ABSTRACT

Amnestic mild cognitive impairment (aMCI) and Alzheimer’s disease (AD) dementia are characterized by pathological changes to the medial temporal lobes, resulting in explicit learning and retention reductions. Studies demonstrate that implicit/procedural memory processes are relatively intact in these populations, supporting different anatomical substrates for differing memory systems. This study examined differences between explicit and procedural learning and retention in individuals with aMCI and AD dementia relative to matched healthy controls. We also examined anatomical substrates using volumetric MRI. Results revealed expected difficulties with explicit learning and retention in individuals with aMCI and AD with relatively preserved procedural memory. Explicit verbal retention was associated with medial temporal cortex volumes. However, procedural retention was not related to medial temporal or basal ganglia volumes. Overall, this study confirms the dissociation between explicit relative to procedural learning and retention in aMCI and AD dementia and supports differing anatomical substrates.

摘要

遗忘性轻度认知障碍 (aMCI) 和阿尔茨海默病 (AD) 痴呆的特征是内侧颞叶发生病理变化，导致显性学习和记忆力下降。研究表明，这些人群的内隐/程序性记忆过程相对完整，支持不同记忆系统的不同解剖学基础。这项研究考察了 aMCI 和 AD 痴呆症患者与匹配的健康对照组相比，显性学习和程序性学习和记忆力之间的差异。我们还使用体积 MRI 检查了解剖基质。结果显示，程序性记忆相对保留的 aMCI 和 AD 患者在显性学习和保留方面存在预期困难。明确的言语保留与内侧颞叶皮层体积相关。然而，程序保留与内侧颞叶或基底神经节体积无关。总体而言，这项研究证实了 aMCI 和 AD 痴呆中外显学习与程序学习和保留之间的分离，并支持不同的解剖学基础。