IEEE J Biomed Health Inform. 2017 May;21(3):743-755. doi: 10.1109/JBHI.2016.2544061. Epub 2016 Mar 18.
The organization of the brain functional network is associated with mental fatigue, but little is known about the brain network topology that is modulated by the mental fatigue. In this study, we used the graph theory approach to investigate reconfiguration changes in functional networks of different electroen-cephalography (EEG) bands from 16 subjects performing a simulated driving task. Behavior and brain functional networks were compared between the normal and driving mental fatigue states. The scores of subjective self-reports indicated that 90 min of simulated driving-induced mental fatigue. We observed that coherence was significantly increased in the frontal, central, and temporal brain regions. Furthermore, in the brain network topology metric, significant increases were observed in the clustering coefficient (Cp) for beta, alpha, and delta bands and the character path length (Lp) for all EEG bands. The normalized measures γ showed significant increases in beta, alpha, and delta bands, and λ showed similar patterns in beta and theta bands. These results indicate that functional network topology can shift the network topology structure toward a more economic but less efficient configuration, which suggests low wiring costs in functional networks and disruption of the effective interactions between and across cortical regions during mental fatigue states. Graph theory analysis might be a useful tool for further understanding the neural mechanisms of driving mental fatigue.
大脑功能网络的组织与精神疲劳有关，但对于精神疲劳调节的大脑网络拓扑结构知之甚少。在这项研究中，我们使用图论方法研究了 16 名受试者在执行模拟驾驶任务时不同脑电（EEG）频段的功能网络的重新配置变化。在正常和驾驶精神疲劳状态下比较了行为和脑功能网络。主观自我报告的分数表明，90 分钟的模拟驾驶引起了精神疲劳。我们观察到，在前额、中央和颞叶脑区，相干性显著增加。此外，在脑网络拓扑度量中，β、α 和 δ 波段的聚类系数（Cp）和所有 EEG 波段的特征路径长度（Lp）均显著增加。归一化度量γ在β、α 和δ波段显著增加，λ在β和θ波段表现出相似的模式。这些结果表明，功能网络拓扑可以将网络拓扑结构转移到更经济但效率较低的配置，这表明在精神疲劳状态下，功能网络的布线成本较低，皮质区域之间的有效相互作用中断。图论分析可能是进一步了解驾驶精神疲劳神经机制的有用工具。
