THE EFFECT OF LANGUAGE PRODUCTION MANIPULATIONS ON NEGATIVE THOUGHT-DISORDER AND DISCOURSE COHERENCE DISTURBANCES IN SCHIZOPHRENIA

This study was designed to test the following hypotheses about the mec hanisms underlying language disturbances in schizophrenia: (1) negativ e thought disorder (reduced verbosity and syntactic complexity, increa sed pausing) reflects a deficit generating a discourse plan; and (2) d iscourse coherence disturbances (tangential responses, loss of goal, d erailment, non-sequiturs, distractible speech) reflect a deficit maint aining a discourse plan. Thirty-nine participants with DSM-III-R schiz ophrenia listened to two stories and answered a series of questions af ter each story. We manipulated two factors: (1) the presence of contex t before the stories (to influence generating a discourse plan); and ( 2) question type (structured vs. unstructured; designed to influence m aintaining a discourse plan). Consistent with our hypotheses, low cont ext was associated with less verbose and syntactically complex speech. In addition, patients produced more discourse coherence disturbances when responding to unstructured than when responding to structured que stions. (C) 1997 Elsevier Science Ireland Ltd.