Alexia

Abstract Alexia refers to an acquired disturbance in reading, adequately defined as loss or impairment of the ability to comprehend written or printed language caused by brain damage. One key consideration in defining alexia concerns the concept of loss. As defined above, alexia is limited to situations in which the ability to read was present and then was lost after brain damage; it is an acquired illiteracy. Many contemporary aphasiologists use the term alexia to designate all acquired reading impairments, but others reserve it for a total loss of reading ability, applying dyslexia to the more common condition of partially impaired reading comprehension. While this distinction is rational, it is a source of confusion as dyslexia is used by many investigators (pediatricians, psychologists, educators) to designate a form of abnormal language development, an inherent inability to acquire reading skills (Critchley, 1985). Dyslexia was formally defined in 1_968 by a committee of the World Federation of Neurology as “a disorder manifested by difficulty in learning to read despite conventional instruction, adequate intelligence, and sociocultural opportunity. It is dependent on fundamental cognitive disabilities which are frequently of constitutional origin.”