抄録
Computer simulation of the neural model suggests that the increment threshold with which the two separate dots are perceived is elevated only when dot separation is less than the diameter of the receptive field center. The implication was tested and confirmed in Experiment I; the critical separation of the dots increased linearly with retinal eccentricity and was almost equal to the diameter of the receptive field center. In Experiment II, the increment threshold was measured for the test spot flanked on both sides at various distance by lines with suprathreshold luminance. The result showed that the diameter of the inhibition field increased monotonically with increasing eccentricity and that it was about 2.9 times as large as the diameter of the receptive field center. The results of both experiments are discussed in terms of Y-cells in human visual system.
