The mathematical strengths and weaknesses of children with dyslexia

This paper reports the findings of two related studies that examined the mathematical strengths and weaknesses of children with dyslexia. In study one, dyslexic children were compared to children without special educational needs on tests that assessed arithmetic fact recall, place value understanding and counting speed. Study two used the same methodology, but matched the dyslexic children with the non‐dyslexic children on a number of factors, including intellectual ability. This excluded the possibility that confounding variables accounted for the differences between the groups in study one. Both studies indicated that the dyslexic children had slower and less accurate number fact recall than the non‐dyslexic children, but had unimpaired place value understanding. The results for counting speed were more equivocal, but there was a trend for the dyslexic children to be slower counters. The results suggest that dyslexia is not normally associated with a general mathematical impairment, but rather an uneven profile of skills. This profile can be explained in terms of the phonological processing weaknesses associated with dyslexia. The finding that dyslexic children have a specific difficulty recalling arithmetic facts suggests that a teaching programme that emphasises mental methods may disadvantage them.     

Development of dyslexic subgroups:

There is a consensus that dyslexia is on a continuum with normal reading skill and that dyslexics fall at the low end of the normal range in phonological skills. However, there is still substantial variability in phonological skill among dyslexic children. Recent studies have focused on the high end of the continuum of phonological skills in dyslexics, identifying a “surface” dyslexic, or “delayed” profile in which phonological skills are not out of line with other aspects of word recognition. The present study extended this work to a longitudinal context, and explored differences among subgroups of dyslexics on a battery of component reading skills. Third grade dyslexics (n=72) were classified into two subgroups, phonological dyslexics and delayed dyslexics, based on comparisons to younger normal readers at the same reading level (RL group). The children were tested at two points (in third and fourth grade). The results revealed that the classification of dyslexics produced reliable, stable, and valid groups. About 82 percent of the children remained in the same subgroup category when retested a year later. Phonological dyslexics were lower in phoneme awareness and expressive language. Delayed dyslexics tended to be slower at processing printed letters and words but not at rapid automatic naming of letters, and relied more heavily on phonological recoding in reading for meaning than did phonological dyslexics. A subset of the delayed dyslexics with the traditional “surface dyslexic” pattern (relatively high pseudoword and low exception word reading) was also identified. The surface subgroup resembled the RL group on most measures and was not very stable over one year. The results are discussed in light of current models of dyslexia and recent subgrouping schemes, including the Double-Deficit Hypothesis.     

Gender ratio in dyslexia

This paper is based on a study carried out in Great Britain on a national sample of 11,804 ten-year olds. The first section describes an attempt to pick out cases of “specific developmental dyslexia” (Critchley 1970), a constellation or syndrome of difficulties which some believe to be recognizable clinically. When specified criteria for dyslexia were used, 269 children qualified as dyslexic (2.28 percent of the sample). These included 223 boys and 46 girls, for a ratio of 4.51 to 1. Two possible difficulties in interpreting these data are discussed, and a defense is offered of the criteria used. Since some recent research papers report a gender ratio much nearer 1:1 (Shaywitz et al. 1990; Wadsworth et al. 1992; Lubs et al. 1993), those papers were examined for possible differences in procedure; it was found that the definition of dyslexia they used was “poor reading in relation to intelligence.” We carried out a further analysis on our own data using the same criterion. Of the 494 children who qualified as dyslexic on the basis of discrepancy criteria alone (4.19 percent of the sample), 314 were boys and 180 were girls for a ratio of 1.69 to 1. It seems, therefore, that the apparent differences in gender ratio reported in the literature have arisen because different criteria for dyslexia have been used. We argue that the definition based on clinical criteria leads to a more powerful taxonomy and that the widespread equation of “dyslexia” with “poor reading” is a hindrance to progress.     

