Quantification of Coherence in Spoken Language asan Indicator for the Schizophrenia Spectrum Disorder

Abstract

A low level of coherence in spoken language is one of the positive symptoms in the schizophrenia spectrum disorder. Previous studies have developed methods that can quantify the coherence level in spoken and written language. These methods are helpful for an objective analysis of discourse. In this paper two existing methods that quantify coherence in spoken language are re-implemented and applied to a new data set consisting of interviews with patients and with a healthy control group. Besides, we present an additional method to quantify coherence of spoken language whose results differ significantly between the patients in the schizophrenia spectrum disorder and healthy controls. Furthermore, an effect size showed a medium positive correlation between the PANSS positive symptoms and the coherence level outputted by new model. Our research has been an improvement to this field due to the use of a larger data set compared to other studies. Hopefully our findings will lead to improvements trying to diagnose more objectively in the schizophrenia spectrum disorder in other studies.