Relationship Between Neural Correlates of Episodic Memory,Age, Memory Performance

与其他类型的记忆相比，情节记忆随着年龄的增长而急剧下降，而且严重 阿尔茨海默病患者。即使是70多岁健康人典型的轻度记忆障碍，S 会对生活质量产生负面影响。此外，记忆功能的变化是阿尔茨海默病的前兆 (Ad)症状出现前几年发病。这一前驱期为疾病提供了一个窗口- 修改干预措施，重视早期发现“不成功”的脑老化轨迹。 因此，了解年龄对情景记忆影响的神经认知基础是很重要的。 本研究的目的是阐明与年龄相关的差异在大脑中的功能意义。 支撑情节记忆的神经活动。我们的目标是确定这些差异中的哪些反映 导致与年龄相关的记忆衰退的过程，这反映了 改善衰退，以及哪些差异是记忆病理的迹象。该节目的重点是 情景编码和提取的神经关联，因为这些都是由fMRI索引的。在一根链子里 研究表明，研究对象将是60多岁和70多岁的遗忘性轻度认知障碍(AMCI)患者， AD的重要危险因素，以及与70岁左右的健康老年人和健康成年人匹配的健康对照组 已经80多岁了。目标是确定哪些神经与成功的情景编码和提取相关 以前在健康人群中发现的也明显存在于aMCI中，这种关联与健康的老年人相同 记忆能力大体相当的个体，尤其是个体所特有的 阿尔茨海默病风险很高。在两项研究中，我们将研究联想编码和提取的神经关联， 和回忆相关的皮质恢复。 我们还将继续推进我们最近在健康衰老和间歇性编码方面的工作。我们有 描述了几种可以预测老年人记忆表现的神经编码措施 大约65-75岁，但不是中年人(45-55岁)或更年轻的人。其中一项措施--“权利” 前额后继记忆效应--在最近的一项研究中，与记忆表现呈正相关，但 与早期研究中的表现呈负相关。我们将检验这一假设，即方向 这种关系的好坏取决于测试记忆的条件。在另一个实验中，我们将 研究年龄对“刺激前”后续记忆效应的影响--神经活动预测性 研究事件之前的后续内存性能。我们预测，刺激前的效果将是 在年龄较大的受试者中会减弱。如果是这样的话，它将构成一种新的记忆编码机制 在以后的生活中会受到损害。在最后的实验中，我们将评估神经中的年龄不变性 成功检索的相关性扩展到检索到的信息必须保留在 在被用于指导反应选择之前的一段时间内的工作记忆。

Episodic memory declines more steeply with increasing age than other types of memory, and is severely impaired in Alzheimer’s Disease. Even the modest memory impairment typical of healthy people in their 70’s can negatively impact quality of life. Moreover, changes in memory function that harbinger Alzheimer’s Disease (AD) onset years before the emergence of symptoms. This prodromal period provides a window for disease- modifying interventions and places a premium on early detection of trajectories of ‘unsuccessful’ brain aging. Thus, it is important to understand the neurocognitive bases of the effects of age on episodic memory. The aim of the present research is to elucidate the functional significance of age-related differences in neural activity underpinning episodic memory. We aim to determine which of these differences reflect processes that contribute to age-related memory decline, which reflect compensatory mechanisms that ameliorate decline, and which differences are indicative of memory pathology. The focus of the program is on the neural correlates of episodic encoding and retrieval as these are indexed by fMRI. In one strand of the research, subjects will be people in their 60s and 70s with amnestic mild cognitive impairment (aMCI), a significant risk factor for AD, along with healthy aged-matched controls aged around 70 yrs, and healthy adults in their 80s. The goal is to identify which of the neural correlates of successful episodic encoding and retrieval previously identified in healthy people are also evident in aMCI, which correlates are shared with healthy older individuals with broadly comparable memory abilities, and which are specific to aMCI, especially to individuals at high risk for AD. In two studies we will examine the neural correlates of associative encoding and retrieval, and recollection-related cortical reinstatement, respectively. We will also continue to advance our recent work on healthy aging and episodic encoding. We have described several neural measures of encoding that are predictive of memory performance in people aged around 65-75 yrs, but not in middle-aged (45-55 yrs) or younger people. One of these measures - the ‘right frontal subsequent memory effect’ – correlated positively with memory performance in a recent study, but correlated negatively with performance in an earlier study. We shall examine the hypothesis that the direction of the relationship depends upon the conditions under which memory is tested. In another experiment, we will investigate the effects of age on ‘pre-stimulus’ subsequent memory effects – neural activity predictive of subsequent memory performance that precedes a study event. We predict that pre-stimulus effects will be attenuated in older subjects. Should this be so, it will constitute a novel mechanism by which memory encoding is compromised in later life. In a final experiment, we will assess whether age-invariance in the neural correlates of successful retrieval extends to circumstances where retrieved information must be retained in working memory for a period prior to being used to guide response selection.