Exploring Cognitive Aging Using Reference Ability Neural Networks

项目概要： 本研究的重点是认知老化的最佳功能和结构成像表征， 临床前阿尔茨海默病（AD）。人们一再证明， 不同认知测试大电池的跨度可以用一组四个参考来简单地表示 能力：情景记忆、感知速度、流动能力和词汇量。相比之下， 研究人员通常会评估与单个动作表现相关的神经激活的年龄差异。 这些特定任务可能或可能不完全代表这些参考能力。成功识别 这些“参照能力神经网络”可能会导致年龄神经基础研究的范式转变 通过关注几项任务共同的广泛和可复制的方面，而不是 个别任务可能具有的特殊特征。我们已经识别出了大脑的潜在网络 在成年期具有四种参考能力中的每一种。在进行功能成像时，我们测试了大的 一组年龄在20到80岁之间的健康成年人，他们接受了一系列12项认知任务，这些任务代表了四个参考任务。 能力（每个结构3个）。利用空间协方差和fMRI成像其他分析方面的独特专业知识 数据，我们已经推导出4个潜在的空间，脑功能磁共振成像网络，与潜在的认知 成年期的参考能力结构。我们目前正在对这一组进行5年随访， 开始描绘这些网络的表达如何随着衰老和轻度 认知障碍和AD。我们使用多模式成像来评估年龄和 痴呆症相关的网络利用差异。这些变化包括脑容量、皮质 厚度、白色物质高强度负荷;白色物质束的完整性;静息CBF;和静息BOLD 网络.重要的是，我们使用PET来评估淀粉样蛋白和tau负荷。我们现在建议延长后续行动 这一重要群体的寿命延长到10年。这项研究开发了一种全新的成像方法， 它是认知老化和临床前AD研究的一部分，其年龄跨度也是独一无二的。它有可能提供关键的 深入了解认知老化背后的神经变化的性质和原因，并更准确地 描述AD的临床前阶段。

PROJECT SUMMARY: This study focus on the optimal functional and structural imaging characterization of the cognitive aging and preclinical Alzheimer's disease (AD). It has been repeatedly demonstrated that performance across the age span on large batteries of diverse cognitive tests can be parsimoniously represented by a set of four reference abilities: episodic memory, perceptual speed, fluid ability, and vocabulary. In contrast, neuroimaging researchers typically evaluate age differences in neural activation associated with the performance of a single specific task that may or may not be fully representative of these reference abilities. Successful identification of these "reference ability neural networks" may lead to a paradigm shift in research on the neural bases of age differences in cognition by focusing on the broad and replicable aspects common to several tasks rather than the possibly idiosyncratic features of individual tasks. We have identified the latent brain networks associated with each of the four reference abilities across adulthood. While undergoing functional imaging, we tested large group of healthy adults aged 20 to 80 with a series of 12 cognitive tasks that represent the four reference abilities (3 per construct). Using unique expertise in spatial covariance and other analyses of the fMRI imaging data, we have derived 4 latent spatial, brain-wide fMRI networks that are associated with the latent cognitive structure of the reference abilities across adulthood. We are presently following up this group at 5 years and beginning to delineate how expression of these networks changes with aging and with the onset of mild cognitive impairment and AD. We use multimodal imaging to evaluate potential mediators of age and dementia-related differences in the utilization of the networks. These include change in brain volume, cortical thickness, white matter hyperintensity burden; integrity of white matter tracts; resting CBF; and resting BOLD networks. Importantly, we use PET to assess amyloid and tau burden. We now propose to extend the follow up of this important cohort to 10 years. The proposed study develops a completely new imaging approach to the study of cognitive aging and preclinical AD and is also unique in its age span. It has the potential to provide key insights into the nature and causes of the neural changes that underlie cognitive aging and to more accurately describe the preclinical phase of AD.