Semantic and pragmatic relations in categorization in early-course psychosis

Abstract

In schizophrenia, language processing indicates an over-inclusiveness (Chen, 1994; Brebi-on, 2010) in category (hypernymy and hyponymy) relations. The aim of this study was to examine the preservation of category relations of semantic memory in first-episode and ear-ly-course schizophrenia-spectrum psychosis as it offers an insight to foundations of schizophrenia language deficits. The study was conducted in cooperation with the University Psychiatric Hospital Vrapče on 17 patients. The patients’ results were correlated with those of a matched control group. The test that was used to conduct the experiment was constructed for the intent of this study, and it consisted of 10 categories, each of which was tested over 5 trials. For each trial, participants had to choose a member of a presented category. Possible answers included the target word (a category member such as hobotnica ‘octopus’), a pragmatic-semantically related distractor (e.g. more ‘sea’), a lexical-semantically related distractor (e.g. krak ‘tentacle’), and an unrelated distractor (e.g. truba ‘trumpet’). None of the unrelated distractors in either group were selected as category members. Although both pragmatic-semantically related and lexical-semantically related distractors were classified as category members more often in the patient group, pragmatic-semantically related distractors were chosen more often than lexical-semantically related distractors. While the results support the theory that concept representations in the semantic memory are not completely lost, the question remains whether the representations are degraded or whether there is a difference in search and retrieval processes in patients with first episode psychosis (FEP) when compared to a healthy control group.