Global features of functional brain networks change with contextual disorder.
Global features of functional brain networks change with contextual disorder.
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DOI：
10.1016/j.neuroimage.2015.05.025
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发表时间：
2015-08-15
期刊：
影响因子：
5.7
通讯作者：
Hasson U
中科院分区：
文献类型：
--
作者：
Andric M;Hasson U
众所周知，环境中的刺激特征会影响人类大脑中功能连接的强度。然而，迄今为止的研究尚未确定这些因素是否也会影响功能网络的整体特征，如模块化强度、模块数量、分区结构或程度分布。我们假设可能强烈影响整体特征的一个环境属性是环境的时间规律性，因为先前的工作表明，规律性的差异影响涉及感觉、注意和记忆过程的区域。我们用功能磁共振成像（fMRI）研究来检验这一点，在这项研究中，参与者被动地听了一系列具有相同物理特征的音调，只是它们的规律性不同，这是由音调之间的过渡结构的强度所定义的。我们发现，序列规律性导致功能网络的整体特征发生系统性变化，包括模块化强度、模块数量、分区结构和程度分布。同时，我们使用了一种新颖的节点级分析来确定大脑区域在不同实验条件下保持模块内连接的程度。该分析表明，初级感觉区域和与默认模式过程相关的区域最有可能在各种情况下保持模块内连接，而前额叶区域最不可能这样做。我们的工作记录了全球水平的大脑网络重组作为上下文功能的重要能力。这些发现表明，模块化和其他核心、全局特征虽然可能受到脑白质结构连接的限制，但并不完全由它们决定。我们研究了全脑功能连接到不同障碍输入的整体特征。模块性、模块数和分区相似度随输入无序度而变化。默认模式和感觉脑区受操纵的影响最小。
It is known that features of stimuli in the environment affect the strength of functional connectivity in the human brain. However, investigations to date have not converged in determining whether these also impact functional networks' global features, such as modularity strength, number of modules, partition structure, or degree distributions. We hypothesized that one environmental attribute that may strongly impact global features is the temporal regularity of the environment, as prior work indicates that differences in regularity impact regions involved in sensory, attentional and memory processes. We examined this with an fMRI study, in which participants passively listened to tonal series that had identical physical features and differed only in their regularity, as defined by the strength of transition structure between tones. We found that series-regularity induced systematic changes to global features of functional networks, including modularity strength, number of modules, partition structure, and degree distributions. In tandem, we used a novel node-level analysis to determine the extent to which brain regions maintained their within-module connectivity across experimental conditions. This analysis showed that primary sensory regions and those associated with default-mode processes are most likely to maintain their within-module connectivity across conditions, whereas prefrontal regions are least likely to do so. Our work documents a significant capacity for global-level brain network reorganization as a function of context. These findings suggest that modularity and other core, global features, while likely constrained by white-matter structural brain connections, are not completely determined by them. We examined global features of whole-brain functional connectivity to inputs with varying disorder. Modularity, module numbers, and partition similarity varied with input disorder. Default-mode and sensory brain regions were least impacted by the manipulation.