Exploring Cognitive Aging Using Reference Ability Neural Networks

描述(由申请人提供)：已经反复证明，在不同年龄段的不同认知测试中的表现可以由一组四种参考能力简约地表示：情景记忆、知觉速度、流动能力和词汇。基于这些发现，Salhouse等人。他们认为，认知老化研究的一个富有成效和有效的方法是试图理解衰老如何影响这一小部分参考能力的表现，而不是在特定任务上。相比之下，神经成像研究人员通常会评估神经激活的年龄差异，这些差异与单个特定任务的表现有关，这些任务可能完全代表这些参考能力，也可能不完全代表这些能力。我们建议确定与Salhouse的4种参考能力中的每一种有关的潜在大脑网络。在进行功能成像的同时，我们将对375名健康成年人(20岁至50岁每十年50人，50岁至80岁每十年75人)进行一系列12项认知任务的测试，这些任务代表四种参考能力(每个结构3项)。利用空间协方差和对fMRI成像数据的其他分析方面的独特专业知识，我们将推导出与成年后参考能力的潜在认知结构相关的潜在空间、全脑fMRI网络。这些“参照能力神经网络”的成功识别可能会导致认知年龄差异神经基础研究的范式转变，将重点放在几个任务共同的广泛和可复制的方面，而不是个别任务可能的特殊特征。在确定这些参考能力神经网络后，我们将使用多模式成像来评估与年龄相关的网络利用差异的潜在中介因素。这些潜在的调节因素将包括脑体积和皮质厚度的变化；白质高强度负荷；白质束的完整性；静息CBF；以及默认网络。拟议的功能磁共振研究将开发一种全新的、更有针对性的成像方法来研究认知老化。结合与年龄相关的大脑变化和病理的多模式成像，该项目有可能为认知老化背后的神经变化的性质和原因提供关键的见解。

DESCRIPTION (provided by applicant): 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. Based on these findings, Salthouse et al. have argued that a productive and efficient approach to cognitive aging research is to try to understand how aging impacts performance of this small set of reference abilities than on specific tasks. 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. We propose to identify the latent brain networks associated with each of Salthouse's 4 reference abilities across adulthood. While undergoing functional imaging, we will test 375 healthy adults (50 per decade from age 20 to 50, 75 per decade for 50 to 80) with a series of 12 cognitive tasks that represent four reference abilities (3 per construct). Using unique expertise in spatial covariance and other analyses of the fMRI imaging data, we will derive the latent spatial, brain-wide fMRI networks that are associated with the latent cognitive structure of the reference abilities across adulthood. 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. After identifying these reference ability neural networks, we will use multimodal imaging to evaluate potential mediators of age-related differences in the utilization of the networks. These potential mediators will include change in brain volume and cortical thickness; white matter hyperintensity burden; integrity of white matter tracts; resting CBF; and the default network. The proposed fMRI study will develop a completely new and more focused imaging approach to the study of cognitive aging. In combination with the multimodal imaging of age-related brain changes and pathology, this project has the potential to provide key insights into the nature and causes of the neural changes that underlie cognitive aging.