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.     

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.     

The issues involved in developing a spelling program for adults with dyslexia

The focus of this paper will be the issues involved in developing a spelling program for an adult with dyslexia. Thus a review of research and identification of the implications of such research will be undertaken. It is appropriate to address spelling because it is poor spelling rather than poor reading which remains a weakness for the dyslexic adult (Singleton, 1991). Spelling is also perceived as being more difficult (Miles 1993). Yet another value in teaching specific spelling skills to dyslexic learners is that some research suggests that spelling training given in conjunction with phonological awareness training facilitates reading development at a faster rate (Ehri, 1989). No attempt will be made to develop specific teaching strategies orto evaluate specific methods for the teaching of dyslexic learners, although reference may be made to either or both of these aspects.     

Computerised screening for dyslexia in adults

Identifying dyslexia in adulthood presents particular challenges because of complicating factors such as acquisition of compensatory strategies, differing degrees of intervention and the problem of distinguishing dyslexic adults from those whose literacy difficulties have non‐cognitive causes. One of the implications is that conventional literacy measures, per se, do not provide a satisfactory basis for screening for dyslexia in adulthood as some dyslexic adults have above‐average literacy skills and some non‐dyslexic adults have very poor literacy skills. This study examined an alternative approach to dyslexia screening, using three tests that depend heavily on phonological processing, lexical access and working memory, but which are not conventional measures of literacy. Using these tests, which are computer delivered, 70 dyslexic adults from three different types of educational institution were compared with 69 non‐dyslexic adults from the same institutions. The results showed that the dyslexic and non‐dyslexic groups were significantly different on all three computer‐based tests, with an average effect size of 1.55. Adaptive versions of these tests were then created to reduce overall administration time for the suite to about 15 minutes. Analysis showed that the combined scaled scores from the adaptive versions of the three tests significantly discriminated the dyslexic from the non‐dyslexic group with an increased effect size of 2.07 and with a sensitivity rate of 90.6% and a specificity rate of 90.0%. It was concluded that this approach is a valid and useful method of identifying dyslexia in adulthood, which, given the ease of administration to large numbers of adults, has noted advantages for education and employment.     

An exploratory factor analysis of the cognitive functioning of first-year bachelor students with dyslexia

An increasing number of students with dyslexia register in higher education. As a consequence, information on their pattern of strengths and weaknesses is essential to construct adequate assessment and diagnostic protocols. In a sample of 100 first-year bachelor students with dyslexia and 100 control students, a large pool of cognitive skills were tested using a variety of tests. When we applied an exploratory factor analysis to scores, a model with ten factors fitted the data best. Effect sizes were used to express the processing costs of students with dyslexia. The factors related to reading, spelling, flashed orthography, phonology, naming, math, and reading fluency resulted in large effect sizes. A factor combining all measures for crystallized IQ had a medium effect size. The subtests for fluid intelligence were divided in two separate constructs. Relationships between all subtest scores are visualized and interpreted in a general theoretical and practical framework.     

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.     

Auditory and motor rhythm awareness in adults with dyslexia

Children with developmental dyslexia appear to be insensitive to basic auditory cues to speech rhythm and stress. For example, they experience difficulties in processing duration and amplitude envelope onset cues. Here we explored the sensitivity of adults with developmental dyslexia to the same cues. In addition, relations with expressive and receptive rhythm tasks, such as tempi recognition and manual tapping to a metronome, were explored. Our goal was to investigate whether the auditory deficits seen in dyslexia are specific to cues to speech rhythm and stress, or are part of a wider rhythmic awareness problem. A group of 19 undergraduate students with dyslexia were compared with 20 age‐ and ability‐matched controls. The findings confirmed a relationship between auditory rhythm sensitivity and literacy in adults, as well as showing an association with metronome inter‐tap‐interval variability.     

Sentence comprehension in young adults with developmental dyslexia

This study investigated the effects of syntactic complexity on written sentence comprehension in compensated adults with dyslexia. Because working memory (WM) plays a key role in processing complex sentences, and individuals with dyslexia often demonstrate persistent deficits in WM, we hypothesized that individuals with dyslexia would perform more poorly on tasks designed to assess the comprehension of syntactic structures that are especially taxing on WM (e.g., passives, sentences with relative clauses). Compared to their nondyslexic peers, individuals with dyslexia were significantly less accurate and marginally slower on passive sentences. For sentences containing relative clauses, the dyslexic group was also less accurate but did not differ in response times. Covarying WM and word reading in both analyses eliminated group differences showing that syntactic deficits in adults with dyslexia are constrained by both WM and word-reading ability. These findings support previous research showing that syntactic processing deficits are characteristic of dyslexia, even among high-achieving students.     

