MEMORY MECHANISMS OF AGING, PRECLINICAL AND EARLY DEMENTIA

这个项目的重点是老年人的认知功能和认知变化，通常衰老是痴呆症和可诊断的AD之前的中间状态。这个项目的主要目标是通过模拟老年人的个体内认知变异性和变化来区分正常认知老化和病理性认知老化。最近的研究表明，老年人存在大量的个体内认知变异性，高水平的变异性可能意味着潜在的神经缺陷，如S阿尔茨海默病或痴呆症之前的中间状态。提出了两项测量密集型纵向研究，这两项研究将从几个重要方面扩展对老年表现变异性和认知障碍之间关系的认识。第一项研究是一项测量突发设计，将检查认知正常的人和有遗忘性认知障碍(ACI)的人认知功能的日常变化。第二项研究是纵向研究，将重点放在每时每刻的性能波动上。这项拟议的研究总体上有三个目标：1)检验压力和身体症状的每日波动可以预测认知的日常变异性的假设。2)确定高水平的认知变异性和较慢的检索速度是否意味着患痴呆症的风险增加。3)确定如何使用有关认知表现的水平、速度和变异性的信息来优化与早期阿尔茨海默氏症相关的认知损害的分类和早期检测 疾病(AD)。这些结果将提供检测临床前和临床AD所需的信息，区分AD相关的认知变化和年龄相关的认知变化，调查非痴呆症的认知老化，提供AD的早期治疗，并将衰老和AD的认知生理、生物、神经病理和神经成像变化联系起来。

This project focuses on cognitive function and cognitive change in older adults with usual aging, the intermediate states that precede dementia and diagnosable AD. The primary objective of this project is to distinguish between normative and pathological cognitive aging by modeling intraindividual cognitive variability and change in older adults. Recent research has demonstrated substantial intraindividual cognitive variability in older adults and that high levels of variability may signify underlying neurological deficits, such a s Alzheimer's disease or the intermediate states that precede dementia. Two measurement-intensive longitudinal studies are proposed that will extend knowledge about the relationship among performance variability and cognitive impairment in aging in several important ways. The first study is a measurement burst design that will examine daily variations in cognitive function in persons who are cognitively normal and in those with Amnestic Cognitive Impairment (ACI). The second study is a longitudinal study that will focus on moment-to-moment performance fluctuations. The proposed research has three overall aims: 1) To test the hypothesis that daily fluctuations of stress and physical symptoms predict day-to-day variability in cognition. 2) To determine whether high levels of cognitive variability and slowed retrieval speed signify elevated risk for developing dementia. 3) To determine how to use information about level, speed, and variability in cognitive performance to optimize classification and early detection of cognitive impairment associated with early Alzheimer's Disease (AD). The results will provide information needed to detect preclinical and clinical AD, discriminate AD-related cognitive changes from age-related cognitive changes, investigate cognitive aging without dementia, provide early treatment of AD, and correlate cognitive physiologic, biologic, neuropathologic and neuroimaging changes in aging and AD.