Aphasia and bilingualism: Cognate and non-cognate verb naming in Kurdish-Persian speakers

Aims and objectives: Bilingual aphasia presents unique challenges due to the interaction of multiple language systems. This study investigates the role of cognates, words that share origin and form across languages, on verb naming in Kurdish-Persian bilinguals with and without aphasia, addressing a gap in existing research that primarily focuses on nouns. Methodology: A cross-sectional study compared nine Kurdish-Persian bilinguals with aphasia following left-hemisphere stroke to 40 healthy bilingual controls. Participants completed a verb-naming task using 90 verbs (42 cognates, 48 non-cognates) presented visually in both Kurdish (L1) and Persian (L2) using DMDX software, with a 1-week interval between assessments. Accuracy and reaction time were the primary outcome measures. Data and analysis: Accuracy was scored as correct (1) for cognate and non-cognate verbs in each language, and mean reaction times were analyzed. Correlations between accuracy and speed were examined within and across groups. Findings and conclusions: Results indicated that healthy participants outperformed bilingual persons with aphasia (BPWA) in both accuracy and speed for verb naming. Both groups exhibited a cognate advantage, with BPWA showing a more pronounced difference in performance, particularly for L1 non-cognates. The findings suggest that shared phonological representations in cognates facilitate lexical access, particularly beneficial for individuals with aphasia. Originality: This study uniquely focuses on verb naming in Kurdish-Persian bilingual aphasia, a population under-represented in the literature. Most prior research on cognate effects in bilingual aphasia has concentrated on nouns. Significance/implications: The findings highlight the importance of considering linguistic factors like cognate status in assessing and treating bilingual aphasia. The cognate advantage suggests the potential for using cognates in therapeutic interventions to improve lexical retrieval and communication skills in BPWA. Therapeutic strategies utilizing cognate verbs may enhance recovery outcomes for bilingual individuals, warranting further exploration within diverse bilingual communities.