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.     

Understanding persistence in adult learning

The paper summarizes recent data on the retention and non‐completion patterns of adult students, especially those over the age of 25 who have had a gap since completing full‐time education. While data on further and higher education suggest that older learners are less likely than younger ones to complete longer, qualification‐bearing programmes, central statistics do not distinguish between students in their early‐to‐mid 20s, many of whom still have much in common with those in their late teens, and those in their 30s, 40s and 50s whose lifestyles, learning goals and aspirations are often qualitatively different.

The section on retention data is followed by a summary of the reasons for not completing courses commonly cited by adults learning in conventional education settings, and reflection on whether these are significantly different from those cited by younger students and students in open or distance learning programmes. The paper ends with a summary of the kind of factors that might increase adult retention rates in both kinds of learning programme.

For the purposes of this paper, ‘adults’ are defined as those over the age of 25 who have had a gap since completing full‐time education.     

Project DyAdd: Implicit learning in adult dyslexia and ADHD

In this study of the project DyAdd, implicit learning was investigated through two paradigms in adults (18–55 years) with dyslexia (n?=?36) or with attention deficit/hyperactivity disorder (ADHD, n?=?22) and in controls (n?=?35). In the serial reaction time (SRT) task, there were no group differences in learning. However, those with ADHD exhibited faster RTs compared to other groups. In the artificial grammar learning (AGL) task, the groups did not differ from each other in their learning (i.e., grammaticality accuracy or similarity choices). Further, all three groups were sensitive to fragment overlap between learning and test-phase items (i.e., similarity choices were above chance). Grammaticality performance of control participants was above chance, but that of participants with dyslexia and participants with ADHD failed to differ from chance, indicating impaired grammaticality learning in these groups. While the main indices of AGL performance, grammaticality accuracy and similarity choices did not correlate with the neuropsychological variables that reflected dyslexia-related (phonological processing, reading, spelling, arithmetic) or ADHD-related characteristics (executive functions, attention), or intelligence, the explicit knowledge for the AGL grammar (i.e., ability to freely generate grammatical strings) correlated positively with the variables of phonological processing and reading. Further, SRT reaction times correlated positively with full scale intelligence quotient (FIQ). We conclude that, in AGL, learning difficulties of the underlying rule structure (as measured by grammaticality) are associated with dyslexia and ADHD. However, learning in AGL is not related to the defining neuropsychological features of dyslexia or ADHD. Instead, the resulting explicit knowledge relates to characteristics of dyslexia.     

Visual search deficits are independent of magnocellular deficits in dyslexia

The aim of this study was to investigate the theory that visual magnocellular deficits seen in groups with dyslexia are linked to reading via the mechanisms of visual attention. Visual attention was measured with a serial search task and magnocellular function with a coherent motion task. A large group of children with dyslexia (n = 70) had slower serial search times than a control group of typical readers. However, the effect size was small (η _p² = 0.05) indicating considerable overlap between the groups. When the dyslexia sample was split into those with or without a magnocellular deficit, there was no difference in visual search reaction time between either group and controls. The data suggest that magnocellular sensitivity and visual spatial attention weaknesses are independent of one another. They also provide more evidence of heterogeneity in response to psychophysical tasks in groups with dyslexia. Alternative explanations for poor performance on visual attention tasks are proposed along with avenues for future research.     

Gender differences in the severity of adult familial dyslexia

Thirty seven adults with a three generation family history of dyslexia and a strong personal history of reading/spelling problems were administered a psychoeducational battery to confirm the diagnosis of dyslexia. Males were not disproportionately represented in the dyslexic sample although they exhibited a more severe profile of reading impairment relative to females. Severity of dyslexia is discussed as a possible mechanism of the reported higher prevalence of dyslexia among males.     

Visual and language processing deficits in compensated and uncompensated college students with dyslexia

In seven experiments, we investigated whether compensated and uncompensated adults with dyslexia show different patterns of deficits in magnocellular visual processing and in language processing tasks. In four visual tasks, we failed to find evidence of magnocellular deficits in either group. However, both groups of adults with dyslexia showed deficits in component language skills, and the degree of reading impairment predicted the nature and extent of these deficits. Uncompensated readers showed deficits in orthographic and especially phonological coding and awareness and were slower on rapid naming. Compensated readers showed word and nonword performance below controls but better than the uncompensated readers. The compensated group was not significantly less accurate than controls on phonological awareness, nor significantly worse overall on rapid naming.     

Dyscalculia and dyslexia

Conclusion It is our hope that more practitioners in the field of learning disabilities will include the diagnosis and treatment of dyscalculia as they work with children and older individuals. Although there is much more to be explored, we believe that our clinical experience indicates that information-processing deficits may be a contributory factor in the disability and thus warrant further investigation. Furthermore, we believe that insights gained in the treatment of specific language disability may be fruitfully applied in the treatment of dyscalculia. This paper is a condensed version of a presentation at the 29th Annual Conference of The Orton Society, November 1978, at Minneapolis, Minnesota.     

