Computational Neuroscience Group, Center for Brain and Cognition, Universitat Pompeu Fabra, Barcelona, Spain.
GIGA-Consciousness, Coma Science Group, University of Liège, Liège, Belgium.
Commun Biol. 2021 Sep 6;4(1):1037. doi: 10.1038/s42003-021-02537-9.
Low-level states of consciousness are characterized by disruptions of brain activity that sustain arousal and awareness. Yet, how structural, dynamical, local and network brain properties interplay in the different levels of consciousness is unknown. Here, we study fMRI brain dynamics from patients that suffered brain injuries leading to a disorder of consciousness and from healthy subjects undergoing propofol-induced sedation. We show that pathological and pharmacological low-level states of consciousness display less recurrent, less connected and more segregated synchronization patterns than conscious state. We use whole-brain models built upon healthy and injured structural connectivity to interpret these dynamical effects. We found that low-level states of consciousness were associated with reduced network interactions, together with more homogeneous and more structurally constrained local dynamics. Notably, these changes lead the structural hub regions to lose their stability during low-level states of consciousness, thus attenuating the differences between hubs and non-hubs brain dynamics.
低意识状态的特征是大脑活动的中断，这些中断维持着觉醒和意识。然而，结构、动力、局部和网络大脑特性如何在不同的意识水平上相互作用尚不清楚。在这里，我们研究了因脑损伤而导致意识障碍的患者和接受异丙酚诱导镇静的健康受试者的 fMRI 大脑动力学。我们表明，病理性和药物诱导的低意识状态表现出较少的复发、较少的连接和更隔离的同步模式，而不是意识状态。我们使用基于健康和受损结构连接的全脑模型来解释这些动力学效应。我们发现，低意识状态与网络相互作用减少有关，同时局部动力学更加同质和更受结构限制。值得注意的是，这些变化导致结构枢纽区域在低意识状态下失去稳定性，从而削弱了枢纽和非枢纽大脑动力学之间的差异。
