Cortical ignition dynamics is tightly linked to the core organisation of the human connectome

by Samy Castro, Wael El-Deredy, Demian Battaglia, Patricio Orio

The capability of cortical regions to flexibly sustain an “ignited” state of activity has been discussed in relation to conscious perception or hierarchical information processing. Here, we investigate how the intrinsic propensity of different regions to get ignited is determined by the specif ic topological organisation of the structural connectome. More specifically, we simulated the resting-state dynamics of mean-field whole-brain models and assessed how dynamic multi-stability and ignition differ between a reference model embedding a realistic human connectome, and alternative models based on a variety of randomised connectome ensembles. We found that the strength of global excitation needed to first trigger ignition in a subset of regions is substantially smaller for the model embedding the empirical human connectome. Furthermore, when increasing the strength of excitation, the propagation of ignition outside of this initial core–which is able to self-sustain its high activity–is way more gradual than for any of the randomised connectomes, allowing for graded control of the number of ignited regions. We explain both these assets in terms of the exceptional weighted co re-shell organisation of the empirical connectome, speculating that this topology of human structural connectivity may be attuned to support enhanced ignition dynamics.

Source: PLoS Computational Biology - July 30, 2020 Category: Biology Authors: Samy Castro Source Type: research