Intelligent Systems Research Centre, Ulster University, UK.
Trinity College Institute of Neuroscience and Cognitive Systems Group, Discipline of Psychiatry, School of Medicine, Trinity College Dublin, Ireland.
Neuroimage. 2018 Dec;183:438-455. doi: 10.1016/j.neuroimage.2018.08.033. Epub 2018 Aug 18.
Current theory suggests brain regions interact to reconcile the competing demands of integration and segregation by leveraging metastable dynamics. An emerging consensus recognises the importance of metastability in healthy neural dynamics where the transition between network states over time is dependent upon the structural connectivity between brain regions. In Alzheimer's disease (AD) - the most common form of dementia - these couplings are progressively weakened, metastability of neural dynamics are reduced and cognitive ability is impaired. Accordingly, we use a joint empirical and computational approach to reveal how behaviourally relevant changes in neural metastability are contingent on the structural integrity of the anatomical connectome. We estimate the metastability of fMRI BOLD signal in subjects from across the AD spectrum and in healthy controls and demonstrate the dissociable effects of structural disconnection on synchrony versus metastability. In addition, we reveal the critical role of metastability in general cognition by demonstrating the link between an individuals cognitive performance and their metastable neural dynamic. Finally, using whole-brain computer modelling, we demonstrate how a healthy neural dynamic is conditioned upon the topological integrity of the structural connectome. Overall, the results of our joint computational and empirical analysis suggest an important causal relationship between metastable neural dynamics, cognition, and the structural efficiency of the anatomical connectome.
目前的理论表明，大脑区域通过利用亚稳态动力学相互作用，以协调整合和分离的竞争需求。一个新兴的共识认识到亚稳态在健康神经动力学中的重要性，其中网络状态随时间的转换取决于大脑区域之间的结构连接。在阿尔茨海默病（AD）-最常见的痴呆形式中-这些耦合逐渐减弱，神经动力学的亚稳定性降低，认知能力受损。因此，我们使用联合实证和计算方法来揭示神经亚稳定性的行为相关变化如何取决于解剖连接组的结构完整性。我们估计了 AD 谱中受试者和健康对照者 fMRI BOLD 信号的亚稳定性，并证明了结构连接中断对同步性和亚稳定性的分离影响。此外，我们通过证明个体认知表现与其亚稳定神经动力学之间的联系，揭示了亚稳定性在一般认知中的关键作用。最后，使用全脑计算机建模，我们证明了健康神经动力学如何取决于结构连接组的拓扑完整性。总的来说，我们的联合计算和实证分析的结果表明，亚稳定神经动力学、认知和解剖连接组的结构效率之间存在重要的因果关系。
