Prevalence of undiagnosed dyslexia in African-American primary school children.

Dyslexia is among the most common neurodevelopmental disorders in children, yet despite its high prevalence all too frequently goes undiagnosed. Consequently dyslexic children all too often fail to receive effective reading interventions. Here we report our findings from a study using a teacher completed evidence-based dyslexia screener to first screen then test predominantly African-American children in grades kindergarten through second grade in two inner city public charter schools in New Orleans. Almost half (49.2%) of the children screened as at risk for dyslexia and of these the majority were found to be dyslexic on more detailed testing. Our results suggest that large numbers of African-American students with dyslexia may be overlooked in schools.

Early reading at first grade predicts adult reading at age 42 in typical and dyslexic readers.

Research indicates that the achievement gap in reading between typical and dyslexic readers is already evident in first grade and persists through adolescence. However, it is not known whether this reading gap persists into adult life. In this report we use an epidemiologic sample of 312 children (typical readers = 246; dyslexic readers = 66), followed longitudinally from age 5 through adulthood and examine two fundamental questions: 1) Is reading level in 1st grade predictive of reading proficiency in adulthood in typical and dyslexic readers? and 2) Are the trajectories of reading development from 1st through 5th grade predictive of reading proficiency in adulthood in typical and dyslexic readers? Our findings indicate that early reading levels in 1st grade as well as the trajectory of reading development through the first five years of school were associated with reading scores in adulthood. This association was stronger for dyslexic than for typical readers, especially the latter factor. These findings indicate that the achievement gap between typical and dyslexic readers persists far beyond adolescence, in fact, into adult life.

Dyslexia in the 21st century.

PURPOSE OF REVIEW: Within the past decade tremendous advances have occurred in our understanding of dyslexia. RECENT FINDINGS: Reliable data now validate the definition of dyslexia as an unexpected difficulty in reading in an individual who has the ability to be a much better reader. That dyslexia is unexpected is now codified in US federal law (PL 115-391). Replicated studies using functional brain imaging have documented a neural signature for dyslexia. Epidemiologic, longitudinal data now demonstrate that dyslexia is highly prevalent, affecting 20% of the population, affecting boys and girls equally. These data further demonstrate that the achievement gap between dyslexic and typical readers is now evident as early as first grade and persists. Evidence-based, efficient, inexpensive screening tools now offer the possibility of universal screening to identify children at risk for dyslexia as early as first grade. Specialized schools which focus on dyslexic students provide welcoming communities, ensuring that dyslexic children will not only survive but thrive. SUMMARY: Taken together, these findings indicate that we must act and act now to ensure that this 21st century knowledge of dyslexia is disseminated to educators, policy makers, and most of all to parents of dyslexic children.

Identifying atypical change at the individual level from childhood to adolescence.

Identifying change at the individual level is an important goal for researchers, educators, and clinicians. We present a set of statistical procedures for identifying individuals who depart from a normative change. Using Latent Change Scores models (LCS), we illustrate how the Individual Likelihood computed from a statistical model for change (IL) and from an alternative unrestricted model (ILsat) can be used to identify atypical trajectories in situations with several measurement occasions. Using LCS and linear regression, we also show how the observed and latent change residuals can be used to identify atypical individual change between 2 measurement occasions. We apply these methods to a measure of general verbal ability (from WISC-R), from a large sample of individuals assessed every 2 years from Grade 1 to 9. We demonstrate the efficiency of these techniques, illustrate their use to identify individual change in longitudinal data, and discuss potential applications in developmental research. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

How Should Medical Schools Respond to Students with Dyslexia?

We examine the dilemmas faced by a medical student with dyslexia who wonders whether he should "out" himself to faculty to receive the accommodations entitled by federal law. We first discuss scientific evidence on dyslexia's prevalence, unexpected nature, and neurobiology. We then examine the experiences of medical students who have revealed their dyslexia to illustrate the point that, far too often, attending physicians who know little about dyslexia can misperceive the motives or behavior of students with dyslexia. Because ignorance and misperception of dyslexia can result in bias against students with dyslexia, we strongly recommend a mandatory course for faculty that provides a basic scientific and clinical overview of dyslexia to facilitate greater understanding of dyslexia and support for students with dyslexia.

Achievement Gap in Reading Is Present as Early as First Grade and Persists through Adolescence.

