Self-repair in dialogues of schizophrenics: effects of hallucinations and negative symptoms

This paper concerns the discourse features of verbal hallucinations and negative symptoms of schizophrenia. A total of 46 schizophrenics, varying in verbal hallucination and in negative symptoms status, and 22 controls were tested on the Reporter Test. The frequency with which they issued inadequate instructions, attempted to repair the inadequacies, and the success of repairs were compared. We observed that schizophrenics, on the whole, issued more wrong and incomplete instructions. This was in part related to their worse working memory, but it was not affected by verbal hallucinations or negative symptoms. We observed, further, that schizophrenics had no particular problems monitoring messages for inadequacies. We did find, however, that schizophrenics with verbal hallucinations had a specific problem with self-repairing wrong instructions. We interpret these results in the framework of Hoffman's (1986b) plan disruption-based model of verbal hallucinations; the Frith (1987) and Frith and Done (1988) internal monitoring model of positive and negative symptoms; and finally Frith and Frith's (1990) model of negative and positive schizophrenia and we use the results to specify the models.