Neuropsychological and computational evidence for a model of lexical processing, verbal short-term memory and learning

Almost without exception, acquired language disorders resulting from focal brain injury are accompanied by impairments of verbal short-term memory (STM) and verbal learning. Moreover, disturbances in verbal STM are generally associated with language dysfunction, in some cases mild and not disruptive to most language activities. The co-occurrence of language and mnestic deficits in the aphasic population affords the opportunity to examine their relationships. Here we review evidence from aphasia supporting the view that verbal STM processes are inextricably linked with the lexical processing system (as opposed to drawing solely on an independent shortterm memory system). These studies are discussed as a foundation for the development of a new model of word processing, verbal STM and learning. An inherent assumption of this model is that spreading activation processes which maintain activation of linguistic representations when generating a single word also contribute to the support of multiple word representations in verbal STM.