Cognitive Brain Activity: Aging and Dementia

描述（申请人提供）：基于在具有设计的记忆需求的任务下获得的脑事件相关电位（ERP），目的是通过1）开发阿尔茨海默病（AD）早期的非侵入性脑活动标记物，和2）用这些标记物预测哪些轻度认知障碍（MCI）患者将继续发展为阿尔茨海默病。大约一半的MCI患者在几年内发展为AD。总体目标是尽早确定哪些患者可能从干预中受益，并更好地了解这些疾病中改变的大脑功能。当参与者执行两个简单的认知任务时，我们记录ERP。在这些任务中，ERP组件在需要不同使用内存和处理资源的条件下有所不同。这两个任务是（1）数字-字母范式，涉及4个连续刺激的每次试验中的数字或字母的比较（工作记忆）;和（2）模式范式，涉及视觉模式的对称性判断，其中一些在试验中重复（内隐记忆）。本研究比较了MCI患者、AD早期患者和相应年龄对照组的任务相关ERP。多变量统计被用来测量ERP组件和开发功能，区分受试者群体和预测AD MCI患者之间。

DESCRIPTION (provided by applicant): Based on brain Event-Related Potentials (ERP) obtained under tasks with designed memory demands, the aim is to improve understanding and foster early interventions by 1) developing non-invasive brain activity marker(s) for Alzheimer's disease (AD) early in its course, and 2) predicting with such marker(s) which patients with mild cognitive impairment (MCI) will go on to develop Alzheimer's disease. About half of MCI patients develop AD within a few years. The overall goal is to determine early enough which patients might benefit from interventions and to understand better the brain functions altered in these diseases. We record ERP's while participants perform two simple cognitive tasks. In each of these tasks, ERP components differ under conditions which demand different use of memory and processing resources. The two tasks are (1) a number-letter paradigm that involves comparisons of numbers or of letters within each trial of 4 sequential stimuli (working memory); and (2) a pattern paradigm which involves symmetry judgments of visual patterns, some of which are repeated over trials (implicit memory). The research entails comparison of tasks-related ERPs of MCI patients, AD patients early in the course of AD, and appropriately aged controls. Multivariate statistics are used to measure the ERP components and to develop functions that discriminate among the subject groups and predict AD among the MCI patients.