基于PASS模型的汉语阅读障碍认知加工特点的实验研究

研究以智力的PASS认知模型为基础,考察了3-5年级阅读障碍组和正常对照组的PASS认知加工特点,探究汉语阅读障碍儿童的PASS认知缺陷模式,为后期的干预提供理论上的支持和帮助。结果发现,PASS四个认知加工均存在明显的年级差异,低年级儿童的PASS认知加工能力明显不如中高年级儿童。汉语阅读障碍儿童在DN: CAS 12项分任务上的成绩均低于正常对照组儿童。同时,大多数汉语阅读障碍儿童存在不止一种的PASS认知加工缺陷,即汉语发展性阅读障碍内部是一个异质群体;阅读障碍儿童在继时性加工上存在的问题最为严重,存在缺陷的人数也最多。     

Dyslexia and dyscalculia: Two learning disorders with different cognitive profiles

This study tests the hypothesis that dyslexia and dyscalculia are associated with two largely independent cognitive deficits, namely a phonological deficit in the case of dyslexia and a deficit in the number module in the case of dyscalculia. In four groups of 8- to 10-year-olds (42 control, 21 dyslexic, 20 dyscalculic, and 26 dyslexic/dyscalculic), phonological awareness, phonological and visual-spatial short-term and working memory, naming speed, and basic number processing skills were assessed. A phonological deficit was found for both dyslexic groups, irrespective of additional arithmetic deficits, but not for the dyscalculia-only group. In contrast, deficits in processing of symbolic and nonsymbolic magnitudes were observed in both groups of dyscalculic children, irrespective of additional reading difficulties, but not in the dyslexia-only group. Cognitive deficits in the comorbid dyslexia/dyscalculia group were additive; that is, they resulted from the combination of two learning disorders. These findings suggest that dyslexia and dyscalculia have separable cognitive profiles, namely a phonological deficit in the case of dyslexia and a deficient number module in the case of dyscalculia.     

发展性阅读障碍亚类型研究进展

发展性阅读障碍是一种特殊的学习障碍,伴有多种认知缺陷并且存在不同的亚类型。依据相关的阅读模型理论,阅读障碍可划分为语音型和表层型。从认知缺陷角度出发,语音加工缺陷是主要的缺陷表现,以此为特征形成一种主要的阅读障碍的亚类型,同时还有以正字法加工缺陷和快速命名缺陷为主的其他亚类型。而以基本感知觉缺陷为标准,主要有以视觉加工缺陷和以听觉加工缺陷为主的两种亚类型。在汉语条件下,依据同样的阅读模型理论,语音型阅读障碍亚类型比例明显低于拼音文字条件下的。汉语阅读障碍也具有分别以语音加工缺陷、快速命名缺陷和正字法加工缺陷为主要认知缺陷的亚类型。未来有必要从神经机制角度进一步明确不同亚类型的神经基础。     

The cognitive profile and multiple-deficit hypothesis in Chinese developmental dyslexia

The present study was conducted to examine the cognitive profile and multiple-deficit hypothesis in Chinese developmental dyslexia. Thirty Chinese dyslexic children in Hong Kong were compared with 30 average readers of the same chronological age (CA controls) and 30 average readers of the same reading level (RL controls) in a number of rapid naming, visual, phonological, and orthographic tasks. Chinese dyslexic children performed significantly worse than the CA controls but similarly to the RL controls on most of the cognitive tasks. The rapid naming deficit was found to be the most dominant type of cognitive deficit in Chinese dyslexic children. Over half of the dyslexic children exhibited deficits in 3 or more cognitive areas, and there was a significant association between the number of cognitive deficits and the degree of reading and spelling impairment. The present findings support the multiple-deficit hypothesis in Chinese developmental dyslexia.     

