Next, we investigate the effect of the network topology of subnetworks in NoNs on the global synchrony. We consider the simplest case, i.e., a NoN consisting of two subnetworks (Figure 3A). Each subnetwork contains 50 nodes connected via the random, SW, SF, or super-hub strategy. Two subnetworks with an equivalent topology are coupled, with nine connections among three selected nodes. In coupling the subnetworks, nodes having the highest degree are selected from each subnetwork, since cortical networks are characterized by the rich-club organization (van den Heuvel and Sporns, 2013; Samu et al., 2014; Gal et al., 2017). This configuration is also inspired by previous studies on identical chaotic oscillators, which explored synchronization in NoNs comprised of two SF subnetworks and discovered that inter-subnetwork connections linking high-degree nodes allow efficient global synchrony (Zhao et al., 2011; Aguirre et al., 2014), while maintaining dynamical clustering of subnetworks (Zhao et al., 2011). For the super-hub topology, the three hub nodes are selected as connector nodes. The intra-subnetwork coupling strength, Kintra, is kept constant at Kintra = 4, and the inter-subnetwork coupling strength, Kinter, is varied.