OBJECTIVES: To determine if differences between dyslexic and typical readers in their reading scores and verbal IQ are evident as early as first grade and whether the trajectory of these differences increases or decreases from childhood to adolescence. STUDY DESIGN: The subjects were the 414 participants comprising the Connecticut Longitudinal Study, a sample survey cohort, assessed yearly from 1st to 12th grade on measures of reading and IQ. Statistical analysis employed longitudinal models based on growth curves and multiple groups. RESULTS: As early as first grade, compared with typical readers, dyslexic readers had lower reading scores and verbal IQ, and their trajectories over time never converge with those of typical readers. These data demonstrate that such differences are not so much a function of increasing disparities over time but instead because of differences already present in first grade between typical and dyslexic readers. CONCLUSIONS: The achievement gap between typical and dyslexic readers is evident as early as first grade, and this gap persists into adolescence. These findings provide strong evidence and impetus for early identification of and intervention for young children at risk for dyslexia. Implementing effective reading programs as early as kindergarten or even preschool offers the potential to close the achievement gap.

Reading outcomes of children and adolescents with attention-deficit/hyperactivity disorder and dyslexia following atomoxetine treatment.

UNLABELLED: Abstract Objective: This study assessed the efficacy of atomoxetine on attention-deficit/hyperactivity disorder (ADHD) symptoms in children and adolescents having ADHD with comorbid dyslexia (ADHD+D) and the effects of the treatment on reading measures. METHODS: The analyses in this report used data from a study designed to examine the effects of a nonstimulant pharmacological agent, atomoxetine, on reading in children with ADHD+D. Patients ages 10-16 years with ADHD or ADHD+D received open-label atomoxetine for 16 weeks. The ADHD Rating Scale (ADHD-RS) and reading subtests of the Kaufman Test of Educational Achievement (K-TEA) were assessed. Changes in ADHD symptoms and reading scores were also analyzed by ADHD subtype. Treatment effect sizes and correlations between changes in ADHDRS and K-TEA scores were calculated. RESULTS: After atomoxetine treatment, both ADHD and ADHD+D patient groups showed significant reduction in ADHD symptom and improvements in K-TEA reading scores. The range of treatment effect sizes on K-TEA scores was 0.35-0.53 for the ADHD group and 0.50-0.62 for the ADHD+D group. Pearson's correlation coefficients revealed only a few weak correlations between changes in ADHD symptoms and reading scores, regardless of diagnostic group. CONCLUSIONS: ADHD symptoms and K-TEA reading scores improved for both the ADHD and ADHD+D groups following atomoxetine treatment. Correlation analyses indicate that improvements in reading outcomes cannot be explained by a reduction of ADHD symptoms alone. These findings support further exploration of the potential effects of atomoxetine on reading in children with ADHD and dyslexia or dyslexia alone.

Disruption of functional networks in dyslexia: a whole-brain, data-driven analysis of connectivity.

BACKGROUND: Functional connectivity analyses of functional magnetic resonance imaging data are a powerful tool for characterizing brain networks and how they are disrupted in neural disorders. However, many such analyses examine only one or a small number of a priori seed regions. Studies that consider the whole brain frequently rely on anatomic atlases to define network nodes, which might result in mixing distinct activation time-courses within a single node. Here, we improve upon previous methods by using a data-driven brain parcellation to compare connectivity profiles of dyslexic (DYS) versus non-impaired (NI) readers in the first whole-brain functional connectivity analysis of dyslexia. METHODS: Whole-brain connectivity was assessed in children (n = 75; 43 NI, 32 DYS) and adult (n = 104; 64 NI, 40 DYS) readers. RESULTS: Compared to NI readers, DYS readers showed divergent connectivity within the visual pathway and between visual association areas and prefrontal attention areas; increased right-hemisphere connectivity; reduced connectivity in the visual word-form area (part of the left fusiform gyrus specialized for printed words); and persistent connectivity to anterior language regions around the inferior frontal gyrus. CONCLUSIONS: Together, findings suggest that NI readers are better able to integrate visual information and modulate their attention to visual stimuli, allowing them to recognize words on the basis of their visual properties, whereas DYS readers recruit altered reading circuits and rely on laborious phonology-based "sounding out" strategies into adulthood. These results deepen our understanding of the neural basis of dyslexia and highlight the importance of synchrony between diverse brain regions for successful reading.

Uncoupling of reading and IQ over time: empirical evidence for a definition of dyslexia.

