Cognitive performance slows down with increasing age. This includes cognitive processes that are essential for the performance of a motor act, such as the slowing down in response to an external stimulus. The objective of this study was to identify aging‐associated functional changes in the brain networks that are involved in the transformation of external stimuli into motor action. To investigate this topic, we employed dynamic graphs based on phase‐locking of Electroencephalography signals recorded from healthy younger and older subjects while performing a simple visually‐cued finger‐tapping task. The network analysis yielded specific age‐related network structures varying in time in the low frequencies (2–7 Hz), which are closely connected to stimulus processing, movement initiation and execution in both age groups. The networks in older subjects, however, contained several additional, particularly interhemispheric, connections and showed an overall increased coupling density. Cluster analyses revealed reduced variability of the subnetworks in older subjects, particularly during movement preparation. In younger subjects, occipital, parietal, sensorimotor and central regions were—temporally arranged in this order—heavily involved in hub nodes. Whereas in older subjects, a hub in frontal regions preceded the noticeably delayed occurrence of sensorimotor hubs, indicating different neural information processing in older subjects. All observed changes in brain network organization, which are based on neural synchronization in the low frequencies, provide a possible neural mechanism underlying previous fMRI data, which report an overactivation, especially in the prefrontal and pre‐motor areas, associated with a loss of hemispheric lateralization in older subjects.

中文翻译：

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刺激转化为运动动作：动态图分析揭示了老年受试者大脑网络通信的后向转移

认知能力随着年龄的增长而减慢。这包括对运动行为的表现至关重要的认知过程，例如对外部刺激的反应减慢。本研究的目的是确定大脑网络中与衰老相关的功能变化，这些变化涉及将外部刺激转化为运动动作。为了研究这个主题，我们采用了基于锁相的动态图，该图基于从健康的年轻和年长受试者记录的脑电图信号的锁相，同时执行简单的视觉提示手指敲击任务。网络分析产生了在低频（2-7Hz）中随时间变化的特定年龄相关网络结构，这与两个年龄组的刺激处理、运动启动和执行密切相关。然而，老年受试者的网络包含几个额外的，特别是半球间的连接，并显示出整体增加的耦合密度。聚类分析揭示了老年受试者子网络的可变性降低，特别是在运动准备期间。在较年轻的受试者中，枕叶、顶叶、感觉运动和中央区域——按时间顺序排列——大量参与枢纽节点。而在老年受试者中，额叶区域的中枢先于感觉运动中枢的出现明显延迟，表明老年受试者的神经信息处理不同。所有观察到的大脑网络组织的变化，都是基于低频的神经同步，提供了一种可能的神经机制，作为先前 fMRI 数据的基础，这些数据报告了过度激活，