Spanish dyslexic spelling abilities: the case of consonant clusters

This paper investigates Spanish dyslexic spelling abilities: specifically, the influence of syllabic linguistic structure (simple vs consonant cluster) on children's spelling performance. Consonant clusters are phonologically complex structures, so it was anticipated that there would be lower spelling performance for these syllabic structures than in simple ones, because of the poor phonological processing of dyslexic children. The participants were 31 dyslexic children, 31 chronological age‐matched children and 31 reading level‐matched children. A dictation task with words and pseudowords (with and without consonant clusters) was used. Word lexical frequency was controlled. The results show that the spelling of consonant clusters presents difficulties for dyslexic spelling performance despite this structure being orthographically consistent. Dyslexic children present a higher performance difference in items with consonant clusters than in simple items, compared with typically developing children. The work raises questions about the items used for the identification of dyslexic children's difficulties.     

Dyslexia and learning musical notation: A pilot study

Both the alphabet and our system of musical notation are largely based on arbitrary conventions and associations. Conforming to the Dyslexic Automatization Deficit Hypothesis, children suffering from dyslexia are supposed to have difficulty in automating these types of conventions and/or associations. Scientific research into the relation between dyslexia and learning musical notation is rare. Therefore, we developed a new intervention paradigm on learning musical notation. This program was followed by five dyslexic children and four children without dyslexia, in order to study and compare the learning processes of both groups. The program consisted of instruction, practice in the skills and knowledge related to musical notation, and test assignments. During each session, the problem-solving process of the individual child was observed and the amount of time required to complete each assignment in the program was recorded. In addition we analyzed the errors made by the two groups of children in each session. A pretest-posttest comparison revealed that dyslexic children needed more time to learn musical notation than did children without dyslexia. Dyslexic children also made more mistakes and produced more ‘third transpositions’. The implications for teaching musical notation are outlined.     

Implicit sequence learning is preserved in dyslexic children

This study investigates the implicit sequence learning abilities of dyslexic children using an artificial grammar learning task with an extended exposure period. Twenty children with developmental dyslexia participated in the study and were matched with two control groups—one matched for age and other for reading skills. During 3 days, all participants performed an acquisition task, where they were exposed to colored geometrical forms sequences with an underlying grammatical structure. On the last day, after the acquisition task, participants were tested in a grammaticality classification task. Implicit sequence learning was present in dyslexic children, as well as in both control groups, and no differences between groups were observed. These results suggest that implicit learning deficits per se cannot explain the characteristic reading difficulties of the dyslexics.     

Visual stress in adults with and without dyslexia

The relationship between dyslexia and visual stress (sometimes known as Meares‐Irlen syndrome) is uncertain. While some theorists have hypothesised an aetiological link between the two conditions, mediated by the magnocellular visual system, at the present time the predominant theories of dyslexia and visual stress see them as distinct, unrelated conditions, a view that has received some support from studies with children. Studies of visual stress in adults are rare, yet recent reports of a high incidence of this phenomenon amongst university students with diagnosed dyslexia call for further investigation of the issue. This study sought to clarify the relationship between visual stress and dyslexia by comparing the reading performance of dyslexic and non‐dyslexic adults with, and without, colour. Degree of susceptibility to visual stress was determined by means of a symptom rating scale. Optimal colour was determined using an Intuitive Colorimeter, which was also employed to assess reading speed under the two experimental conditions. Only the dyslexic students with high visual stress showed significant gains in reading speed when using optimal colour. The use of response to treatment (rather than symptomatology) as a diagnostic criterion for visual stress is questioned, especially when applied to adults, as this may give misleading findings. On the basis of reported symptomatology, students who experience high levels of visual stress are more likely to show improvements in reading rate with optimal colour if they also have dyslexia than if they do not have dyslexia. Although not establishing an aetiological link, these findings imply an interaction between the two conditions with major implications for theory, diagnosis and treatment.     

