Abstract

Time-based prospective memory (TBPM) allows us to remember to perform intended actions at a specific time in the future. TBPM is sensitive to the effects of age, but the neural substrates of this decline are still poorly understood. The aim of the present study was thus to better characterize the brain substrates of the age-related decline in TBPM, focusing on macrostructural gray matter and microstructural white matter integrity. We administered a TBPM task to 22 healthy young (26 ± 5.2 years) and 23 older (63 ± 5.9 years) participants, who also underwent volumetric magnetic resonance imaging and diffusion tensor imaging scans. Neuroimaging analyses revealed lower gray matter volumes in several brain areas in older participants, but these did not correlate with TBPM performance. By contrast, an age-related decline in fractional anisotropy in several white-matter tracts connecting frontal and occipital regions did correlate with TBPM performance, whereas there was no significant correlation in healthy young subjects. According to the literature, these tracts are connected to the anterior prefrontal cortex and the thalamus, 2 structures involved in TBPM. These results confirm the view that a disconnection process occurs in aging and contributes to cognitive decline.

中文翻译：

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老化中基于时间的前瞻性记忆衰退的脑基质：基于体素的形态测量和扩散张量成像研究。

摘要

基于时间的前瞻性记忆 (TBPM) 使我们能够记住在未来的特定时间执行预期的操作。TBPM 对年龄的影响很敏感，但这种下降的神经底物仍然知之甚少。因此，本研究的目的是更好地表征与年龄相关的 TBPM 下降的大脑基质，重点关注宏观结构灰质和微观结构白质完整性。我们对 22 名健康年轻（26 ± 5.2 岁）和 23 名年长（63 ± 5.9 岁）参与者进行了 TBPM 任务，他们还接受了体积磁共振成像和弥散张量成像扫描。神经影像学分析显示，老年参与者的几个大脑区域的灰质体积较低，但这些与 TBPM 表现无关。相比之下，在连接额叶和枕叶区域的几个白质束中，与年龄相关的分数各向异性下降确实与 TBPM 表现相关，而在健康的年轻受试者中没有显着相关性。根据文献，这些神经束与前额叶皮层和丘脑相连，这是 TBPM 中涉及的 2 个结构。这些结果证实了这样一种观点，即衰老过程中会发生断开过程并导致认知能力下降。