Many studies on aphasia have described disproportioned impairment of either verbs or nouns and have broached the issue of mental implementation of the grammatical class distinction. A clear picture has not yet been reached and, while evidence has been found to indicate the lemma level as the possible locus of this distinction (Crepaldi et al., 2006), some alternative interpretations have been proposed (e.g., Rapp & Caramazza, 2002).

These studies have focused almost exclusively on picture naming tasks, and have practically ignored the assessment of the dissociation in spontaneous speech. A remarkable exception is the study by Bastiaanse and Jonkers (1998) in which, however, the authors considered only verb-impaired patients and focused exclusively on the production of verbs. The results of this study indicate that the naming performance resulting from picture naming tasks does not always correlate with lexical retrieval in spontaneous speech. The present study aims at verifying: (i) whether the disproportionate verb or noun impairment that emerges from a picture naming task is also present in spontaneous speech, and (ii) whether this occurs irrespective of the type of aphasia.