Hub-driven remote synchronization in brain networks

Vladimir Vlasov,Angelo Bifone

doi:10.1038/s41598-017-09887-7

Abstract

The phenomenon of “remote synchronization” (RS), first observed in a star network of oscillators, involves synchronization of unconnected peripheral nodes through a hub that maintains independent dynamics. In the RS regime the central hub was thought to serve as a passive gate for information transfer between nodes. Here, we investigate the physical origin of this phenomenon. Surprisingly, we find that a hub node can drive remote synchronization of peripheral oscillators even in the presence of a repulsive mean field, thus actively governing network dynamics while remaining asynchronous. We study this novel phenomenon in complex networks endowed with multiple hub-nodes, a ubiquitous feature of many real-world systems, including brain connectivity networks. We show that a change in the natural frequency of a single hub can alone reshape synchronization patterns across the entire network, and switch from direct to remote synchronization, or to hub-driven desynchronization. Hub-driven RS may provide a mechanism to account for the role of structural hubs in the organization of brain functional connectivity networks.

Highlights

Synchronization of oscillatory units is a pervasive phenomenon that is responsible for the emergence of collective behaviors in natural and artificial systems[1]
In the first part of this paper we have summarized the analytical results obtained in ref. 25 for the Kuramoto-Sakaguchi model on star networks
We have explicitly shown that “remote synchronization” (RS), in Bergner’s definition[14], can be observed in systems of Kuramoto phase oscillators if a non-zero phase shift is introduced in the coupling terms

Summary

Introduction

Synchronization of oscillatory units is a pervasive phenomenon that is responsible for the emergence of collective behaviors in natural and artificial systems[1]. We leverage recent electrophysiological[21] and structural connectivity data[22, 23] to model the dynamics of spontaneous activity in the macaque brain, and demonstrate a potential role for hub-driven remote synchronization in shaping patterns of coherent activity, sometimes referred to as functional connectivity.

Results

Conclusion