ABSTRACT
In America, the concept of "developmental dyslexia" was promoted by Samuel T. Orton, whose Reading, Writing and Speech Problems in Children, published in 1937, was highly influential. It was Orton who argued that dyslexia is more common in individuals who are neither firmly right-handed nor firmly left-handed. The World Federation of Neurology definition mentions "fundamental cognitive disabilities" of possible "constitutional origin". The quest for those disabilities and their origins in the constitution of the individual has preoccupied most of the researchers who have been drawn into the study of dyslexia. Many psychologists who have worked with dyslexic children have come to the view that dyslexics are not all alike, but differ one from another in ways that need to be described and explained. Acquired surface dyslexics lean heavily on phonological letter-sound conversion procedures when attempting to read aloud. In most people, the left hemisphere of the brain is responsible for language processes.
