Process types in Persian-speaking aphasic discourse: a systemic functional approach

Abstract

This research explores the verbs used in aphasic spoken data by using Hallidayan systemic functional linguistic framework and compares them with the type of verbs used by healthy subjects. Persian aphasia test was used to recruit eight right-handed aphasic patients (mean age of 57.5 years) based on convenient sampling, and there was also another control group of six healthy participants (mean age of 52.2±2.04 years). They were interviewed orally and the process types in each group were determined and compared. These processes were compared to each other by using descriptive statistics characteristics such as the mean and standard deviations of the processes. In order to study descriptive results more precisely, statistical inference was used and ‘test for comparing two binominal populations’ was implemented to analyze differences of the process proportions between two groups. Results showed that aphasics significantly used more material processes than normal individuals (p=0.021); on the other hand, aphasics significantly used less relational (p=0.012) and behavioral (p=0.018) processes than normal individuals. There could be seen no significant differences for the use of mental, verbal, and existential processes between the two groups (p>0.05). Relying more on some processes and less on some others in aphasics implies the linguistic areas where they have more problems with and suggests where they base their speech in the process of recovering linguistic abilities. These findings has implications for both linguists and language pathologists.