Effects of Aging on Recollection, Familiarity, and Conceptual Priming

描述（由申请人提供）：衰老认知神经科学的一个主要目标是识别因衰老而受损与幸免的认知能力的神经基础。回忆是记忆的一种形式，最容易受到健康衰老和老年痴呆症的损害。回忆是指生动地记住过去的事件，包括其相关的上下文细节，它不同于熟悉，熟悉是指模糊的感觉，即事件发生在过去，即使细节无法检索。行为研究提供了强有力的证据，表明老年人的记忆力受损，但熟悉度基本上没有受损（有关评论，请参阅Yonelinas，2002）。对于这种分离的神经基础知之甚少。在年轻人中，回忆被证明更依赖于海马体和前额叶皮层（PFC），而熟悉感更依赖于鼻腔皮层。然而，目前还不清楚是否年龄相关的记忆下降主要是由海马或PFC功能障碍介导的。此外，它是不确定的，是否与保守的概念启动，一种形式的内隐记忆，其中的记忆性能是由以前的接触语义相关的信息促进的熟悉。拟议的研究整合了三种方法来调查老年人受损和保存的情景记忆过程的范围和限制。首先，功能性磁共振成像（fMRI）被用来确定老年人和年轻人在回忆，熟悉和概念启动过程中是否使用相似或不同的大脑区域。其次，扩散张量成像（DTI）用于量化连接感兴趣区域的通路中的白色物质完整性。最后，一个测试电池被用来评估神经心理状态（NS）的个体差异，并确定是否不同水平的执行和记忆功能可以解释在任务性能和相关的大脑活动的差异。这三种方法将一起用于研究每个感兴趣的问题。拟议的项目意义重大，原因有几个。虽然PFC功能障碍被认为在认知老化中起着重要作用，但该区域对老年人记忆缺陷的贡献仍然不确定。此外，鼻皮质是阿尔茨海默病神经病理学的第一个部位之一;因此，了解其在记忆中的确切作用是区分健康衰老和病理衰老的重要一步。此外，如果我们能够证明，在熟悉度测量过程中，概念信息的重新参与是用来影响和改善记忆判断的，那么这就为认知训练和康复提供了一条潜在的途径。因此，调查这些问题在基础和应用层面都很重要。 公共卫生相关性：鼻皮质是阿尔茨海默病神经病理学的第一个部位之一;因此，了解其在记忆中的确切作用是区分健康衰老和病理衰老的重要一步。此外，如果我们能够证明，在熟悉度测量过程中，概念信息的重新参与是用来影响和改善记忆判断的，那么这就为认知训练和康复提供了一条潜在的途径。因此，调查这些问题在基础和应用层面都很重要。

DESCRIPTION (provided by applicant): A major goal in cognitive neuroscience of aging is to identify the neural bases of cognitive abilities that are impaired vs. spared by aging. Recollection is the form of memory most impaired by healthy aging and Alzheimer's Disease. Recollection refers to vividly remembering a past event including its associated contextual details, and it differs from familiarity, which refers to the vague feeling that the event occurred in the past even though details cannot be retrieved. Behavioral studies have provided strong evidence that older adults are impaired in recollection but largely unimpaired in familiarity (for a review, see Yonelinas, 2002). Very little is known about the neural bases of this dissociation. In young adults, recollection has been shown to be more dependent on the hippocampus and prefrontal cortex (PFC), while familiarity is more dependent on the rhinal cortex. However, it is unclear whether age-related declines in recollection are primarily mediated by hippocampal or PFC dysfunction. Furthermore, it is uncertain whether the sparing of familiarity is related to the preservation of conceptual priming, a form of implicit memory in which memory performance is facilitated by previous exposure to semantically-related information. The proposed study integrates three methodological approaches to investigate the scope and limits of impaired and preserved episodic memory processes in older adults. First, functional magnetic resonance imaging (fMRI) is used to determine whether older and younger adults use similar or different brain regions during recollection, familiarity, and conceptual priming. Second, diffusion tensor imaging (DTI) is used to quantify white matter integrity in pathways linking regions of interest. Finally, a test battery is used to assess individual differences in neuropsychological status (NS) and determine whether varying levels of executive and memory function can account for differences in task performance and in associated brain activity. These three approaches will be used together to investigate each question of interest. The proposed project is significant for several reasons. Although PFC dysfunction is assumed to play a major role in cognitive aging, the contribution of this region to memory deficits in older adults is still uncertain. In addition, the rhinal cortex is one of the first sites of Alzheimer's Disease neuropathology; thus, understanding its precise role in memory is an important step in distinguishing healthy aging from pathological aging. Moreover, if we can show that the reengagement of conceptual information during measures of familiarity is used to influence and improve memory judgments, then this offers a potential avenue for cognitive training and rehabilitation. Thus, investigating these questions is important at both basic and applied levels. PUBLIC HEALTH RELEVANCE: The rhinal cortex is one of the first sites of Alzheimer's Disease neuropathology; thus, understanding its precise role in memory is an important step in distinguishing healthy aging from pathological aging. Moreover, if we can show that the reengagement of conceptual information during measures of familiarity is used to influence and improve memory judgments, then this offers a potential avenue for cognitive training and rehabilitation. Thus, investigating these questions is important at both basic and applied levels.