Figure 1.

Schematic of retina and common receptive field models. (A) Schematic of the major cell classes in the retinal circuitry, illustrating convergence (left) and divergence (right). Numbers of converging cones are much higher than depicted. (B) Difference-of-Gaussians receptive field model. (C) LN model for ganglion cell responses. Stimuli are passed through a linear spatiotemporal filter, and the filter output is passed through a time-independent nonlinear step. Spike responses are generated from a Poisson process. Extensions of the model include a spike-dependent feedback term that provides for a history dependence in spike generation.