Subnet Communicability: Diffusive Communication Across the Brain Through a Backbone Subnetwork

One of the fundamental challenges in modern neuroscience is understanding the interplay between the brains functional activity and its underlying structural pathways. To address this question, we propose a novel communication pattern called subnet communicability, which models diffusive communication between pairs of regions through a small, intermediary subnetwork of brain regions as opposed to spreading messages through the entire network. We demonstrate that subnet communicability strengthens coupling between the structural and functional connectomes better than previous models, including communicability. Over two large datasets, we show that the optimal subnetwork is consistent across the population. Subnet communicability provides new insights into structure-function coupling in the brain and offers a balance between redundancy in message passing and economy of brain wiring.