Language deficits in dyslexic children: speech perception, phonology, and morphology

We investigated the relationship between dyslexia and three aspects of language: speech perception, phonology, and morphology. Reading and language tasks were administered to dyslexics aged 8-9 years and to two normal reader groups (age-matched and reading-level matched). Three dyslexic groups were identified: phonological dyslexics (PD), developmentally language impaired (LI), and globally delayed (delay-type dyslexics). The LI and PD groups exhibited similar patterns of reading impairment, attributed to low phonological skills. However, only the LI group showed clear speech perception deficits, suggesting that such deficits affect only a subset of dyslexics. Results also indicated phonological impairments in children whose speech perception was normal. Both the LI and the PD groups showed inflectional morphology difficulties, with the impairment being more severe in the LI group. The delay group's reading and language skills closely matched those of younger normal readers, suggesting these children had a general delay in reading and language skills, rather than a specific phonological impairment. The results are discussed in terms of models of word recognition and dyslexia.     

Reading in callosal agenesis

It has been suggested that deficits in explicit phonological processing are causal in developmental dyslexia. Deficits in such skills have been reported in developmental phonological dyslexia, though not in developmental surface dyslexia. The reading performance of two children with callosal agenesis, who have been previously shown to have impairments on rhyming tasks, are reported. Neither child is dyslexic in the traditional sense, since word reading levels are appropriate for age. However, both children have impaired development of the phonological reading route despite normal lexical skills. The pattern of their reading is therefore comparable to developmental phonological dyslexia. Problems in explicit phonological processing may be causal in the failure to establish an efficient phonological reading route but this is insufficient to create difficulty with word recognition itself. The corpus callosum may be essential for the normal development of a phonological reading route.     

汉语发展性阅读障碍亚类型的初步探讨

以阅读水平匹配组为参照对29名汉语发展性阅读障碍儿童的认知缺陷模式进行了分析,并考察了不同亚类型阅读障碍儿童的汉字识别模式。结果表明汉语发展性阅读障碍存在不同的亚类型,以语音缺陷型、快速命名缺陷型及两者结合的双重缺陷型为主,与英语国家研究中的双重缺陷假设一致。语音缺陷型儿童汉字识别时有更多的语义错误,对声旁中的部分语音线索不敏感;快速命名缺陷型儿童汉字识别时依赖声旁语音线索,表现出阅读发展的一般延迟;双重或多重认知缺陷型是阅读损伤最严重的亚类型     

The role of sensorimotor impairments in dyslexia: a multiple case study of dyslexic children

This study attempts to investigate the role of sensorimotor impairments in the reading disability that characterizes dyslexia. Twenty-three children with dyslexia were compared to 22 control children, matched for age and non-verbal intelligence, on tasks assessing literacy as well as phonological, visual, auditory and motor abilities. The dyslexic group as a whole were significantly impaired on phonological, but not sensorimotor, tasks. Analysis of individual data suggests that the most common impairments were on phonological and visual stress tasks and the vast majority of dyslexics had one of these two impairments. Furthermore, phonological skill was able to account for variation in literacy skill, to the exclusion of all sensorimotor factors, while neither auditory nor motor skill predicted any variance in phonological skill. Visual stress seems to account for a small proportion of dyslexics, independently of the commonly reported phonological deficit. However, there is little evidence for a causal role of auditory, motor or other visual impairments.     

In search of subtypes of Chinese developmental dyslexia

The dual-route model offers a popular way to classify developmental dyslexia into phonological and surface subtypes. The current study examined whether this dual-route model could provide a framework for understanding the varieties of Chinese developmental dyslexia. Three groups of Chinese children (dyslexics, chronological-age controls, and reading-level controls) were tested on Chinese exception character reading, pseudocharacter reading (analogous to English nonword reading), novel word learning, and some phonological and orthographic skills. It was found that Chinese exception character reading and pseudocharacter reading were highly correlated and that orthographic skills was a better predictor of both Chinese exception character and pseudocharacter reading than was phonological skills. More than half (62%) of the children in the dyslexia sample were classified as belonging to the surface subtype, but no children were classified as belonging to the phonological subtype. These results suggested that the lexical and sublexical routes in Chinese are highly interdependent or that there may be only one route from print to speech as suggested by the connectionist models. Chinese dyslexic children generally are characterized as having delays in various phonological and orthographic skills, but some, such as those identified as surface dyslexics in the current study, are more severely impaired.     

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.     

