Lexical Semantics and Memory for Words in Aphasia

Aphasic and non-neurological patients were assessed on a word recognition memory task. On any one trial, some words were instances of the same superordinate category, thus presupposing a common abstract conceptual feature, and some words could be linked thematically in the sense of forming context-dependent relations. Observing the temporal order in which patients pointed to the words they recognized permitted an assessment of the extent to which they clustered their responses either in terms of superordinate categories or along thematic lines. The conceptual structures indicated by these clusters were compared with those observed in a previous task requiring judgments of word relatedness. The data suggest that verbal memory limitations in aphasia are only in part linked to constraints on the conceptual features structuring lexical knowledge; and relatedly they raise the possibility that aphasics may have a disturbance of mnemonic processing quite apart from any disruption to language.