Hardware Coupled Nonliear Oscillators as a Model of Retina

Abstract

An electronic circuit consisting of coupled nonlinear oscillators⁴＇⁵ simulates the spatiotemporal processing in retina. Complex behavior recorded in vivo from ganglion cells in the cat retina 6 in response to flickering light spots is matched by setting the coupling parameters in the hardware oscillators. An electronic neuron (c-neuron) is composed of four coupled oscillators: three representing the light driven generator potential of the ganglion cell, the other representing membrane spiking. A 1-D ring of e-neurons reflects the connectivity in the retina: strong neighborhood excitation, and wider inhibition. E-neurons, like retinal ganglion cells, exhibit spontaneous spiking. Driving more than one e-neuron with a sinusoidally modulated input increases regularity in the e-neurons responses, as is found in the retina. We encoded c-neuron activity into single-bit spike trains and found chaotic spontaneous oscillations using close return histograms. The model's behavior gives a new understanding of neurophysiological findings.