Abstract

The electroretinogram in response to pattern reversal stimuli (PERG) consists of two distinct components: contribution from the nonlinearities of the local luminance response and effect of lateral interactions in the retina. By subtracting the local luminance nonlinearities from the PERG we extracted the lateral interaction component for checkerboard pattern stimuli of different check sizes. This response component is of special interest as it originates from neural interactions in the retina and cannot be accounted for by nonlinearities of any single active element. This decomposition of the pattern reversal response leads to two components of a strikingly simple structure. Both components have the characteristics of adaptive mechanisms. Both seem to be of second order, as the fourth-order kernels are negligible in size. The second-order luminance kernel has a structure consistent with a luminance gain control mechanism and a time course, which is in general agreement with known psychophysical and microelectrophysiological data. The lateral interaction component has a similar structure and could be interpreted as contrast gain control. It distinguishes itself by its slightly longer latency and a faster adaptation rate.

© 1988 Optical Society of America