Electroencephalograph (EEG) signals and graph theory measures have been widely used to characterize the brain functional networks of healthy individuals and patients by calculating the correlations between different electrodes over an entire time series. Although EEG signals have a high temporal resolution and can provide relatively stable results, the process of constructing and analyzing brain functional networks is inevitably complicated by high time complexity. Our goal in this research was to distinguish the brain function networks of schizophrenia patients from those of healthy participants during working memory tasks. Consequently, we utilized a method involving microstates, which are each characterized by a unique topography of electric potentials over an entire channel array, to reduce the dimension of the EEG signals during working memory tasks and then compared and analyzed the brain functional networks using the microstates time series (MTS) and original time series (OTS) of the schizophrenia patients and healthy individuals. We found that the right frontal and parietal-occipital regions neurons of the schizophrenia patients were less active than those of the healthy participants during working memory tasks. Notably, compared with OTS, the time needed to construct the brain functional networks was significantly reduced by using MTS. In conclusion, our results show that, like OTS, MTS can well distinguish the brain functional network of schizophrenia patients from those of healthy individuals during working memory tasks while greatly decreasing time complexity. MTS can thus provide a method for characterizing the original time series for the construction and analysis of EEG brain functional networks.

通过计算整个时间序列中不同电极之间的相关性，脑电图（EEG）信号和图论测量已广泛用于表征健康个体和患者的大脑功能网络。尽管脑电信号具有较高的时间分辨率并可以提供相对稳定的结果，但是构建和分析大脑功能网络的过程不可避免地会因时间复杂而变得复杂。我们在这项研究中的目标是在工作记忆任务期间将精神分裂症患者的大脑功能网络与健康参与者的大脑功能网络区分开。因此，我们利用了一种涉及微状态的方法，每个微状态的特征是整个通道阵列上的电势具有独特的形貌，在工作记忆任务期间减少EEG信号的大小，然后使用精神分裂症患者和健康个体的微状态时间序列（MTS）和原始时间序列（OTS）对大脑功能网络进行比较和分析。我们发现，在工作记忆任务期间，精神分裂症患者的右额叶和顶枕区神经元的活动性较健康参与者低。值得注意的是，与OTS相比，使用MTS大大减少了构建大脑功能网络所需的时间。总之，我们的结果表明，与OTS一样，MTS在工作记忆任务期间可以很好地区分精神分裂症患者的大脑功能网络与健康个体的大脑功能网络，同时大大降低了时间复杂度。