Preference for denotative as opposed to connotative meanings in schizophrenics

Twenty schizophrenics, 20 manics and 20 subjects with a depressive illness were asked to select the pair of words from a group of three which went together best. The groups of words were arranged such that potential pairings reflected shared denotative (e.g., linked by being antonyms) or shared connotative meaning (e.g., linked at a metaphorical level). The measure "denotative-based--connotative-based selections" was significantly lower in schizophrenics than manics and just failed to significantly distinguish schizophrenics from depressives. In a second experiment schizophrenics were significantly different from the depressives in showing less inclination to select a metaphorical meaning to an ambiguous adjective in a sentence. It is suggested that these results arise because the schizophrenic relies more on their left hemisphere lexicon in carrying out such semantic tasks.