How selective are selective word class deficits? Two case studies of action and object naming

In this article two case studies of fluent aphasic speakers are presented. Both patients performed significantly worse on an action-naming task than on an object-naming task, whereas comprehension of verbs was spared. The items of the action-naming test were controlled not only for the well-known factors that may influence word retrieval (e.g. word-frequency and imageability), but also for other variables that might be of relevance-that is, instrumentality, name relation to a noun and transitivity. Although both patients retrieved nouns better than verbs, word class as such did not seem to be the discriminating factor. In one patient name relation to a noun was particularly helpful in verb retrieval (verbs related in name to nouns were retrieved as easily as nouns in general), whereas in the other patient transitivity demonstrated an effect: he retrieved transitive verbs significantly better than intransitive verbs. It will be argued that the often-made distinction between verbs and nouns may be too rough, and may create artefacts. More careful matching on linguistic and extralinguistic criteria is necessary to learn more about the cognitive representation of verbs and nouns, and to obtain a better understanding of the effect of brain damage on word retrieval.