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We review the evolution of the conceptualisation of dyslexia and along with it the current, 21st century definition of dyslexia. Our starting point is the seminal report by Pringle Morgan in 1896, followed by early 20th century reports by Hinshelwood, and continuing with concepts of brain injury and minimal brain dysfunctions then to the emergence of 'learning disability' in the mid-20th century. Within this historical framework we note the emergence and scientific validation of an 'unexpected' model culminating in the first definition of dyslexia in U.S. federal law in late 2018 and in recent U.S. federal civil rights law. We next address the issue of whether dyslexia is 'real' by showing how advances in non-invasive functional brain imaging have led to a replicated, robust neural signature for dyslexia. We close by illustrating how science has informed policy, emphasising the focus on evidence-based practices beginning with the report of the National Reading Panel and including the creation of the What Works Clearinghouse. Early screening for dyslexia represents another important policy accomplishment with dyslexia laws now passed in over 30 states. Evidence-based effective interventions for dyslexia, including free, public charter schools specialised for dyslexic children exemplify the most recent policy initiative. [ABSTRACT FROM AUTHOR]

Response to Intervention (RTI) models of diagnosis and intervention are being implemented rapidly throughout the schools. The purposes of invoking an RTI model for disabilities in the schools clearly are laudable, yet close examination reveals an unappreciated paucity of empirical support for RTI and an overly optimistic view of its practical, problematic issues. Models are being put into practice without adequate research and logistical support and neglect the potential negative long-term impact on students with disabilities. Many implementation problems exist: (a) the vagaries of critical details of the model in practice; (b) the lack of consideration of bright struggling readers; (c) the relativeness, contextual, situation dependent nature of who is identified; (d) the worrisome shortcomings of the RTI process as a means of diagnosis or determination of a disability; and (e) the apparent lack of student-based data to guide effective choice of approaches and components of intervention. Practiced as a model of prevention, the authors agree with the concept of RTI. As the authors witness its application to disability determination sans the benefit of a reliable and valid empirical basis, the potential benefits to some children with disabilities remain an unproven hypothesis while the potential detriment to some children with disabilities remains a very real possibility. [ABSTRACT FROM AUTHOR]

J. M. Fletcher and S. Vaughn (2009) describe recent changes to federal laws governing special education eligibility for specific learning disabilities (LDs) focusing on what is commonly known as response to intervention (RTI). The article appears to be a selective review of empirical support for RTI and a consequently overly optimistic view of many practical issues surrounding the implementation of RTI models that neglects the potential negative long-term impact on the range of students with and without an LD. These include (a) the lack of a firm evidence base reflected in vagaries and ambiguity of the critical details of the model in practice; (b) the worrisome shortcomings of the RTI process as a means of diagnosis or determination of a disability; (c) the contextual, situation-dependent nature of who is identified; (d) the seeming lack of consideration of bright struggling readers in the RTI process; and (e) the apparent lack of student-based data to guide the most effective choice of approaches to, and specific components of, intervention. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

: BackgroundA range of neurobiological investigations shows a failure of left hemisphere posterior brain systems to function properly during reading in children and adults with reading disabilities. Such evidence of a disruption in the normal reading pathways provides a neurobiological target for reading interventions. In this study, we hypothesized that the provision of an evidence-based, phonologically mediated reading intervention would improve reading fluency and the development of the fast-paced occipitotemporal systems serving skilled reading.: MethodsFunctional magnetic resonance imaging was used to study the effects of a phonologically based reading intervention on brain organization and reading fluency in 77 children aged 6.1–9.4 years (49 with reading disability and 28 control subjects). Children comprised three experimental groups: experimental intervention (n = 37), community intervention (n = 12), and community control subjects (n = 28).: ResultsImmediately after the year-long intervention, children taught with the experimental intervention had made significant gains in reading fluency and demonstrated increased activation in left hemisphere regions, including the inferior frontal gyrus and the middle temporal gyrus; 1 year after the experimental intervention had ended these children were activating bilateral inferior frontal gyri and left superior temporal and occipitotemporal regions.: ConclusionsThese data indicate that the nature of the remedial educational intervention is critical to successful outcomes in children with reading disabilities and that the use of an evidence-based phonologic reading intervention facilitates the development of those fast-paced neural systems that underlie skilled reading. [Copyright &y& Elsevier]