Developmental dyslexia is defined as an unexpected difficulty in reading in individuals who otherwise possess the intelligence and motivation considered necessary for fluent reading, and who also have had reasonable reading instruction. Identifying factors associated with normative and impaired reading development has implications for diagnosis, intervention, and prevention. We show that in typical readers, reading and IQ development are dynamically linked over time. Such mutual interrelationships are not perceptible in dyslexic readers, which suggests that reading and cognition develop more independently in these individuals. To our knowledge, these findings provide the first empirical demonstration of a coupling between cognition and reading in typical readers and a developmental uncoupling between cognition and reading in dyslexic readers. This uncoupling was the core concept of the initial description of dyslexia and remains the focus of the current definitional model of this learning disability.

Paying attention to reading: the neurobiology of reading and dyslexia.

Extraordinary progress in functional brain imaging, primarily advances in functional magnetic resonance imaging, now allows scientists to understand the neural systems serving reading and how these systems differ in dyslexic readers. Scientists now speak of the neural signature of dyslexia, a singular achievement that for the first time has made what was previously a hidden disability, now visible. Paralleling this achievement in understanding the neurobiology of dyslexia, progress in the identification and treatment of dyslexia now offers the hope of identifying children at risk for dyslexia at a very young age and providing evidence-based, effective interventions. Despite these advances, for many dyslexic readers, becoming a skilled, automatic reader remains elusive, in great part because though children with dyslexia can be taught to decode words, teaching children to read fluently and automatically represents the next frontier in research on dyslexia. We suggest that to break through this "fluency" barrier, investigators will need to reexamine the more than 20-year-old central dogma in reading research: the generation of the phonological code from print is modular, that is, automatic and not attention demanding, and not requiring any other cognitive process. Recent findings now present a competing view: other cognitive processes are involved in reading, particularly attentional mechanisms, and that disruption of these attentional mechanisms play a causal role in reading difficulties. Recognition of the role of attentional mechanisms in reading now offer potentially new strategies for interventions in dyslexia. In particular, the use of pharmacotherapeutic agents affecting attentional mechanisms not only may provide a window into the neurochemical mechanisms underlying dyslexia but also may offer a potential adjunct treatment for teaching dyslexic readers to read fluently and automatically. Preliminary studies suggest that agents traditionally used to treat disorders of attention, particularly attention-deficit/hyperactivity disorder, may prove to be an effective adjunct to improving reading in dyslexic students.

The education of dyslexic children from childhood to young adulthood.

The past two decades have witnessed an explosion in our understanding of dyslexia (or specific reading disability), the most common and most carefully studied of the learning disabilities. We first review the core concepts of dyslexia: its definition, prevalence, and developmental course. Next we examine the cognitive model of dyslexia, especially the phonological theory, and review empiric data suggesting genetic and neurobiological influences on the development of dyslexia. With the scientific underpinnings of dyslexia serving as a foundation, we turn our attention to evidence-based approaches to diagnosis and treatment, including interventions and accommodations. Teaching reading represents a major focus. We first review those reading interventions effective in early grades, and then review interventions for older students. To date the preponderance of intervention studies have focused on word-level reading; newer studies are beginning to examine reading interventions that have gone beyond word reading to affect reading fluency and reading comprehension. The article concludes with a discussion of the critical role of accommodations for dyslexic students and the recent neurobiological evidence supporting the need for such accommodations.

Longitudinal models of developmental dynamics between reading and cognition from childhood to adolescence.

The authors applied linear dynamic models to longitudinal data to examine the dynamics of reading and cognition from 1st to 12th grade. They used longitudinal data (N=445) from the Connecticut Longitudinal Study (S. E. Shaywitz, B. A. Shaywitz, J. M. Fletcher, & M. D. Escobar, 1990) to map the dynamic interrelations of various scales of the Wechsler Intelligence Scales for Children--Revised (i.e., Full, Performance, and Verbal) and specific markers of the Woodcock-Johnson Psycho-Educational Battery--Revised reading cluster (i.e., Letter-Word ID, Decoding, and Comprehension). The results of these analyses indicate that (a) there is a positive dynamic relation between reading and cognition across the selected age range; (b) this dynamic relation is symbiotic, with positive influences in both directions; (c) the influence from cognition to reading is stronger when considering the Wechsler Intelligence Scales for Children Performance--Revised Performance scale and weaker with the Verbal scale; (d) when examining the different Reading subtests, the influences from cognition are more apparent for Letter-Word ID and Comprehension and are less perceptible for Decoding; and (e) the dynamics of reading and cognition appear to be of stronger magnitude during 1st to 3rd grade, less strong during 4th to 8th grade, and weaker from 9th to 12th grade.

Management of dyslexia, its rationale, and underlying neurobiology.

