How Do White Matter Tracts Constrain Brain Oscillation Propagation? A Diffusion MRI-MEG Study

Motivation: Substantial effort has been invested into understanding how brain structure constrains function. However, research has primarily focused on understanding structure, rather than linking brain dynamics to it. Goal(s): Compare oscillation propagation delays estimated using neuronal avalanches from MEG resting-state data with the underlying white matter structure estimated through tractography. Approach: We characterised the relationship between pathways length and the related propagation delays, using deterministic and probabilistic approaches, and looking at different frequency bands. Results: While higher frequency bands scale proportionally with propagation delays and length, lower frequency bands show constant delays, regardless of tract length, for both deterministic and probabilistic tractography. Impact: This multi-modal approach has the potential to improve understanding of how underlying white matter structure constrains brain [oscillatory] activity. Future research will focus on integrating additional structural and microstructural measurements to inform biophysical models of brain structural and functional connectivity.