Multiplex core-periphery organization of the human connectome

TL;DR

This paper introduces a new framework for identifying core-periphery structures in multiplex networks, specifically applied to human brain connectomes, revealing both known and novel core regions.

Contribution

The authors develop a general method for core-periphery detection in multi-layer networks, advancing analysis of complex systems like the human connectome.

Findings

Confirmed known brain hubs

Identified novel core regions in the human cortex

Validated method on synthetic and real networks

Abstract

The behavior of many complex systems is determined by a core of densely interconnected units. While many methods are available to identify the core of a network when connections between nodes are all of the same type, a principled approach to define the core when multiple types of connectivity are allowed is still lacking. Here we introduce a general framework to define and extract the core-periphery structure of multi-layer networks by explicitly taking into account the connectivity of the nodes at each layer. We show how our method works on synthetic networks with different size, density, and overlap between the cores at the different layers. We then apply the method to multiplex brain networks whose layers encode information both on the anatomical and the functional connectivity among regions of the human cortex. Results confirm the presence of the main known hubs, but also suggest the existence of novel brain core regions that have been discarded by previous analysis which focused exclusively on the structural layer. Our work is a step forward in the identification of the core of the human connectome, and contributes to shed light to a fundamental question in modern neuroscience.