Since 1874, when Carl Wernicke published ten case studies of “brain-injured” patients with language disorders (Wernicke, 1874), scientists have been intrigued with the phenomenon experienced by now more than 4.4 million children in the United States who are of at least average intellect, have no sensory disorders that would cause academic difficulty (e.g., blindness, deafness), but still struggle in learning and in life’s daily demands. Samuel Kirk coined the term “learning disability” (LD) in his 1962 textbook, Educating Exceptional Children. He defined LD as follows:
A retardation, disorder, or delayed development in one or more of the processes of speech, language, reading, writing, arithmetic, or other school subject resulting from a psychological handicap caused by a possible cerebral dysfunction and/or emotional or behavioral disturbances. It is not the result of mental retardation, sensory deprivation, or cultural and instructional factors (Kirk, 1962, p.34).