Document Type
Article
Publication Date
7-1-2016
Journal
Brain Struct Funct
Volume
221
Issue
6
First Page
2985
Last Page
2997
URL with Digital Object Identifier
10.1007/s00429-015-1083-y
Abstract
This paper studies the link between resting-state functional connectivity (FC), measured by the correlations of fMRI BOLD time courses, and structural connectivity (SC), estimated through fiber tractography. Instead of a static analysis based on the correlation between SC and FC averaged over the entire fMRI time series, we propose a dynamic analysis, based on the time evolution of the correlation between SC and a suitably windowed FC. Assessing the statistical significance of the time series against random phase permutations, our data show a pronounced peak of significance for time window widths around 20-30 TR (40-60 s). Using the appropriate window width, we show that FC patterns oscillate between phases of high modularity, primarily shaped by anatomy, and phases of low modularity, primarily shaped by inter-network connectivity. Building upon recent results in dynamic FC, this emphasizes the potential role of SC as a transitory architecture between different highly connected resting-state FC patterns. Finally, we show that the regions contributing the most to these whole-brain level fluctuations of FC on the supporting anatomical architecture belong to the default mode and the executive control networks suggesting that they could be capturing consciousness-related processes such as mind wandering.
Notes
This is a post-peer-review, pre-copyedit version of an article published in Brain Structure and Function. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00429-015-1083-y”.