The impact of virtual reality on parents’ awareness of cognitive perceptions of a dyslectic child

Parents of dyslexic children encounter many difficulties in understanding and accepting their children’s disability. This affects the child’s self-image and the way s/he copes (Hallahan and Kauffman 1991; Einat 2003). The goal of this study was to develop VR immersive simulated states. The simulation was designed to help the parents of dyslexic children experience the kind of errors their children make when reading. Two groups of parents of dyslexic children participated in this experiment, an experimental group (N = 37), which experienced ten 3D worlds simulating different kinds of reading errors, and a control group (N = 30), that watched a movie describing and explaining similar errors. All the subjects were administered a cognitive questionnaire (Shavit 2005) before and after the intervention. In addition, the participants in the experimental group were interviewed before and after the intervention. The results indicate that experiencing a variety of simulated types of dyslexia with virtual reality can bring about improvement in parents’ awareness of the dyslexic child’s cognitive experiences, and that this improvement is significantly greater than that achieved by watching a film about dyslexia.     

Reversing letters and reading transformed text in dyslexia: A reassessment

The visual deficit hypothesis of development dyslexia has largely been abandoned because many of the phenomena that initially motivated it could not be replicated under controlled experimental conditions, while phonological processing deficits were found to provide a better explanation for the replicable phenomena. Nevertheless, many teachers and special educators continue to subscribe to the hypothesis that deficits of visual perception are a major cause of reading failure in dyslexia. As part of a larger family study, we reexamined the questions (1) whether probands and affected relatives in dyslexia families reverse easily confused letters more frequently under experimental conditions than normal readers from the same families, and (2) whether they show unusual facility in reading geometrically transformed text. The findings indicated that young dyslexia students reverse easily confused letters more often than normal readers. Reading group differences of letter reversal were significant in children from 7–10 years but not thereafter; and virtually no subject reversed letters when spelling whole words. Furthermore, dyslexic persons in every age group from 7–60 years actually took longer than normal readers to decode geometrically transformed text; and the time to decode transformed texts increased progressively with age after adolescence in both dyslexic persons and normal readers. Thus, reading group differences in decoding easily confused letters and reading geometrically transformed text do not support the visual deficit hypothesis and probably do not help to clarify the etiology of developmental dyslexia.     

Do dyslexic and other poor readers differ in reading-related cognitive skills?

The rationale for the study was that if dyslexic and garden-variety poor readers differ in reading-related cognitive skills, there is justification for believing dyslexia to be a distinct entity. Subjects were 110 children aged 6 to 10 years, divided into groups of dyslexic poor readers varying in verbal IQ, garden-variety poor readers, and good readers. Findings suggest that there are valid grounds for believing that dyslexia is a separate entity from garden-variety poor reading, and that it is found among children at all verbal IQ levels. Poor phonological awareness and nonword reading, in relation to normal readers, were shared by dyslexic and garden-variety poor readers. Deficits unique to dyslexic poor readers were problems in both automatic visual recognition and phonological recoding of graphic stimuli. The study supports the phonological-core variable-difference model of Stanovich (1988) in that both dyslexic and garden-variety poor readers showed phonological processing deficits, but they were more extensive in dyslexics.     

Gender ratio and cognitive profiles in dyslexia: a cross-national study

The purpose of this study was to analyze possible gender-related differences in the prevalence of dyslexia. A cross-national comparison of Spain and Guatemala was conducted. Both countries speak the same language but have a different standard of living and educational level. A second purpose of this study was to analyze the cognitive profile of Guatemalan and Spanish males and females children with dyslexia. The log-linear analysis indicated that the number of dyslexics detected was different across the countries but there were no differences as a function of gender. Similarly, there were no significant or meaningful differences between dyslexic males and females in the cognitive processes involved in reading. Therefore, gender differences do not appear to be characteristic of developmental 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.     

