Agrammatism as a variable phenomenon

Abstract

With a group of 11 Dutch agrammatic speakers, the studies on production and comprehension of word order by Saffran et al. (1980) and Schwartz et al. (1980) were replicated. We found a pattern of errors that was qualitatively the same as observed by these authors. However, the absolute number of errors was much lower: as a group our agrammatics performed highly above chance. In a second study, we asked seven patients to order various types of sentences in which the position of the verb varied. Again the level of performance was highly above chance. There was no effect of sentence type with respect to verb position (VSO or SOV). Another effect of sentence type, however, was apparent. If the position of the verb could be determined by processing a cue that was within the clause to be ordered, the sentences elicited few errors. Sentences with out-of-clause cues were much more difficult. It seems that there is variability, both between patients and between sentences. A series of possible accounts of this variability is discussed. It is concluded that only some accounts are adequate, in particular those that assume the involvement of memory limitation due to restrictions in space or time. However, even these accounts cannot explain telegraphic speech. Therefore, to supplement them, a new theory of Broca's aphasia is proposed.