School of Life Science and Technology, Xidian University, Xi'an, P. R. China.
Department of Anesthesiology and Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, P. R. China.
Int J Neural Syst. 2021 Jun;31(6):2150021. doi: 10.1142/S0129065721500210. Epub 2021 May 7.
Connected consciousness refers to the state when external stimuli can enter into the stream of our consciousness experience. Emerging evidence suggests that although patients may not respond behaviorally to external stimuli during anesthesia, they may be aware of their surroundings. In this work, we investigated whether EEG based brain decoding could be used for detecting connected consciousness in the absence of behavioral responses during propofol infusion. A total of 14 subjects participated in our experiment. Subjects were asked to discriminate two types of auditory stimuli with a finger press during an ultraslow propofol infusion. We trained an EEG based brain decoding model using data collected in the awakened state using the same auditory stimuli and tested the model on data collected during the propofol infusion. The model provided a correct classification rate (CCR) of [Formula: see text]% when subjects were able to respond to the stimuli during the propofol infusion. The CCR dropped to [Formula: see text]% when subjects ceased responding and further decreased to [Formula: see text]% when we increased the propofol concentration by another 0.2 [Formula: see text]g/ml. After terminating the propofol infusion, we observed that the CCR rebounded to [Formula: see text]% before the subjects regained consciousness. With the classification results, we provided evidence that loss of consciousness is a gradual process and may progress from full consciousness to connected consciousness and then to disconnected consciousness.
连通意识是指外部刺激可以进入我们意识体验流的状态。新出现的证据表明，尽管患者在麻醉期间可能不会对外界刺激做出行为反应，但他们可能会意识到周围的环境。在这项工作中，我们研究了在异丙酚输注期间没有行为反应的情况下，是否可以使用基于 EEG 的大脑解码来检测连通意识。共有 14 名受试者参加了我们的实验。要求受试者在超慢异丙酚输注期间用手指按压来区分两种类型的听觉刺激。我们使用相同的听觉刺激在清醒状态下收集的数据来训练基于 EEG 的大脑解码模型，并在异丙酚输注期间收集的数据上测试该模型。当受试者能够在异丙酚输注期间对刺激做出反应时，该模型的正确分类率（CCR）为[Formula: see text]%。当受试者停止反应时，CCR 下降到[Formula: see text]%，当我们将异丙酚浓度再增加 0.2[Formula: see text]g/ml 时，CCR 进一步下降到[Formula: see text]%。在停止异丙酚输注后，我们观察到 CCR 在受试者恢复意识之前反弹至[Formula: see text]%。通过分类结果，我们提供了证据表明意识丧失是一个渐进的过程，可能从完全意识状态进展到连通意识状态，然后再到不连通意识状态。
