A Linguistic Study of a Phonemic Verbal Fluency Test for Dementia Screening

Abstract

This study proposes, from a linguistic perspective, a criterion for and new classifications of phonemes for cognitive tests to detect dementia in Korea. The currently used phonemes or characters in the phonemic fluency test are “ᄀ”, “ᄋ”, “ᄉ”, and “ᄂ”, which are selected based on their frequency in the dictionary. However, results show that the less frequent phoneme “ᄉ” is uttered more in dementia patients’ speech than the more frequent one “ᄀ” is. It shows that the currently used classifications of phonemes do not properly represent linguistic capacity. Moreover, comparison between “ᄀ” and “ᄉ” or between “ᄀ” and “ᄂ” is inappropriate because the given phonemes differ in their places of articulation as well as manners of articulation. Thus, we discuss different statuses of phonemes in terms of language acquisition, language impairments, and VOT measurements. We, then, propose to select a single parameter, i.e., either place or manner of articulation, in order to assess the linguistic ability of the dementia patients.