Abstract
This article examines the nature of syntactic disorders in agrammatic aphasics from the viewpoint of current linguistic theory, i. E. the generative grammar (Chomsky, 1993, 1995). It is shown that Hagiwara (1995) 's generalization on grammatical disorders, which state that the lower the functional projections are, the more accessible they are to an agrammatic aphasic, has been replicated by the experiments on many languages including Hebrew, Arabic, Dutch, and French and that cumulative evidence shows the validity of the hypothesis. The explanation of this phenomena is proposed in Hagiwara (1995) in that agrammatics's grammar allows convergence, i. E. successful computation at lower functional projections, because such structure are less costly from a global economy perspective (i. E. comparing different syntactic derivations : Chomsky, 1993). We maintain that this Economy Principle on agrammatism is more highly adequate than the other proposals with respect both to its coverage of the modality of patients' performance and to the level of explanatory adequacy. The last part of this article discusses the assessment of grammatical disorders along the line of hierarchical syntactic structures and its application to language therapy.
