Granger causality analysis in the neural mass model

The study of brain functional connectivity has become an important aspect of neuroscience. With the development of different methods to detect functional connectivity, the neural mass model based on physiology provides a basis for validating methods. As a popular method of discovering functional connectivity, Granger causality is applied to many fields of neurophysiology, but the mapping between Granger causality and coupling strength of neural mass model is unclear. To explore this relationship, we make a simulation to change the coupling strength of a double-column mass model, and calculate the corresponding Granger causality value. It is found that Granger causality and coupling strength has a relationship but nonlinear.