Here’s an image display technology promising to elicit full trichromatic color vision in a red-green colorblind person, or tetrachromacy in a human trichromat. At least it can evoke the experience of a new colour called olo.
Theoretically, novel colors are possible through bypassing the constraints set by the cone spectral sensitivities and activating M cone cells exclusively. In practice, we confirm a partial expansion of colorspace toward that theoretical ideal. Attempting to activate M cones exclusively is shown to elicit a color beyond the natural human gamut, formally measured with color matching by human subjects. They describe the color as blue-green of unprecedented saturation.
Most humans are trichromats, a few are tetrachromats. If a majority were tetrachromats, I imagine it could have effects on colour vocabulary and use of colours in various contexts (e.g architecture). Please feel free to comment the article, enhanced colour vision, or the nature of colours.
“Novel colors” don’t exist. A person with an additional cone in their eye may be able to see more of the electromagnetic spectrum, but that does not mean they can see more colors. Colors are socially constructed categories, and unless society in general can see the same thing, the society will not construct social categories to label it.
So it seems we can use precision optics to elicit the perception of a new colour.
With the technology, the new colour recurs systematically, like ordinary colours recur systematically, but it doesn’t recur in nature.
It requires the technology. The technology is like a precision drug that can elicit a distinct hallucination. That’s what makes it different from ordinary colours.
Ordinary colours recur systematically in nature in our interaction with pigments and materials that reflect or emit distinct wavelengths of EM-radiation. That’s how we learn to know them and name them.
What physically exists are photons of different frequencies interacting with the rods and cones in your eye. Colors are the names we construct to conveniently describe it. They are socially constructed and ultimately arbitrary. What colors even “exist” can differ from one culture to the next.
The reference relation distinguishes the name from what it describes.
For example, the name ‘blue’ refers to the colour of blue skies. Skies are blue in the middle of the day because of the behavior of light.
In Japan a blue sky may look a bit different (brighter) than in Italy (saturated) or Sweden (lighter). The angle of sunlight is different because of the different locations on Earth. Such physical differences have effects on biological and linguistic behavior as in how we talk of colours. But regardless of such differences, I think we are still referring to the colours, not to our own words.
Sort of. The human population has more than one type of cone covering the low frequency part of the spectrum, and a minority of women have both kinds of cone.
However, the frequency range of the two forms of L-cone almost entirely overlap. So, while it is possible that these women have a somewhat better appreciation of color, particularly reds, it’s very different to true tetrachromacy in, for example, birds.
Birds have four color cones with very little overlap. So if they have subjective experience of color, they will perceive a vastly richer set of colors than we can.
One thing I learned recently is that while, to us, most elemental metals look grey or silvery, it’s only because most metals have a characteristic absorption frequency in the UV part of the spectrum. Gold and copper are two exceptions, having an absorption frequency within the blue part of the spectrum, hence why we perceive them has having color, but the rest all basically reflect all RGB light equally.
But, to a bird, most elemental metals will look clearly distinct.
Color exists as a subjective experience, but how we label colors is somewhat arbitrary. For example, some cultures don’t have a word for “pink”, they just say light red. And conversely, in English we say light blue for a color that some cultures have a discrete name for.
But if a person were capable of seeing a part of the EM spectrum that others could not, and it appeared distinct from anything in the RGB part of the spectrum, they may give it a name. And other people capable of seeing that color could agree on that name – because they can point to an object and all agree it’s “schellow”.
And even those of us that couldn’t see schellow could understand that it’s a label for a different color. Just as people born with a form of color-blindness can nonetheless come to understand there is a color that humans agree on, and can consistently label objects with, that they themselves cannot perceive.
That’s interesting. I’ve read about UV-absorbing liquids that we can’t see, but we can paint them on large windows to prevent birds from crashing into them.
Beside helping colourblind see colours, I don’t know why one would want to mess with the eye’s internal processes. There are other ways to detect colours beyond the natural human gamut: e.g. spectrometers, special cameras.
It would be pretty freaking sweet to see more colors imo.
