年長者之後設記憶隨時間變化之進程：探索其與執行功能之間的關聯性

Abstract

主觀記憶衰退（SCD）是後設記憶的一種表現形式，與發展失智症的風險增加有關，但其與客觀記憶表現之關聯仍有所爭議。正常老年人與輕度認知功能障礙患者可能由於執行功能的不同，導致後設記憶能力存在差異。然而，不同的評估方法可能導致在後設記憶和執行功能之間產生不同的關聯性。本研究旨在使用學習判斷（Judgment of learning）和知感（Feeling of Knowing）的測量方法，以比較正常老年人與輕度認知功能障礙患者隨時間變化的記憶和後設記憶表現，並探討後設記憶表現的變化、後設記憶的不同表現形態、以及不同執行功能之間的關聯性。本研究顯示，輕度認知功能障礙患者的記憶和後設記憶表現與正常老年人相似，但其自由回憶表現比正常老年人較低。此外，在正常老年人中可以發現執行功能的不同面向在後設記憶變化中有不同的影響，且推理能力在學習判斷的不同表現類型上有顯著差異，但在輕度認知功能障礙患者中未能發現類似的關聯性。總體而言，僅靠執行功能可能難以完全解釋輕度認知功能障礙患者與正常老年人的後設記憶變化，而輕度認知障礙患者可能使用替代機制來調整其後設記憶之判斷。

Subjective memory decline (SCD) among older adults, a manifestation of metamemory, is linked to an increased risk of developing dementia, yet the relationship between SCD and objective memory performance remains disputed. Older adults with and without mild cognitive impairment (MCI) exhibit varied metamemory ability, likely due to differences in executive function. However, different assessment methods may yield distinct associations between metamemory and executive function. This study aimed to examine memory and metamemory performance changes over time in healthy controls (HCs) compared to patients with MCI, using Judgment of learning (JOL) and Feeling of knowing (FOK) measures. Additionally, the study explored the association between changes in metamemory performance and various executive functions while considering demographic and clinical variables in HCs and patients with MCI. Furthermore, differences in executive functions were investigated among subgroups based on accurate and inaccurate metamemory adjustments, as indicated by changes in bias scores in different metamemory paradigms in patients with MCI and HCs. The analyses included using analyses of covariance and hierarchical regression analyses to assess the relationship between executive functions and metamemory abilities after controlling for sex, gender, education, and depressive symptoms. The findings revealed that patients with MCI exhibited similar memory and metamemory performances to HCs, except for recall performance. Moreover, different aspects of executive functions appeared to have distinct roles in the observed changes in metamemory judgments over time in HCs, but no significant correlations were found in the MCI group. Regarding the correlation between subgroups and executive functions, the result revealed that only the two HC subgroups based on JOL exhibited significant differences in reasoning ability. Overall, the results suggested that executive functions alone could not fully explain the observed changes in metamemory among patients with MCI compared to HCs, indicating that individuals with MCI may employ alternative mechanisms to adjust their metamemory judgments.