Production of relative clauses: differences between normal and aphasic performance
Abstract
The commonly used Aachener Aphasie Test for the diagnosis of aphasia in German speaking subjects has deficits in distinguishing non-aphasic subjects from slightly impaired ones. Many of such patients classified as “Restaphasiker” or even as non-aphasics by the AAT may still have problems with more complex language material, Our paper will present a theoretical and empirical possibility to uncover impairments in grammatical encoding in the case of these complex tasks. To test the hypotheses derived from the language production model of Schade (Schade & Eikmeyer, 1998), we designed an experiment in which the subjects had to complete the beginning of a sentence containing a centre-embedded relative clause. In contrast to the sentences used by Bock and Miller (1991), our subjects had to replenish both the relative clause and the main clause. The results indicate that the group of aphasic subjects does indeed have considerably more difficulties in performing the task than the healthy controls. That means that the aphasic subjects gave significantly fewer correct answers than the healthy controls and made significantly more lexical and syntactical reproduction errors, Besides the effect of aphasia, the role of the relative pronoun led to significant differences in the syntactical reproduction condition.