Shouldn't directional movement detection necessarily be "colour-blind"?
It is shown that a directionally-selective movement detector attains maximum sensitivity to movement only when it sacrifices colour information. This could explain the widespread occurrence of colour-blindness among movement-detecting systems.
D000818:Animals; D003118:Color Perception / Q000502:physiology*; D006801:Humans; D009039:Motion Perception / Q000502:physiology*; D010786:Photoreceptor Cells / Q000502:physiology; D013057:Spectrum Analysis