Effect of Adaptation on the Retinal Nerve Code

Abstract

WE recently presented evidence that rods encoded ϕ, the quantum catch from a flash, into a nerve signal of magnitude N, where N=ϕ/(ϕ+σ), and σ, the semi-saturation constant, is about 800 quanta absorbed per rod per flash. The electroretinogram (ERG) was also recorded for various intensities of ϕ, and it was found that N coincided with the a wave amplitude when both were plotted against log ϕ and scaled to the same maximum¹. Thus it seemed possible that a was the electric sign of N. Here we consider adaptation by steady backgrounds for the light this throws on N and also the a and b waves of the ERG.