿童阅读中的问题解决提供了新的角度,解释并澄清了传统阅读研究中出现的很多争议,为相关问题解决提供了科学的证据。由此,我们应遵循儿童学习阅读过程中的脑活动规律,分阶段设定阅读教学目标;基于儿童阅读的脑与认知科学规律,选择恰当的教学方式;结合儿童阅读困难的脑机制研究,开展差异性阅读教学。 相似文献
9.
相比于阅读正确性,透明文字阅读障碍儿童的阅读流畅性问题更突出。本文用多基线干预性混合实验设计,考察形-音联结和重复阅读两种训练对3~5年级不同水平维吾尔文阅读障碍儿童阅读流畅性的单独和综合干预效果。结果发现:(1)基线时,不同水平阅读障碍儿童的单词阅读正确性和阅读理解成绩不存在显著差异,但在阅读流畅性测验得分上严重阅读障碍儿童显著落后于一般阅读障碍儿童;(2)形-音联结和重复阅读两种训练分别提高了阅读障碍儿童的假词和真词阅读速度,两种训练结合使用时提高了阅读理解成绩,其中严重阅读障碍儿童的阅读理解成绩提高的更明显。 相似文献
10.
Lisa M. Henderson Natassa Tsogka Margaret J. Snowling 《Journal of Research in Special Educational Needs》2013,13(1):57-65
Visual stress (the experience of visual distortions and discomfort during prolonged reading) is frequently identified and alleviated with coloured overlays or lenses. Previous studies have associated visual stress with dyslexia and as a consequence, coloured overlays are widely distributed to children and adults with reading difficulty. However, this practice remains controversial. We investigated whether overlays have advantageous and reliable benefits for reading in undergraduate students with and without dyslexia. Both groups read jumbled text faster with a coloured overlay than without. The dyslexic group did not show greater gains than controls, despite reporting significantly more symptoms of visual stress. However, coloured overlays did not improve reading rate or comprehension of connected text. The improvement in reading speed with an overlay was not reliable and was significantly reduced at retesting for dyslexic students. These results question the value of coloured overlays as a tool for identifying visual stress and as a form of remediation for the reading difficulties associated with dyslexia. 相似文献
11.
汉语阅读障碍儿童与普通儿童朗读错误研究 总被引：1，自引：0，他引：1
为反映汉语阅读障碍儿童朗读的特点,采用错误分析技术,对10名汉语阅读障碍儿童和10名普通儿童的朗读错误进行了系统的分析.结果发现:汉语阅读障碍儿童朗读流畅性与准确性都低于普通儿童,朗读中的替代错误、添加错误、省略错误都显著多于普通儿童.而二者在颠倒错误上的差异不显著.在替代错误中,音似、形似、语义及无关替代显著地多于普通儿童.与普通儿童相比,汉语阅读障碍儿童的朗读问题主要表现为错误数量更多,而不是表现为错误类型上的特点.最后结合研究发现对阅读障碍的诊断与干预提出了建议. 相似文献
12.
This is an individual case study combined with subject sampling which compared the reading performance of good and poor Brazilian 4th grade children with Scottish children of equivalent reading competence and age range. A measure of efficient performance -- low error rates and fast vocal reaction-times for correct responses to words (of varying familiarity, regularity and length) and non-words (of varying length) -- was obtained and used as a basis for the identification of inefficiencies among the subjects whose results were outside the main range. Competent reading in Brazilian Portuguese and Scottish showed similarities in regard to time processing and error rates for the reading of words and non-words and mainly differed in terms of the generality of the regularity effect and of the rate of letter processing of words and for non-words. In what concerns impaired reading, in both nationalities there were examples of pure phonological dyslexia and of impairments affecting both lexical and non-lexical processes with a bias to the phonological pattern. In contrast to the Scottish sample, no cases of predominant morphemic dyslexia nor ambiguous cases were found among the Brazilians. 相似文献
13.
K. Gross-Glenn Bonnie Jallad Loriana Novoa Valerie Helgren-Lempesis H. A. Lubs 《Reading and writing》1990,2(2):161-173
We examined Nonsense-Passage oral reading in adults, using data derived from new and previously published studies (Finucci et al 1976, Gross-Glenn et al 1985). Time-scores and error-frequency data are presented for five samples of non-dyslexic readers with a minimum of a high-school education and no childhood history of dyslexia (N=127). Considerable uniformity is demonstrated across these samples, and reading performance of non-dyslexic individuals contrasts sharply with that observed in four samples of adult familial dyslexics. Both affected and compensated-affected dyslexic subjects read the passages significantly more slowly and with more errors than did nondyslexic readers. Results are discussed in relation to the cognitive and neural processes that may underlie this specific reading difficulty in dyslexics. We have found Nonsense-Passage reading to be especially useful in family studies of inherited dyslexia as a means of quantifying oral reading deficits in adults who have learned to compensate for their children reading difficulties. 相似文献
14.
