Cerebral functional connectivity periodically (de)synchronizes with anatomical constraints
Raphaël Liégeois, Erik Ziegler, Pierre Geurts, Francisco Gómez, Mohamed Ali Bahri, Christophe Phillips, Andrea Soddu, Audrey Vanhaudenhuyse, Steven Laureys, Rodolphe Sepulchre
arXiv Preprint Archive September 19, 2014 preprint
Study at a glance
AI-extracted from the abstract| Characteristics | Observational neuroimaging analysis |
|---|---|
| Keywords | Q-bio.nc |
| Key findings | The correlation between structural connectivity and windowed functional connectivity peaks in statistical significance at window widths of roughly 20-30 TR (40-60 seconds). At this width, functional connectivity patterns oscillate between high-modularity phases shaped primarily by anatomy and low-modularity phases shaped primarily by inter-network connectivity. The authors argue that structural connectivity serves as a transitory architecture between distinct resting-state patterns, and that consciousness-related networks such as the default mode network contribute more to these fluctuations than motor or somatosensory networks, which they suggest reflects mind-wandering. |
Abstract
This paper studies the link between resting-state functional connectivity (FC), measured by the correlations of the fMRI BOLD time courses, and structural connectivity (SC), estimated through fiber tractography. Instead of a static analysis based on the correlation between SC and the 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 sec). 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 networks implied in consciousness-related processes, such as the default mode network (DMN), contribute more to these brain-level fluctuations compared to other networks, such as the motor or somatosensory networks. This suggests that the fluctuations between FC and SC are capturing mind-wandering effects.