Direction-selective motion discrimination by traveling waves in visual cortex
Fig 2
The Wilson-Cowan model of reciprocally-coupled excitatory and inhibitory neural populations.
A: Schematic of the coupling where the weight for the connection to e from i is denoted by wei. J(t) is an external stimulus. B: The sigmoidal firing rate function. C: Time course of the mean firing rates U(t) for both the excitatory and inhibitory populations in response to the unit-step stimulus. D: The limit cycle (black) in the phase plane. Nullclines are shown in green. E: Bifurcation diagram showing the emergence of the limit cycle (shaded region) via a supercritical Hopf bifurcation. Thick solid line indicates stable fixed points. Dashed lines indicate unstable fixed points. H is the Hopf point. The thin solid lines emanating from the Hopf point describe the envelope of the oscillation in Ue.