執行功能對老年人客觀與主觀記憶評估之一致性影響

Abstract

過去研究發現主觀記憶抱怨與客觀記憶表現之關聯相當不一致。本研究依主、客觀記憶評估之落差分數（discrepancy score）反映主觀評估的準確程度與落差方向，以瞭解正常老年人及輕度認知功能障礙患者之執行功能對主、客觀記憶評估一致性的影響。研究發現執行功能可預測主、客觀記憶評估的落差方向，高執行功能與低估其記憶功能相關，低執行功能與高估其記憶功能相關，且正常老年人組較易出現低估傾向，輕度認知功能障礙組則較易出現高估傾向。本研究指出正常老年人及輕度認知功能障礙患者之執行功能在主觀記憶抱怨與客觀記憶表現的關聯中扮演重要角色，暗示過去研究發現的不一致結果可能和此存在於主、客觀記憶評估的落差有關。

Previous literature has demonstrated inconsistent connection between subjective memory complaint (SMC) and objective memory performance. This study aimed to examine the relationship between the level of executive functioning and accuracy of SMC in cognitively intact older adults and individuals with mild cognitive impairment (MCI). Sixty-five cognitively normal (CN) and 54 MCI participants were recruited. Discrepancy scores between SMC and objective memory performances were calculated to indicate the degree and directionality of the concordance between subjective and objective measures. The results showed that executive functioning significantly predicted discrepancy scores above and beyond the non-cognitive (e.g., demographical variables) and clinical (e.g., health conditions, ApoEε4 status) factors. Lower executive functioning was associated with overestimation of objective memory functioning, while higher executive functioning was associated with underestimation. The CN and MCI groups reported similar degrees of SMC; however, the MCI group was more likely to overestimate their memory functioning, whereas the CN group was more likely to underestimate their memory functioning. Overall, these results indicate the level of executive functioning appears to play a unique role above and beyond the contribution of the demographic and clinical factors for the concordance between subjective and objective memory measures, which is related to the equivocal relationship between SMC and objective memory performance in both cognitively intact elderly and MCI individuals.