Understanding the neural mechanisms underlying the benefits of unitization on associative memory in young and older adults

抽象的。到2050年，仅美国就将有8370万人超过65岁。在这 在老年人中，记忆力下降是与年龄相关的认知问题的最前沿。联想记忆，或 将多条信息连接在一起的能力，特别容易受到老化的影响。联想记忆是 是日常记忆功能的中心，支持我们记住脸-名字联想的能力 药物和每日剂量之间的联系。因此，迫切需要确定 可以改善老年人的联想记忆。我们的长期目标是确定有效的，理论驱动的， 增强老年人联想记忆的循证方法。本申请的目的 目的是阐明单位化对联想记忆的认知和神经益处的机制。 总体假设是，单元化通过创建镜像对象对的表示来操作 单个项目是如何在记忆中编码的，不需要有意识的、战略性的实施， 语义相关性（Semantic Relationship）。相反，我们认为，单位化可以有效地诱导通过 信息呈现给人的方式。我们预计，单位化将导致从 基于大脑皮层的联想处理到基于皮层的项目处理，观察到类似的变化 在整个记忆网络中，与单元化相关的活动模式更类似于项目级 与关联处理相比。此外，如果单元化通过形成一个集成的 表示项对，则单元化的集合应该被编码并且随后被检索为 一个单一的合奏，与检索过程镜像的项目检索。这一假设是基于a）调查结果 年轻人的项目处理区域处理单位化信息，B）完形能力 将单个项目的表示转换为整体表示的原则。最后，我们重申， 单元化不限于在共同出现的静态呈现的项目之间进行绑定， 时间上呈现的视觉和听觉信息。这种方法是创新的，因为它直接 应用了一个完善的知觉理论来改善联想记忆中的绑定负担 处理，目的是增强衰老中的联想记忆。该方法采用了尖端的 多变量和网络连接分析，以测试应用程序背后的神经认知机制 在记忆的各个阶段都是单元化的。这项研究意义重大，因为它 测试了一种在老化过程中增强记忆力的方法，该方法可以在一系列没有 受试者生成的策略部署。在这样做的过程中，这项工作是阐明 神经处理过程中的记忆功能的改善。通过确定改进方法， 年轻人和老年人的记忆功能，这项工作有可能1）增强其他认知过程， 2)改善老年生活质量，3）帮助将正常衰老与痴呆症的早期症状分离开来。

Abstract. By 2050, roughly 83.7 million individuals in the U.S. alone will be over the age of 65. Within this population, memory declines are at the forefront of age-related cognitive complaints. Associative memory, or the ability to link together multiple pieces of information, is especially vulnerable to aging. Associative memory is central to everyday memory function, supporting everything from our ability to remember face-name associations to links between medicines and their daily dosages. As such, there is an urgent need to identify methods that can improve associative memory in older adults. Our long-term goal is to identify effective, theory-driven, evidence-based approaches for enhancing associative memory in older adults. The objective of this application is to elucidate the mechanism underlying the cognitive and neural benefits of unitization on associative memory. The overarching hypothesis is that unitization operates by creating representations of object pairs that mirror how single items are encoded in memory, and does not require conscious, strategic implementation [nor is it dependent on semantic relatedness]. Instead we posit that unitization can be effectively induced through the way in which information is presented to a person. We expect that unitization will result in shifts from hippocampal-based associative processing to cortical-based item processing, with similar shifts observed throughout the memory network, whereby patterns of unitization-related activity are more similar to item-level processing than to associative processing. Additionally, if unitization operates by forming an integrated representation of item pairs, then the unitized ensemble should be both encoded and subsequently retrieved as a single ensemble, with retrieval processes mirroring that of item retrieval. This hypothesis is based on a) findings that unitized information is processed by item-processing regions in young adults and b) the ability of Gestalt principles to transform the representations of individual items into a holistic representation. Finally, we posit that unitization is not limited to binding amongst co-occurring statically presented items, but can occur across temporally presented visual and auditory information as well. The approach is innovative because it directly applies a well-established theory of perception to ameliorate the burden of binding in associative memory processing, with the goal of enhancing associative memory in aging. The approach employs cutting-edge multivariate and network connectivity analyses to test the neurocognitive mechanism underlying the application of unitization to associative memory at all stages of memory. The proposed research is significant because it tests a method for enhancing memory in aging that can be employed across a range of applications absent of subject-generated strategy deployment. In doing so, the work is a critical step in elucidating the flexibility of neural processing across the lifespan to the betterment of memory function. By identifying ways to improve memory function in young and older adults, this work has the potential to 1) enhance other cognitive processes, 2) improve the quality of life in aging, and 3) help dissociate normal aging from early signs of dementia.