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A reading disability that is not caused by an identifiable physical problem (such as brain damage, visual or auditory problems).

Dyslexia is a specific learning disability characterized by a significant disparity between an individual's general intelligence and his or her language skills, usually reflected in school performance.

Estimates of people with dyslexia range from 2% to the National Institutes of Health figure of 15% of the U.S. population. It is a complicated disorder with no identifiable cause or cure, yet it is highly responsive to treatment in the form of special instruction. The most obvious symptoms of the dyslexic show up in reading and writing, but listening, speaking, and general organizational skills are also affected. The dyslexic may have trouble transferring information across modalities, for example from verbal to written forms. The dyslexic's characteristic reversal of letters, confusion between similar letters such as "b" and "d," omission of words when reading aloud, trouble sounding out words, and difficulty following written instructions were first thought to be the result of vision and perceptual problems—i.e., a failure of taking in the stimulus. Only a small percentage of dyslexics have vision disorders, however, and it is now generally agreed by physicians, researchers, and educators that dyslexia is primarily a language disorder. Whereas the non-dyslexic intuitively learns phonic (sound) rules while learning to read, the dyslexic needs specific, methodical drill and practice to learn the visual-auditory associations necessary for reading comprehension and written expression.

Originally it was thought that dyslexia affected more males than females (in a ratio of 5:1), but later studies found males to be only slightly more likely than females to be dyslexic. Figures for diagnosed child dyslexics are skewed because for various reasons boys tend to be referred more frequently for special education. Diagnosis is complicated by the fact that anywhere from 20% to 55% of dyslexics also suffer from attention deficit/hyperactivity disorder (ADHD), a behavioral disorder which can aggravate reading problems. There are many different theories about the causes and classifications of different types of dyslexia, but few hard conclusions. It is definitely familial, and about 40% of boys and 20% of girls with a dyslexic parent show the disorder. Several genetic studies have found gene linkages which demonstrate heterogeneous (multiple methods of) transmission. Dyslexics have average or above average intelligence, and it is speculated that they have heightened visual-spatial and motor awareness. Thomas Edison, Albert Einstein, Woodrow Wilson, General George Patton, and Auguste Rodin are thought to have been dyslexic.

There are many treatment approaches available to the public, ranging from visual stimulation to diets to enhancement of regular language education. However, it is generally agreed that specialized education is the only

Typical writings of a dyslexic. (Will & Deni McIntyre/Science Source, National Audubon Society Collection/Photo Researchers, Inc. Reproduced with permission.)

successful remedy, and the American Academy of Ophthalmology, the American Academy of Pediatrics, and the American Association for Pediatric Ophthalmology and Strabismus have issued a policy statement warning against visual treatments and recommending a cross-disciplinary educational approach. In fact the first researcher to identify and study dyslexia, Samuel Torrey Orton, developed the core principles of such an approach in the 1920s. The work of three of his followers—teachers Bessie Stillman, Anna Gillingham, and Beth Slingerland—underlies many of the programs in wide use today such as project READ, the Wilson Reading System, and programs based on the Herman method. These and other successful programs have three characteristics in common. They are:

(1) Sound/symbol based. They break words down into their smallest visual components: letters and the sounds associated with them.

(2) Multisensory. They attempt to form and strengthen mental associations among visual, auditory, and kinesthetic channels of stimulation. The dyslexic simultaneously sees, feels, and says the sound-symbol association; for example, a student may trace the letter or letter combination with his finger while pronouncing a word out loud.

(3) Highly structured. Remediation begins at the level of the single letter-sound, works up to digraphs, then syllables, then into words and sentences in a very systematic fashion. Repetitive drill and practice serve to form necessary sound-symbol associations.

If caught early, especially before the third grade, dyslexia is highly treatable through special education.

Further Reading

Bowler, Rosemary F., ed. Annals of Dyslexia. Baltimore, MD: The Orton Dyslexia Society, 1983.

Galaburda, A., ed. Dyslexia and Development: Neurobiological Aspects of Extraordinary Brains. Cambridge, MA: Harvard UP, 1993.

Miles. T.R. Dyslexia. Philadelphia: Open University Press, 1990.

Lytle, Vicky. "Edison, Rockefeller, Rodin, and the Reading Problem: Detecting Dyslexia in Students." NEA Today 4, (October 1985): 10-11.

Rooney, Karen. "Dyslexia Revisited: History, Educational Philosophy, and Clinical Assessment Applications." Intervention in School and Clinic 31, no. 1, (1995): 6-15.

Rumsey, Judith M. "The Biology of Developmental Dyslexia: Grand Rounds at the Clinical Center of the National Institutes of Health." JAMA 19, no. 7, (1992): 912-16.

Further Information

Council for Learning Disabilities. P.O. Box 40303, Overland Park, KS 66204.

Foundation for Children with Learning Disabilities. 99 Park Avenue, New York, NY 10016.

Orton Dyslexia Society. 8600 LaSalle Road, Chester Building, Suite 382, Baltimore, MD 21286-2044, (410) 296–0232, information line: (800) ABC-D123.

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