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1.
To elucidate the timing and the nature of neural disturbances in dyslexia and to further understand the topographical distribution of these, we examined entire brain regions employing the non-invasive auditory oddball P300 paradigm in children with dyslexia and neurotypical controls. Our findings revealed abnormalities for the dyslexia group in (i) P300 latency, globally, but greatest in frontal brain regions and (ii) decreased P300 amplitude confined to the central brain regions (Fig. 1). These findings reflect abnormalities associated with a diminished capacity to process mental workload as well as delayed processing of this information in children with dyslexia. Furthermore, the topographical distribution of these findings suggests a distinct spatial distribution for the observed P300 abnormalities. This information may be useful in future therapeutic or brain stimulation intervention trials. 相似文献
2.
Kenneth R. Pugh W. Einar Mencl Annette R. Jenner Jun Ren Lee Leonard Katz Stephen J. Frost Sally E. Shaywitz Bennett A. Shaywitz 《Learning disabilities research & practice》2001,16(4):240-249
Converging evidence from a number of neuroimaging studies, including our own, suggest that fluent word identification in reading is related to the functional integrity of two left hemisphere posterior systems: a temporo-parietal system and a ventral occipito-temporal system. These posterior systems are functionally disrupted in developmental dyslexia. Reading disabled, relative to nonimpaired, readers demonstrate heightened reliance on both inferior frontal and right hemisphere posterior regions, presumably in compensation for the LH posterior difficulties. We propose a neurobiological account suggesting that for normally developing readers the temporo-parietal system predominates at first, and is associated with aspects of processing critical in learning to integrate orthography with phonological and lexical-semantic features of printed words. The occipito-temporal system, by contrast, constitutes a fast, late-developing, word-identification system that underlies fluent word recognition in skilled readers. 相似文献
3.
Usha Goswami 《Mind, Brain, and Education》2009,3(3):176-184
Neuroscience has the potential to make some very exciting contributions to education and pedagogy. However, it is important to ask whether the insights from neuroscience studies can provide "usable knowledge" for educators. With respect to literacy, for example, current neuroimaging methods allow us to ask research questions about how the brain develops networks of neurons specialized for the act of reading and how literacy is organized in the brain of a reader with developmental dyslexia. Yet quite how these findings can translate to the classroom remains unclear. One of the most exciting possibilities is that neuroscience could deliver "biomarkers" that could identify children with learning difficulties very early in development. In this review, I will illustrate how the field of mind, brain, and education might develop biomarkers by combining educational, cognitive, and neuroscience research paradigms. I will argue that all three kinds of research are necessary to provide usable knowledge for education. 相似文献
4.
Corpus callosum morphology in attention deficit-hyperactivity disorder: morphometric analysis of MRI 总被引：11，自引：0，他引：11
G W Hynd M Semrud-Clikeman A R Lorys E S Novey D Eliopulos H Lyytinen 《Journal of learning disabilities》1991,24(3):141-146
Although behavioral evidence provides support for the notion that attention deficit-hyperactivity disorder (ADHD) is related to central nervous system dysfunction, there is little direct evidence to reveal which neurometabolic systems or brain structures are involved. Recent magnetic resonance imaging (MRI) studies suggest that, compared to nondisabled controls, ADHD children may have a smaller right frontal region. Morphometric analysis of MRI scans was used in this exploratory study to determine whether correlated regional variation might exist in the corpus callosum of children with ADHD. While all MRI scans were judged to be clinically normal, morphometric analysis revealed that, compared to nondisabled controls, ADHD children had a smaller corpus callosum, particularly in the region of the genu and splenium, and in the area just anterior to the splenium. Interhemispheric fibers in these regions interconnect the left and right frontal, occipital, parietal, and posterior temporal regions. These results suggest that subtle differences may exist in the brains of children with ADHD and that deviations in normal corticogenesis may underlie the behavioral manifestations of this disorder. 相似文献
5.
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
6.
Francina J. Clayton 《Scientific Studies of Reading》2018,22(2):137-151
The automatic letter-sound integration hypothesis proposes that the decoding difficulties seen in dyslexia arise from a specific deficit in establishing automatic letter-sound associations. We report the findings of 2 studies in which we used a priming task to assess automatic letter-sound integration. In Study 1, children between 5 and 7 years of age were faster to respond to a speech-sound when primed by a congruent letter, indicating that automatic activation of sounds by letters emerges relatively early in reading development. However, there was no evidence of a relationship between variations in the speed of activating sounds by letters and reading skill in this large unselected sample. In Study 2, children with dyslexia demonstrated automatic activation of sounds by letters, though they performed slowly overall. Our findings do not support the theory that a deficit in automatic letter-sound integration is an important cause of reading difficulties but do provide further evidence for the importance of phonological skills for learning to read. 相似文献
7.
