The epidemic spreading model and the direction of information flow in brain networks.
The interplay between structural connections and emerging information flow in the human brain remains an open research problem. A recent study observed global patterns of directional information flow in empirical data using the measure of transfer entropy. For higher frequency bands, the overall direction of information flow was from posterior to anterior regions whereas an anterior-to-posterior pattern was observed in lower frequency bands. In this study, we applied a simple Susceptible-Infected-Susceptible (SIS) epidemic spreading model on the human connectome with the aim to reveal the topological properties of the structural network that give rise to these global patterns. We found that direct structural connections induced higher transfer entropy between two brain regions and that transfer entropy decreased with increasing distance between nodes (in terms of hops in the structural network). Applying the SIS model, we were able to confirm the empirically observed opposite information flow patterns and posterior hubs in the structural network seem to play a dominant role in the network dynamics. For small time scales, when these hubs acted as strong receivers of information, the global pattern of information flow was in the posterior-to-anterior direction and in the opposite direction when they were strong senders. Our analysis suggests that these global patterns of directional information flow are the result of an unequal spatial distribution of the structural degree between posterior and anterior regions and their directions seem to be linked to different time scales of the spreading process.
Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, P.O Box 5031, 2600 GA Delft, The Netherlands. Electronic address: j.m.meier@tudelft.nl.
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Meier
Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, P.O Box 5031, 2600 GA Delft, The Netherlands. Electronic address: c.xyzhou@outlook.com.
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Zhou
Department of Clinical Neurophysiology and Magnetoencephalography Center, VU University Medical Centre, Amsterdam, The Netherlands. Electronic address: a.hillebrand@vumc.nl.
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Hillebrand
Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands; Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, United Kingdom. Electronic address: prejaas.tewarie@nottingham.ac.uk.
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Tewarie
Department of Clinical Neurophysiology, VU University Medical Center, Amsterdam, The Netherlands. Electronic address: cj.stam@vumc.nl.
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Stam
Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, P.O Box 5031, 2600 GA Delft, The Netherlands. Electronic address: p.f.a.vanmieghem@tudelft.nl.
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Van Mieghem
D001921:Brain / Q000502:physiology*; D063132:Connectome / Q000379:methods*; D006801:Humans; D008959:Models, Neurological; D009434:Neural Pathways / Q000502:physiology; D012815:Signal Processing, Computer-Assisted
Brain networks; Effective connectivity; Global patterns; Information flow; SIS model; Transfer entropy