Effects of Aging on Recollection, Familiarity, and Conceptual Priming

描述(申请人提供)：认知神经科学关于衰老的一个主要目标是确定认知能力因衰老而受损或幸免于难的神经基础。记忆是健康衰老和阿尔茨海默氏症最容易损害的记忆形式。回忆是指生动地回忆一件过去的事件，包括它相关的语境细节，它与熟悉性不同，熟悉性是指即使细节无法找回，但仍模糊地感觉到该事件发生在过去。行为研究提供了强有力的证据表明，老年人的记忆力受到损害，但熟悉程度基本上没有受到影响(有关综述，请参阅Yonelinas，2002)。人们对这种解离的神经基础知之甚少。在年轻人中，记忆更多地依赖于海马体和前额叶皮质(PFC)，而熟悉程度更多地依赖于鼻皮质。然而，目前尚不清楚与年龄相关的记忆力下降是否主要由海马区或PFC功能障碍所致。此外，尚不确定熟悉度的减少是否与概念启动的保存有关，概念启动是一种内隐记忆，其记忆表现是通过先前接触语义相关信息来促进的。这项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度。首先，功能磁共振成像(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使用相似或不同的大脑区域。其次，扩散张量成像(DTI)被用来量化连接感兴趣区域的路径中的白质完整性。最后，一组测试被用来评估神经心理状态(NS)的个体差异，并确定不同水平的执行和记忆功能是否可以解释任务表现和相关大脑活动的差异。这三种方法将一起用于调查每个感兴趣的问题。拟议中的项目之所以意义重大，有几个原因。尽管PFC功能障碍被认为在认知老化中起主要作用，但该区域对老年人记忆缺陷的贡献仍不确定。此外，鼻皮质是阿尔茨海默病神经病理的最早部位之一；因此，了解其在记忆中的准确作用是区分健康衰老和病理性衰老的重要一步。此外，如果我们能够证明，在测量熟悉度的过程中，概念信息的重新参与被用来影响和改善记忆判断，那么这就为认知训练和康复提供了一条潜在的途径。因此，研究这些问题在基础和应用两个层面都很重要。 与公共卫生相关：鼻皮质是阿尔茨海默病神经病理的最早部位之一；因此，了解其在记忆中的准确作用是区分健康衰老和病理性衰老的重要一步。此外，如果我们能够证明，在测量熟悉度的过程中，概念信息的重新参与被用来影响和改善记忆判断，那么这就为认知训练和康复提供了一条潜在的途径。因此，研究这些问题在基础和应用两个层面都很重要。

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.