Tense and agreement processing in native Spanish speakers with aphasia

Several cross-linguistic studies have reported an impairment of verbal morphosyntax in People with Aphasia (PWA), highlighting a greater impact on tense morphology in contrast to agreement-inflectional morphology (Benedet, Christiansen & Goodglass, 1998; Friedmann & Grodzinsky, 1997, 2000; Gavarr & ograve; & Mart & iacute;nez-Ferreiro, 2007; Kok et al., 2007; Wenzlaff & Clahsen, 2004). The Diacritical Encoding and Retrieval Hypothesis (DERH, Faroqi-Shah & Thompson, 2007) postulates that this deficit is due to a specific difficulty projecting the semantic time information to the morphosyntax of verbs, related to processing limitations in PWA. This study aimed to assess the processing of the tense and agreement inflection in Spanish-speaking PWA. A group of 9 PWA completed four tasks designed to study verbal inflection production and comprehension in Spanish: Sentence Completion, Sentence Elicitation, Grammaticality Judgements and Sentence-Picture Matching. As expected, PWA showed a significatively greater impairment in tense inflection compared to agreement inflection. Furthermore, the analysis showed that this differential impairment manifested when PWA were asked to encode semantic time information and retrieve the corresponding verb morphology. These findings are consistent with the postulates of the DERH.