Students with reading difficulties/dyslexia: a longitudinal Swedish example

The aim of this study was to investigate the longitudinal development of students having difficulties with reading and their decoding ability in Swedish compulsory school. Another aim was to relate this to the experiences of educational activities expressed by students and parents. The decoding ability was assessed by a word chain test given at three occasions and was compared with results on a letter chain test. Retrospective interviews were performed with students and parents. The decoding ability tended to improve for most of the students over time, although some of them failed to improve or even decreased their scores, indicating a lack of environmental adjustment. Special educational support was according to students and parents organised in small and often very heterogeneous groups where the students sometimes received adequate support but often felt deviant from friends in their regular classes. The responsibility for helping the children with their schoolwork was allocated to the parents. Research in this area demonstrates the necessity of a well‐structured and stimulating learning situation. Yet, the development of these students’ decoding abilities, personal experiences, and parental involvement indicate that competence and resources at school regarding children at risk for developing reading difficulties are often lacking in the Swedish educational system.     

Secondary symptoms of dyslexia: a comparison of self-esteem and anxiety profiles of children with and without dyslexia

The secondary symptoms of individuals with dyslexia, such as high anxiety and low self-esteem, have aroused various debates not only in the educational, but also in the clinical context. Since pro and contra arguments are supported by a more or less equal number of empirical findings, no final conclusion could be drawn for this specific phenomenon. The current study aims to contribute more data in this respect and offers a possible explanation for both sides that either support or reject the relationship between dyslexia and its secondary symptoms. The main investigation of this study is the comparison of anxiety and self-esteem profiles of children with and without dyslexia. Participants are 124 school children aged between eight and 11 years. Their IQ as well as their reading and writing ability were also measured and used as control variables. All data were collected and analysed using a quantitative approach. Effect sizes are also provided in order to facilitate meta-analysis in the future and to confirm the results of a significant test. The results indicate that children with dyslexia have anxiety and self-esteem issues in the specific context or domain. However, their general anxiety and self-esteem were not impaired. A discussion regarding the possibility and/or the necessity of the secondary symptoms of dyslexia is also provided.     

Dyslexia heterogeneity: cognitive profiling of Portuguese children with dyslexia

Recent studies have emphasized that developmental dyslexia is a multiple-deficit disorder, in contrast to the traditional single-deficit view. In this context, cognitive profiling of children with dyslexia may be a relevant contribution to this unresolved discussion. The aim of this study was to profile 36 Portuguese children with dyslexia from the 2nd to 5th grade. Hierarchical cluster analysis was used to group participants according to their phonological awareness, rapid automatized naming, verbal short-term memory, vocabulary, and nonverbal intelligence abilities. The results suggested a two-cluster solution: a group with poorer performance on phoneme deletion and rapid automatized naming compared with the remaining variables (Cluster 1) and a group characterized by underperforming on the variables most related to phonological processing (phoneme deletion and digit span), but not on rapid automatized naming (Cluster 2). Overall, the results seem more consistent with a hybrid perspective, such as that proposed by Pennington and colleagues (2012), for understanding the heterogeneity of dyslexia. The importance of characterizing the profiles of individuals with dyslexia becomes clear within the context of constructing remediation programs that are specifically targeted and are more effective in terms of intervention outcome.     

A technique for group screening of dyslexia among adults

This paper reports on the development of a battery of phonological processing tasks to screen adults with dyslexia. The battery consisted of tasks tapping reversed spoonerism, phonological choice, working memory, and vocabulary with confusable alternatives. A self-report questionnaire consisting of two scales, one examining symptoms of dyslexia and the other reading interests, was also constructed. All these tasks showed high discrimination between a group of adults with dyslexia and a control group, all recruited from adult education centers. The tasks also correlated highly with word recognition. The results of the study show that it is possible to develop a sensitive battery of “nonvocalized” tasks to screen adults with dyslexia on a group basis and that self-reports add to the screening. The group administration is both time-saving and cost-effective.     

WAIS-R scores as predictors of employment success and failure among adults with learning disabilities

The transition of adults with learning disabilities to successful employment is contingent upon numerous factors. Eighty-six adults (55 males and 31 females), 18 to 59 years old (mean age 26.7 years), with learning disabilities were evaluated clinically using the Wechsler Adult Intelligence Scale-Revised (WAIS-R) (Wechsler, 1981) to determine the value of WAIS-R IQs and subtest scores in predicting successful employment. Significant relationships were identified between subjects' WAIS-R IQs and scaled scores and job success. Conclusions and recommendations were reported.     

