Zheng Li, Gao Zhiyao, Doner Stephanie, Oyao Alexis, Forloines Martha, Grilli Matthew D, Barnes Carol A, Ekstrom Arne D
Psychology Department, University of Arizona, Tucson, AZ 85719.
Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305.
bioRxiv. 2023 Nov 2:2023.06.28.546918. doi: 10.1101/2023.06.28.546918.
Older adults show declines in spatial memory, although the extent of these alterations is not uniform across the healthy older population. Here, we investigate the stability of neural representations for the same and different spatial environments in a sample of younger and older adults using high-resolution functional magnetic resonance imaging (fMRI) of the medial temporal lobe. Older adults showed, on average, lower neural pattern similarity for retrieving the same environment and more variable neural patterns compared to young adults. We also found a positive association between spatial distance discrimination and the distinctiveness of neural patterns between environments. Our analyses suggested that one source for this association was the extent of informational connectivity to CA1 from other subfields, which was dependent on age, while another source was the fidelity of signals within CA1 itself, which was independent of age. Together, our findings suggest both age-dependent and independent neural contributions to spatial memory performance.
老年人的空间记忆会出现衰退，尽管这些变化的程度在健康老年人群中并不一致。在此，我们使用内侧颞叶的高分辨率功能磁共振成像（fMRI），研究了年轻和老年成年人样本中相同和不同空间环境下神经表征的稳定性。与年轻人相比，老年人在检索相同环境时平均表现出较低的神经模式相似性，且神经模式更具变异性。我们还发现空间距离辨别与不同环境之间神经模式的独特性呈正相关。我们的分析表明，这种关联的一个来源是其他子区域与CA1的信息连接程度，这取决于年龄，而另一个来源是CA1自身信号的保真度，这与年龄无关。总之，我们的研究结果表明，年龄依赖性和独立性神经因素均对空间记忆表现有影响。
