Dyslexia

The traditional formal definition of developmental dyslexia is ‘‘a disorder in children who, despite conventional classroom experience, fail to attain the language skills of reading, writing and spelling commensurate with their intellectual abilities’’ (World Federation of Neurology, 1968, p. 26). Dyslexia is the most prevalent of the developmental disorders, and the most researched, with the U.S. National Institute for Child Health and Human Development funding its dyslexia program at $10 to 20 million per year since the late 1980s. Despite this intensive research, lively and unresolved controversies remain as to the underlying cause, the appropriate methods of diagnosis, and the optimal means of support for dyslexic children; many influential researchers question the very concept of dyslexia as a coherent syndrome. 

It is important to note that dyslexia is traditionally defined in terms of a discrepancy between actual reading performance and what would be expected based on the child’s intelligence. A central problem with this definition is that a child must fail to learn to read for two years or so before a formal diagnosis is considered valid. It is, of course, very destructive for a child to have the crucial early years at school blighted by failure to acquire one of the fundamental skills. In the later school years, there is also the danger of a vicious circle of poor reading leading to poor motivation, avoidance of text-based school work, emotional trauma, and adoption of maladaptive strategies such as clowning around, disruptive behavior, or truancy. Even in adulthood, many dyslexic people still feel intensely angry about the way they were treated at school. Nevertheless, many dyslexic children turn out to be creative and successful, and it has been suggested that a disproportionate number of our most creative artists and scientists were dyslexic (West, 1991).

Explanation in the Developmental Sciences In common with that in many Western countries, dyslexia research in the United States and the UK has been remarkably successful in its political objectives over the past decade. Dyslexia is now established as a key disability, and hence dyslexic children and adults benefit fully from increasingly powerful disability legislation. In the United States, the 2004 Disabilities Education Improvement Act (IDEA) introduced the concept of identifying children ‘‘at risk’’ and intervening early, recognizing the importance of preliteracy skills in the development of the young child. IDEA advocates an inclusive approach whereby support is provided early for children withan at-risk profile, so that intervention is more effective and cost-effective.

One of the fascinating aspects of dyslexia research is that, whatever one’s speciality as a researcher—reading, phonology, writing, spelling, education, memory, speed, creativity, hearing, vision, balance, learning, skill, genetics, brain structure, or brain function—dyslexic children will show interesting and unusual differences in that domain. Given the need for specialization in science, many researchers have undertaken incisive and insightful studies in their specific domain of expertise.

A major source of confusion in theoretical dyslexia research derives from the different motivations of different researchers. In particular, many applied theoreticians are concerned with educational attainment, and in particular literacy. Consequently, they analyse the different components of reading, investigate the differential effects of various interventions, and often stress (correctly) the need for support for any child who is at risk of reading failure, whether or not he or she is dyslexic.

Definitions of Developmental Dyslexia

Consider the following attempts to define developmental dyslexia:

1. Developmental dyslexia is a disorder in children who, despite conventional classroom experience, fail to attain the language skills of reading, writing, and spelling commensurate with their intellectual abilities (World Federation of Neurology, 1968).

2. Developmental dyslexia, or specific reading disability, is defined as an unexpected, specific, and persistent failure to acquire efficient reading skills despite conventional instruction, adequate intelligence, and sociocultural opportunity (American Psychiatric Association [APA], 1994).

3. Developmental dyslexia is a specific language-based disorder of constitutional origin, characterized by difficulties in single word decoding, usually reflecting insufficient phonological processing abilities (Orton Society,1995).

4. Dyslexia is evident when accurate and fluent word reading and/or spelling develops very incompletely or with great difficulty (Reason [BPS], 1999).

5. The term learning disability refers to a class of specific disorders. They are due to cognitive deficits intrinsic to the individual and are often unexpected in relation to other cognitive abilities. Such disorders result in performance deficits in spite of quality instruction and predict anomalies in the development of adaptive functions having consequences across the life span (U.S. Office for Special Education Programs [USOSEP], 2002).

6. Dyslexia is a specific learning disability that is neurological in origin. It is characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities. These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction. Secondary consequences may include problems in reading comprehension and reduced reading experience that can impede the growth of vocabulary and background knowledge (International Dyslexia Association [IDA], 2002).

Source : The Learning and Skills Development Agency and NIACE. A Framework for Understanding Dyslexia. - www.dfes.gov.uk/readwriteplus/understandingdyslexia