English validation study of the Schizophrenia Communication Disorder Scale (SCD)

Language defects are one of the nuclear features of schizophrenia, and difficulties in semantic memory processing have been considered to be at the core of these deficits. However, the underlying mechanisms of deficits in semantic memory processing and their relationship to the overt symptoms of schizophrenia are still not entirely understood. Furthermore, tools for assessing language deficits in schizophrenia are sparse and the existing ones are based on observations rather than a pathophysiological understanding of these deficits. The first part of this thesis is a literature review aiming to explore the underlying mechanisms of language deficits in schizophrenia. The review focuses on the findings produced by the studies employing event related potential techniques that aim to provide objective measures of pathophysiological mechanisms of language deficits and relate them to overt, behavioural symptoms in schizophrenia. Given the wealth of data produced by these studies, the review focuses on the recent advances in this area of research and discusses the possible directions for the future research. Part two is an empirical paper presenting a validation of the English version of the Schizophrenia Communication Disorder Scale (SCD). SCD is a clinical scale designed to quantify communication deficits in schizophrenia by assessing the underlying deficits of language disorder in schizophrenia, as demonstrated by electrophysiological findings presented in the review paper. Specifically, the SCD measures contextual information processing and theory of mind abilities. The original version was published in French, and we aimed to translate the scale in to English and provide the preliminary findings on the reliability and validity of the English version. Additionally, SCD data for a healthy control sample has been presented for the first time. Part three includes my personal reflections going through the experience of research. It also includes a critical appraisal of the research project

Mismatch negativity in schizophrenia: a meta-analysis

MMN deficits are a robust feature in chronic schizophrenia and indicate abnormalities in automatic context-dependent auditory information processing and auditory sensory memory in these patients. Reports of normal MMN in first-episode schizophrenia and the association of deficits in frequency MMN with illness duration suggest that MMN may index ongoing neuropathological changes in the auditory cortex in schizophrenia