Neural basis of aging and implicit learning

衰老和内隐学习的神经基础

• 批准号: 7912176
• 负责人: Jessica Rose Simon
• 金额: $ 2.97万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-12 至 2012-04-11
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7912176
• 关键词: Affect; Age; Aging; Alzheimer' s Disease; Awareness; Behavior; Brain; Brain region; Characteristics; Cognitive; Complex; Conscious; Corpus striatum structure; Disease; Dissociation; Early Diagnosis; Elderly; Environment; Event; Functional Magnetic Resonance Imaging; Future; Goals; Hippocampus (Brain); Image; Independent Living; Learning; Longevity; Medial; Parkinson Disease; Process; Rehabilitation therapy; Research; Stimulus; Technology; Temporal Lobe; Training; age difference; age group; age related; base; cognitive neuroscience; design; flexibility; healthy aging; neural recruitment; normal aging; programs; public health relevance; relating to nervous system; skills; young adult

DESCRIPTION (provided by applicant): The primary goal of the proposed research is to identify differences between young and old adults in the neural processes underlying implicit learning. Implicit learning is the non-conscious acquisition of information that occurs without intent or awareness of what has been learned. Research in aging has mostly focused on explicit learning, and thus, the effects of healthy age-related brain changes on implicit learning have remained largely ignored, limiting the scope of the cognitive neuroscience of aging. This is unfortunate because sensitivity to regularities in the environment makes it possible to anticipate and process future events more effectively and this ability is essential throughout the lifespan. Whether implicit learning declines with healthy aging is unclear, though age-related deficits are observed when the stimuli to be learned are complex and when people are given extended training. Here, 24 young and 24 old adults will undergo functional magnetic resonance imaging (fMRI) while they learn and practice a complex, probabilistic sequential implicit skill. It is predicted that old adults will learn as well as the young early in training, but with more practice, age-related deficits will emerge (Specific Aim 1), making this proposed study the first to assess brain activity during implicit learning when behavior is both spared and impaired. The dissociation between early and practiced implicit learning is important to cognitive neuroscience for two reasons. First, previous imaging studies suggest that skill learning involves different brain regions as learning progresses; early learning involves the medial temporal lobes (i.e. hippocampus) and later, practiced learning involves the striatum (i.e. caudate). The proposed study will be among the first to examine whether these same learning-activation relationships are characteristic of implicit learning (Specific Aim 2), by using a paradigm in which explicit learning can be ruled out. Second, the brain regions underlying early and practiced learning differ in the extent to which they are compromised by aging. In the proposed study, functional connectivity analyses will examine relationships between brain activity and early versus practiced learning to assess how age-related differences in neural recruitment vary with the level of practice (Specific Aim 3). It is predicted that early implicit learning will activate the hippocampus or MTL networks in both age groups, reflecting the relatively preserved MTL in healthy aging. In practiced learning, younger adults will demonstrate activation in caudal or striatal networks. Due to aging- related declines, caudate activation will not be as dominant in older adults; older adults will rely on their intact learning-related brain regions, including the hippocampus and surrounding MTL. These findings would be consistent with the view that healthy aging affects the striatum more than the MTL. PUBLIC HEALTH RELEVANCE: Implicit learning of subtle sequential events can promote independent living by supporting cognitive flexibility and can help older adults anticipate and adapt to an ever-changing world (i.e. new settings, people, and technologies). Thus, establishing the kinds of implicit learning that are intact versus impaired may be useful for designing educational programs or enhancing rehabilitation efforts, because such training could take advantage of the older persons' spared capacities and compensate for those that have declined in order to maximize successful aging. Defining normal age differences in brain function may also help in early detection of common age-related diseases, such as Alzheimer's and Parkinson's.

描述（由申请人提供）：本研究的主要目的是确定年轻人和老年人在潜在内隐学习的神经过程中的差异。内隐学习是一种无意识的信息获取，发生在没有意图或意识到所学内容的情况下。关于衰老的研究主要集中在外显学习上，因此，健康的年龄相关的大脑变化对内隐学习的影响在很大程度上被忽视，限制了认知神经科学对衰老的研究范围。这是不幸的，因为对环境规律的敏感性使得更有效地预测和处理未来事件成为可能，这种能力在整个生命周期中都是必不可少的。内隐学习是否会随着健康的年龄增长而下降尚不清楚，尽管当要学习的刺激是复杂的，当人们接受长时间的训练时，可以观察到与年龄相关的缺陷。在这里，24名年轻人和24名老年人将接受功能磁共振成像（fMRI），同时他们学习和练习一项复杂的、概率顺序隐性技能。据预测，在早期的训练中，老年人的学习能力和年轻人一样好，但随着更多的练习，年龄相关的缺陷将出现（Specific Aim 1），这使得这项拟议的研究首次评估了内隐学习中行为保留和受损时的大脑活动。早期内隐学习和实践内隐学习之间的分离对认知神经科学很重要，原因有二。首先，先前的成像研究表明，随着学习的进展，技能学习涉及不同的大脑区域；早期学习涉及内侧颞叶（即海马体），后来，练习学习涉及纹状体（即尾状体）。该研究将是第一个研究这些相同的学习-激活关系是否是内隐学习的特征的研究（具体目标2），通过使用一个可以排除外显学习的范式。其次，早期学习和实践学习的大脑区域因年龄增长而受损的程度不同。在拟议的研究中，功能连接分析将检查大脑活动与早期与实践学习之间的关系，以评估神经招募的年龄相关差异如何随实践水平而变化（具体目标3）。预测早期内隐学习将激活两个年龄组的海马或MTL网络，反映了健康衰老中相对保存的MTL。在实际学习中，年轻人会表现出尾状或纹状体网络的激活。由于衰老相关的衰退，尾状核激活在老年人中不会占主导地位；老年人将依赖于他们完整的与学习相关的大脑区域，包括海马体和MTL周围。这些发现将与健康衰老对纹状体的影响大于MTL的观点相一致。