A linguistic dissociation in Williams syndrome: Good at gender agreement but poor at lexical retrieval

Abstract

Williams syndrome (WS) is a rareneuro-developmental disorder characterised byspared language in the face of serious deficitsin nonlinguistic cognitive abilities. Weconducted a study on ten WS individuals inwhich gender agreement and gender assignmentwere assessed by means of two tasks: gendercategorisation and gender concord. Subjectsperformed gender categorisation to real nounswhose gender was regular or exceptional giventheir ending, and to invented nouns which werecomposed of nonword or word stems and realword-endings. The same material was used in thegender concord task in which subjects had tomatch the items with the appropriate form ofthe article and the adjective carrying genderagreement. In the gender categorisation of realwords, WS were lower than controls but bothgroups demonstrated a similar sensitivity togender-ending regularities. In the gendercategorisation of nonwords, the results showeda clear dissociation. The WS subjects producedmore ending-consistent responses than thecontrols. Contrary to the controls, WS reliedheavily on the gender clue provided by theending even when the gender of the word evokedby the stem of the invented word was opposed tothat evoked by the ending. Participants with WSwere not influenced by the specific word evokedby the stem of the invented word. In the secondtask (concord task), the WS subjects performed well although lower than thecontrols. We concluded that the WS people werenot impaired in gender agreement which relieson syntactic rules and/or on the extraction ofregularities but experienced difficulties inretrieving lexical instances.