Chen Yan, Cao Zhenjing, Mao Min, Sun Wei, Song Qipeng, Mao Dewei
School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China; College of Sport and Health, Shandong Sport University, Jinan, Shandong 250102, China.
College of Sport and Health, Shandong Sport University, Jinan, Shandong 250102, China.
Brain Cogn. 2022 Nov;163:105904. doi: 10.1016/j.bandc.2022.105904. Epub 2022 Sep 2.
By analyzing the cortical activation and functional connectivity of the prefrontal cortex (PFC) during dual-task obstacle negotiation in the older adults, cognitive resources allocation and neural regulatory mechanisms of aging brain were shed light on in complex walking conditions.
Twenty-eight healthy right-handed subjects participated in the study, including 15 men and 13 women (age: 68.6 ± 4.1 years, height: 162.96 ± 6.05 cm, weight: 63.63 ± 9.64 kg). There were four tasks: Normal Walk (NW), Obstacle Negotiation during Normal Walk (NW + ON), Walk while performing Cognitive Task (WCT), and Obstacle Negotiation during Walk while performing Cognitive Task (WCT + ON). Participants wore functional near-infrared spectroscopy (fNIRS) to collect hemodynamic signals from various regions of interest (ROIs) in the PFC, while the three-dimensional motion capture system was used to test the gait velocity. Cognitive task data was recorded.
In WCT + ON, the HbO concentration change value (△HbO) of the left dorsolateral prefrontal cortex was significantly greater than that in the other three tasks (p < 0.05), and the△HbO of the right dorsolateral prefrontal cortex was significantly greater than that in NW + ON (p < 0.05). The gait velocities in the four tasks were significantly different (p < 0.05) (NW > WCT > NW + ON > WCT + ON). There was no significant difference in cognitive performance between in the WCT and WCT + ON (p > 0.05). In WCT + ON, the left and right dorsolateral prefrontal areas had strong functional connectivity and the left frontal pole was most widely connected to the other ROIs. Compared to that in NW, the functional connectivity of the left prefrontal lobe was significantly enhanced in WCT + ON (p < 0.05).
As walking difficulty increased, the PFC activation in the older adults changed from right-sided to bilateral activation, indicating that the left PFC cognitive resources compensated for the right PFC in dual-task obstacle negotiation. The cognitive resources recruitment in dual-task obstacle negotiation might be achieved by synchronization and coordination of associated brain areas in the PFC, primarily to maintain dynamic postural balance when walking.
通过分析老年人在双任务障碍谈判过程中前额叶皮质（PFC）的皮质激活和功能连接，揭示复杂行走条件下衰老大脑的认知资源分配和神经调节机制。
28名健康右利手受试者参与研究，其中男性15名，女性13名（年龄：68.6±4.1岁，身高：162.96±6.05厘米，体重：63.63±9.64千克）。有四项任务：正常行走（NW）、正常行走时障碍谈判（NW+ON）、执行认知任务时行走（WCT）、执行认知任务时行走且障碍谈判（WCT+ON）。参与者佩戴功能近红外光谱仪（fNIRS）收集PFC中各个感兴趣区域（ROI）的血流动力学信号，同时使用三维运动捕捉系统测试步态速度。记录认知任务数据。
在WCT+ON中，左侧背外侧前额叶皮质的血红蛋白氧（HbO）浓度变化值（△HbO）显著大于其他三项任务（p<0.05），右侧背外侧前额叶皮质的△HbO显著大于NW+ON（p<0.05）。四项任务中的步态速度有显著差异（p<0.05）（NW>WCT>NW+ON>WCT+ON）。WCT和WCT+ON之间的认知表现无显著差异（p>0.05）。在WCT+ON中，左右背外侧前额叶区域有很强的功能连接，左侧额极与其他ROI连接最广泛。与NW相比，WCT+ON中左侧前额叶的功能连接显著增强（p<0.05）。
随着行走难度增加，老年人的PFC激活从右侧激活转变为双侧激活，表明在双任务障碍谈判中左侧PFC认知资源补偿了右侧PFC。双任务障碍谈判中的认知资源招募可能是通过PFC中相关脑区的同步和协调实现的，主要是为了在行走时维持动态姿势平衡。
