Noun-verb dissociations in brain-damaged patients: Further evidence

We report four patients (EO, DA, RI and SM) with noun-verb dissociation, EO had a disproportionate deficit for nouns in oral and written naming but not in comprehension. DA had a disproportionate deficit for nouns both in naming and in comprehension. RI and SM had a selective deficit for verbs in oral and written naming but not in comprehension, None of the patients showed modality-specific grammatical class effect. Patients with deficit for verbs were agrammatic and presented, to a different extent, short-term memory impairment. The functional locus of noun-verb dissociation and the possible role of short-term memory in generating verb deficit and some aspects of agrammatic syndrome are discussed. The neuroanatomical correlates of selective grammatical class deficit are also considered.