Evolution of human colour vision other two human opsins. Middle Wavelength Sensitive Opsin (Green-sensitive opsin) – Encoded by the OPN1MW gene with a λmax of 530 found in the green region of the electromagnetic spectrum. Short Wavelength Sensitive Opsin (Blue opsin) – Encoded by the OPN1SW gene with a λmax of 430 found in the blue region of the electromagnetic spectrum. Certain parts of opsin genes and the vision of various species, including humans, has been known to change over time with different environmental changes. Recent studies have shown that primitive nocturnal mammalian ancestors had dichromatic vision consisting of UV–sensitive and red–sensitive traits. A change
Colour centre ventral occipital area plays an important role in colour vision. The search for the human equivalent of V4 led to the discovery of other areas that were stimulated by colour. The most significant was an area anterior in the ventral occipital lobe, subsequently named V4α. Further fMRI experiments found that V4α had a different function than V4, but worked cooperatively with it. V4α is involved in a number of processes, and is active during tasks requiring colour ordering, imagery, knowledge about colour, colour illusions, and object colour. The V4 and V4α areas are separate entities, but because of their close