Minimality effects in agrammatic comprehension: The role of lexical restriction and feature impoverishment

Cross-linguistic studies in agrammatic aphasia have attested asymmetries in the comprehension of semantically reversible structures with canonical vs. non-canonical argument order, with the latter compromised. Recently, Grillo, 2005, Grillo, 2008, Grillo, 2009 introduced the Relativized Minimality approach to locality in syntax as a possible explanation for agrammatic deficits, suggesting that minimality effects arise between an A'-moved element and its copy/trace if there is an intervener with similar morphosyntactic features. In an extension of this approach, Friedmann et al. (2009) suggested that the source of minimality effects is the presence of lexical NP restriction in the displaced and in the intervening element. The present study aimed at investigating whether the predictions within this version of RM can be confirmed by the data obtained from six Greek-speaking agrammatic individuals. Our results provide some support for Friedmann et al.'s RM approach but are not entirely compatible with it. We suggest that minimality effects in the agrammatic speakers' comprehension can emerge even in the absence of lexical NP restriction, and that the internal structure of the A'-moved element and of the intervener crucially modulates these effects, although to a lesser extent. Last, we show that morphological case does not facilitate agrammatic speakers' comprehension, and, thus, we conclude that morphology does not provide cues that can 'resolve' minimality effects in language breakdown.