Neural correlates of item and spatial context memory in high vs. lower-performance groups

高绩效组与低绩效组中项目和空间上下文记忆的神经相关性

• 批准号: RGPIN-2018-05761
• 负责人: Rajah, Maria
• 金额: $ 4.81万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=763672
• 关键词: Neural; correlates; item; spatial; context

Episodic memory refers to our ability to encode and retrieve past experiences in rich context detail. Healthy aging is generally associated with episodic memory decline. Yet, not all healthy older adults (OA; 60-75 yrs old) exhibit memory decline compared to healthy young adults (YA; 18-35yrs old). Moreover, there is significant variability in how YA and OA perform on specific episodic memory tasks, i.e. spatial context memory tasks. Based on these observations, the goals of my current research program are to identify the neural correlates of successful spatial context encoding and retrieval in YA, and determine the neuro/cognitive strategies that differentiate YA and OA who perform in the upper quartile on memory tasks (high-performers) from lower performing YA and OA. I am interested in determining if high-performing OA (High-OA) are those who: i) exhibit similar patterns of structural integrity and brain-behavior associations as high-performing YA (High-YA), and are thus maintaining' cognitive function better than their lower performing OA (Low-OA)(Maintenance Hypothesis of successful aging); or ii) exhibit different patterns of brain-behavioral associations to high-YA and low-OA, which correlate with better memory performance (Compensation Hypothesis of successful aging). I will conduct two fMRI studies, one in YA (Study 1) and one in OA (Study 2). I will have high-, moderate- and low-performing YA and OA participate in a spatial context memory task while undergoing fMRI scans during encoding and retrieval phases. This task is designed to differentiate item/familiarity retrieval from spatial recollection. In Study 1, I will test specific hypotheses about the roles of distinct medial temporal, parietal and frontal regions in episodic encoding and retrieval in YA. I will use comparative measures of regional brain activity, brain variability and inter-regional connectivity to advance our models of human episodic memory and brain function. In Study 2, I will compare the three performance groups, within and between age-groups, to advance our understanding of performance vs. age-related differences in brain function. I will test if, consistent with the Maintenance Hypothesis: High, Moderate and Low performance cohorts exhibit different patterns of brain activity, connectivity, variability and brain-behavior associations, and that these differences do not interact with age-group. I will also test the aforementioned Compensation Hypothesis.Impact: Our results will advance our models of learning & memory in the brain and inform us if successful aging is related to brain maintenance and/or the recruitment of unique compensatory mechanisms. Thus, this work may identify potential neurocognitive processes that can be leveraged to develop new training methods/tools for memory optimization in humans and inform neuro-computational model of human memory.

情景记忆是指我们在丰富的背景细节中编码和检索过去经验的能力。 健康老龄化通常与情景记忆衰退有关。然而，与健康的年轻人（YA; 18- 35岁）相比，并非所有健康的老年人（OA; 60-75岁）都表现出记忆力下降。此外，YA和OA在特定情景记忆任务（即空间上下文记忆任务）上的表现存在显著差异。基于这些观察，我目前的研究计划的目标是确定成功的空间上下文编码和检索的神经相关的YA，并确定区分YA和OA谁在上四分位数的记忆任务（高性能）从低性能YA和OA的神经/认知策略。 我感兴趣的是确定高绩效OA（High-OA）是否是那些：i）表现出与高绩效YA（High-YA）相似的结构完整性和大脑行为关联模式，因此比低绩效OA（Low-OA）更好地保持“认知功能”（成功老化的维持假说）;或ii）对高YA和低OA表现出不同的脑行为关联模式，这与更好的记忆表现相关（成功衰老的补偿假说）。我将进行两项fMRI研究，一项在YA（研究1），一项在OA（研究2）。我将让高、中、低表现的YA和OA参与空间背景记忆任务，同时在编码和提取阶段接受功能磁共振成像扫描。该任务旨在区分项目/熟悉性提取和空间回忆。在研究1中，我将测试特定的假设，不同的内侧颞叶，顶叶和额叶区域的作用，在情节编码和提取在雅。我将使用区域大脑活动，大脑变异性和区域间连接的比较措施来推进我们的人类情景记忆和大脑功能模型。在研究2中，我将比较三个表现组，在年龄组内和年龄组之间，以促进我们对表现与年龄相关的大脑功能差异的理解。我将测试是否与维持假设一致：高，中，低性能队列表现出不同的大脑活动模式，连接性，变异性和大脑行为关联，并且这些差异不会与年龄组相互作用。影响：我们的研究结果将推进我们的大脑学习和记忆模型，并告诉我们成功的衰老是否与大脑维护和/或独特的补偿机制的招募有关。因此，这项工作可以识别潜在的神经认知过程，可以利用这些过程来开发用于人类记忆优化的新训练方法/工具，并为人类记忆的神经计算模型提供信息。