On the lack of lateral inhibition within the receptive fields of goldfish retinal ganglion cells

Abstract

We have applied our method of response-summation and sensitivity-summation to the specific question of whether or not one can demonstrate lateral interactions within the centers of the receptive fields of goldfish retinal ganglion cells. We demonstrate that the curvature evident on the response-summation plot cannot be attributed to interactions, for there is no corresponding inflexion on the sensitivitysummation plot. We also demonstrate that the response-summation and sensitivity-summation plots are unchanged by changing the spatial separation of the two areas stimulated; since lateral interactions would be expected to have a distance dependence, this indicates a lack of interactions. Finally, we show that our data are consistent with the previously demonstrated validity of Ricco's Law, and that the perfect summation of luminous flux within the center of the field does not require the postulation of lateral interactions to be consistent with a non-linear transformation of light intensity.