Spatial Summation Properties Inferred by Double Stimuli Method

Abstract

Spatial summation properties were examined by the spatial double stimuli method, in which summation indices were obtained for various separations between two stimuli. Results were expressed by summation index curves where summation index was plotted as a function of separation. Summation index curves of three subjects showed diphasic nature having inhibitory interaction at separation of 5.2', but curves of four subjects showed only monophasic nature. Even when more proper optical correction was performed, they did not show any inhibition. It was suggested the receptive field properties were different among subjects.