Effects of verb argument structure and the types of presentation modality on verb production in individuals with aphasia using a verb-final language

Abstract

Objectives: The purpose of this study was to evaluate the naming performance of persons with aphasia (PWA) by presentation mode and verb argument structure and to investigate the factors that can predict the severity of aphasia. Methods: The participants of this study were 16 aphasia patients and 16 normal individuals who were matched in age and years of education. Verbs were classified into four categories, one-place unergative, one-place unaccusative, two-place, three-place according to the argument structure, and were presented in static and dynamic modes. The correct responses of the participants were calculated and converted into accuracy (%). Results: The PWA showed significantly lower performance than the control group on the verb naming task. The control group did not show significant difference in verb naming task by verb argument structure and presentation mode, however PWA showed a significant increase in performance on one-place unaccusative and two-place verbs in both presentation modes. Among the variables by presentation mode and verb argument structure, the most predictive variables for severity of aphasia were one-place unergative and unaccusative verb in static mode which predicted the severity of aphasia at a rate of approximately 57.9%. For the dynamic mode, one-place unaccusative verbs were the most predictive variable for severity of aphasia and it predicted severity of aphasia 80.9% of the time. Conclusion: These results indicated that PWA had more difficulties in naming verbs than the control group and were affected by presentation mode for verb naming tasks. The severity of aphasia was predicted by computational load of passive structure process from object movement on one-place unaccusative verbs.