Supporting academic persistence in low‐skilled adult learners

The current literature review explores the factors that contribute to academic persistence for adult learners. The aim of the study is to identify current research‐based strategies aimed at supporting learner persistence, particularly for low‐skilled adults. Elements of three theoretical frameworks, namely, expectancy‐value theory (EVT), goal theory (GT) and self‐determination theory (SDT) are conceptualised in a new, melded cognitive model to explain better the constructs that contribute to academic persistence. These theories are used to frame and explain the challenges that adult learners face when returning to school and to understand better the psychosocial demands on adult learners, based on social cognitive theory. This study is particularly significant in the light of current national attention directed towards redesigning adult basic education programmes to include more workforce development and strategies aimed at accelerating the progress of adult learners through basic skills and into post‐secondary education and/or career training. Questions guiding the current study include identifying research‐based strategies that instructors can use, and elements of programme design that support student persistence.     

Nonsense passage reading as a diagnostic aid in the study of adult familial dyslexia

We examined Nonsense-Passage oral reading in adults, using data derived from new and previously published studies (Finucci et al 1976, Gross-Glenn et al 1985). Time-scores and error-frequency data are presented for five samples of non-dyslexic readers with a minimum of a high-school education and no childhood history of dyslexia (N=127). Considerable uniformity is demonstrated across these samples, and reading performance of non-dyslexic individuals contrasts sharply with that observed in four samples of adult familial dyslexics. Both affected and compensated-affected dyslexic subjects read the passages significantly more slowly and with more errors than did nondyslexic readers. Results are discussed in relation to the cognitive and neural processes that may underlie this specific reading difficulty in dyslexics. We have found Nonsense-Passage reading to be especially useful in family studies of inherited dyslexia as a means of quantifying oral reading deficits in adults who have learned to compensate for their children reading difficulties.     

Assessing dyslexia in higher education: the York adult assessment battery‐revised

Although there are a number of standardised measures to assess dyslexia in children, there are comparatively fewer instruments suitable for the assessment of dyslexia in adults. Given the growing number of students entering UK higher education institutions, there is a need to develop reliable tools for assessing the additional needs of those with dyslexia and related difficulties. This study reports data from a revised version of the York Adult Assessment: An Assessment Battery for Dyslexia Screening in Higher Education. The current York Adult Assessment‐Revised (YAA‐R) is an assessment battery consisting of tests of reading, spelling, writing and phonological skills. Data from a normative sample of 106 adults without dyslexia and a validation sample of 20 adults with dyslexia illustrate significant group differences on the tests comprising the YAA‐R. Additionally, the YAA‐R has good discriminatory power yielding 80% sensitivity and 97% specificity. Taken together, the YAA‐R is a suitable test battery for the assessment and identification of dyslexia in university students.     

Immune disorders and dyslexia

The Geschwind-Behan-Galaburda hypothesis of cerebral lateralization postulates an association between immune disorders and learning disabilities. So far, the empirical evidence for such a relationship has been ambiguous. The present study is an attempt to investigate the hypothesis in a population where all the individuals were affected by immune disorders. Thus, 29 students in a special school for asthmatic children (total number of students in the school: 32) were investigated. A number of reading tests with special focus on word decoding were administered. The parents filled in a detailed questionnaire on the prevalence of reading difficulties and immune disorders among the other family members. The proportion of students with reading problems — especially phonological problems — was much higher than would be expected in a normal population. Among the family members we also found an elevated incidence of both reading problems and immune disorders. A cautious interpreptation of these findings leads to tentative and partial support of the Geschwind-Behan-Galaburda hypothesis.     

Developmental dyslexia revisited and projected

There are three parts to this paper. First, I review briefly the signposts from research, theory, and application in developmental dyslexia in the 1960s and the 1970s that have led us from there to here, and show the pitfalls to avoid. Second, I discuss some of the pertinent issues of the 1980s: the role of intelligence in the diagnosis of children with specific reading disabilities, the distribution of reading difficulties and disabilities, and the important place of verbal efficiency. Third, I project to the 1990s to emphasize the challenge of the computer technology as mediated learning and the challenge of “bounded rationality” and “collective rationality” in education. Throughout this survey, the paramount role of knowledgeable and caring teachers is implicit. Portions of this paper were given at the British Dyslexia Association Conference on Dyslexia in Bath in 1989 and The Orton Dyslexia Society Annual Conference in Washington, D.C. in 1990. The writing of the paper was assisted in part by research grant No. 410-89-0128 from the Social Sciences and Humanities Research Council of Canada     

The nootropic concept and dyslexia

A review is presented of controlled studies using intensive teaching intervention to improve dyslexics’ reading ability. The results of eight controlled studies reveal only one showing the superiority of teaching. Taking this as a background, the work on Nootropics is reviewed. Both animal and clinical work with Piracetam (the first of the Nootropics) seems to indicate that this medication lacks significant or serious side effects and appears to promote memory and learning. Many double-blind studies of Piracetam have now been conducted on dyslexic children. These studies suggest that Piracetam improves the reading ability of dyslexics. In addition electrophysiological studies support the notion that Piracetam may be “left hemisphere active.” Such encouraging trends will doubtless lead to further research in this interesting area.