The influence of the typicality feature in the production of language associations in schizophrenia

Abstract

Language deficits in schizophrenia are hypothesized to be a result of increased spreading of activation in the semantic memory during language processing. The spreading of activation is determined by the features of concepts activated in search and retrieval processes. One of the features thought to have a great influence on processing is the typicality feature (Holmes & Ellis, 2006). The aim of this study was to establish whether there are differences in language processing in schizophrenia subjects compared to a healthy control group in a verbal fluency task based upon the typicality feature. Specifically, the analysis was limited to the first cluster of the verbal fluency task because it requires the least effort in terms of task restrictions (Venneri et al., 2008). The study included 8 patients diagnosed with schizophrenia from the University Psychiatric Hospital Vrapče and 8 healthy control subjects. A category semantic fluency task was conducted on both groups, and the healthy control group was given a typicality rating task consisting of exemplars produced by both groups in the first cluster of the former task. Results analysis showed no differences in the typicality ratings of exemplars between the groups in any of the categories except the animals category. These results also indicate differences in the language processing of the animals category and could suggest differences in the processing of animacy features. Additionally, the results show that there are no differences in language processing of the typicality feature in other semantic categories in first-episode psychosis subjects in relation to the healthy control group. Future studies should additionally analyze the processing of animacy features and typicality in schizo-phrenia-spectrum disorders across different illness phases.