Liu Meng, Nie Zhi-Yu, Li Ren-Ren, Zhang Wei, Huang Li-He, Wang Jie-Qun, Xiao Wei-Xin, Zheng Jialin C, Li Yun-Xia
Department of Neurology, Tongji University School of Medicine, Tongji Hospital, Tongji University, Shanghai, China.
Research Center for Ageing Language and Care, School of Foreign Languages, Tongji University, Shanghai, China.
Front Neurol. 2021 Jul 12;12:665218. doi: 10.3389/fneur.2021.665218. eCollection 2021.
Visual working memory (VWM), the core process inherent to many advanced cognitive processes, deteriorates with age. Elderly individuals usually experience defects in the processing of VWM. The dorsolateral prefrontal cortex is a key structure for the top-down control of working memory processes. Many studies have shown that repeated transcranial magnetic stimulation (rTMS) improves VWM by modulating the excitability of neurons in the target cortical region, though the underlying neural mechanism has not been clarified. Therefore, this study sought to assess the characteristics of brain memory function post-rTMS targeting the left dorsolateral prefrontal cortex. The study stimulated the left dorsolateral prefrontal cortex in elderly individuals by performing a high-frequency rTMS protocol and evaluated behavioral performance using cognitive tasks and a VWM task. Based on the simultaneously recorded electroencephalogram signals, event-related potential and event-related spectral perturbation analysis techniques were used to investigate the variation characteristics of event-related potential components' (N2PC and CDA) amplitudes and neural oscillations in elderly individuals to elucidate the effect of high-frequency rTMS. The results found that rTMS enhanced VWM performance and significantly improved attention and executive function in elderly individuals with subjective cognitive decline. We therefore speculate that rTMS enhances VWM by increasing the N2PC and CDA amplitude, alongside increasing β oscillation activity. This would improve the attention and allocation of resources in elderly individuals such as to improve an individual's VWM.
视觉工作记忆（VWM）是许多高级认知过程所固有的核心过程，会随着年龄的增长而衰退。老年人通常在VWM处理方面存在缺陷。背外侧前额叶皮层是对工作记忆过程进行自上而下控制的关键结构。许多研究表明，重复经颅磁刺激（rTMS）通过调节目标皮质区域神经元的兴奋性来改善VWM，但其潜在的神经机制尚未阐明。因此，本研究旨在评估针对左侧背外侧前额叶皮层进行rTMS后大脑记忆功能的特征。该研究通过执行高频rTMS方案刺激老年人的左侧背外侧前额叶皮层，并使用认知任务和VWM任务评估行为表现。基于同步记录的脑电图信号，采用事件相关电位和事件相关频谱微扰分析技术，研究老年人事件相关电位成分（N2PC和CDA）的振幅和神经振荡的变化特征，以阐明高频rTMS的作用。结果发现，rTMS提高了主观认知衰退老年人的VWM表现，并显著改善了他们的注意力和执行功能。因此，我们推测rTMS通过增加N2PC和CDA振幅以及增加β振荡活动来增强VWM。这将改善老年人的注意力和资源分配，从而提高个体的VWM。
