Neural Mechanisms Underlying Cognitive Aging

描述（由申请人提供）：许多老年人的认知能力障碍是一个有充分证据的现象，影响多个领域，如工作记忆、情景记忆和注意力。这些认知缺陷给许多老年人带来了巨大的痛苦，他们觉得自己过高质量生活的能力受到了这种衰退的负面影响，这通常被认为是衰老最令人衰弱的方面。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改变。功能磁共振成像（fMRI）和脑电图（EEG）将用于一系列认知实验，以评估自上而下调节和服务神经网络的年龄相关变化。fMRI的高空间分辨率和EEG的高时间分辨率提供了独特但互补的数据，并且通过同时记录整个功能人脑的活动，它们非常适合研究网络相互作用。自上而下的调节是一种神经过程，它使我们能够选择性地将认知资源集中在与目标相关的感官信息上，而忽略无关的信息，从而作为选择性注意的神经基础和成功记忆存储的关键基础。我们最近记录了与年龄相关的自上而下调节缺陷。具体来说，健康的老年人表现出无法有效抑制与分散注意力的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。本项目的具体目的是：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节变化在不同认知操作中的普遍性。提出的实验将告诉我们衰老大脑中自上而下调节变化的潜在神经基础，评估这种缺陷的更广泛的认知含义，并更有效地指导治疗干预措施的发展。随着年龄增长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不断增长，这一问题的严重性也在不断增加。识别老化大脑的潜在变化对于建立治疗干预措施的发展框架以减轻认知障碍是必要的。

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.