IEEE Trans Neural Syst Rehabil Eng. 2021;29:2378-2387. doi: 10.1109/TNSRE.2021.3125420. Epub 2021 Nov 17.
This study investigates intra-regional connectivity and regional hemispheric asymmetry under two vigilance states: alertness and vigilance decrement. The vigilance states were induced on nine healthy subjects while performing 30 min in-congruent Stroop color-word task (I-SCWT). We measured brain activity using Electroencephalography (EEG) signals with 64-channels. We quantified the regional network connectivity using the phase-locking value (PLV) with graph theory analysis (GTA) and Support Vector Machines (SVM). Results showed that the vigilance decrement state was associated with impaired information processing within the frontal and central regions in delta and theta frequency bands. Meanwhile, the hemispheric asymmetry results showed that the laterality shifted to the right-temporal in delta, right-central, parietal, and left frontal in theta, right-frontal and left-central, temporal and parietal in alpha, and right-parietal and left temporal in beta frequency bands. These findings represent the first demonstration of intra-regional connectivity and hemispheric asymmetry changes as a function of cognitive vigilance states. The overall results showed that vigilance decrement is region and frequency band-specific. Our SVM model achieved the highest classification accuracy of 99.73% in differentiating between the two vigilance states based on the frontal and central connectivity networks measures.
本研究旨在探究两种警觉状态（警觉和警觉下降）下的区域内连接和半球间不对称性。在九名健康受试者执行 30 分钟不一致的斯特鲁普颜色-单词任务（I-SCWT）期间，我们使用脑电图（EEG）信号和 64 通道来测量大脑活动。我们使用相位锁定值（PLV）和图论分析（GTA）以及支持向量机（SVM）来量化区域网络连接。结果表明，警觉下降状态与 delta 和 theta 频段中额叶和中央区域内的信息处理受损有关。同时，半球间不对称性结果表明，在 delta 频段中向右侧颞叶、右侧中央、顶叶和左侧额叶，在 theta 频段中向右侧额叶和左侧中央、颞叶和顶叶，在 alpha 频段中向右侧额叶和左侧中央、颞叶和顶叶，在 beta 频段中向右侧顶叶和左侧颞叶发生了侧化。这些发现代表了认知警觉状态作为函数的区域内连接和半球间不对称性变化的首次证明。总体结果表明，警觉下降是特定于区域和频段的。我们的 SVM 模型基于额区和中央区连接网络的测量，在区分两种警觉状态方面取得了 99.73%的最高分类准确率。
