Light is an electromagnetic wave; its wavelength is what we perceive as colour. For instance, waves with a wavelength of approximately 450 nm (nanometres \u2013 a millionth of a millimetre) appear blue, while those around 620 nm appear red. Humans have three types of colour-sensitive cells in the retina \u2013 known as cones \u2013 and each type is sensitive to different wavelengths. These three types are broadly responsive to blue, green and red light. By combining input from these cones, we are able to perceive a broad palette of colours. Nerve cells transmit the information from the cones in the eyes to the brain, where the experience of colour is formed.<\/p>\n\n\n\n
I describe light with a wavelength around 620 nm as \u2018red\u2019, and you would do the same because you possess the same types of cones, and we have both learnt that this is referred to as red. But does it actually look the same to both of us? Perhaps the wavelength is identical, and you call it red, but your experience might be akin to what I perceive when I see green. One could argue that there is \u2018something\u2019 within our experience which cannot be reduced to measurable, physical phenomena that we can discuss. If this is indeed the case, we cannot say with certainty that we all experience colours in the same way. Experience, after all, cannot be measured \u2013 only described.<\/p>\n\n\n\n
A well-known philosophical essay that develops this idea further is \u2018What is it like to be a bat?\u2019 by Thomas Nagel. In this work, Nagel offers another example: we can never truly know what it feels like to be a bat navigating its surroundings via sonar. This argument thus extends beyond the perception of colours alone.<\/p>\n\n\n\n
Neuroscience continues to progress, and we now know that some people have four types of cones in their retinas instead of the usual three. This may apply to as many as 12% of women (though, unfortunately, likely no men)! Some of these individuals can describe colours in remarkably detailed ways. When we compare their descriptions to those of people with the standard three types of cones, clear differences emerge. It seems that people with four types of cones perceive colours in a richer, more nuanced way.<\/p>\n\n\n\n
Linguistics also offers insights into variations in how colours are perceived. Different languages divide the spectrum of colours differently. For instance, Russian distinguishes between what English speakers call \u2018blue\u2019 with two separate terms: light blue (\u2018goluboy\u2019) and dark blue (\u2018siniy\u2019). Unlike English, Russian has no overarching term equivalent to \u2018blue\u2019. Research has shown that native Russian speakers, likely because of this linguistic distinction, are quicker to identify differences between light and dark blue than English speakers.<\/p>\n\n\n\n
There is considerable variation in how our eyes respond to light wavelengths (due to differences in cones) and how the brain processes this information (influenced by factors like language). Thus, it\u2019s clear that not everyone sees colour similarly. However, if you and I share similar cultural backgrounds, speak similar languages, and possess the same types of cones, the difference in our colour perception is likely minimal. The idea that \u2018your red is my green\u2019 cannot be completely ruled out, but only if we assume there is something about perception that cannot be measured or articulated. So far, this does not appear to be the case.<\/p>\n\n\n\n
Nagel, T. (1974) What is it like to be a bat? The Philosophical Review.<\/a> Light is an electromagnetic wave; its wavelength is what we perceive as colour. For instance, waves with a wavelength of approximately 450 nm (nanometres \u2013 a millionth of a millimetre) appear blue, while those around 620 nm appear red. Humans … Lees verder
Jordan, G. & Mollon, J. (2019) Tetrachromacy: the mysterious case of extra-ordinary color vision. Current Opinion in Behavioral Sciences.<\/a>
Winawer, J., et al. (2007) Russian blues reveal effects on language on color discriminination. Proceedings of the National Academy of Sciences.<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"