Objectives: The purpose of this study was to identify preferences of thematic role assignment in aphasia patients and to figure out the connection between thematic roles and verbs. Methods: Eighteen persons with aphasia and twenty individuals who matched their age and years of education and lived in Seoul or Gyeonggi participated in this study. The thematic role preference task measured ratio (%) of thematic role preference and the verb selection task measured accuracy (%). Results: First, both groups preferred theme to instrument. This can be interpreted to mean that in Korean thematic role hierarchy, theme is higher than the instrument. Second, the performance of persons with aphasia in the verb selection task was lower. This means that persons with aphasia have difficulty accessing verbs and the elements in their sentences. The difference in performance of the task was not significant, but persons with aphasia had a higher accuracy than the instrument. This can be interpreted as showing that the instrument becomes more active than theme when connected to verb. Third, both thematic roles showed strong correlations with aphasia severity. Theme was the prediction of aphasia severity approximately 74.5% of the time. This showed that persons with aphasia are also affected by the necessity of the argument. Conclusion: The preference of thematic role in persons with aphasia is influenced by its hierarchy. But in the connection of thematic role and verb, it is influenced by activation through semantic relation rather than syntactic structure. In particular, theme is a variable that predicts the aphasia severity.
- Thematic role