Electrophysiological correlates of dyslexic subtypes.

The construct validity of Boder's typology of dyslexia was investigated using quantified EEG. Thirty-nine children, ranging in age from 7-0 to 10-11, were recorded during a contextual reading task and at rest. During reading, children with dyslexia were expected to show increased theta and beta amplitude compared to nondisabled readers. These differences were expected in regions of presumed strength for each subtype as a sign of overengagement in task. Children with phonological deficits (dysphonetic dyslexia) were expected to adopt visuospatial processing strategies (right occipital-parietal activation), those with orthographic deficits (dyseidetic dyslexia) to emphasize phonetic strategies (left temporal-parietal activation). Results supported beta frequency differences in anticipated regions by subtype during the reading task. However, the direction of difference hypothesis was not supported. Decreased amplitudes in both groups with dyslexia compared to normally achieving readers suggest reconceptualization of the theoretical base for the Boder subtyping system.     

Orthographic processing efficiency in developmental dyslexia: an investigation of age and treatment factors at the sublexical level

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.     

Phonological and Surface Subtypes among University Students with Dyslexia

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.     

Foreign language reading and spelling in gifted students with dyslexia in secondary education

A few studies suggest that gifted children with dyslexia have better literacy skills than averagely intelligent children with dyslexia. This finding aligns with the hypothesis that giftedness-related factors provide compensation for poor reading. The present study investigated whether, as in the native language (NL), the level of foreign language (FL) literacy of gifted students with dyslexia is higher than the literacy level of averagely intelligent students with dyslexia and whether this difference can be accounted for by the difference in their NL literacy level. The sample consisted of 148 Dutch native speaking secondary school students divided in four groups: dyslexia, gifted/dyslexia, typically developing (TD), and gifted. All students were assessed on word reading and orthographic knowledge in Dutch and English when they were in 7th or 8th grade. A subsample (n = 71) was (re)assessed on Dutch, English, French, and German literacy one year later. Results showed that Dutch gifted students with dyslexia have higher NL literacy levels than averagely intelligent students with dyslexia. As in the NL, a stepwise pattern of group differences was found for English word reading and spelling, i.e., dyslexia < gifted/dyslexia < TD < gifted. However, it was not found for French and German literacy performance. These results point towards compensation: the higher English literacy levels of gifted/dyslexic students compared to their averagely intelligent dyslexic peers result from mechanisms that are unique to English as a FL. Differences in results between FLs are discussed in terms of variation in orthographic transparency and exposure.     

Whole‐word shape effect in dyslexia

The research question here was whether whole‐word shape cues might facilitate reading in dyslexia following reports of how normal‐reading children benefit from using this cue when learning to read. We predicted that adults with dyslexia would tend to rely more on orthographic rather than other cues when reading, and therefore would be more affected by word shape manipulations. This prediction was tested in a lexical decision task on words with a flat or a non‐flat outline (i.e. without or with letters with ascending/descending features). We found that readers with dyslexia were significantly faster when reading non‐flat compared with flat words, while typical readers did not benefit from whole‐word shape cues. The interaction of participants' group and word shape was not modulated by word frequency; that is word outline shape facilitated reading for both rare and frequent words. Our results suggest that enhanced sensitivity to orthographic cues is developed in some cases of dyslexia when normal, phonology‐based word recognition processing is not exploited.     

