Dyslexia as a Multifactorial Disorder

This review of the scientific literature addresses studies of dyslexia. Different views of the roles of genetic and external factors in the etiology and pathogenesis of this disorder are discussed. Results from neuropsychological and neurophysiological studies evidencing impairments to particular parts of higher mental functions in dyslexia are presnted. The main types of cognitive deficit seen in dyslexia are discussed: impairments to a number of measures of attention and working memory, decreases in information processing speed, and insufficiency of new skill automation processes. These data indicate that dyslexia is a multifactorial disorder with multiple deficits.