First Stage of a Human Visual System Simulator: The Retina

We propose a configurable simulation platform that reproduces the analog neural behavior of different models of the Human Visual System at the early stages. Our software can simulate efficiently many of the biological mechanisms found in retina cells, such as chromatic opponency in the red-green and blue-yellow pathways, signal gathering through chemical synapses and gap junctions or variations in the neuron density and the receptive field size with eccentricity. Based on an imageprocessing approach, simulated neurons can perform spatiotemporal and color processing of the input visual stimuli generating the visual maps of every intermediate stage, which correspond to membrane potentials and synaptic currents. An interface with neural network simulators has been implemented, which allows to reproduce the spiking output of some specific cells, such as ganglion cells, and integrate the platform with models of higher brain areas. Simulations of different retina models related to the color opponent mechanisms, obtained from electro-physiological experiments, show the capability of the platform to reproduce their neural response.