Abstract

The majority of retinal ganglion cells produce a continuous discharge even in the absence of any specific visual stimulus. The rate of this discharge is more or less independent of the mean light level but is modulated by any change in the relative strengths of stimulation of the opponent center and surround regions of the receptive field. Stimuli of low contrast modulate the firing rate in proportion to stimulus contrast (there is no threshold nonlinearity) and the detectability of any modulation is limited only by the irregularity of the discharge. At high contrasts there may be some degree of response compression.

© 1991 Optical Society of America