Aging and the Cognitive and Neural Bases of Implicit Associative Learning

衰老与内隐联想学习的认知和神经基础

• 批准号: 7864870
• 负责人: Darlene V. Howard
• 金额: $ 44.12万
• 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: 2010-05-15 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7864870
• 关键词: Address; Adopted; Adult; Affect; Age; Aging; Alzheimer' s Disease; Area; Behavior; Behavioral; Brain; Caregivers; Cognitive; Cognitive aging; Corpus striatum structure; Educational Status; Elderly; Environment; Equilibrium; Fostering; Functional Magnetic Resonance Imaging; Independent Living; Injury; Joints; Lead; Learning; Medial; Memory; Patients; Pattern; Performance; Prefrontal Cortex; Probability; Process; Quality of life; Relative (related person); Reporting; Research; Resources; Schools; Stimulus; Stroke; Structure; System; Technology; Temporal Lobe; Testing; Time; Training; Triplet Multiple Birth; age difference; age group; age related; base; behavior test; classical conditioning; cognitive neuroscience; functional decline; healthy aging; improved; middle age; neuroimaging; pathological aging; public health relevance; relating to nervous system; remediation; skills; task analysis; young adult

DESCRIPTION (provided by applicant): The overall aim is to understand the cognitive and neural bases of implicit probabilistic associative learning and how these vary with adult age. Learning is said to be implicit when people acquire information about structural regularities without intending to learn or becoming aware of what they have learned. Implicit learning is likely more important for adapting to the world than its explicit/declarative counterparts, particularly in later adulthood when little time is spent in formal schooling, a setting which emphasizes explicit learning. Nonetheless, the aging of implicit learning has been studied much less, perhaps because age-related deficits have sometimes been small or non-existent. This apparent sparing creates a paradox: Associative implicit learning calls on neural systems that show structural and functional declines in healthy aging, and so how would older people be relatively good at it? This is addressed by adopting themes from two research areas: Cognitive neuroscience provides evidence that two interactive learning systems--one based on the Medial Temporal Lobe (MTL) and the other based on the striatum--can contribute to such learning. The cognitive neuroscience of aging provides evidence that one of these neural systems is more sensitive to aging than the other, and that older brains often do the same task differently from younger brains. These themes lead to two hypotheses. First, that implicit probabilistic associative learning is not spared in healthy aging, but rather is characterized by persistent age-related learning deficits that can be detected as early as middle-age. These deficits are more pronounced as practice progresses, and cannot be attributed solely to age-related deficits in general processing resources. Rather, they reflect a fundamental deficit in the function of the striatal learning system. Second, the relative balance of these systems changes with age; early in training the MTL system dominates in both young and old adults, but as training proceeds the young adults come to rely on the striatal system, whereas the old continue to rely on their relatively intact MTL system. This enables old adults to maintain near- young levels of performance very early in training, but not later. These hypotheses will be tested by conducting behavioral and neuroimaging studies, using a recently developed triplets-learning-task (TLT). Aim 1 is to characterize age differences in implicit probabilistic associative learning. Aim 2 is to test behavioral implications for aging of the interactive systems hypothesis, and Aim 3 is to characterize the neural bases of implicit probabilistic associative learning in young and old adults, and relate them to behavior. These aims are important for fostering successful aging and independent living, because implicit associative learning is needed for adapting to new people, environments, and technologies, as well as for relearning skills after injury. PUBLIC HEALTH RELEVANCE: Understanding the cognitive and neural bases of implicit forms of learning, and how to maximize such learning at all ages, is key to fostering successful aging, because implicit learning is essential for adapting to new environments and people, and for recovering function after injury and stroke. Further, identifying how implicit learning is affected by healthy aging will ultimately help to distinguish healthy from pathological aging (e.g., Alzheimer's disease). To the extent that implicit learning is spared in pathological aging, it can be the basis for remediation, thereby extending independent living, and improving the quality of life of patients and caregivers.

描述(由申请人提供)：总体目标是了解内隐概率联想学习的认知和神经基础，以及这些基础如何随着成年年龄的变化而变化。当人们在不打算学习或意识到他们所学的情况下获得关于结构规则的信息时，学习被认为是内隐的。在适应世界方面，内隐学习可能比外显/陈述性学习更重要，特别是在成年后期，因为在正规学校学习的时间很少，这种环境强调外显学习。尽管如此，对内隐学习老化的研究要少得多，这可能是因为与年龄相关的缺陷有时很小，甚至根本不存在。这种明显的节制产生了一个悖论：联想内隐学习需要神经系统在健康衰老时显示出结构和功能的下降，那么老年人如何才能相对擅长呢？这是通过采用两个研究领域的主题来解决的：认知神经科学提供了证据，证明两个互动学习系统--一个基于内侧颞叶(MTL)和另一个基于纹状体--可以促进这种学习。衰老的认知神经科学提供的证据表明，这些神经系统中的一个对衰老比另一个更敏感，而且老年人的大脑经常以不同于年轻大脑的方式完成同样的任务。这些主题引出了两个假设。首先，内隐概率联想学习在健康老龄化中并不幸免，而是以持续的与年龄相关的学习缺陷为特征，这种缺陷可以在中年就被发现。随着实践的发展，这些缺陷更加明显，不能完全归因于一般加工资源中与年龄有关的缺陷。相反，它们反映了纹状体学习系统功能的根本缺陷。第二，这些系统的相对平衡随着年龄的增长而变化；在训练早期，MTL系统在年轻人和老年人中都占主导地位，但随着训练的进行，年轻人开始依赖纹状体系统，而老年人继续依赖他们相对完整的MTL系统。这使得老年人在训练的早期就能保持接近年轻的表现水平，但不能晚些时候。这些假说将通过进行行为和神经成像研究，使用最近开发的三胞胎学习任务(TLT)来验证。目的1是研究内隐概率联想学习的年龄差异。目的2是检验交互系统假说对衰老的行为暗示，目标3是表征年轻人和老年人内隐概率联想学习的神经基础，并将其与行为联系起来。这些目标对于培养成功的老龄化和独立生活非常重要，因为内隐联想学习对于适应新的人、环境和技术以及受伤后的重新学习技能是必要的。 公共卫生相关性：了解内隐学习形式的认知和神经基础，以及如何在所有年龄段最大限度地利用这种学习，是培育成功老龄化的关键，因为内隐学习对于适应新的环境和人，以及在受伤和中风后恢复功能至关重要。此外，确定健康衰老是如何影响内隐学习的，最终将有助于区分健康衰老和病理性衰老(例如，阿尔茨海默病)。内隐学习在一定程度上避免了病理性衰老，它可以作为补救的基础，从而延长独立生活，并改善患者和照顾者的生活质量。