Developmental dyslexia is characterized by an unexpected difficulty in reading in children and adults who otherwise possess the intelligence and motivation considered necessary for accurate and fluent reading. Dyslexia is the most common and most carefully studied of the learning disabilities, affecting 80% of all individuals identified as learning disabled. Although in the past the diagnosis and implications of dyslexia were often uncertain, recent advances in the knowledge of the epidemiology, the neurobiology, the genetics, and the cognitive influences on the disorder now allow the disorder to be approached within the framework of a traditional medical model. This article reviews these advances and their implications for the approach to patients presenting with a possible reading disability.

Age-related changes in reading systems of dyslexic children.

OBJECTIVE: To examine age-related changes in the neural systems for reading in nonimpaired and dyslexic children and adolescents. METHODS: Functional magnetic resonance imaging was used to study age-related changes in the neural systems for reading in a cross-sectional sample of 232 right-handed children 7 to 18 years of age (113 dyslexic readers and 119 nonimpaired readers) as they read pseudowords. RESULTS: In nonimpaired readers, systems in the left anterior lateral occipitotemporal area developed with age, whereas systems in the right superior and middle frontal regions decreased. In contrast, in dyslexic readers, systems in the left posterior medial occipitotemporal regions developed with age. Older nonimpaired readers were left lateralized in the anterior lateral occipitotemporal area; there was no difference in asymmetry between younger and older dyslexic readers. INTERPRETATION: These findings offer a possible neurobiological explanation for the differences in reading acquisition between dyslexic and nonimpaired readers and provide further evidence of the critical role of the left occipitotemporal region in the development of reading.

Error-related event-related potentials in children with attention-deficit hyperactivity disorder, oppositional defiant disorder, reading disorder, and math disorder.

We studied error-related negativity (ERN) and error positivity (Pe) during a discrimination task in 319 unmedicated children divided into subtypes of ADHD (Not-ADHD/inattentive/combined), learning disorder (Not-LD/reading/math/reading+math), and oppositional defiant disorder. Response-locked ERPs contained a frontocentral ERN and posterior Pe. Error-related negativity and positivity exhibited larger amplitude and later latency than corresponding waves for correct responses matched on reaction time. ADHD did not affect performance on the task. The ADHD/combined sample exceeded controls in ERN amplitude, perhaps reflecting patients' adaptive monitoring efforts. Compared with controls, subjects with reading disorder and reading+math disorder performed worse on the task and had marginally more negative correct-related negativities. In contrast, Pe/Pc was smaller in children with reading+math disorder than among subjects with reading disorder and Not-LD participants; this nonspecific finding is not attributable to error processing. The results reflect anomalies in error processing in these disorders but further research is needed to address inconsistencies in the literature.

The role of functional magnetic resonance imaging in understanding reading and dyslexia.

Converging evidence from a number of lines of investigation indicates that dyslexia represents a disorder within the language system and more specifically within a particular subcomponent of that system, phonological processing. Recent advances in imaging technology, particularly the development of functional magnetic resonance imaging (fMRI), provide evidence of a neurobiological signature for dyslexia, specifically a disruption of 2 left hemisphere posterior brain systems, 1 parietal-temporal, the other occipital-temporal, with compensatory engagement of anterior systems around the inferior frontal gyrus and a posterior (right occipital-temporal) system. Furthermore, good evidence indicates a computational role for the left occipital-temporal system: the development of fluent (automatic) reading. In addition, fMRI studies of young adults with reading difficulties followed prospectively and longitudinally from age 5 through their mid 20s suggests that there may be 2 types of reading difficulties, 1 primarily reflecting a genetic basis, the other, and far more common, reflecting environmental influences. The brain systems for reading are malleable and their disruption in children with dyslexia may be remediated by provision of an evidence-based, effective reading intervention. These studies offer the promise for more precise identification and effective management of dyslexia in children, adolescents, and adults.

DCDC2 is associated with reading disability and modulates neuronal development in the brain.

DYX2 on 6p22 is the most replicated reading disability (RD) locus. By saturating a previously identified peak of association with single nucleotide polymorphism markers, we identified a large polymorphic deletion that encodes tandem repeats of putative brain-related transcription factor binding sites in intron 2 of DCDC2. Alleles of this compound repeat are in significant disequilibrium with multiple reading traits. RT-PCR data show that DCDC2 localizes to the regions of the brain where fluent reading occurs, and RNA interference studies show that down-regulation alters neuronal migration. The statistical and functional studies are complementary and are consistent with the latest clinical imaging data for RD. Thus, we propose that DCDC2 is a candidate gene for RD.