The Characteristics of semantic association task performance in elderly with subjective memory impairment and mild cognitive impairment

주관적 기억장애 및 경도인지장애 노인의 의미연상과제 수행 특성

Abstract

The loss of semantic knowledge and impairments in semantic associations by semantic category is gaining increasing attention, as indicators of early-stage cognitive decline. As such, we assigned semantic association task (SAT) to normal elderly (NE) and those with subjective memory impairment (SMI) or mild cognitive impairment (MCI) to examine their performance by semantic subcategories and the differences in error patterns. We found a significant difference in the number of correct response and reaction time under the SAT categories among the three groups, with the highest performance observed in 'function' and the lowest performance in 'superordinate' and 'part/whole'. Moreover, the error frequency was the lowest in NE, followed by those with SMI and MCI, with the latter two groups showing a significant increase in no-response. Our findings demonstrate the varying extent and process of impairments in the semantic network by category over different stages of cognitive decline. Thus, we proposed SAT performance as an indicator to detect and follow-up on cognitive decline in elderly with cognitive disorder.

초기의 인지 감퇴를 판단하는 요소로 의미지식 및 의미 연관관계의 범주별 손상 유무가 주목을 받고 있다. 본 연구에서는 정상 및 주관적 기억장애, 경도인지장애 노인을 대상으로 의미연상과제를 사용하여 인지 감퇴의 정도에 따라 관찰되는 의미 하위범주별 수행과 오류유형의 차이를 살펴보고자 하였다. 연구 결과, 의미연상과제 범주별 정반응 점수와 반응시간에서 세 군 간 유의한 차이를 보였으며, 하위범주 중, '기능'에서 가장 높은 수행력을, '상위'와 '부분/전체'에서 가장 낮은 수행력을 보였다. 또한, 오류유형별 산출 횟수는 정상에서 경도인지장애 노인으로 갈수록 유의하게 높아졌으며, 무반응은 주관적 기억장애 노인부터 유의하게 증가하였다. 결론적으로, 인지 감퇴가 진행될수록 의미연결망에서 범주별 손상의 정도와 과정이 다르므로, 기억장애 노인의 인지적 감퇴를 확인하고 추적 관찰하기 위한 지표로 의미연상과제 수행력을 활용할 수 있을 것이다.

Fig. 1. Modification process of SAT

Fig. 2. composition of SAT

Fig. 3. Calculation method of IES

Fig. 4. Post-hoc test result on the total number of correct response and reaction time of SAT by group

Fig. 5. Post-hoc test result on the number of correct response of SAT by each subcategory

Fig. 6. Post-hoc test result on reaction time of SAT by each subcategory

Fig. 7. Post-hoc test result on the number of errors by error type

Table 1. demographic information of participants

Table 2. Descriptive statistics on the total number of correct response and reaction time of SAT between three groups

Table 3. Descriptive statistics on the number of correct response by each sub-category of SAT between three groups

Table 4. Post-hoc test result on the number of correct response of SAT by group

Table 5. Post-hoc test result on the number of correct response of SAT depending on groups by each subcategory

Table 6. Descriptive statistics on reaction time by each subcategory of SAT between three groups

Table 7. Post-hoc test result on reaction time of SAT by group

Table 8. Descriptive statistics on the number of errors by error type between three groups

Table 9. Post-hoc test result on the number of error of SAT by group

Table 10. Post-hoc test result on the differences of the number of errors by error type within group