Erratum

The main aims of this study were a) to assess the cerebellar deficit hypothesis examining children's performance in cerebellar and cognitive tasks associated with the dyslexic syndrome and b) to investigate if there is a differentiation in articulation speed in children with dyslexia. A battery consisted of five cerebellar tests, five cognitive tests, and an articulation speed test was administered to three age- and sex-matched groups of dyslexics, children with attention deficit/hyperactivity disorder (ADHD) and normal readers aged 8–12 years. The dyslexics showed significant impairment in one cerebellar test compared with the control group and in two cognitive tests compared with both the control and the ADHD group. Additionally, the dyslexic children performed significantly worse than the control group during the articulation speed test; such a difference was not observed between the control and the ADHD group. The present study provides clues to support the cerebellar deficit hypothesis and the possible relationship between reading impairment and speed of articulation. Further research is considered essential to clarify the relationship between cerebellar function, dyslexia, and oral language speed.     

Performance of Dyslexic Children on Cerebellar and Cognitive Tests

In a previous study (A. J. Fawcett, R. I. Nicolson, & P. Dean, 1996), the authors had found strong behavioral evidence for cerebellar deficit in a panel of children with dyslexia. In the present study, the generality of those results was assessed. A battery of clinical tests for cerebellar dysfunction was administered, together with selected cognitive tests, to a further 59 dyslexic and 67 control children. The dyslexic children showed highly significant impairments on the cerebellar tests, with deficits on postural stability and muscle tone comparable in magnitude with their reading and spelling deficits. Furthermore, over 95&percent; of the dyslexic children showed clear evidence of deficit on muscle tone or stability. The findings provide further evidence of the generality of cerebellar impairment in dyslexia. The implications of the cerebellar tests for screening in dyslexia are discussed.     

发展性阅读障碍书写加工缺陷及其神经机制

发展性阅读障碍是学习障碍的主要类型之一, 严重影响个体认知、情感与社会适应性的发展。书写与阅读关系密切, 阅读障碍者常常表现出书写加工缺陷。在行为层面, 阅读障碍者书写缺陷表现在书写质量差、速度慢和停顿多等多个方面。在脑机制层面, 脑成像研究发现, 阅读障碍者书写加工缺陷与字形加工脑区活动, 以及字形与运动区脑功能与结构连接异常有关。总体而言, 阅读障碍者书写过程中的字形通达缺陷的证据比较充分, 但字形与运动编码的衔接以及运动执行是否存在困难, 尚缺乏研究证据。相对于字母语言, 书写与阅读的关系在汉语中更为紧密, 汉语阅读障碍的书写研究将为开发汉语特色的诊治方案提供重要指导。     

Performance of Dyslexic Children on Cerebellar and Cognitive Tests

In a previous study (A. J. Fawcett, R. I. Nicolson, & P. Dean, 1996), the authors had found strong behavioral evidence for cerebellar deficit in a panel of children with dyslexia. In the present study, the generality of those results was assessed. A battery of clinical tests for cerebellar dysfunction was administered, together with selected cognitive tests, to a further 59 dyslexic and 67 control children. The dyslexic children showed highly significant impairments on the cerebellar tests, with deficits on postural stability and muscle tone comparable in magnitude with their reading and spelling deficits. Furthermore, over 95% of the dyslexic children showed clear evidence of deficit on muscle tone or stability. The findings provide further evidence of the generality of cerebellar impairment in dyslexia. The implications of the cerebellar tests for screening in dyslexia are discussed.     

阅读障碍儿童的技能自动化能力

以自动化缺陷假说为理论背景,采用系列反应时学习任务,探讨了41名五、六年级的汉语发展性阅读障碍儿童和41名正常儿童的技能自动化能力,通过比较对系列刺激和随机刺激的反应时差异,发现障碍组儿童的反应时虽然普遍长于正常组,但两组儿童都表现出了相同模式的系列学习效应,不支持发展性阅读障碍的技能自动化缺陷假说.     