Bruce F. Pennington 《Annals of dyslexia》1989,39(1):81-93
This paper reviews what is currently known about the genetics of dyslexia and shows how genetic studies can help clarify which
symptoms are primary and which are secondary in dyslexia. On the genetic side, current evidence supports the view that dyslexia
is familial, substantially heritable, and heterogeneous in its genetic mechanisms. At least some forms of familial dyslexia
appear to be autosomal dominant, with linkage studies supporting both a major locus on chromosome 15 and genetic heterogeneity.
On the symptom side, current evidence supports the view that the primary symptom in dyslexia is a deficit in the phonological
coding of written language. This primary symptom likewise appears to be heritable. Recent evidence suggests that the heritable
precursor to this written language deficit is a spoken language deficit in the skill of phoneme segmentation and awareness. 相似文献
8.
Gad Elbeheri John Everatt Gavin Reid Haya al Mannai 《Journal of Research in Special Educational Needs》2006,6(3):143-152
Despite advancements in empirical studies of developmental dyslexia, progress on methods of dyslexia assessment have been hampered by ongoing debate concerning diverse issues such as the role and validity of IQ in the assessment process, labelling and definitions ( Miles, 1994 ; Stanovich, 1991, 1992 ). With the emergence of cross-linguistic studies of dyslexia came the realisation that the manifestation of dyslexia is different in different languages ( Goulandris, 2003 ; Smythe, Everatt & Salter, 2004 ). It follows that the assessment of dyslexia should consider specific linguistic features of the language spoken by the individual to be assessed. This paper argues for the need of culture-fair assessment and calls for considerations to be given when assessing monolingual Arabic-speaking individuals with dyslexia which would take into account the specific linguistic feature of the Arabic language. 相似文献
9.
Zheng-luan Liao Yun-fei Tan Ya-ju Qiu Jun-peng Zhu Yan Chen Si-si Lin Ming-hao Wu Yan-ping Mao Jiao-jiao Hu Zhong-xiang Ding En-yan Yu 《Journal of Zhejiang University. Science. B》2018,19(12):924-934
The purpose of this study was to explore the differences in interhemispheric functional connectivity in patients with Alzheimer’s disease (AD) and amnestic mild cognitive impairment (aMCI) based on a triple network model consisting of the default mode network (DMN), salience network (SN), and executive control network (ECN). The technique of voxel-mirrored homotopic connectivity (VMHC) analysis was applied to explore the aberrant connectivity of all patients. The results showed that: (1) the statistically significant connections of interhemispheric brain regions included DMN-related brain regions (i.e. precuneus, calcarine, fusiform, cuneus, lingual gyrus, temporal inferior gyrus, and hippocampus), SN-related brain regions (i.e. frontoinsular cortex), and ECN-related brain regions (i.e. frontal middle gyrus and frontal inferior); (2) the precuneus and frontal middle gyrus in the AD group exhibited lower VMHC values than those in the aMCI and healthy control (HC) groups, but no significant difference was observed between the aMCI and HC groups; and (3) significant correlations were found between peak VMHC results from the precuneus and Mini Mental State Examination (MMSE) and Montreal Cognitive Scale (MOCA) scores and their factor scores in the AD, aMCI, and AD plus aMCI groups, and between the results from the frontal middle gyrus and MOCA factor scores in the aMCI group. These findings indicated that impaired interhemispheric functional connectivity was observed in AD and could be a sensitive neuroimaging biomarker for AD. More specifically, the DMN was inhibited, while the SN and ECN were excited. VMHC results were correlated with MMSE and MOCA scores, highlighting that VMHC could be a sensitive neuroimaging biomarker for AD and the progression from aMCI to AD. 相似文献
10.
The results from studies using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) in adults have largely revealed the involvement of left-hemisphere perisylvian areas in the reading process, including extrastriate visual cortex, inferior parietal regions, superior temporal gyrus, and inferior frontal cortex. Although the recruitment of these regions varies with the particular reading-related task, general networks of regions seem to be uniquely associated with different components of the reading process. For example, visual word form processing is associated with occipital and occipitotemporal sites, whereas reading-relevant phonological processing has been associated with superior temporal, occipitotemporal and inferior frontal sites of the left hemisphere. Such findings are evaluated in light of the technical and experimental limitations encountered in functional brain imaging studies, and the implications for pediatric studies are discussed. 相似文献
11.
《Scientific Studies of Reading》2013,17(3):225-240
Sentences convey relationships between the meanings of words, such as who is accomplishing an action or receiving it. Functional neuroimaging based on positron-emission tomography and functional magnetic resonance imaging has been used to identify areas of the brain involved in structuring sentences and determining aspects of meaning associated with sentences. This article reviews this literature, beginning with studies that compare sentences to low-level baselines, which identify brain regions involved in many language functions, and progressing to more narrowly constructed experiments that contrast one sentence type with another, which are designed to identify brain regions involved in quite specific sentence-level processing operations. These studies suggest that at least some syntactic and sentence-level interpretive operations, and/or the resource system that supports them, utilize the same brain areas regardless of whether language is spoken or written. They also suggest that several brain regions may provide support in these processes and that there are individual differences in what parts of the brain are involved in these functions. 相似文献
12.
13.
