Sentence processing deficits: Theory and therapy

Abstract

Investigations of sentence processing were carried out using two patients with impairments in comprehending and producing sentences. The deficits observed were interpreted as resulting from impairments to the procedures which map thematic relations in sentence comprehension and production (Schwartz, Linebarger, & Saffran, 1985). Therapy for these mapping disorders was carried out, and as a result of the treatment, improvements were measured in sentence comprehension and production for both patients, despite the fact that they had both been aphasic for at least five years prior to this therapy. The improvement observed was specific to tasks in which mapping of thematic relations is crucial. Impairments in carrying out tasks unrelated to the mapping procedure were not improved by the mapping therapy. Furthermore, therapy was then applied for one of the patients to an untreated function which then improved, suggesting that all the improvements measured were specific effects of the treatment applied. The results of the sentence-processing therapy lend support to the mapping deficit hypothesis as an interpretation of the deficit shown by some patients in comprehending and producing sentences, but suggest that the mapping of different types of thematic relations should be investigated further.