Representation, referentiality, and processing in agrammatic comprehension: two case studies.

A number of investigators have argued that agrammatic comprehension, the pattern of sentence comprehension often associated with Broca's aphasia, can be characterized in terms of a representational disruption in one or another module of the normal grammar. In this study, these proposals are reviewed and their adequacy is examined in light of two case studies of agrammatic comprehension. In particular, we present data from sentences that have composed the core of the agrammatic comprehension pattern, as well as data from three different classes of sentences including comprehension of the matrix clause of center-embedded relative constructions, pronoun and anaphor dependencies, and Wh-questions. Our conclusion is that none of the existing representational models provides a fully adequate account of the data, and we propose some alternative approaches that distinguish between referential and nonreferential elements and potential processing differences between the two.