Appreciation of metaphoric alternative word meanings by left and right brain-damaged patients

Appreciation of metaphoric and nonmetaphoric alternative word meanings was assessed in 19 aphasic, left (LHD) and 15 non-aphasic, right (RHD) hemisphere brain-damaged stroke patients. With the one exception in the aphasic group, all patients were male. In an unspeeded sorting task, subjects responded on the basis of less frequent, alternative meanings of polysemous target words. Targets were either polysemous adjectives (e.g. "warm") having metaphoric alternative meanings (loving) or polysemous nouns (e.g., "pen") having non-metaphoric alternative meanings (writing implement, cage). Both patient groups performed worse overall than a group of nonbrain-damaged control subjects. Relative to the RHD patients, LHD patients showed a spared appreciation of metaphoric alternative meanings. In addition, LHD, but not RHD, patients performed better on metaphoric adjective trials when there was high similarity between a word's dominant and (metaphoric) alternative meaning. The results suggest a pervasive insensitivity of RHD patients to alternative interpretations of linguistic units, and a special role for the intact right hemisphere in lexical-semantic processes related to metaphor comprehension.