Category specific access dysphasia.

In this study we report our investigations of the residual auditory-verbal comprehension skills of a global dysphasic who had sustained a major left hemisphere infarction. Clinically V.E.R.'s capacity for propositional speech and her comprehension of the simplest verbal instructions appeared to be absent. Nevertheless using matching-to-sample techniques it was possible to demonstrate the selective preservation (foods, animals and flowers) and the selective impairment (objects) of specific semantic categories. Furthermore there was evidence from analyses of response consistency and presentation rate effects that her deficit was primarily one of access to the full semantic representation of words. We suggest that this access impairment arose because the system had become refractory, such refractoriness being category specific.