An fMRI study of processing novel metaphoric sentences

Due to inconsistentfindings, the role of the two cerebral hemispheres in processingmetaphoric language iscontroversial. The present study examined the possibility that these inconsistentfindings may be due, at least partly, to differences in the type (i.e., wordsvs. sentences) or/and the familiarity or salience of the linguistic material.Previous research (Mashal, Faust & Hendler, 2005) has shown that directcomparison of novel two-word metaphoric expressions and unrelated word pairsshowed stronger activation in the right homologue of Wernicke's area for thenovel metaphors than for the unrelated word pairs. In the present study, fMRIwas used to identify the left (LH) and right hemisphere (RH) neural networksassociated with processing unfamiliar, novel metaphoric sentences taken frompoetry, as compared to those involved in processing familiar salient literalsentences and unfamiliar nonsalient nonsensical sentences. Across subjects,several left lateralized brain regions showed stronger activation for novelmetaphoric sentences than for the nonsensical sentences although both types ofsentence represent unfamiliar, nonsalient linguistic expressions. Moreover, themetaphoric sentences elicited more activation in the left dorsolateralprefrontal cortex and the posterior middle temporal gyri than did both the literalsentences and the nonsensical sentences.