It’s one reason why, if we ever have the ability to make virtual realities directly with a neural connection, those realities will quickly feel more real than the real world. More colors and other senses, none of the fuzziness of light needing to go through a lens and layer of cells.
(I’m aware that’s quite a big topic lunge but I think philosophy forums are the one place we can go on such out there tangents )
First we show them the blue box and ask them to name its colour and then we show them the green box and ask them to name its colour. They will use the same word both times. But if we ask them if the two boxes we showed them look the same they’ll say that they don’t; what they see is not the same thing as what word they use to describe what they see.
It might be that they say that the boxes are two shades of the same colour rather than two different colours but this kind of distinction isn’t relevant to the science of colour vision, e.g. as in the article. The relevant point is that we can be made to experience novel visual qualities related to an object’s colour (rather than, say, related to its shape).
If the word “color” is the color, then the words “What physically exists are photons of different frequencies interacting with the rods and cones in your eye” are What physically exists are photons of different frequencies interacting with the rods and cones in your eye.
Like for a brain in a vat, you’d see colours evoked by the technology, not the object of the experience (the projected image). In this sense it’s hallucination, not visual experience.
All perception is hallucination. It’s not like colors can shine directly into your brain. Your brain receives a data feed and evokes colors, tastes, pain etc on the basis of that data.
No, a perception is evoked by brain processes that have a causal relation to the perceived object. Basically, you experience its cause (the object).
Hallucinations are evoked by brain processes only. They lack the causal relation to an object. For example, if you hallucinate holding a snake, there is no snake. That’s why it’s called hallucination.
Now, the suggested technology evokes an extraordinary colour experience, but the object of the experience is an image which doesn’t possess such colours. The colours are evoked by lasers stimulating specific cones. Basically, you’re seeing colours which do not exist in the object of the experience (the projected image). You’re hallucinating its colours.
I agree. It matters, however, whether the “data feed” is causally related to what you see, taste, feel etc, or something entirely different (e.g. drugs, impaired synapses, or technology stimulating cones or brain tissue).
In both the case that a) a laser stimulates the cones in my eyes and b) an object reflects light that stimulates the cones in my eyes, there is a causal connection between some distal object and the colour experienced.
Why do you say that only in (b) is the colour experienced (also?) a property of the distal cause? What’s the relevant difference between a laser emitting light and a box reflecting light? What if the laser is emitted by the entire surface of a box, e.g. it’s a novel kind of lamp?
I agree with the person you replied to. The colour experienced just is what occurs when the brain reacts to the eye’s stimulation (whether in (a) or in (b)). That it seems to (also?) be a property of the object that reflected the light into the eyes is an illusion.
Of course, yes.
What I thought you were getting at, is the common feeling many have (and I think some upthread have said), that colors exist “out there” and we passively see them. This is easy to debunk (I’ll see if anyone disagrees first though). Colors are made in the brain in response to particular frequencies of light being detected.
But if your objection was just that color in a virtual world is like a hallucination. Yes, sure.
The laser in this case is not only emitting light, nor projecting an image, it’s selectively targeting individual cells, bypassing limitations in the eye, which enables it to elicit new colour experiences, regardless of the visible properties of the depicted object. The causal link is hijacked.
Why does it matter if the laser bypasses “limitations” in the eye?
There’s nothing special about the human eye. It’s not as if it’s been built by God to show us the “one true” way a distal object “really” looks.
Different organisms have different eyes and so the same things looks different to them. The colour I see a strawberry to be isn’t the colour a tetrachromat sees it to be, or a dog, or a mantis shrimp.
The very notion that objects have colours that are then visible to us (if we have functioning eyes and it’s daylight) is mistaken. Objects just have a surface of electrons that reflect photons of certain wavelengths, with these photons causing different organisms with differently structured eyes to have different colour experiences, just as the chemicals that make up a cake cause different organisms with differently structured tongues to have different taste experiences.
It’s the causal link that matters. With the link, you see the object’s actual colours. Without it, you don’t. Simulated or enhanced experiences can be useful still.
It’s not mistaken. Objects have colours in the sense that their properties systematically elicit certain colour experiences for certain observers (e.g trichromats) under certain conditions of observation (e.g. white light).
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