Grammatical and lexical pronoun dissociation in French speakers with agrammatic aphasia: A usage-based account and REF-based hypothesis

- A usage based theory assigns grammatical status to only a subgroup of pronouns.
- This theory links up structural and neurocognitive complexity in language.
- As predicted, in agrammatic speech grammatical pronouns are more severely affected.
- Individual variability may be understood as the result of adaptive strategies.

BackgroundPronouns have been shown to be impaired in agrammatic production but not all types of pronouns are equally affected. For instance, clitic pronouns are more impaired than non-clitic ones. A usage-based theory of grammatical status suggests a reclassification of pronouns into grammatical and lexical and predicts that grammatical pronouns are more impaired in agrammatic production. Besides, the reorganization of elementary functions (REF) model, which describes the underlying neurocognitive processes of post-injury recovery, explores the variability across individuals with agrammatism.AimsThe current study hypothesizes that those pronouns that by the usage-based theory of grammatical status are grammatical are more affected than the lexical ones in agrammatic speech. In addition to this, the REF-model predicts that individuals with agrammatism will either build up unique strategies to cope with the deficit or they will rely more on fixed expressions.Method& Procedures: Spontaneous speech data collected from six French speaking individuals with agrammatism and nine non-injured controls in three different contexts (autobiography, narrative speech and descriptive speech) was used to test the hypothesis. We categorized 137 French pronouns into lexical and grammatical and calculated a grammatical pronoun index (GPI) for the groups and the individual speakers with agrammatism. We also conducted a qualitative analysis to look for adaptive strategies.ResultsFour individuals with agrammatism out of six produced significantly fewer grammatical pronouns than the non-injured group in the autobiography task. The two individuals with agrammatism who did not significantly differ from the control group were more fluent than the other four. The exclusion of pronouns containing fixed expressions did not result in drastic changes. The pronoun-verb analysis showed that there is no consistent connection between subject pronoun production and verb finiteness.ConclusionsGrammatical pronoun production is indeed more severely impaired in agrammatic production. Moreover, the impairment pattern varies across individuals with agrammatism. Variability is observed both across participants with agrammatism and across tasks, which may indicate the use of unique adaptive strategies, as predicted by the REF-model.