Division of Anaesthesia, School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Hills Rd., Cambridge CB2 0QQ, UK; Department of Clinical Neurosciences, School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Hills Rd., Cambridge CB2 0QQ, UK.
Division of Anaesthesia, School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Hills Rd., Cambridge CB2 0QQ, UK; Division of Neurosurgery, School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Hills Rd., Cambridge CB2 0QQ, UK.
Neuroimage. 2022 Jul 1;254:119128. doi: 10.1016/j.neuroimage.2022.119128. Epub 2022 Mar 22.
Small world topologies are thought to provide a valuable insight into human brain organisation and consciousness. However, functional magnetic resonance imaging studies in consciousness have not yielded consistent results. Given the importance of dynamics for both consciousness and cognition, here we investigate how the diversity of small world dynamics (quantified by sample entropy; dSW-E) scales with decreasing levels of awareness (i.e., sedation and disorders of consciousness). Paying particular attention to result reproducibility, we show that dSW-E is a consistent predictor of levels of awareness even when controlling for the underlying functional connectivity dynamics. We find that dSW-E of subcortical, and cortical areas are predictive, with the former showing higher and more robust effect sizes across analyses. We find that the network dynamics of intermodular communication in the cerebellum also have unique predictive power for levels of awareness. Consequently, we propose that the dynamic reorganisation of the functional information architecture, in particular of the subcortex, is a characteristic that emerges with awareness and has explanatory power beyond that of the complexity of dynamic functional connectivity.
小世界拓扑结构被认为为理解人类大脑组织和意识提供了有价值的见解。然而，意识的功能磁共振成像研究并未产生一致的结果。鉴于动态性对意识和认知都很重要，我们在这里研究小世界动力学多样性（通过样本熵量化；dSW-E）如何随意识水平（即镇静和意识障碍）的降低而变化。特别关注结果的可重复性，我们表明，即使在控制潜在功能连接动力学的情况下，dSW-E 也是意识水平的一致预测因子。我们发现，皮质下和皮质区域的 dSW-E 是可预测的，前者在分析中表现出更高且更稳健的效应量。我们发现，小脑中模块间通信的网络动力学对意识水平也具有独特的预测能力。因此，我们提出，功能信息架构的动态重新组织，特别是皮质下的动态重新组织，是一种随着意识出现的特征，其解释力超越了动态功能连接复杂性的解释力。
