The flicker fusion frequency of the blue-sensitive mechanism of colour vision.

1. The flicker fusion frequency for blue stimuli on zero background increases steadily with increasing luminance up to 50 c/s, but if a strong yellow background is added it increases steadily only to about 18 c/s, and then remains nearly independent of luminance over a range of a factor of 20.2. It is argued that the maximum flicker fusion frequency is about three times lower for the blue-sensitive mechanism of colour vision than for the red- or green-sensitive.