深入研究睡眠过程中的大脑机制对于睡眠健康非常重要。同步脑电图（EEG）和功能磁共振成像（fMRI）技术的提出使我们能够同时利用EEG的高时间分辨率和fMRI的高空间分辨率的特点得到高时空分辨率的大脑活动图像，为研究睡眠过程的脑功能提供了强有力的工具。然而神经元活动位置和fMRI激活区存在空间不匹配会造成EEG-fMRI融合模型的准确性变差。本项目将提出由神经活动和fMRI激活动态约束的优化融合模型解决EEG和fMRI空间不匹配造成准确性变差的问题，然后将此模型运用于静息态和睡眠过程EEG微状态的研究中，将首次揭示从清醒到睡眠过程EEG微状态对应的大脑活动机制的变化模式。本项目的开展将推动同步EEG-fMRI技术的发展，加深对睡眠过程脑功能活动机制的了解，对促进睡眠健康具有重要的意义。

It is very important to study the brain mechanisms during sleep for understanding sleep health. Multimodal functional neuroimaging by combining EEG and fMRI is able to provide high spatiotemporal resolution mapping of brain activity and has been a powerful tool for investigations of brain function during sleep. However, the accuracy of EEG-fMRI fusion model may be degraded by potential spatial mismatches between the locations of fMRI activation and electrical source activities. To address this problem, this project will propose an optimized EEG-fMRI fusion model by combining the electrical source activities and fMRI activities in a time-variant manner to reduce the impact of the spatial mismatch effect. Then we will apply the model to EEG microstates during resting state and sleep to reveal the underlying brain mechanisms of EEG microstates from wakefulness to sleep for the first time. This project will promote development on simultaneous EEG-fMRI technology, be helpful and meaningful for exploring the brain functional characteristics during sleep and improving sleep health.