汉语发展性阅读障碍儿童的主要亚类型分析*

采用语音意识测验、语素意识测验、正字法意识测验和快速命名测验对发展性阅读障碍儿童和阅读水平匹配组儿童进行测验。采用标准差切分法对阅读障碍的主要亚类型进行分析。结果发现,具有语音意识缺陷的人数比例最大,其次是正字法意识缺陷。结论:汉语发展性阅读障碍的主要亚类型为语音意识缺陷和正字法意识缺陷,快速命名缺陷和语素意识缺陷在汉语阅读障碍儿童中存在,但只是次要缺陷。     

双重缺陷汉语发展性阅读障碍儿童的言语工作记忆和阅读能力研究

选取语音意识和快速自动命名双重缺陷的汉语发展性阅读障碍儿童,探讨其言语工作记忆和阅读能力的发展特点。实验选取双重缺陷的发展性阅读障碍（DD）、年龄匹配（CA）和能力匹配（RL）三组儿童各25名,要求他们完成言语工作记忆（数字广度、汉字广度）和阅读（一分钟词汇阅读、三分钟句子阅读）任务。结果发现,DD儿童的数字倒背位数、一分钟读词数、三分钟读过字数和句子理解正确率均显著低于CA儿童,而与RL儿童差异不显著;DD儿童的句子阅读正确率显著低于CA、RL儿童。表明双重缺陷DD儿童在言语工作记忆和阅读能力上存在一定程度的发展滞后和缺陷。     

The "temporal processing deficit" hypothesis in dyslexia: new experimental evidence

The notion that developmental dyslexia may result from a general, nonspecific, defect in perceiving rapidly changing auditory signals is a current subject of debate (so-called "temporal processing deficit" hypothesis). Thirteen phonological dyslexics (age 10-13 years) and 10 controls matched for chronological and reading 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 relevance of the temporal deficit hypothesis, the task also included two additional conditions where either the two stimuli were artificially slowed or the interstimulus interval was expanded. 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 no significant improvement occurred when increasing the interstimulus interval. Finally dyslexics' performances, especially on the slowed condition, were found correlated with several tests of phonological processing (phoneme deletion, rhyme judgment, and nonword spelling tasks). These results lend support to the general temporal deficit theory of dyslexia.     

Picture naming deficits in developmental dyslexia in German

Recent research with English developmental dyslexics comparing the picture naming performance of these children to the picture naming performance of non-dyslexic (‘garden variety’) poor readers, reading age matched controls and chronological age matched controls has suggested that a selective difficulty in retrieving the phonological codes of known names on demand underlies the picture naming deficit found in developmental dyslexia (Swan & Goswami, Picture naming deficits in developmental dyslexia: the phonological representations hypothesis, Brain and Language, 56 (1997), 334–353). If the underlying causal factors in dyslexia are independent of the orthography that the child is learning to read, then a difficulty in retrieving the phonological codes of known names on demand should also be found in developmental dyslexics who are learning to read other languages. We therefore set out to replicate Swan and Goswami’s study with a group of German developmental dyslexics. We were interested to see whether a phonological deficit is characteristic of dyslexia in all orthographies, even those, such as German, in which high orthographic transparency means that dyslexic children read with considerable accuracy.     

Copying skills in relation to word reading and writing in Chinese children with and without dyslexia

Because Chinese character learning typically relies heavily on rote character copying, we tested independent copying skill in third- and fourth-grade Chinese children with and without dyslexia. In total, 21 Chinese third and fourth graders with dyslexia and 33 without dyslexia (matched on age, nonverbal IQ, and mother’s education level) were given tasks of copying unfamiliar print in Vietnamese, Korean, and Hebrew as well as tests of word reading and writing, morphological awareness, rapid automatized naming (RAN), and orthographic processing. All three copying tasks distinguished dyslexic children from nondyslexic children with moderate effect sizes (.67-.80). Zero-order correlations of the three copying tasks with dictation and reading ranged from .37 to .58. With age, Raven’s, group status, RAN, morphological awareness, and orthographic measures statistically controlled, the copying tasks uniquely explained 6% and 3% variance in word reading and dictation, respectively. Results suggest that copying skill itself may be useful in understanding the development and impairment of literacy skills in Chinese.     

Is dyslexia a visual perceptive disorder? New empirical data

Several studies have shown that a phonological deficit is the origin of developmental dyslexia, because dyslexics have important difficulties in mapping orthographic to phonological codes. However, visual criteria are still used for the diagnosis of dyslexia and to develop methods of intervention. This study attempts to determine whether there are visual problems in dyslexic children. To this aim, dyslexic children and children without reading difficulties, matched by chronological age, participated in two experiments. One study was based on the Reversal test and the other was a visual decision task in which participants had to decide whether two letters were the same or different. There were 40 pairs of letters, to measure reaction times and mistakes. The results showed that dyslexics had similar performance to controls in the detection of different visual stimuli. Developmental dyslexics do not appear to have visual perceptual problems, but a particular difficulty to retrieve the phonological code of graphemes.     

Learning to read in children with Williams syndrome

People with Williams syndrome are characterized by linguistic abilities that are higher than their level of intelligence. There is controversy concerning their reading level because there are few studies. The aim of this work was to test reading abilities in a group of school-age children with Williams syndrome. Their performance was contrasted with a control group of the same mental age. Three kinds of tasks were used: word and pseudoword reading, phonological awareness, and naming speed. Results show that the Williams syndrome children performed similarly to control children in reading accuracy but were slower in reading words and pseudowords. They were also slower in the naming speed tasks. These results suggest that Williams syndrome children do not have difficulties in developing grapheme-phoneme decoding but do present some difficulties in developing lexical reading.     

