Perception of functional morphology in agrammatic Broca’s aphasia

Abstract

Individuals with agrammatic Broca’s aphasia show marked deficits in production of functional morphemes such as complementizers (like that and if) and tense and agreement markers (like –ed and –s). Furthermore, production of complementizers appears to be more impaired in many aphasic individuals than production of verbal morphology (Friedmann Hagiwara, 1995; & Grodzinky, 1997; Milman, Dickey, & Thompson, 2004). Some accounts, in particular the Tree-Pruning Hypothesis (Friedmann & Grodzinky, 1997), have linked this production deficit to the hierarchical syntactic structure associated with these morphemes. Specifically, morphemes associated with higher functional projections (e.g., complementizers) are more impaired than those associated with lower projections (e.g., verbal inflections). This paper presents the results of two grammaticality judgment experiments examining the perception of complementizers and verb inflections by English speakers with Broca’s aphasia. If perception patterns with production, perception of complementizers is expected to be more impaired than perception of verbal morphology, particularly under the Tree-Pruning Hypothesis.