It has long puzzled biologists and linguists why humans universally perceive and name colors as a mixture of four pure hues — red, yellow, green, and blue (plus black and white) — that exist in opposing pairs, with red the opposite of green and yellow the opposite of blue. Scientists haven’t been able to explain this perception based on the three types of cone photoreceptors in the eye that detect different wavelengths of light or other features of the visual system, but a new study from the lab of HWNI member Bruno Olshausen published in the Journal of the Optical Society of America A proposes a theory that would explain this phenomenon.
Olshausen is a professor of neuroscience and optometry & vision science, and a member and former director of HWNI’s Redwood Center for Theoretical Neuroscience. In the study, led by postdoctoral fellow Alexander Belsten, the researchers used a large data set of natural scenes to assess the color distribution in nature and simulated how human cone photoreceptors would respond to it. Based on their analysis, the researchers propose that the simplest way for the brain to encode the colors in nature would be to represent them as combinations of red, yellow, green, and blue, which fits with how we perceive color.
