Aging, implicit learning, and white matter integrity

衰老、内隐学习和白质完整性

基本信息

批准号：
7637355
负责人：
Ilana Jacqueline Bennett
金额：
$ 2.83万
依托单位：
GEORGETOWN UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-08-06 至 2009-08-05
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The primary goal of the proposed research is to understand the relationship between implicit learning and white matter microstructure in younger and older adults. Examining the role of white matter integrity in the aging of implicit learning will extend the emerging literature on lifespan cognitive neuroscience. Implicit learning occurs without intent or awareness of what has been learned, and until recently it has been studied less that its explicit counterpart. This is unfortunate because sensitivity to regularities in the environment is essential throughout life. Recent cognitive and neuroscience research on implicit learning indicates that there are multiple forms of implicit learning that call on different neural substrates, but aging research usually treats implicit learning as though it is unitary. Here, we will focus on a dissociation between two types of implicit learning, sequence learning and spatial context learning, that are especially important for studying age changes in brain-behavior relationships because they call on different brain systems that are differentially affected by healthy aging. Imaging and patient studies suggest that implicit sequence learning relies on a frontal-striatal-cerebellar network, and implicit spatial context learning is mediated by the medial temporal lobes. The proposed experiment will be the first to examine this dissociation in the same group of participants using diffusion tensor imaging (DTI) to measure the integrity of white matter that connects neural networks (Specific Aim 2). DTI research has shown that white matter integrity declines with aging, especially in anterior brain regions, which may affect cognitive performance in healthy older adults. In this study, older adults are expected to be impaired at implicit sequence learning, but not implicit spatial context learning (Specific Aim 1), a finding consistent with the view that healthy aging affects the frontal-striatal system more than the medial temporal lobes. Multiple regression analyses will also examine if age-related brain changes affect the relationships between these two implicit learning tasks and white matter integrity from their corresponding neural networks, being the first to-assess age differences in brain-behavior relationships using implicit learning tasks in which behavioral performance is both impaired and spared with aging (Specific Aim 3). Results from this study are relevant to successful aging. Implicit learning promotes independent living by enabling people to adapt to change (i.e. new settings, people, and technologies), and can facilitate recovery from brain damage following accidents or strokes. Thus, identifying age-related stability between forms of implicit learning and their underlying white matter connectivity is important for training programs aimed at maximizing successful aging and recovery after brain damage.

描述（由申请人提供）：拟议研究的主要目标是了解年轻和老年人中隐性学习与白质微观结构之间的关系。研究白质完整性在隐性学习衰老中的作用将扩展有关寿命认知神经科学的新兴文献。隐式学习是没有意图或对所学知识的意图而发生的，直到最近，它的显式对应物进行了较少的研究。这是不幸的，因为对环境中规律的敏感性在整个生命中至关重要。对隐式学习的最新认知和神经科学研究表明，有多种形式的隐式学习呼吁不同的神经底物，但是衰老的研究通常将隐性学习视为统一。在这里，我们将重点关注两种类型的隐式学习，序列学习和空间上下文学习之间的分离，这对于研究脑行为关系的年龄变化尤其重要，因为它们呼吁受健康衰老差异影响的不同大脑系统。成像和患者研究表明，隐式序列学习依赖于额叶纹状体网络，而隐式空间上下文学习是由内侧颞叶介导的。拟议的实验将是第一个使用扩散张量成像（DTI）在同一组参与者中检查这种分离的方法，以测量连接神经网络的白质的完整性（特定目标2）。 DTI研究表明，白质的完整性随着衰老而下降，尤其是在前脑区域，这可能会影响健康老年人的认知表现。在这项研究中，预计老年人会受到隐式序列学习的损害，而不是隐性的空间上下文学习（特定目标1），这一发现与健康衰老对额叶系统更大的观点一致，而不是内侧颞叶。多元回归分析还将检查与年龄相关的大脑变化是否影响了这两个隐式学习任务和白质完整性之间的关系，这是其相应的神经网络的关系，这是使用隐式学习任务中的第一个待办事项年龄差异，其中使用隐式学习任务，而行为表现既受损害又受到损害（特定的目标3）。这项研究的结果与成功的衰老有关。隐性学习通过使人们能够适应变化（即新的环境，人和技术）来促进独立的生活，并可以促进事故或中风后脑损伤的恢复。因此，确定隐式学习形式与其潜在的白质连接性之间与年龄相关的稳定性对于旨在最大程度地提高脑损伤后成功衰老和恢复的培训计划很重要。