Effects of local excitations on large-scale brain network dynamics: Insights from coupled Wilson-Cowan oscillators under perturbative stimulation

Composed of many coupled dynamical units, the brain is a canonical example of a complex network. At the macroscale, it consists of large neuronal populations that generate time-varying activity and that interconnect via a web of anatomical links. However, despite recent progress, we still lack a mechanistic understanding of how large-scale brain networks shape system-wide dynamics, and specifically, how local changes in neural activity affect functional interactions across the brain as a whole. Motivated by a vast literature suggesting that synchronization of activity underlies the coordination of distinct brain areas, we combine structural connectivity data and biophysical modeling to study how regional excitations of activity modulate network-wide synchrony. By employing computational modeling, we examine how the impacts of excitations depend on the location of the perturbation, and, crucially, on the baseline state of the system. Furthermore, we uncover state-specific relationships between brain network properties and the effects of local excitations on the coherence of network dynamics. As a whole, this work provides insight into how local changes in neural activity can propagate via structural links to cause distributed alterations to inter-regional communication patterns.