FILLING-IN OF DOTS ON THE BLIND SPOT
We examined whether filling-in of dots occurred in the blind spot, when dots were presented either on one side or on opposite sides of the blind spot. Stimuli consisted of dots and a probe. The observersâ€™ task was to judge whether the number of dots on the blind spot side against the probe increased or not. When dots were presented on one side, the probabilities that more dots than one on the blind spot side against the probe were perceived were higher in vertical configurations than in horizontal configurations. However, when dots were presented on opposite sides of the blind spot, the probability was higher in horizontal configuration than in vertical configuration, and was lower in the 2.8 degree diameter condition than in the other diameter conditions. The results suggest that filling-in of dots in the blind spot is affected by the orientation and size of dots.