Spanish developmental dyslexia: Prevalence, cognitive profile, and home literacy experiences

This study was designed to examine the prevalence, cognitive profile, and home literacy experiences in subtypes of Spanish developmental dyslexia. The subtyping procedure used comparison with chronological-age-matched and reading-level controls on reaction times and accuracy responses to high-frequency words and pseudowords. Using regression-based procedures, 8 phonological dyslexics and 16 surface dyslexics were identified from a sample of 35 dyslexic fourth graders by comparing them with chronological-age-matched controls on reaction times to high-frequency word and pseudoword reading. However, when the dyslexic subtypes were defined by reference to reading-level controls, 12 phonological dyslexics were defined but only 5 surface dyslexics were identified. Both dyslexic subtypes showed a deficit in phonological awareness, but children with surface dyslexia also showed a deficit in orthographical processing assessed by a homophone comprehension task. This deficit was associated with poor home literacy experiences, with the group of parents with children matched in reading age, in comparison with the group of parents with children with surface dyslexia, reporting more literacy home experiences.     

Developmental dyslexia: the visual attention span deficit hypothesis

The visual attention (VA) span is defined as the amount of distinct visual elements which can be processed in parallel in a multi-element array. Both recent empirical data and theoretical accounts suggest that a VA span deficit might contribute to developmental dyslexia, independently of a phonological disorder. In this study, this hypothesis was assessed in two large samples of French and British dyslexic children whose performance was compared to that of chronological-age matched control children. Results of the French study show that the VA span capacities account for a substantial amount of unique variance in reading, as do phonological skills. The British study replicates this finding and further reveals that the contribution of the VA span to reading performance remains even after controlling IQ, verbal fluency, vocabulary and single letter identification skills, in addition to phoneme awareness. In both studies, most dyslexic children exhibit a selective phonological or VA span disorder. Overall, these findings support a multi-factorial view of developmental dyslexia. In many cases, developmental reading disorders do not seem to be due to phonological disorders. We propose that a VA span deficit is a likely alternative underlying cognitive deficit in dyslexia.     

Temporal processing and phonological impairment in dyslexia: effect of phoneme lengthening on order judgment of two consonants

The evidence of supporting phonological deficit as a cause of developmental dyslexia has been accumulating rapidly over the past 2 decades, yet the exact mechanisms underlying this deficit remain controversial. Some authors assume that a temporal processing deficit is the source of the phonological disorder observed in dyslexic children. Others maintain that the phonological deficit in dyslexia is basically linguistic, not acoustic, in nature. Three experiments were conducted and tested the impact of the temporal alteration and the impact of complex syllabic structure on consonant order judgments. Thirteen phonological dyslexics (age 10-13) and 10 controls matched for chronologial age were compared on a Temporal Order Judgment (TOJ) task using the succession of two consonants (/p/ /s/) within a cluster. In order to test the possible relevance of the temporal deficit hypothesis, the task also included two additional conditions where either the two stimuli were artificially slowed or two phonological structures were opposed (CCV and CVCV). As expected, the TOJ performance was significantly poorer in dyslexics than in controls. Moreover, in the "slowed speech" condition dyslexics' performance improved to reach the normal controls' level, whereas manipulating the phonological structure complexity provided no significant improvement. Finally dyslexics' performances, especially on the slowed condition, were found correlated with several tests of phonological processing. These results lend support to the general temporal deficit theory of dyslexia.     

