Linguistic characteristics of primary progressive aphasia in a verb-final language

Purpose: The current study aimed to examine the linguistic characteristics of Korean-speaking individuals diagnosed with primary progressive aphasia(PPA). Methods: Two individuals with agrammatic/non-fluent variants of nfvPPA and two with semantic variants of svPPA participated in this study. Picture description tasks were used to collect connected speech samples. Analysis focused on linguistic variables, including quantitative(number of utterances, words, nouns, and verbs), syntactic(mean length of utterance in morphemes, case markers per utterance, predicates per utterance), and semantic variables(correct information units, verb types). Additionally, participants completed two types of confrontation naming tasks. Results: The nfvPPA group exhibited fewer linguistic units overall compared to the svPPA group, with noun-verb dissociation apparent only in the nfvPPA group. The svPPA group showed poorer performance in content-related linguistic variables. A notable clinical symptom specific to Korean, case marker deficits, was observed in the nfvPPA group. Discussion: The study identified distinct linguistic patterns associated with the subtype of PPA in Korean speakers. The evaluation and interpretation of Korean-specific linguistic variables are crucial for classifying Korean-speaking individuals with PPA. Understanding these variables can enhance our comprehension of the unique linguistic deficits present in Korean PPA, particularly in relation to confrontation naming tasks and their implications for diagnosis and classification.