Teaching children with dyslexia to spell in a reading-writers’ workshop

To identify effective treatment for both the spelling and word decoding problems in dyslexia, 24 students with dyslexia in grades 4 to 9 were randomly assigned to treatments A (n?=?12) or B (n?=?12) in an after-school reading-writers’ workshop at the university (thirty 1-h sessions twice a week over 5 months). First, both groups received step 1 treatment of grapheme–phoneme correspondences (gpc) for oral reading. At step 2, treatment A received gpc training for both oral reading and spelling, and treatment B received gpc training for oral reading and phonological awareness. At step 3, treatment A received orthographic spelling strategy and rapid accelerated reading program (RAP) training, and treatment B continued step 2 training. At step 4, treatment A received morphological strategies and RAP training, and treatment B received orthographic spelling strategy training. Each treatment also had the same integrated reading–writing activities, which many school assignments require. Both groups improved significantly in automatic letter writing, spelling real words, compositional fluency, and oral reading (decoding) rate. Treatment A significantly outperformed treatment B in decoding rate after step 3 orthographic training, which in turn uniquely predicted spelling real words. Letter processing rate increased during step 3 RAP training and correlated significantly with two silent reading fluency measures. Adding orthographic strategies with “working memory in mind” to phonics helps students with dyslexia spell and read English words.     

Cognitive processing skills and developmental dyslexia in Chinese

The purpose of the present study was twofold: (a) to examine the extent to which Chinese dyslexic children experience deficits in phonological and orthographic processing skills and (b) to examine if Chinese dyslexia is associated with deficits in Planning, Attention, Simultaneous, and Successive (PASS) processing. A total of 27 Grade 4 children with dyslexia (DYS), 27 Grade 4 chronological age (CA) controls, and 27 Grade 2 reading age (RA) controls were tested on measures of phonological awareness, rapid naming, phonological memory, PASS, reading accuracy, and reading fluency. The results indicated that the DYS group performed significantly poorer than the CA and RA groups on both measures of phonological awareness and on a measure of orthographic processing but comparably to the RA group on a measure of rapid naming and both measures of phonological memory. In regard to the PASS processing skills, the DYS group performed worse than the CA controls on Successive and Simultaneous processing but comparably to the RA group on all PASS processing skills. Implications of these findings for early identification and intervention of reading difficulties are discussed.     

Spelling difficulties in Spanish-speaking children with dyslexia / Dificultades de escritura en niños españoles con dislexia

In addition to reading difficulties, a significant proportion of developmental dyslexics have spelling problems, which persist into adulthood. Studies carried out in languages with opaque orthographies have found that dyslexics frequently make phonological substitutions when spelling and have difficulties in developing orthographic representations of irregular words. Those errors seem to derive from an excessive use of phonological codes when writing. Minimal research in Spanish (relatively transparent orthography) about the relationship between dyslexia and spelling difficulties has been carried out to date. In this study, 19 Spanish-speaking developmental dyslexics (from 7 to 11 years old) and 28 controls (from 6 to 11 years old, distributed in two groups, one matched for age and the other for reading level with the dyslexics) performed a dictation task of 80 stimuli with different levels of orthographic consistency, in order to discover the codes they use in the writing process. Results showed that Spanish children with dyslexia made significantly more spelling errors, especially among the ruled and irregular words. These findings are consistent with the idea that these children have difficulties in developing orthographic representations and use phonological codes more frequently than non-dyslexics, resulting in phonologically plausible errors when writing irregular words. These results have important implications for the treatment of spelling difficulties in children with dyslexia, highlighting the need to focus on the correct acquisition of grapheme-phoneme conversion rules as well as the development of appropriate orthographic representations.     

Spelling consistency affects reading in young Dutch readers with and without dyslexia

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.     

Dynamic visual perception and reading development in Chinese school children

The development of reading skills may depend to a certain extent on the development of basic visual perception. The magnocellular theory of developmental dyslexia assumes that deficits in the magnocellular pathway, indicated by less sensitivity in perceiving dynamic sensory stimuli, are responsible for a proportion of reading difficulties experienced by dyslexics. Using a task that measures coherent motion detection threshold, this study examined the relationship between dynamic visual perception and reading development in Chinese children. Experiment 1 compared the performance of 27 dyslexics and their age- and IQ-matched controls in the coherent motion detection task and in a static pattern perception task. Results showed that only in the former task did the dyslexics have a significantly higher threshold than the controls, suggesting that Chinese dyslexics, like some of their Western counterparts, may have deficits in magnocellular pathway. Experiment 2 examined whether dynamic visual processing affects specific cognitive processes in reading. One hundred fifth-grade children were tested on visual perception and reading-related tasks. Regression analyses found that the motion detection threshold accounted for 11% and 12%, respectively, variance in the speed of orthographic similarity judgment and in the accuracy of picture naming after IQ and vocabulary size were controlled. The static pattern detection threshold could not account for any variance. It is concluded that reading development in Chinese depends to a certain extent on the development of dynamic visual perception and its underlying neural pathway and that the impact of visual development can be specifically related to orthographic processing in reading Chinese.     

