Aphasics' sentence repetition behavior as a funciton of grammaticality

Twenty asphasics repeated grammatical and ungrammatical sentences. Ungrammatical sentences were characterized by violations of syntactic and/or semantic structure. Aphasics repeated accurately more grammatical than ungrammatical sentences. Ungrammatical sentences with violations of syntactic structure were repeated less accurately than those with preserved syntax. Aphasics' repetition errors were classified as: incorrect repetition, inapropriate correction, morphological error, lexical deletion and substitution responses. Repetition errors appeared to result from performance deficits, such as reduced retention span and physiological limitations of the speech musculature. Results suggest that asphasics are to some extent guided by a greater residual linguistic knowledge or competence than might be inferred from their spontaneous production.