A cognitive approach

‘Dyslexia’, defined as a disability affecting the uses of written language, has been acknowledged since the publication of various pioneering investigations during the nineteenth century. The classical studies of Déjerine established that dyslexia could occur in adulthood as a consequence of damage to particular areas of the brain and that an acquired reading disorder of this type might or might not be accompanied by a dysgraphia (a disorder of writing and spelling) ( Geschwind, 1965 ). Other authors, particularly Hinshelwood (1917 ), presented case studies illustrating that reading difficulties might also occur congenitally, that is as an impairment of the development during childhood of basic reading and orthographic skills in the absence of evidence of neurological trauma as a precipitating factor.