小脑与发展性阅读障碍

发展性阅读障碍是学龄儿童面临的学习问题之一。近年来,许多行为和神经生理学、影像学实验都发现,发展性阅读障碍的儿童有明显的运动功能失调,如平衡性差、身体灵敏度不够以及自动化水平低。Nicolson等人提出的小脑理论认为,阅读障碍者的小脑功能失调影响了书写及发音,导致语音及阅读能力不足,而且小脑与时间控制有关,阅读障碍者的时间估计能力有缺陷与他们的小脑功能失调有关。本文回顾了有关小脑理论的研究,并指出小脑的认知功能还有待进一步的研究。     

Visual rapid naming and phonological abilities: different subtypes in dyslexic children

One implication of the double-deficit hypothesis for dyslexia is that there should be subtypes of dyslexic readers that exhibit rapid naming deficits with or without concomitant phonological processing problems. In the current study, we investigated the validity of this hypothesis for Portuguese orthography, which is more consistent than English orthography, by exploring different cognitive profiles in a sample of dyslexic children. In particular, we were interested in identifying readers characterized by a pure rapid automatized naming deficit. We also examined whether rapid naming and phonological awareness independently account for individual differences in reading performance. We characterized the performance of dyslexic readers and a control group of normal readers matched for age on reading, visual rapid naming and phonological processing tasks. Our results suggest that there is a subgroup of dyslexic readers with intact phonological processing capacity (in terms of both accuracy and speed measures) but poor rapid naming skills. We also provide evidence for an independent association between rapid naming and reading competence in the dyslexic sample, when the effect of phonological skills was controlled. Altogether, the results are more consistent with the view that rapid naming problems in dyslexia represent a second core deficit rather than an exclusive phonological explanation for the rapid naming deficits. Furthermore, additional non-phonological processes, which subserve rapid naming performance, contribute independently to reading development.     

Unilateral implicit motor learning deficit in developmental dyslexia

It has been suggested that developmental dyslexia involves various literacy, sensory, motor skill, and processing speed deficits. Some recent studies have shown that individuals with developmental dyslexia exhibit implicit motor learning deficits, which may be related to cerebellar functioning. However, previous studies on implicit motor learning in developmental dyslexics have produced conflicting results. Findings from cerebellar lesion patients have shown that patients' implicit motor learning performance varied when different hands were used to complete tasks. This suggests that dyslexia may have different effects on implicit motor learning between the two hands if cerebellar dysfunction is involved. To specify this question, we used a one-handed version of a serial reaction time task to compare the performance of 27 Chinese children with developmental dyslexics with another 27 age-matched children without reading difficulties. All the subjects were students from two primary schools, Grades 4 to 6. The results showed that children with developmental dyslexic responded more slowly than nondyslexic children, and exhibited no implicit motor learning in the condition of left-hand response. In contrast, there was no significant difference in reaction time between two groups of children when they used the right hand to respond. This finding indicates that children with developmental dyslexia exhibited normal motor skill and implicit motor learning ability provided the right hand was used. Taken together, these results suggested that Chinese children with developmental dyslexia exhibit unilateral deficits in motor skill and implicit motor learning in the left hand. Our findings lend partial support to the cerebellar deficit theory of developmental dyslexia.     

Dyslexia,authorial identity,and approaches to learning and writing: A mixed methods study

Background. Dyslexia may lead to difficulties with academic writing as well as reading. The authorial identity approach aims to help students improve their academic writing and avoid unintentional plagiarism, and could help to understand dyslexic students’ approaches to writing. Aims. (1) To compare dyslexic and non‐dyslexic students’ authorial identity and approaches to learning and writing; (2) to compare correlations between approaches to writing and approaches to learning among dyslexic and non‐dyslexic students; (3) to explore dyslexic students’ understandings of authorship and beliefs about dyslexia, writing and plagiarism. Sample. Dyslexic (n= 31) and non‐dyslexic (n= 31) university students. Method. Questionnaire measures of self‐rated confidence in writing, understanding of authorship, knowledge to avoid plagiarism, and top‐down, bottom‐up and pragmatic approaches to writing (Student Authorship Questionnaire; SAQ), and deep, surface and strategic approaches to learning (Approaches and Study Skills Inventory for Students; ASSIST), plus qualitative interviews with dyslexic students with high and low SAQ scores. Results. Dyslexic students scored lower for confidence in writing, understanding authorship, and strategic approaches to learning, and higher for surface approaches to learning. Correlations among SAQ and ASSIST scores were larger and more frequently significant among non‐dyslexic students. Self‐rated knowledge to avoid plagiarism was associated with a top‐down approach to writing among dyslexic students and with a bottom‐up approach to writing among non‐dyslexic students. All the dyslexic students interviewed described how dyslexia made writing more difficult and reduced their confidence in academic writing, but they had varying views about whether dyslexia increased the risk of plagiarism. Conclusions. Dyslexic students have less strong authorial identities, and less congruent approaches to learning and writing. Knowledge to avoid plagiarism may be more salient for dyslexic students, who may benefit from specific interventions to increase confidence in writing and understanding of authorship. Further research could investigate how dyslexic students develop approaches to academic writing, and how that could be affected by perceived knowledge to avoid plagiarism.     

