Toward the Development of a Cognitive-Linguistic Model of Semantic Dementia: Evidence from Lexical Processing

Semantic Dementia (SD) results in progressive cognitive-linguistic impairment. Little is known regarding the interaction of phonological and semantic processes in SD. However, preserved lexical-phonological processing may be critical for language recovery in this population. We propose a temporal model illustrating the cascading decline of semantic and lexical factors in SD. We report data in support of this model from auditory lexical decision, where a subtle deficit produced “reversal of the concreteness effect” despite accurate lexical decisions. Integrity of semantic processing correlated strongly with lexical decision ability. These findings illustrate the contribution of preserved phonology to lexical processing in SD