Fig. 2

Two schematic representations of the NMM with double excitatory feedbacks. P: main population of pyramidal neurons. I: interneuron population. \(P'\): secondary population of pyramidal neurons. Red (resp. green) arrows in (a): excitatory (resp. inhibitory) interactions. Box \(h_{E}\) (resp. \(h_{I}\)): second-order process converting action potentials into excitatory (resp. inhibitory) postsynaptic potential. Box \(\hat{\mathcal {S}}\): process converting average membrane potential into average action potential density discharge by neurons of populations P, \(P'\), and I, respectively. \(C_{i}\) for \(1 \leq i \leq4\): coupling gain parameters depending on the maximum number C of synaptic connections between two populations. G: direct feedback coupling gain. \(p(t)\): external input. \(y_{0}\), \(y_{1}\), \(y_{2}\): state variables. \(x_{0}\), \(x_{1}\), \(x_{2}\): intermediary variables