: BackgroundA range of neurobiological investigations shows a failure of left hemisphere posterior brain systems to function properly during reading. Such evidence of a disruption in the normal reading pathways provides a neurobiological target for reading interventions. In this study, we hypothesized that the provision of an evidence-based, phonologically mediated reading intervention would improve reading fluency and the development of the fast-paced occipitotemporal systems serving skilled reading.: MethodsFunctional magnetic resonance imaging was used to study the effects of a phonologically based reading intervention on brain organization and reading fluency in 77 children aged 6.1–9.4 years (49 with reading disability and 28 control subjects). Children comprised three experimental groups: experimental intervention (n = 37), community intervention (n = 12), and community control subjects (n = 28).: ResultsImmediately after the year-long intervention, children taught with the experimental intervention had made significant gains in reading fluency and demonstrated increased activation in left hemisphere regions, including the inferior frontal gyrus and the middle temporal gyrus; 1 year after the experimental intervention had ended these children were activating bilateral inferior frontal gyri and left superior temporal and occipitotemporal regions.: ConclusionsThese data indicate that the nature of the remedial educational intervention is critical to successful outcomes in children with reading disabilities and that the use of an evidence-based phonologic reading intervention facilitates the development of those fast-paced neural systems that underlie skilled reading. [Copyright &y& Elsevier]

This paper elaborates on components of a working definition of developmental dyslexia. It follows the general format of a paper published in the periodical Annals of Dyslexia in 1995, which elaborated on a working definition proposed in 1994. The current definition agreed on by the work group updates and expands on the working definition from 1994. Dyslexia is a specific learning disability that is neurobiological in origin. It is characterized by difficulties with accurate and fluent word recognition and by poor spelling and decoding abilities.

Abstract. The Yale Children's Inventory rating scales for completion by parents were developed to improve the ability of clinicians and researchers to evaluate the school-related problems of children. The inventory consists of 11 narrow-band and two broad-band scales, the Behavioral and the Cognitive. The concurrent and predictive validity of the Yale Children's Inventory scales are reported in a school-based sample of 103 boys. External criterion variables were obtained from parents, teachers, and standardized tests administered to the children. We found that the Attention scale overlaps both broad-band domains, indicating the importance and the intrinsic relationship of attention to both behavioral and cognitive functions, which supports the Diagnostic and Statistical Manual of Mental Disorders, ed 3 nosology for disorders of attention and activity regulation. It also increases the number of children whose assessment may be enhanced by the availability of systematic parent report forms. Pediatrics 1988;81:562-571; attention deficit disorder, behavior, school-related problems, learning disability. [ABSTRACT FROM AUTHOR]

Focuses on a study which examined the prevalence of reading disability in boys and girls. Clinical characteristics of subjects; Criterion measures used; Characteristics of reading disability in the subjects.

Presents a review of advances in medical knowledge and the implication for treating patients with a possible reading or learning disability, developmental dyslexia. Epidemiology of dyslexia; Neurobiologic influences; Cognitive influences; Implications of the phonologic model of dyslexia; Approach to the diagnostic evaluation; Evaluation of school-age children; Special considerations in younger and older age groups; Diagnosis; Management.

Examines distinctions and interrelationships between attention deficit disorder (ADD), learning disability and oppositional/conduct disorder in children. Referral patterns of children with learning and behavioral disorders; Relationship between referral source and diagnosis of ADD; Diagnosis of ADD according to diagnostic method; Composition of referral cohort according to method of diagnosis.

Introduces papers about aspects of attention deficit disorder (ADD). Definition and dimensions of ADD; Distinctions and interrelationships within subtypes of ADD and between ADD and learning disability; Neural mechanisms influencing ADD; Practical details of therapies for ADD; Learning difficulties and academic achievement deficiencies of children with ADD.

Abstract: 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. [Copyright &y& Elsevier]

Simulated data were used to demonstrate that groups formed by imposing cut-points based on either discrepancy or low-achievement definitions of learning disabilities (LD) are unstable over time. Similar problems were demonstrated in longitudinal data from the Connecticut Longitudinal Study, where 39% of the children designated as having LD in Grade 3 changed group placement with repeated testing in Grade 5. These results show that the practice of subdividing a normal distribution with arbitrary cut-points leads to instability in group membership. Approaches to the identification of children as having LD based solely on individual test scores not linked to specific behavioral criteria lead to invalid decisions about individual children. Low-achievement definitions are not a viable alternative to IQ-discrepancy definitions in the absence of other criteria, such as the traditional exclusions and response to quality intervention. If we accept the premise of multiple classes of low achievers, then we must develop identification systems that are valid and abandon systems whose only merits are their historical precedence and convenience. [ABSTRACT FROM AUTHOR]

Addresses the issue of specificity in reading disability by comparing two approaches to defining and selecting children with reading disabilities. Effect of variations in definitions used to identify children as reading disabled; Definition of learning disabilities by statistical comparisons of intelligence quotient and achievement standard scores.