S-sli: Two Different Impairments

Individuals with agrammatic aphasia and children with syntactic SLI (Specific Language Impairment) have difficulties understanding object relative clauses, difficulties that have been ascribed to a deficit in phrasal movement. The aim of the current study was to explore the nature of this deficit in movement in the two populations, and to examine whether the underlying deficit in the two populations is the same. Individuals with Broca's agrammatic aphasia show significant difficulties in the comprehension of object relative clauses, object Wh-questions, and These impaired structures share a syntactic property: they are all derived by movement of a phrase that results in a non-canonical order of the arguments. This led researchers of agrammatism to suggest that individuals with agrammatism have an impairment in phrasal movement (Grodzinsky, 1990, 2000). Similarly, some researchers of SLI suggest that the deficit in these structures in SLI is related to a deficit in for an earlier suggestion that the difficulty is in sentences in which the surface structure is different from the deep structure). Yet, the exact nature of the deficit in movement is still an open question. What exactly is impaired when movement is impaired in these two populations? Is the deficit related to the construction of syntactic structure and traces, or is the structure constructed correctly and the deficit relates to a failure to transfer thematic roles via chains?