Thirty years ago in this journal, Aylett Royall Cox reported on the development of Alphabetic Phonics, a revision of the existing Orton Gillingham treatment for children with dyslexia. This paper continues that discussion and reports on the evolution of that curriculum as it is represented in a comprehensive dyslexia treatment program informed by intervention research. The paper describes the curriculum and reports data from a hospital-based learning disabilities clinic that provides qualified support for treatment efficacy and the value of added comprehension instruction. The results are then discussed in the context of current and future issues in dyslexia intervention. 相似文献
14.
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
15.
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
16.
Johansson BB 《Annals of dyslexia》2006,56(1):13-50
Current neuroimaging and neurophysiologic techniques have substantially increased our possibilities to study processes related
to various language functions in the intact human brain. Learning to read and write influences the functional organization
of the brain. What is universal and what is specific in the languages of the world are important issues. Most studies on healthy
bilinguals indicate that essentially the same neural mechanisms are used for first and second languages, albeit with some
linguistic and cultural influences related to speech and writing systems, particularly between alphabetical and nonalphabetical
languages. Proficiency, age of acquisition, and amount of exposure can affect the cerebral representations of the languages.
Accumulating data support the important role of working memory for acquiring high proficiency in the reading of native and
second languages. It is proposed that longitudinal studies on second language acquisition are essential and that the specific
problems related to second language learning in dyslexic children should have high priority. 相似文献
17.
Cognition-related brain responses to meaningful and meaningless figures were registered in 5-year-old kindergarten children who either had been subtyped as being at-risk of developing an L- or P-type dyslexia (LAL versus LAP) or who were not at-risk. While identifying, naming, or categorizing pictures, event-related potentials (ERP) were registered. Three cognition-related components were found: the N460, the P780, and the Slow Wave (SW). LAP-children produced weak N460 activity across tasks, whereas LAL children, and to a lesser degree, non-risk children produced robust task-dependent activity. This finding may indicate that LAP-children lack semantic input while processing the figures. P780 latencies to frequently occurring figures were found hemisphere-dependent: LAP-children showed longer latencies in the right than in the left hemisphere, whereas the distribution was reversed in the LAL and non-risk children. It was also found that the right hemisphere is generally responsible for a lion's share of the processing of figures and therefore it seems that the right hemisphere of LAP-children invests ample time in doing so. Whereas LAP-children showed largest SW amplitude differences between frequent and infrequent stimuli at posterior locations, LAL children did so at frontal locations. Assuming that the SW represents working-memory processes, it may be that working-memory in LAP-children deals with figure-relevant visual-spatial information and with figure-derived concepts in LAL children. Overall, the findings suggest that LAL and LAP represent two different groups of kindergartners at risk of dyslexia and that these differences, to some degree, fit with the presumed etiology of L- and P-type dyslexia. 相似文献
18.
Previous research suggests that individuals with developmental dyslexia perform below typical readers on non-linguistic cognitive tasks involving the learning and encoding of statistical-sequential patterns. However, the neural mechanisms underlying such a deficit have not been well examined. The aim of the present study was to investigate the event-related potential (ERP) correlates of sequence processing in a sample of children diagnosed with dyslexia using a non-linguistic visual statistical learning paradigm. Whereas the response time data suggested that both typical and atypical readers learned the statistical patterns embedded in the task, the ERP data suggested otherwise. Specifically, ERPs of the typically developing children (n?=?12) showed a P300-like response indicative of learning, whereas the children diagnosed with a reading disorder (n?=?8) showed no such ERP effects. These results may be due to intact implicit motor learning in the children with dyslexia but delayed attention-dependent predictive processing. These findings are consistent with other evidence suggesting that differences in statistical learning ability might underlie some of the reading deficits observed in developmental dyslexia. 相似文献
19.
阅读障碍是指词汇加工能力受损;而发展性阅读障碍是个体成长中出现的阅读障碍。一般从认知角度和生理基础角度出发研究阅读障碍的成因。通过对生理基础取向研究的回顾我们发现,发展性阅读障碍者阅读过程中的障碍存在脑部机能缺陷,主要包括脑电异常和脑功能异常。未来的研究应更加关注阅读障碍的定义,使之明确化;研究方法和手段要多元化;要开展多学科合作研究。 相似文献
20.
In this paper we report and analyse findings from part of a two‐year evaluation project which focuses on parent–professional communications over the issues of learning difficulties arising from dyslexia. The key concepts in this study are dyslexia friendly schools and parental partnership, which are discussed in the current policy interest in inclusive education and parent partnership. A conceptual framework has been derived from the study which focuses on parental strategies to ensure adequate provision for their children, knowledge about dyslexia and identity, in particular that of the mother of the child with dyslexia. Excerpts from in‐depth interviews of parents are then presented to illustrate the framework. The significance of the findings is examined in relation to other studies of parent partnership. Implications for a more inclusive version of extended professionalism are also considered.
Parental agency, identity and knowledge: mothers of children with dyslexia
Published online:
23 January 2007 Figure 1. Conceptual framework 相似文献