Ann Marie Casserly 《Journal of Research in Special Educational Needs》2013,13(1):79-91
This paper reports on a four‐year research project examining the experiences of children with dyslexia in mainstream schools and reading schools/classes. The focus of this paper is on the socio‐emotional effects of dyslexia on a group of children attending a reading school/class for a specific duration before returning to mainstream. The findings suggest that while the primary focus of attending such a placement is to attain greater levels of literacy, other gains such as increased positive socio‐emotional manifestations and confidence are also evident. Therefore, the emotional elements of learning must work in tandem with the academic elements in helping children with dyslexia access the curriculum in full. The roles of attribution, motivational and expectancy theories are explored and how a comprehensive understanding of these theories can help teachers explain and respond to the exhibited behaviours of children with reading difficulties. 相似文献
15.
Most research on dyslexia to date has focused on early childhood, while comparatively little is known about the nature of dyslexia in adolescence. The current study had two objectives. The first was to investigate the relative contributions of several cognitive and linguistic factors to connected‐text oral reading fluency in a sample of adolescents with dyslexia (n = 77). The second was to test the hypothesis that the effect of verbal working memory on connected‐text oral reading fluency is moderated by word‐level skills and/or vocabulary knowledge. The results suggest that many deficits associated with childhood dyslexia remain prominent in adolescence, but the nature of the relationships between key cognitive and linguistic predictors (i.e., word‐level reading, vocabulary, verbal working memory) and reading fluency appear to be different in adolescence. For example, while word‐level skills remain a significant predictor, the strength of the effect is relatively weak. In contrast, the data support an increased role for vocabulary and verbal working memory, including an interaction between these factors. The presence of an interaction can be interpreted as evidence that the influence of verbal working memory on connected‐text oral reading fluency in adolescents with dyslexia depends on individual differences in vocabulary knowledge. These results offer support for the changing nature of dyslexia across development, and suggest that researchers should study dyslexia in adolescents on its own terms, rather than treating it as an extension of reading problems in early childhood. 相似文献
16.
Although many are critical of the uptake of unproven practices by teachers and families in their search for treatment for children with reading difficulties, there has been little examination of the specific conditions that persuade teachers and families to adopt such practices. This article traces the emergence and evolution of a particular meme, space dyslexia, and related memes. The space dyslexia meme is shown to be an unfounded concept, but one that has proved attractive to the popular media and presumably to those seeking alternative treatments. 相似文献
17.
The present study used the tip-of-the-tongue (TOT) experimental paradigm in a picture naming task to explore the source of the naming deficits of children with dyslexia. Compared with a control group of typically developing readers, the children with dyslexia showed fewer correct responses and spontaneous recalls, more don't know (DK) and TOT responses, and less accurate feeling of knowing (FOK) judgments. When they failed to retrieve a target word, the children with dyslexia did not differ from the control group in the partial semantic information they provided, but they gave less valid and more invalid partial phonological information. The children with dyslexia also benefited less from phonological cues. The phonologically related responses of the children with dyslexia elicited during the administration of the TOT procedure were related to their performance on a phonological awareness test. These findings suggest that the naming problems of children with dyslexia arise because of their difficulty in accessing the phonological word forms after the corresponding abstract lexical representation has been successfully accessed. The results are discussed in relation to the claim that two-stage models of naming can be profitably used in the early identification and treatment of reading disabilities. 相似文献
18.
Speech perception in dyslexia is characterized by a categorical perception (CP) deficit, demonstrated by weaker discrimination of acoustic differences between phonemic categories in conjunction with better discrimination of acoustic differences within phonemic categories. We performed a meta-analysis of studies that examined the reliability of the CP deficit in dyslexia. The results show a reliable CP deficit in individuals with dyslexia compared to both chronological-age and reading-level controls. The CP deficit is stronger for discrimination than for identification, suggesting that the latter may only reveal between-category differences that do not fully reflect the CP deficit. The implications of these findings for the allophonic theory of dyslexia are discussed. 相似文献
19.
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
20.
Simon Gibbs 《Journal of Research in Special Educational Needs》2005,5(2):62-67
Using data from a longitudinal comparative study of children at risk of dyslexia ( Snowling, Gallagher & Frith, 2003 ), this paper reports some replication of work by Gibbs (2004) . It was found that the development of phonological awareness might, for children between the ages of 6 and 8 years of age and not considered to be at risk of dyslexia, be facilitated by an interaction of memory span and lexical knowledge. This effect was not, however, found for children of the same age who were considered to be at risk of dyslexia. For these children an interaction, with contrasting implications, was found between the ages of 3 years 9 months and 6 years. Some theoretical and practical implications of these findings are outlined. 相似文献