Genes, language development, and language disorders

Genetic factors are important contributors to language and learning disorders, and discovery of the underlying genes can help delineate the basic neurological pathways that are involved. This information, in turn, can help define disorders and their perceptual and processing deficits. Initial molecular genetic studies of dyslexia, for example, appear to converge on defects in neuronal and axonal migration. Further study of individuals with abnormalities of these genes may lead to the recognition of characteristic cognitive deficits attributable to the neurological dysfunction. Such abnormalities may affect other disorders as well, and studies of co-morbidity of dyslexia with attention deficit disorder and speech sound disorder are helping to define the scope of these genes and show the etiological and cognitive commonalities between these conditions. The genetic contributions to specific language impairment (SLI) are not as well defined at this time, but similar molecular approaches are being applied to identify genes that influence SLI and comorbid disorders. While there is co-morbidity of SLI with dyslexia, it appears that most of the common genetic effects may be with the language characteristics of autism spectrum disorders rather than with dyslexia and related disorders. Identification of these genes and their neurological and cognitive effects should lay out a functional network of interacting genes and pathways that subserve language development. Understanding these processes can form the basis for refined procedures for diagnosis and treatment.     

汉语阅读障碍的语音加工及正字法加工缺陷的实验研究

本研究对汉语阅读障碍的加工缺陷进行探讨,期望有助于揭示语言加工的普遍性与特殊性,以及阅读障碍的成因,并可为后期的干预提供帮助。研究采用改编的言语认知测验对阅读水平匹配组与阅读障碍组和生理年龄匹配组进行比较后发现,阅读障碍组在语音意识和正字法加工任务上的成绩均明显差于生理年龄控制组和阅读水平匹配组;阅读障碍组在快速命名和语音记忆任务上的成绩不如生理年龄匹配组,仅达到阅读水平匹配组水平。因此,汉语发展性阅读障碍儿童存在语音意识和正字法加工缺陷,这两种缺陷可能是阅读障碍儿童面临的最主要的两大缺陷;阅读障碍儿童在快速命名和语音记忆上的不足可能是发展迟滞所致。同时,大多数的汉语阅读障碍儿童存在不止一种的认知缺陷。阅读障碍儿童在语音意识和正字法加工上存在缺陷的比例最高。     

The Nature of the Automatization Deficit in Chinese Children with Dyslexia

Clarifying whether automatization deficits constitute the primary causes or symptoms of developmental dyslexia, we focused on three critical issues of the dyslexic automatization deficit, namely universality, domain specificity, and severity. Thirty Chinese dyslexic children (mean age 10 years and 5 months), 30 chronological-age-, and 30 reading-level-matched children were tested in 4 areas of automaticity: motor, visual search, Stroop facilitation effects, and automatic word recognition. The results showed that the dyslexic children performed significantly worse than the CA-controls but not the RL-controls in all the tasks except for Stroop congruent-color words, on which they performed worse than children in both control groups. The deficits reflect a lag in reading experiences rather than a persistent cognitive deficit.