Age Related Changes in the Top-Down Modulation of Working Memory

工作记忆自上而下调节的年龄相关变化

• 批准号: 7920816
• 负责人: THEODORE P ZANTO
• 金额: $ 5.67万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7920816
• 关键词: Address; Adult; Age; Age-Years; Attention; Behavioral; Biological Neural Networks; Cognitive; Cognitive deficits; Cues; Distal; Elderly; Electroencephalography; Evaluation; Event-Related Potentials; Functional Magnetic Resonance Imaging; Goals; Individual; Intervention; Laboratories; Life; Memory; Nature; Performance; Population; Prefrontal Cortex; Procedures; Process; Property; Reaction Time; Research; Resolution; Role; Sensory; Short-Term Memory; Site; Source; Staging; Stimulus; Techniques; Time; Transcranial magnetic stimulation; Visual; Visual Cortex; Visual attention; age related; association cortex; effectiveness measure; follow-up; improved; normal aging; public health relevance; relating to nervous system; research study

DESCRIPTION (provided by applicant): The goal of this project is to elucidate the spatio-temporal properties of neural network components involved in top-down modulation and evaluate how these networks may change due to normal aging. Topdown modulation refers to our ability to focus attention on pertinent sensory information and ignore irrelevant stimuli thereby improving our performance on cognitive tasks such as working memory. It has seen hypothesized that the neural networks underlying top-down modulation are long-range connections between sensory and distal cortices. Moreover, the prefrontal cortex (PFC) and the visual association cortex (VAC) have been identified as components of a distributed network involved in visual working memory and have been suggested to change in functionality during normal aging. Therefore, this project will focus on the interactions within the PFC-VAC network as attentional control influences memory and evaluate what changes may occur after normal aging. Specific Aim 1: Characterize the spatio-temporal properties of the PFC-VAC network during a working memory task. Through the use of an fMRI guided TMS/EEG recording approach, network activity may be localized, recorded and perturbed to study the causal effects of the intrinsic connectivity and functionality. Event-related potential, spectral and bivariate analysis will help characterize the nature of the long-range reciprocal neural influences between the frontal and visual cortices. I hypothesize the PFC yields separable modulatory activity on the VAC through suppression and enhancement of neural activity. Specific Aim 2: Evaluate changes in the PFC-VAC network due to normal aging. The second experiment will utilize the same paradigm and address the same questions as Experiment 1; however, the subject population will consist of older (60-75 years of age) adults as opposed to the younger (18-35 years of age) population in Experiment 1. Thus, generizability of a PFC role in modulating visual working memory may be determined through the observation of age related changes. I hypothesize that older adults will display a more widely distributed processing network due to fewer suppression and more compensatory mechanisms. PUBLIC HEALTH RELEVANCE: Differences in the connectivity and functionality of networks subserving top-down modulation may underlie a wide range of cognitive deficits associated with aging. The exploration of these basic neuralmechanisms is a critical step towards developing interventions that may alleviate this burden.

描述（由申请人提供）：该项目的目标是阐明自上而下调制中涉及的神经网络组件的时空特性，并评估这些网络如何因正常老化而发生变化。自上而下的调节是指我们能够将注意力集中在相关的感官信息上，而忽略不相关的刺激，从而提高我们在工作记忆等认知任务中的表现。已经看到假设，自上而下调制的神经网络是感觉和远端皮层之间的长距离连接。此外，前额叶皮层（PFC）和视觉关联皮层（VAC）已被确定为参与视觉工作记忆的分布式网络的组成部分，并已被建议在正常老化过程中改变功能。因此，本项目将重点关注PFC-VAC网络内的相互作用，因为注意力控制会影响记忆，并评估正常老化后可能发生的变化。具体目标1：表征工作记忆任务期间PFC-VAC网络的时空特性。通过使用fMRI引导的TMS/EEG记录方法，可以定位、记录和扰动网络活动，以研究内在连接和功能的因果效应。事件相关电位，频谱和双变量分析将有助于表征额叶和视觉皮层之间的长程相互神经影响的性质。我假设PFC通过抑制和增强神经活动对VAC产生可分离的调节活性。具体目标2：评价PFC-VAC网络因正常老化而发生的变化。第二个实验将使用与实验1相同的范例并解决与实验1相同的问题;然而，受试者群体将由老年人（60-75岁）组成，而不是实验1中的年轻人（18-35岁）。因此，PFC在调节视觉工作记忆中的作用可以通过观察年龄相关的变化来确定。我推测，老年人将显示一个更广泛分布的处理网络，由于更少的抑制和更多的补偿机制。公共卫生相关性：自上而下调制网络的连通性和功能差异可能是与衰老相关的广泛认知缺陷的基础。探索这些基本的神经机制是开发可能减轻这种负担的干预措施的关键一步。