Peking University Institute of Mental Health (Sixth Hospital) (JW, WD, MZ, JT, TS, XY, HW), Beijing, China; National Clinical Research Center for Mental Disorders, NHC Key Laboratory of Mental Health (Peking University) (JW, WD, MZ, JT, TS, XY HW), Beijing, China; Beijing Municipal Key Laboratory for Translational Research on Diagnosis and Treatment of Dementia (JW, MZ, TS, XY, HW), Beijing, China.
Key Laboratory of Computer Vision and System (Ministry of Education), School of Computer Science and Engineering, Tianjin University of Technology (YG), Tianjin, China.
Am J Geriatr Psychiatry. 2020 Jul;28(7):722-731. doi: 10.1016/j.jagp.2020.02.006. Epub 2020 Feb 19.
Lifetime intellectual engagement may be associated with cognitive ability late in life. However, the current evidence on whether cognitive activities will improve and/or maintain cognitive function is heterogeneous. Drawing on knowledge of the brain's intrinsic small-world organization which combines regional specialization and efficient global information transfer, we aimed to explore that whether individual differences in the small-worldness of resting-state functional connectivity (rsFC) networks would explain the variability in the strength of the association between intellectual engagement and cognitive functioning.
Sixty-five elderly people without dementia were enrolled and scanned with a 52-channel near-infrared spectroscopy system. The number, frequency, and participation hours of intellectual activities were investigated to measure intellectual engagement. Global cognition was assessed by the Montreal Cognitive Assessment. The general linear models and the simple slope analysis were employed to measure the modulatory role of network properties.
The small-worldness of the brain network emerged as a moderator of the association between intellectual engagement and cognition. Exclusively among elderly people with lower small-worldness, greater intellectual engagement, including the frequency and participation hours of activities, was associated with greater global cognitive function. Furthermore, we observed that elderly people with lower small-worldness exhibited decreased rsFC across the bilateral frontopolar areas and increased rsFC across the bilateral parietal cortex.
The individual differences in the small-worldness of rsFC networks might explain the varying strength of the association between intellectual engagement and cognitive functioning. Our findings imply that the intrinsic small-worldness of the brain network might be a potential neurobiological contributor that interacts with the intellectual engagement in enhancing the cognitive ability in late life.
终身智力投入可能与晚年的认知能力有关。然而，目前关于认知活动是否会改善和/或维持认知功能的证据存在差异。借鉴大脑内在小世界组织的知识，该组织结合了区域专业化和有效的全局信息传递，我们旨在探索静息态功能连接（rsFC）网络小世界特性的个体差异是否可以解释智力投入与认知功能之间关联强度的可变性。
共纳入 65 名无痴呆的老年人，并使用 52 通道近红外光谱系统进行扫描。通过调查智力活动的数量、频率和参与时间来测量智力投入。采用蒙特利尔认知评估量表评估整体认知能力。采用一般线性模型和简单斜率分析来衡量网络特性的调节作用。
大脑网络的小世界特性是智力投入与认知之间关联的调节因素。仅在小世界特性较低的老年人中，更多的智力投入，包括活动的频率和参与时间，与更好的整体认知功能相关。此外，我们观察到小世界特性较低的老年人表现出双侧额极区 rsFC 减少，双侧顶叶皮层 rsFC 增加。
rsFC 网络小世界特性的个体差异可能可以解释智力投入与认知功能之间关联强度的差异。我们的研究结果表明，大脑网络的内在小世界特性可能是一种潜在的神经生物学贡献因素，它与智力投入相互作用，以提高晚年的认知能力。
