Age-Related Differences in Episodic Memory Encoding

描述（由申请人提供）：有充分的证据表明，我们的记忆能力随着年龄的增长而下降，尽管并非所有记忆的表达都以相同的速度下降。有大量证据表明，衰老不成比例地影响了我们从过去中选择独特事件的能力。虽然与年龄相关的情景记忆下降是普遍存在的，但导致这种下降的因素并不完全清楚。先前的研究表明，衰老与经历事件时对事件的分化程度较低的神经表征有关。这些分化程度较低的神经表征可能会导致老年人编码不太具体的高度重叠的记忆痕迹，从而导致记忆障碍。此外，在年轻人中，最近的证据表明，在事件发生之前立即发生的过程与随后的记忆有关。然而，前刺激编码过程在记忆老化中的作用还没有得到很好的理解。研究1使用ERPs来检验这一假设，即年轻人，而不是老年人，从事前刺激过程，支持编码的事件，后来可以成功地回忆。重要的是，这项研究将试图确定老年人是否在有效参与这些过程方面受到全面损害，或者他们是否只是没有自发地参与这些过程。研究2使用功能磁共振成像来检验这一假设，即记忆的年龄降低与经历事件的分化程度较低的神经表征有关。这一假设将通过检查特征选择性后续记忆效应与选择特定事件的上下文细节的能力之间的关系来研究。这项研究的主要目的是调查不同阶段的记忆编码过程如何影响与年龄相关的情景记忆衰退。

DESCRIPTION (provided by applicant): It is well documented that our memory abilities decline as we age, although not all expressions of memory decline at the same rate. There is substantial evidence that aging disproportionately impacts our ability to recollect unique episodes from our past. Whereas age-related decline in episodic memory is ubiquitous, the factors causing this decline are not completely understood. Previous research indicates that aging is associated with less differentiated neural representations of an event while the event is being experienced. These less differentiated neural representations might cause older adults to encode less specific highly overlapping memory traces that result in memory impairments. Moreover, in young adults, recent evidence indicates that the processes occurring immediately prior to an event are related to subsequent memory. However, the role of pre-stimulus encoding processes in memory aging is not well understood. Study 1 uses ERPs to examine the hypothesis that younger adults, but not older adults, engage pre-stimulus processes that support the encoding of events that can later be successfully recollected. Importantly, this study will seek to determine if older adults are globally impaired at effectively engaging these processes, or whether they merely do not engage them spontaneously. Study 2 uses fMRI to examine the hypothesis that age reductions in memory are related to less differentiated neural representations of an experienced event. This hypothesis will be investigated by examining the relationship between feature-selective subsequent memory effects and the ability to recollect specific, contextual details of an event. The overarching aim of the proposed research is to investigate how processes engaged at different stages of memory encoding impact age-related declines in episodic memory.