Comparison of deficits in cognitive and motor skills among children with dyslexia

There is a growing body of evidence that children with dyslexia have problems not just in reading but in a range of skills including several unrelated to reading. In an attempt to compare the severity and incidence of deficits across these varied domains, children with dyslexia (mean ages 8, 12, and 16 years), and control groups of normally achieving children matched for IQ and for age or reading age, were tested on a range of primitive (basic) skills. The children with dyslexia performed significantly worse than the same-age controls on most tasks, and significantly worse even than the reading-age controls on phoneme segmentation, picture naming speed, word tachistoscopic word recognition, speeded bead threading and some balance tasks. The overall performance of the children with dyslexia is interpreted as showing less complete automatization than normal.     

Spelling errors in adults with a form of familial dyslexia

We compared the spelling errors on the WRAT II made by adults (N = 24) with an apparent autosomal dominant form of dyslexia to those made by their normal adult relatives (N = 17) and by spelling-age matched normal controls (N = 17) using a computerized error evaluation program (SEEP). The normal adult relatives were significantly better than the dyslexics in both reading and spelling, but did not differ in age, education, or IQ. SEEP evaluated each error independently for both phonological and orthographic accuracy at 2 levels of complexity. Each level of complexity was analyzed separately using a 3 X 2 (group X dimension) analysis of variance. The main finding of interest was a significant group X dimension interaction effect at the complex level, which indicated that the dyslexics had a qualitatively different profile across the 2 dimensions than either normal group who had parallel profiles. The dyslexics performed like the younger normal group on the complex phonological dimension but like the adult normal group on the complex orthographic dimension. These results indicate a dissociation in this form of familial dyslexia between these 2 dimensions of spelling development, and suggest that these dyslexics may fit the subtype of dysphonetic or phonological dyslexia. The implications of these results for the underlying cognitive deficit in this form of dyslexia are discussed.     

Reading comprehension skills of young adults with childhood diagnoses of dyslexia

This study explores the contribution of cognitive processes to comprehension skills in adults who suffered from childhood developmental dyslexia (CD). The performance of adults with CD (ages 17 to 23), chronological age-matched (CA) adults, and reading level-matched (RL) children was compared on measures of phonological processing, naming speed, working memory (WM), general knowledge, vocabulary, and comprehension. The results showed that adults with CD scored lower on measures of phonological processing, naming speed, WM, general knowledge, and vocabulary when compared to CA readers but were comparable to RL children on the majority of process measures. Phonological processing, naming speed, vocabulary, general knowledge, and listening comprehension contributed independent variance to reading comprehension accuracy, whereas WM, intelligence, phonological processing, and listening comprehension contributed independent variance to comprehension fluency. Adults with CD scored lower than CA adults and higher than RL children on measures of lexical processing, WM, and listening comprehension when word recognition and intelligence were partialed from the analysis. In summary, constraints in phonological processing and naming speed mediate only some of the influence of high-order processes on reading comprehension. Furthermore, adults with CD experience difficulties in WM, listening comprehension, and vocabulary independently of their word recognition problems and intellectual ability.     

The cognitive profiles of Jordanian students at risk for math disability

The Cattell–Horn–Carroll (CHC) factors of the Woodcock–Johnson (WJ) Arabic Tests of Cognitive Abilities were studied with a group of students at risk of Math Disability (MD) (n50) and average students (n50) between second and fourth grades. Specifically, several statistical analyses were conducted using the seven CHC factors identified by the WJ Arabic Tests and the level of math calculation skills. The two groups were matched on grade, gender, age, and father’s level of education. The findings indicated that average students had higher scores in all tests, but no statistical difference exists between at risk of MD and average groups in terms of Visual-Spatial Thinking or Auditory Processing scores. In addition, the best model for predicting math calculation skills was based on a combined measure of Processing Speed and Short-Term Working Memory factors. Implications of the findings are also discussed.     

Reading profiles for adults with low-literacy: cluster analysis with power and speeded measures

The United States’ National Institute for Literacy’s (NIFL) review of adult literacy instruction research recommended adult education (AE) programs assess underlying reading abilities in order to plan appropriate instruction for low-literacy learners. This study developed adult reading ability groups using measures from power tests and speeded tests of phonemic decoding, word recognition, fluency, and comprehension. A multiple cluster analysis of these reading ability scores from 295 low-literacy AE participants yielded seven reading ability groups. These groups are described in terms of instructional needs relevant to an instructor’s planning and activities.