Verb retrieval in action naming and spontaneous speech in agrammatic and anomic aphasia

Abstract

The production of verbs in an action naming test and in spontaneous speech was evaluated in 16 aphasic patients: eight agrammatics and eight anomics. Action naming was also compared to object naming. The action naming test was controlled for factors known to be relevant for verb retrieval (i.e. word frequency, instrumentality, name-relation to a noun, transitivity and argument structure) and the objects were related to the verbs and chosen to match the verbs as precisely as possible on word frequency. For both aphasic subgroups object naming was better than action naming and there was no difference between agrammatics and anomics, neither in object naming, nor in action naming. In spontaneous speech, both agrammatics and anomics differed from normal controls on ‘verb diversity’ furthermore the agrammatics were significantly worse than normal speakers (and the anomics) in verb inflection and the proportion of verbs produced without internal argument was higher than in normal speakers (and in anomics). There was no significant correlation between the scores on the action naming tests and the diversity of verbs produced in spontaneous speech. It is suggested that for the anomics, this is due to the fact that for some patients it is more difficult to retrieve verbs in spontaneous speech than in isolation. For the agrammatics, the interference between verb retrieval and verb inflection seems responsible for the lack of a significant correlation.