Foundation-level dyslexia: assessment and treatment.

It is supposed that there is an early, foundation stage in beginning reading during which children acquire basic letter-sound knowledge, a capability for alphabetic processing, and a logographic sight vocabulary. An assessment of foundation processes was administered to Scottish children with reading difficulties (n = 51) and to reading-level-matched controls (n = 56). The results suggested that the foundation is normally in place by the time a reading age of about 7 years has been achieved. Foundation-level dyslexia is identifiable in children with reading difficulty whose reading ages fall below this level. Differing patterns of dyslexia were observed, depending on whether the primary effect was on letter-sound learning (literal dyslexia), the acquisition of the alphabetic process (alphabetic dyslexia), or retention of a sight vocabulary (logographic dyslexia). Balanced dyslexia, in which both alphabetic and logographic functions were impaired, was also found. Some implications for assessment and treatment are discussed.