Conceptions of Research and Methodology Learning

In 15–16 year olds from Oslo, Norway, we investigated the occurrence of self‐reported dyslexia and reading/writing difficulties (RWD), and we measured dyslexic symptoms using the Duvan dyslexia screening test. The prevalence of self‐reported dyslexia was 8.2%, while 10.4% reported severe or moderate RWD. The group of self‐reported dyslexics obtained lower mean‐values on Duvan than the non‐dyslexic group (125.7 [SD = 20.2] versus 153.2 [SD = 23.4]), but not on the test of general ability. The questionnaire items on dyslexia and RWD, as well as gender, ethnicity and general ability, significantly predicted Duvan scores (explained variance, R ² = 0.25). More research is needed to explore the precision of Duvan as a screening tool for dyslexic symptoms among Norwegian adolescents.     

The relationship between dyslexia and Meares‐Irlen Syndrome

Meares‐Irlen Syndrome (MIS) is characterised by symptoms of visual stress and visual perceptual distortions that are alleviated by using individually prescribed coloured filters. Coloured overlays (sheets of transparent plastic that are placed upon the page) are used to screen for the condition. MIS is diagnosed on the basis of either the sustained voluntary use of an overlay or an immediate improvement (typically of more than 5%) on the Wilkins Rate of Reading Test (WRRT). Various studies are reviewed suggesting a prevalence of 20–34% using these criteria. Stricter criteria give a lower prevalence: for example, 5% of the population read more than 25% faster with an overlay. It has been alleged that MIS is more common in dyslexia, but this has not been systematically investigated. We compared a group of 32 dyslexic with 32 control children aged 7–12 years, matched for age, gender and socio‐economic background. Participants were tested with Intuitive Overlays, and those demonstrating a preference had their rate of reading tested using the WRRT with and without their preferred overlay. Both groups read faster with the overlay, and more so in the dyslexic group. ANOVA revealed no significant effect of group, but a significant improvement in WRRT with overlay (p=0.009) and a significant interaction between group and overlay (p=0.031). We found a similar prevalence of MIS in the general population to that in previous studies and a prevalence in the dyslexic group that was a little higher (odds ratio for >5% criterion: 2.6, 95% confidence limit 0.9–7.3). The difference in prevalence in the two groups did not reach statistical significance. We conclude that MIS is prevalent in the general population and possibly a little more common in dyslexia. Children with dyslexia seem to benefit more from coloured overlays than non‐dyslexic children. MIS and dyslexia are separate entities and are detected and treated in different ways. If a child has both problems then they are likely to be markedly disadvantaged and they should receive prompt treatments appropriate to the two conditions. It is recommended that education professionals as well as eye‐care professionals are alert to the symptoms of MIS and that children are screened for this condition, as well as for other visual anomalies.     

The existence of dyslexia without severe literacy problems

This paper is concerned with those who display positive indicators on tests for dyslexia but seemingly do not have any severe literacy problems. A case study is presented by way of illustration. On the basis of data from the British Births Cohort Study (12,905 10-year-old children), it was found that some seemingly normal achievers who showed signs of dyslexia (N=422) obtained different results on five measures associated with dyslexia than did other normal achievers without such signs (N=4,998). The measures used were: underachievement at word recognition; and underachievement at spelling, reading comprehension, pseudoword reading, and mathematics. The proportion of boys to girls in the groups was also noted. It is suggested that these were cases of mild dyslexia, who, on the basis simply of reading and spelling tests, might escape detection. The consequences for the concept of dyslexia are discussed, and it is suggested that the needs of dyslexics with only mild literacy problems should not be overlooked.     

Performance of children with developmental dyslexia on high and low topological entropy artificial grammar learning task

Graph complexity as measured by topological entropy has been previously shown to affect performance on artificial grammar learning tasks among typically developing children. The aim of this study was to examine the effect of graph complexity on implicit sequential learning among children with developmental dyslexia. Our goal was to determine whether children’s performance depends on the complexity level of the grammar system learned. We conducted two artificial grammar learning experiments that compared performance of children with developmental dyslexia with that of age- and reading level-matched controls. Experiment 1 was a high topological entropy artificial grammar learning task that aimed to establish implicit learning phenomena in children with developmental dyslexia using previously published experimental conditions. Experiment 2 is a lower topological entropy variant of that task. Results indicated that given a high topological entropy grammar system, children with developmental dyslexia who were similar to the reading age-matched control group had substantial difficulty in performing the task as compared to typically developing children, who exhibited intact implicit learning of the grammar. On the other hand, when tested on a lower topological entropy grammar system, all groups performed above chance level, indicating that children with developmental dyslexia were able to identify rules from a given grammar system. The results reinforced the significance of graph complexity when experimenting with artificial grammar learning tasks, particularly with dyslexic participants.     

