Thresholds and latencies of retinal ganglion cell responses in cats to local stimulation of various parts of their receptive field

Abstract

Depending on their responses to separate stimulation of the center and periphery of the receptive field, all ganglion cells of the cat retina can be subdivided into two types: ON-center (OFF-periphery) and OFF-center (ON-periphery). By all the parameters studied these ON- and OFF-systems were symmetrical. This apparently reflects, first, the equality of informativeness of illumination and darkening of individual areas of the visual field and, second, adaptation in order to widen the dynamic range of the visual channel of information transmission. Thresholds of unit responses to stimulation of the periphery and center of their receptive fields were identical. The latent periods of the unit responses were much longer in the first case than in the second. This is regarded as providing the functional basis for discrimination between "central" and "peripheral" unit responses by higher structures.