We compared the dynamics of two seminal neural mass models, representing the integration of many neurons within a population. We investigated phase synchronization and criticality in two voltage-based (JR) and rate-based (WC) neural mass models. The two models were utilized in the same structural network representing the same topology. We observed two profound phenomena in brain activity. First, the global synchronicity of these networks was calculated by considering the Kuramoto order parameter.
Synchronization is a phenomenon observed in neuronal networks involved in diverse brain activities. Neural mass models such as Wilson-Cowan (WC) and Jansen-Rit (JR) manifest synchronized states. Despite extensive research on these models over the past several decades, their potential of manifesting second-order phase transitions (SOPT) and criticality has not been sufficiently acknowledged. In this study, two networks of coupled WC and JR nodes with small-world topologies were constructed and Kuramoto order parameter (KOP) was used to quantify the amount of synchronization. In addition, we investigated the presence of SOPT using the synchronization coefficient of variation. Both networks reached high synchrony by changing the coupling weight between their nodes. Moreover, they exhibited abrupt changes in the synchronization at certain values of the control parameter not necessarily related to a phase transition. While SOPT was observed only in JR model, neither WC nor JR model showed power-law behavior. Our study further investigated the global synchronization phenomenon that is known to exist in pathological brain states, such as seizure. JR model showed global synchronization, while WC model seemed to be more suitable in producing partially synchronized patterns.
Sheida Kazemi, AmirAli Farokhniaee, Yousef Jamali