On the theory of synchronization of lateral optic-nerve responses in Limulus. II. nonuniform excitation and inhomogenous inhibition

Abstract

The theory of synchronization of optic-nerve responses in the retina of Limulus, which was discussed in the preceding paper [1], is here applied to retinas in which either the lateral inhibitory interactions between ommatidia or the excitations of ommatidia by light exhibit random spatial variations. Numerical calculations show that in either case strong lateral inhibition can support a synchronous periodic response to uniform illumination similar to that found in [1]. The maximum strength of lateral inhibition required for such a response to occur depends only weakly on the degree of randomness of the inhibitory interactions, but it increases rapidly with increasingly random excitations. When the synchronous response exists, its period is equal to that calculated in [1] for an “ideal” retina in which the excitation by uniform illumination is uniform and lateral inhibition is spatially homogeneous.