|Alternative Title||Definition-based Unitization Enhances Associative Memory in Older Adults：Its Cognitive Neural Correlates and Application|
|Place of Conferral||北京|
|Keyword||一体化 定义 联结记忆 老化 记忆训练|
|Abstract||研究目的：人们的记忆能力随着年龄的增长而逐渐下降，但是老化对不同类型的记忆有着不同的影响。老年人在依赖于回忆性（recollection）的联结记忆能力存在损伤，但是在依赖于熟悉性(familiarity)的项目记忆能力依然保存完好。定义一体化（definition-based unitization）是把两个不相关词整合成一个新概念的过程。研究发现，定义一体化可以促使青年人做出基于熟悉的联结再认。那么，定义一体化能否帮助老年人利用保留较好的熟悉性补偿依赖于回忆性的联结记忆损伤？本论文通过三个研究对此问题进行了探讨。研究一利用事件相关脑电位(event related potential, ERP)技术探讨定义一体化能否减少年龄相关的联结记忆损伤及其提取阶段的神经机制。研究二在记忆编码阶段使用项目分心（divided attention with item processing）和关系分心（divided attention with relational processing）任务，考察不同类型的注意资源对定义一体化编码的影响，进一步探究定义一体化编码的认知加工过程。研究三通过对老年人进行定义法的编码策略训练，探索定义法的记忆训练是否能够减少老年人联结记忆的损伤，并与传统的造句法训练开展比较。|
研究结论: 定义一体化的编码能够减少年龄相关的联结记忆损伤,老年人在通过定义一体化编码后可依赖于熟悉性进行联结再认。定义一体化编码过程是把两个不相关词整合成一个新的概念进行表征的过程。 定义法和传统的造句法的训练都可以提高老年人联结记忆成绩，但是不同语言能力的老年人从定义法和造句法的训练中获益情况不同。语言能力高的老年人能够更多从定义法训练获益，而语言能力低的老年人则能够更多从造句法训练获益。
|Other Abstract||Objective: While memory generally declines with increasing age, aging has varied effects on different types of memory. Older adults have impaired associative memory that depends on recollection, whereas they reserve relatively intact item memory that depends on familiarity. The Definition-based unitization refers to the process that participants encode the word pair with unrelated nouns into a new single concept representation. Previous studies have demonstrated that definition-based unitization enhance familiarity-based associative recognition in younger adults. It is not clear whether older adults can also benefit from the implementation of definition-based unitization by using their reserved familiarity to compensate for age-related associative memory deficit. In this dissertation, to discern this issue three studies were carried out. The first study aimed to examine whether definition-based unitization would reduce age-related associative memory deficit and its underlying neural mechanism by recording event-related potentials (ERPs) during retrieval. The second study focused on the cognitive process of definition-based unitized encoding. Item and relation distraction tasks were employed during encoding to investigate how they differently affected the unitized encoding. The third study investigated whether definition memory training would reduce associative memory deficit in older adults in comparison with not only a no-training control group, but also a traditional sentence-completion training group.|
Results：In study one, behavioral results showed definition-based unitization reduced age-related associative memory deficit. A double dissociation of frontal old/new effect and parietal old/new effect was observed under definition and sentence conditions in older adults, specifically, definition condition only induced frontal old/new effect but not parietal old/new effect, whereas sentence-completing condition induced parietal old/new effect but not frontal old/new effect. In study two, divided attention with item processing has impaired unitized encoding. However, the divided attention with relational processing had no influence on unitized encoding. In study three, both training groups performed better than the control group after training. Moreover, the training gains were associated with verbal abilities of the participants. Those with higher verbal ability benefited more from unitized definition training, while those with lower verbal ability benefited more from sentence-completion training. From group level perspective, memory training using the method of definition and traditional sentence-making both improved associative memory performance in older adults. Form the individual level perspective, training benefit for the older adults from different method showed individual differences in verbal ability.
Conclusion: Definition-based unitization reduced age-related association memory deficit. The mechanisms might be that definition involves the process that participants encode the word pair of unrelated nouns into a single concept representation, which facilitated familiarity-based retrieval for associative recognition. Definition-based memory training was effective for improving elders’ associative memory performance, and results training gains were positively correlated with their verbal abilities.
|王宝玺. 定义一体化促进老年人联结记忆—认知神经机制及其应用研究[D]. 北京. 中国科学院研究生院,2014.|
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