Characteristics of confrontation naming ability according to word frequency in patients with amnestic mild cognitive impairment: A preliminary study

Abstract

Objectives: Characteristics of word finding difficulty due to cognitive decline may be influenced by word frequency. We investigated the characteristics of confrontation naming ability of mild cognitive impairment (MCI) patients according to word frequency and examined the relationship between overall cognitive function and confrontation naming ability. Methods: We performed Korean version of Boston Naming Test (K-BNT) and a low frequency word naming task (Difficult Naming Test, DNT) in 40 normal elderly and 35 amnestic-MCI (aMCI) patients. In both tasks, response scores to each item and the type of errors in low frequency word naming tasks between the two groups were analyzed. In addition, we analyzed the correlation between Korea version of Mini-Mental Status Examination (K-MMSE) scores and K-BNT scores and DNT scores. Results: First, the aMCI group showed significantly lower performance in all tasks than the normal elderly group. Both groups showed lower scores in the DNT than in the K-BNT, but these differences in performance were greater in the aMCI group. Second, aMCI group showed a significantly higher ratio of semantic error, visual errors, and non-related errors. Third, there was a statistically significant correlation between the K-MMSE scores and the DNT scores in the aMCI group. Conclusion: High frequency words are strong and stable in representations stored in the semantic system, but low frequency words usually have weaker intensity of semantic representation. Therefore, they may be more sensitive indicators of the neurological changes of aMCI. In terms of clinical application, DNT can be used to identify and distinguish functional decline in individuals with aMCI.