A few words about dyslexia.

More and more, one encounters people who describe themselves as dyslectic. What is dyslexia? A detailed article in the July issue of Science, explains the phenomenon, and related aspects (1). The following are some of its points. Dyslexia is characterized by a difficulty is understanding and using alphabetic or logographic principles to acquire accurate and fluent reading skills. Dyslexia is persistent: a child who fails to read adequately in 1st grade has a high probability of reading poorly in 4th grade and in high school. Thus, difficulty in early reading limits reading comprehension in the later years of education, as students shift from learning to read to reading to learn. Dyslexia is often defined by a discrepancy between an average or above-average score on a test of general intelligence (intelligence quotient [IQ] test) and a low score on a standardized reading test. There is an observation that dyslexia is independent of other talents that allow some children with dyslexia to grow into re markably successful adults. Dyslexia is strongly heritable, occurring in up to 70% of identical twins and 50% of individuals who have a parent or sibling with dyslexia. Environmental factors are also important in reading development, even in children at genetic risk for dyslexia. Dyslexia can be treated. Once children are diagnosed with dyslexia because of reading failure, treatments are instructional. Instruction yields substantial improvement in reading accuracy for many, but not all, children if instruction is more intensive (for instance, 100 minutes per day for 8 weeks), occurs in small groups (1 or 2 students per teacher), and includes explicit and systematic instruction in phonological awareness and decoding strategies.