发展性阅读障碍的神经机制及其对第二语言学习的影响

研究表明拼音文字系统的发展性阅读障碍者与以中文为代表的表意文字系统的发展性阅读障碍者在阅读过程中大脑的激活部位存在差异。关于母语阅读障碍儿童对第二语言学习的影响是近年来发展性阅读障碍研究的热点。双语发展性阅读障碍的理论假设主要有两种语言相互依赖假设和正字法依赖假设。前者认为母语的阅读障碍可以自动迁移到第二语言的学习中;后者认为母语的阅读障碍是否会迁移到第二语言的学习中,要依赖两种语言的正字法特征。我们认为这两种理论不是相互矛盾的,阅读障碍是否会同时出现在两种语言中可能取决于这两种语言是否共用了相同的有缺陷的神经系统。     

How does reading performance modulate the impact of orthographic knowledge on speech processing? A comparison of normal readers and dyslexic adults

Studies on proficient readers showed that speech processing is affected by knowledge of the orthographic code. Yet, the automaticity of the orthographic influence depends on task demand. Here, we addressed this automaticity issue in normal and dyslexic adult readers by comparing the orthographic effects obtained in two speech processing tasks that are or not sensitive to strategies developed by participants. Our finding showed that while participants’ performance in a metaphonological task, which is known to be strategy prone, was affected by their orthographic knowledge regardless of the childhood diagnosis of dyslexia or of their actual reading-related skills, this latter factor significantly modulated the orthographic influence found in a more natural speech recognition task. The finding supports the claim that while any individuals who know a reading code are able to resort to their orthographic knowledge when they process speech, a more profound modification of the speech processing system by the orthographic code takes place only in readers who have reached a certain level of reading expertise.     

Regularisation of nonwords in dyslexia: contributions of visual orthographic and phonological onsets

This study investigated the contributions of visual orthographic (analogy) and phonological processes in mediating nonword reading in children with dyslexia. Three groups of primary school age children (n=15 in each group) were recruited. The first group were children with dyslexia (mean age 11 years 3 months, mean reading age 8 years 3 months), the second group were chronological age controls (mean age 11 years 3 months, mean reading age 11 years 8 months) and the third group were reading age matched controls (mean age 7 years 11 months, mean reading age 8 years 3 months). All participants were required to read aloud a list of nonwords. Nonwords in the list were derived from paired regular and irregular keywords in which onsets were manipulated to be either phonologically or visually similar to keyword onsets. ANOVAs revealed firstly that children with dyslexia were the least likely to regularise nonword pronunciation and secondly, that all groups displayed an overall preference for words that were phonologically manipulated. These findings have been interpreted within the context of dual‐route theory.     

Reading in French-speaking adults with dyslexia

This study investigated the reading and reading-related skills of 15 French-speaking adults with dyslexia, whose performance was compared with that of chronological-age controls (CA) and reading-level controls (RL). Experiment 1 assessed the efficiency of their phonological reading-related skills (phonemic awareness, phonological short-term memory, and rapid automatic naming (RAN)) and experiment 2 assessed the efficiency of their lexical and sublexical (or phonological) reading procedures (reading aloud of pseudowords and irregular words of different lengths). Experiment 1 revealed that adults with dyslexia exhibited lower phonological reading-related skills than CAs only, and were better than RL controls on the RAN. In experiment 2, as compared with RL controls, only a deficit in the sublexical reading procedure was observed. The results of the second experiment replicated observations from English-language studies but not those of the first experiment. Several hypotheses are discussed to account for these results, including one related to the transparency of orthographic systems.     

