The influence of a working memory load manipulation on language production in schizophrenia.

The present study examined the hypothesis that working memory deficits contribute to both negative thought disorder and some components of formal thought disorder (discourse coherence and fluency deficits) in individuals with schizophrenia. We examined the language produced by 44 patients with either schizophrenia or schizoaffective disorder during baseline and a dual-task condition designed to decrease working memory capacity. Results indicated that decreasing working memory capacity significantly increased negative thought disorder, but not discourse coherence or fluency deficits. However, both negative thought disorder and discourse coherence deficits were significantly correlated with working memory deficits. In addition, increases in negative thought disorder and discourse coherence deficits in the dual-task condition were negatively correlated, consistent with the hypothesis that these two types of language deficits may reflect alternative manifestations of working memory deficits.