[Relationship between electroretinogram parameters and the intensity of a photic stimulus]

The dependence of frog's and cat's electroretinogram (ERG) amplitude upon intensity of light stimuli within the range from 3.5-10(-3) to 3.5-10(3) lk, had a logarithmic character within the limited range of about 1.5--2.0 log. units (from 3--5 to 150--200 lk). This range corresponded to the maximal increase of the ERG amplitude upon a unit of light intensity, i.e., the maximal sensitivity of the retina. In accordance with some psychophysical facts, the range from 3--5 to 150--200 lk seems to be the most informative in respect to encoding light intensity in visual system.