Effects of ambiguous and unambiguous stimulus word differences on popular responses of schizophrenics.

Tested that aspect of response interference theory that predicts that schizophrenics give fewer dominant and more competing responses for ambiguous, but not unambiguous, conditions. It was hypothesized that schizophrenics would evidence in a word association task greater gains, after treatment, in response popularity for ambiguous, but not for unambiguous, stimulus words. The prediction was assessed by administering a specially-constructed wordlist balanced for idiodynamic semantic sets (Moran, 1966). Results, from a pre- and posttest control group design, met predictions for 24 matched pairs of schizophrenics and neurotics: after 5 weeks of treatment, schizophrenics gained significantly in popular responses for ambiguous but not for unambiguous stimulus words, whereas neurotics did not gain significantly for either condition. Positive correlation for schizophrenics between ambiguous word response popularity gains in home and community adjustment as rated by a significant other coincided with expectations from response interference theory (Broen, 1968).