MEMORY MECHANISMS OF AGING, PRECLINICAL AND EARLY DEMENTIA

本项目重点关注正常衰老的老年人的认知功能和认知变化，痴呆和可诊断的AD之前的中间状态。该项目的主要目的是通过模拟老年人的个体认知变异性和变化来区分规范性和病理性认知衰老。最近的研究表明，老年人的认知存在很大的个体差异，这种差异可能意味着潜在的神经缺陷，如阿尔茨海默病或痴呆症之前的中间状态。提出了两个测量密集的纵向研究，将从几个重要的方面扩展对表现变异性和认知障碍之间关系的认识。第一项研究是一个测量突发设计，将检查认知正常和遗忘性认知障碍（ACI）患者认知功能的日常变化。第二项研究是一项纵向研究，将重点放在每时每刻的绩效波动上。这项拟议的研究有三个总体目标：1)检验压力和身体症状的日常波动预测认知的日常变化的假设。2)确定高水平的认知变异性和缓慢的检索速度是否意味着患痴呆症的风险增加。3)确定如何利用认知表现的水平、速度和变异性信息来优化与早期阿尔茨海默病相关的认知障碍的分类和早期检测

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.