Vision is one of the senses that we and many other creatures use to identify the world around us. However, the concept of “colour” is an illusion and internal experience that every individual experiences differently. This happens because our brains convert a range of electromagnetic waves and interpret them as certain colours. Those wavelengths outside of our visible light spectrum still exist; we just don’t experience them as colour.
Mary’s Room is a thought experiment that attempts to establish that there are non-physical properties and attainable knowledge that can only be acquired through conscious experience. The thought experiment was originally proposed by Frank Jackson and it goes something like this:
Mary knows all there is to know about colour. However, Mary lives in a black and white house and has never seen or been outside. If one day, she was to go outside and actually experience colour, will she learn anything?
Mary’s experience can be compared to those who experience colour vision deficiency (more commonly known as colour blindness). If you are not suffering from a colour vision deficiency it is very hard to imagine how it looks like to be vision deficient.
There are resources online that can help you better understand colour vision deficiency. You can use the Coblis Colour Blindness Simulator to compare how different types of colour deficiency sees the same object. EnChroma, a company based in Berkeley, California created a line of EnChroma Glasses that allow colour blind to see colour. The reactions from vision deficient people when they experience colour are very fun to watch. It is amazing to see how the experience of colour can be so dramatic
Case Study – Tetrochromacy
The first hint that tetrachromats might exist came in a 1948 paper on color blindness. Dutch scientist HL de Vries believed that colour vision deficiency ran in families, affecting men but not women. While the men had two normal cones and one mutant cone, the mothers and daughters had the mutant cone and three normal cones, resulting in four separate cones in their eyes. He suspected the extra cone could be why the women perceived colour differently—not because they saw less than most people but because they saw more.
There are researchers currently investigating human tetrachromacy at the Institute of Neuroscience at Newcastle University. Concetta Antico, an Australian artist, was confirmed to be a tetrachromat in 2012. The research on tetrochromacy is still ongoing and those interested and meet the criteria can sign up here. By understanding more about the condition and how the neural pathways involved with colour perception can be trained, they might be able to discover a way for others to boost the amount of colours they see as well.
If tetrochromacy became the norm, would those who are trichromatic (what we consider normal today) become colour vision deficient?