Visual and Auditory Morphological Priming in Adults With Developmental Dyslexia

The quality of implicit morphological knowledge in adult Hebrew readers with developmental dyslexia was investigated. The priming paradigm was used to examine whether these adults extract and represent morphemic units similarly to normal readers during online word recognition. The group with dyslexia as a whole did not exhibit priming with visual presentation as opposed to both age- and reading-level controls. Priming was absent when the prime and target words shared a morpheme and even when the prime and the target were identical. Only the students with phonological dyslexia, who exhibited relatively good performance in the orthographic judgment task, exhibited repetition priming but not morphological priming. Strong repetition and morphological priming effects were found for participants with dyslexia when the stimuli were auditory. The implications of the dissociation between visual and auditory priming for the locus of the deficit in morphological processing during word recognition are discussed.     

Spelling deficits in dyslexia: evaluation of an orthographic spelling training

Orthographic spelling is a major difficulty in German-speaking children with dyslexia. The aim of the present study was to evaluate the effectiveness of an orthographic spelling training in spelling-disabled students (grade 5 and 6). In study 1, ten children (treatment group) received 15 individually administered weekly intervention sessions (60 min each). A control group (n = 4) did not receive any intervention. In study 2, orthographic spelling training was provided to a larger sample consisting of a treatment group (n = 13) and a delayed treatment control group (n = 14). The main criterion of spelling improvement was analyzed using an integrated dataset from both studies. Repeated-measures analysis of variance revealed that gains in spelling were significantly greater in the treatment group than in the control group. Statistical analyses also showed significant improvements in reading (study 1) and in a measure of participants’ knowledge of orthographic spelling rules (study 2). The findings indicate that an orthographic spelling training enhances reading and spelling ability as well as orthographic knowledge in spelling-disabled children learning to spell a transparent language like German.     

Dyslexia and second language reading: A second bite at the apple?

An unexpected and remarkable preference for second language reading among some dyslexics has been noted, presenting a challenge to accepted theory on dyslexia and the capacity for second language learning. The current study was designed to examine this phenomenon by systematically looking at the differential reading scores in the first and second languages of reading-disabled young Swedish adults who claimed to prefer reading in their second language (English). Three groups were selected for study: a group of 10 reading-disabled young adults who prefer to read English; a second group of 10 reading-disabled with no special preference for second language reading, matched on word recognition efficiency, age group, gender and educational level and a group of 10 normal readers matched on age group and educational level. The test battery was designed to compare overall reading efficiency in English and Swedish and therefore encompassed both speed and accuracy measures. The battery covered seven phonological measures, four orthographic measures,three isolated word reading measures, two continuous text reading measures, a comprehension task and an author recognition task. All tasks were carried out in both English and Swedish. The results showed that two dyslexic groups differed significantly in the degree to which task performance, including reading efficiency, was impeded by the English format. A tentative hypothesis was forwarded as to how the exceptional and unexpected facility with English might be explained.     

Sounds,letters and meanings: the independent influences of phonological,morphological and orthographic skills on early word reading accuracy

This study was designed to examine the independent contributions of phonological awareness, orthographic processing and morphological awareness on early word reading. English‐speaking children in Grades 1 and 3 completed measures of these three constructs, as well as standardised measures of real and pseudoword reading and of vocabulary. Each of the three reading‐related variables made an independent contribution to both real and pseudoword reading. Independent contributions of phonological awareness (7–17%) were consistently larger than those of orthographic processing (5–10%) or of morphological awareness (1–2%). In terms of differences between the grades, there was particular evidence of an increase in greater contribution of orthographic processing to pseudoword reading at Grade 3 than at Grade 1. These findings are discussed in light of current models of reading development.