基于PASS理论对阅读障碍儿童的认知研究及干预综述

阅读障碍会影响儿童的正常发展,国外一些研究基于PASS理论探讨了阅读障碍儿童的认知机制,证明了基于PASS理论对阅读障碍儿童干预的有效性。文章综述了PASS理论在阅读障碍儿童中的应用,比较了国内外基于PASS理论关于阅读障碍儿童认知机制的研究,并介绍了国外学者基于PASS理论设计的阅读障碍儿童认知干预方案,及一些对方案效果验证性的实验,为我国阅读障碍儿童的研究及干预提供借鉴。     

汉语发展性阅读障碍儿童语素分辨及运用能力

比较汉语发展性阅读障碍儿童和阅读正常儿童完成同音语素分辨任务和语素构词任务的情况,测查汉语发展性阅读障碍儿童的语素分辨及运用能力。研究一考察了语素分辨能力,结果发现:与阅读正常儿童相比,阅读障碍儿童完成语素分辨任务的反应时更长、准确率更低。研究二考察了语素运用能力,结果发现:与阅读正常儿童相比,阅读障碍儿童完成语素运用相关任务的反应时更长、正确率更低。两个研究的结果提示我们,汉语发展性阅读障碍儿童存在语素意识缺陷,从语素分辨能力到语素运用能力的落后,说明语素意识缺陷是造成汉语发展性阅读障碍的重要原因,汉语的语素意识在儿童阅读中起着至关重要的作用。     

Influence of increased letter spacing and font type on the reading ability of dyslexic children

Recent research studies have shown that increased letter spacing has a positive effect on the reading ability of dyslexic individuals. This study aims to investigate the effect of spacing on the readability of different fonts for children with and without dyslexia. Results did not support the hypothesis of better performance among children with dyslexia when reading text in Dyslexie than in other fonts. They, however, revealed that only spacing plays a role in enhancing dyslexic individuals’ reading performance because Dyslexie and the Times New Roman interspaced font have no difference. Furthermore, the negative effect of the unfriendly fonts Times New Roman Italic and Curlz MT was eliminated through increased interletter spacing.     

Phonological and lexical reading in Italian children with dyslexia

In this study we explore the development of phonological and lexical reading in dyslexic children. We tested a group of 14 Italian children who have been diagnosed with dyslexia and whose reading age is end of grade 1. We compared this group with a group of 70 typically developing children who have been tested for reading at the end of grade 1. For each dyslexic child we also selected a participant who was attending the same grade, was close in age, and showed typical reading development when tested with a narrative passage reading task (Cornoldi, Colpo, & Gruppo MT, 1981) for correctness and reading speed. Children in this group are “same grade controls.” We used a reading task consisting of 40 three syllables words. A qualitative and quantitative method of coding children’s naming allowed us to distinguish several components of their reading performance: the grapheme and word recognition, the size of orthographic units involved in the aloud orthography–phonology conversion, the reading process used to recognize words. The comparison of the dyslexic group with the reading age and the same grade control groups reveals different trends of delayed reading processes. Considering dyslexic children’s chronological age, lexical reading is greatly delayed. Considering dyslexic children’s reading age, the type of reading process that is more deeply delayed is phonological reading. The rate of fragmented phonological reading (i.e., a type of syllabized phonological reading) is much higher in dyslexic children compared to the reading age group, suggesting that some factors undermine the possibility of internalizing the orthography–phonology conversion and the blending processes.