Neural Mechanisms Underlying Cognitive Aging

描述(申请人提供)：许多老年人的认知能力受损是一个有充分证据的现象，影响到多个领域，如工作记忆、情景记忆和注意力。这些认知缺陷是许多老年人感到非常痛苦的一个原因，他们认为这种下降对他们过高质量生活的能力产生了负面影响，而且它通常被认为是衰老最令人虚弱的方面。我们的目标是利用人类神经生理学的工具来识别导致广泛的年龄相关认知缺陷的基本神经机制的潜在变化。功能磁共振成像(FMRI)和脑电(EEG)将用于一系列认知实验，以评估自上而下调制和从属神经网络中与年龄相关的变化。FMRI的精细空间分辨率和EEG的高时间分辨率提供了独特但互补的数据，通过同时记录整个功能人类大脑的活动，它们非常适合研究网络相互作用。自上而下的调制是一种神经过程，它支持我们有选择地将认知资源集中在与我们的目标相关的感觉信息上，而忽略无关的信息，从而成为选择性注意的神经基础和成功记忆存储的关键基础。我们最近记录了自上而下调制中与年龄相关的缺陷。具体地说，健康的老年人表现出无法有效地抑制与分散信息相关的神经活动，这种抑制缺陷与工作记忆表现的损害有关。本研究的具体目的是：1)阐明年龄相关的自上而下抑制缺陷的基础；2)探索年龄相关的自上而下调制变化对不同认知操作的概括性。提出的实验将告诉我们老化大脑自上而下调制变化的潜在神经基础，评估这种缺陷的更广泛的认知影响，并更有效地指导治疗干预的发展。随着老龄化而出现的认知障碍是一个普遍存在的公共卫生问题，随着我国老年人口规模的持续增长，这个问题的规模也在不断增加。确定老化大脑的潜在变化是必要的，以建立一个框架，以开发治疗干预措施，以减轻认知障碍。

DESCRIPTION (provided by applicant): Impairments in cognitive abilities of many older adults are a well-documented phenomenon that impacts multiple domains, such as working memory, episodic memory and attention. These cognitive deficits are a cause of great distress to many older adults who feel that their ability to lead high-quality lives is negatively impacted by this decline, and it is often considered the most debilitating aspect of aging. Our objective is to utilize the tools of human neurophysiology to identify underlying alterations in fundamental neural mechanisms that lead to the wide range of age-related cognitive deficits. Functional MRI (fMRI) and electroencephalography (EEG) will be used in a series of cognitive experiments to evaluate age-related changes in top-down modulation and subserving neural networks. The fine spatial resolution of fMRI and high temporal resolution of EEG provide unique but complementary data, and by simultaneously recording activity from the entire functioning human brain they are ideally suited to study network interactions. Top-down modulation is the neural process that underlies our ability to selectively focus our cognitive resources on sensory information relevant to our goals and ignore irrelevant information, thus serving as a neural basis for selective attention and a critical foundation for successful memory storage. We recently documented an age-related deficit in top-down modulation. Specifically, healthy older adults exhibit an inability to effectively suppress neural activity associated with distracting information, and this suppression deficit correlates with impairments in working memory performance. The specific aims of this project are to: 1) Elucidate the basis of the age-related top down suppression deficit, and 2) Explore the generalizability of age-related top-down modulation changes to different cognitive operations. The experiments proposed will inform us of the underlying neural basis of top-down modulation changes in the aging brain, assess the broader cognitive implications of this deficiency and more effectively guide the development of therapeutic interventions. Cognitive impairment that occurs with aging is a pervasive public health issue that continues to increase in magnitude as the size of the older population in our country continues to grow. The identification of underlying changes in the aging brain is necessary to establish a framework for the development of therapeutic interventions to alleviate cognitive impairments.