Not all phonological awareness deficits are created equal: evidence from a comparison between children with Otitis Media and poor readers

Children with reading difficulties and children with a history of repeated ear infections (Otitis Media, OM) are both thought to have phonological impairments, but for quite different reasons. This paper examines the profile of phonological and morphological awareness in poor readers and children with OM. Thirty‐three poor readers were compared to individually matched chronological age and reading age controls. Their phonological awareness and morphological awareness skills were consistently at the level of reading age matched controls. Unexpectedly, a significant minority (25%) of the poor readers had some degree of undiagnosed mild or very mild hearing loss. Twenty‐nine children with a history of OM and their matched controls completed the same battery of tasks. They showed relatively small delays in their literacy and showed no impairment in morphological awareness but had phonological awareness scores below the level of reading age matched controls. Further analysis suggested that this weakness in phonological awareness was carried by a specific weakness in segmenting and blending phonemes, with relatively good performance on phoneme manipulation tasks. Results suggest that children with OM show a circumscribed deficit in phoneme segmentation and blending, while poor readers show a broader metalinguistic impairment which is more closely associated with reading difficulties.     

Deep dyslexia in childhood?

Deep dyslexia is an acquired reading disorder in which semantic substitutions (e.g., city read as town) are made in reading single isolated words. In this paper, evidence for deep dyslexic-type errors is presented from the word-recognition responses of six children, aged 7 years and 0 month to 8 years and 9 months, with severe reading disorders. These semantic substitutions occur in the absence of phonological skills. Therefore, it appears that there exists a small subset of developmental dyslexics who at the beginning of acquisition of reading skills are able to engage in semantic processing, but who show severe impairment of phonological processing. The existence of these reading errors indicate that the use of a phonological code is not necessary to extract meaning from the printed word.     

Phonological–semantic flexibility and its role in reading for Chinese kindergarten children

The present study aimed to examine the role of phonological–semantic flexibility (PSF) in learning to read Chinese. PSF refers to a specific flexibility applied to process the dual linguistic dimensions of words (i.e., sound and meaning). A correlational study (Study 1) was conducted to determine the unique contribution of PSF to three aspects of early reading abilities, including word reading accuracy, word reading fluency and reading comprehension. A total of 190 Chinese kindergarten children were tested on a PSF task and a range of cognitive, linguistic and reading tasks. Results of hierarchical regressions showed that PSF uniquely and significantly contributed to the reading abilities beyond the effects of established cognitive factors (IQ, working memory, inhibition control, and cognitive flexibility) and linguistic factors (syllable skills, morphological skill and vocabulary skill). In the second part, an intervention study (Study 2) was conducted in which two groups of kindergarten children received explicit training on PSF (27 children) and colour–shape flexibility (26 children) respectively. Children in the PSF group showed significantly more improvement in PSF and word reading fluency than the control group. Overall, the present study demonstrated the theoretical and practical importance of PSF for learning to read Chinese.     

阅读发展相关的认知技能：汉语和英语的比较

对英语和汉语阅读获得所需要的认知技能及发展性阅读障碍儿童认知缺陷的研究进行了回顾。分析表明阅读发展所需认知资源表现出了跨语言的一致性,都要求有充足的学习与记忆能力和正常的视觉正字法技能,语音和语义知识表征足够精细;阅读障碍儿童的主要认知缺陷也表现出了跨文字的一致性,都包括语音缺陷和一般的学习与记忆问题。然而儿童所面临的语言文字特性会影响到阅读技能获得的难易和发展性阅读障碍的表现     

Morphological Processing in Adult Dyslexia

This study employed the masked-priming paradigm [Forster and Davis (J Exp Psychol bearn Mem Cogn 10: 680–698, 1984).], along with traditional methods of evaluation of morphological awareness and phonological processing, to obtain a finer-grained picture of the relationship between morphological abilities and reading in adult dyslexic readers. Participants were 21 dyslexic and 21 normally reading native Hebrew-speaking male college students. The results with masked priming demonstrated almost normal status of morphological knowledge in adult dyslexic readers with the presence of characteristic processing slowness. Phonological processing and morphological awareness were also shown to contribute primarily to word decoding in the regular and dyslexic group alike. At the same time, the contribution of different phonological skills to morphological priming effects (for pattern and root) dropped to zero. The findings demonstrated that weakness of dyslexic readers in morphological awareness tasks cannot be explained either by hypotheses on the structural deficit of morphological knowledge in dyslexia or by phonological deficit hypotheses. The explanation for this phenomenon seems to lie in the specific deficit of morphological processing, or even, more generally, in metalinguistic processing deficiency in dyslexia.     

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。