Mind over grammar: reasoning in aphasia and development

Research on propositional reasoning (involving 'theory of mind' understandi ng) in adult patients with aphasia reveals that reasoning can proceed in th e absence of explicit grammatical knowledge. Conversely, evidence from stud ies with deaf children shows that the presence of such knowledge is not suf ficient to account for reasoning. These findings are in keeping with recent research on the development of naming, categorization and imitation, indic ating that children's reasoning about objects and actions is guided by infe rences about others' communicative intentions. We discuss the extent to whi ch reasoning is supported by, and tied to, language in the form of conversa tional awareness and experience rather than grammar.