Language use and schizophrenia. An analysis of coherence relations and connectives in schizophrenia spectrum disorder

Abstract

Schizophrenia spectrum disorder is a disorder that affects several aspects of language and cognition are affected. In the present study we examined the usage of coherence relations expressed by a connective. A coherence relation is a conceptual relation between two phrases or two sentences. Earlier research found that some coherence relations are less complex than others. The question answered in this study is whether there are differences in the usage of coherence relations expressed by a connective between schizophrenia spectrum disorder subjects and healthy controls. We used transcripts of interviews of twenty participants from the PRAAT research for the present study. All connectives expressing a coherence relation were marked and for each connective we determined a coherence relation. After that, all total amounts of the different coherence relations were compared between the two groups. The percentage connectives of all words is 3.63% in the schizophrenia spectrum disorder group and 3,71% in the healthy control group. Relations containing the primitive ‘negative’, ‘positive’, ‘temporal’ and ‘objective’ differ significantly between the two groups. Relations which contain the primitive negative are used more often by healthy controls, in contrast to relations which contain the primitive positive, which are used more frequently by subjects with schizophrenia spectrum disorder. Relations which are temporal are used more often by the subjects with schizophrenia spectrum disorder as are relations which contain the primitive objective. The differences in the use of the negative, positive and objective connectives were as expected. The difference in the use of temporal connectives was, however, contrary to our expectations. It is not clear how this could be explained. If we look at the combinations of different primitives, only the combinations of ‘positive-temporal-objective-basic order’ and ‘negative-non causal’ differ significantly. The first combination is used more often by subjects with schizophrenia spectrum disorder and the second combination by healthy controls. Schizophrenia spectrum disorder subjects probably use the first combination more often because they use more temporal connectives in general. For the ‘negative-non causal’ this is presumably because of the fact that the combination negative and non-causal is less complex than the combination negative and causal. Therefore the latter finding is as expected.