Department of Psychology, College of Science, National Taiwan University, Taipei, Taiwan; Department of Neurology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan; Clinical Psychology Center, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
Department of Psychology, College of Science, National Taiwan University, Taipei, Taiwan; Department of Neurology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan; Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan; Center for Artificial Intelligence and Advanced Robotics, National Taiwan University, Taipei, Taiwan.
Biol Psychol. 2023 Oct;183:108657. doi: 10.1016/j.biopsycho.2023.108657. Epub 2023 Aug 8.
Associative memory is a type of hippocampal-dependent episodic memory that declines with age. Studies have examined the neural substrates underlying associative memory and considered the hippocampus holistically; however, the association between associative memory decline and volumetric change in hippocampal subfields in the context of normal aging remains uncharacterized. Leveraging the distinct linguistic features of Chinese characters to evaluate distinct types of false recognition, we investigated age-related differences in associative recognition and hippocampal subfield volumes, as well as the relationship between behavioral performance and hippocampal morphometry in 25 younger adults and 32 older adults. The results showed an age-related associative memory deficit, which was exacerbated after a 30-min delay. Older adults showed higher susceptibility to false alarm errors with recombined and orthographically related foils compared to phonologically or semantically related ones. Moreover, we detected a disproportionately age-related, time-dependent increase in orthographic errors. Older adults exhibited smaller volumes in all hippocampal subfields when compared to younger adults, with a less pronounced effect observed in the CA2/3 subfield. Group-collapsed correlational analyses revealed associations between specific hippocampal subfields and associative memory but not item memory. Additionally, multi-subfield regions had prominent associations with delayed recognition. These findings underscore the significance of multiple hippocampal subfields in various hippocampal-dependent processes including associative memory, recollection-based retrieval, and pattern separation ability. Moreover, our observations of age-related difficulty in differentiating perceptually similar foils from targets provide a unique opportunity for examining the essential contribution of individual hippocampal subfields to the pattern separation process in mnemonic recognition.
联想记忆是一种依赖海马体的情景记忆，随着年龄的增长而衰退。研究已经检查了联想记忆的神经基础，并从整体上考虑了海马体;然而，在正常衰老的背景下，联想记忆下降与海马亚区体积变化之间的关联仍未得到描述。利用汉字的独特语言特征来评估不同类型的错误识别，我们调查了联想识别和海马亚区体积与年龄相关的差异，以及行为表现与 25 名年轻成年人和 32 名老年成年人海马形态之间的关系。结果显示，与年轻成年人相比，老年成年人存在与年龄相关的联想记忆缺陷，且在 30 分钟延迟后更为严重。与语音或语义相关的干扰项相比，老年成年人对重新组合和正字法相关的干扰项更容易产生错误警报错误。此外，我们检测到与年龄相关的、时间依赖性的正字法错误增加不成比例。与年轻成年人相比，老年成年人的所有海马亚区体积都较小，而 CA2/3 亚区的影响则不那么明显。组间相关分析显示，特定的海马亚区与联想记忆而不是项目记忆之间存在关联。此外，多亚区区域与延迟识别有显著关联。这些发现强调了多个海马亚区在各种依赖海马体的过程中的重要性，包括联想记忆、基于回忆的检索和模式分离能力。此外，我们观察到年龄相关的困难在于从目标中区分出感知相似的干扰项，这为检查个体海马亚区对记忆识别中模式分离过程的基本贡献提供了一个独特的机会。
