The Cone Artist

In those days my hold on the real world was always slight at best, but the combination of long walks, fresh air, and lack of distraction left me hopelessly vulnerable to any stray wisp of fantasy or conjecture that chose to carry me off. Generally for a start I would spend a little while thinking about Bizarro World. . . Then I might move on to imponderables. How could we be sure that we all saw the same colors? Maybe what I see as green you see as blue. Who could actually say? And when scientists say that dogs and cats are color-blind (or not - I could never remember which it was), how do they know? What dog is going to tell them? And how do migrating birds know which one to follow? What if the lead bird just wants to be alone? And when you see two ants going in opposite directions pause to check each other out, what information exactly are they exchanging? - "Hey, nice feelers!" "Don't panic, but that kid that's watching us has got matches and lighter fluid" - and how do they know to do whatever they are doing? Something is telling them to go off and bring home a leaf or a granule of sand - but who and how?"

Bill Bryson, from The Life and Times of the Thunderbolt Kid

Amusing, and not a bad description of how the monkey mind works. Stray wisps of fantasy and conjecture carry us from one thought to another, and we lose sight of the real world around us as we walk around cocooned in our minds.

For the record, cats, dogs and most mammals are more or less color blind, not seeing the world in black-and-white necessarily, but color blind the way some humans who have a difficult time distinguishing red from green are.

Color vision evolved in animals a long time ago - fish can see colors, the dinosaurs could see in color. But the earliest nocturnal mammals didn't need color vision to see in the night, and seemingly gave up the ability to see colors (as we know them) in favor of better light-gathering, night-vision eyes. But the diurnal old world monkeys rediscovered color vision about 23 million years ago, and now the old world monkeys and apes (basically the tail-less primates, including humans) have three sets of cone cells in their eyes that allow them to see red, green and blue. And by combining these three primary colors, we can perceive millions of shades and tones of the spectrum.

But some animals can see color better, or differently, than us. Pit vipers can see well into the infrared spectrum, and bees can see well into the ultraviolet. Some other animals such as turtles have, instead of three sets of red, green and blue cone cells in their eyes, four sets of cone cells. We can only speculate on how color must appear to them. As Richard Dawkins writes in The Ancestor's Tale,

Some cones are slightly more sensitive towards the red end of the spectrum, others toward the blue. It is the comparison between the cones that makes colour vision possible, and the quality of our colour vision depends largely on how many different classes of cones there are to compare. Dichromatic animals have only two populations of cones interspersed with one another. Trichromats have three, tetrachromats four. Each cone has a graph of sensitivity, which peaks somewhere in the spectrum and fades away, not particularly symmetrically, on either side of the peak.

Since tetrachromatic turtles have a far more sophisticated visual palette that us trichromatic humans, they see colors more intensely than we do, and we trichromatic humans see color more richly than dichromatic cats and dogs. But if a turtle were to watch our finest plasma television, with its mere trichromatic red, green and blue pixels, it would find the picture as unrealistic and disappointing as we would find an image created by a color printer with one empty cartridge.

So we humans have three sets of cones corresponding to what we call the three primary colors, and all the colors that we perceive are based on the way our brains interpret the signals sent to it by the cones. But even the purest light always stimulates all three classes of cones to some extent since their spectra overlap with each other, so we never see "pure" red, "pure" green, or "pure" blue. There's always some bleed-through.

What would these pure colors look like? Imagine that I took a tiny probe and inserted it into a red cone in your eye and stimulated that single cell only. Would your mind then perceive a "pure" red, a red the likes of which you've never seen before? Would the same happen if I stimulated a green cone, a blue cone?

A new art form: cone art. The cone artist abandons reliance on light bouncing from the artwork to the eye, and actually creates the artwork inside of the eye itself. Utilizing neurobiological techniques, the cone artist directly stimulates first a red cone at the back of the viewer's eye, so that your view explodes into the purest of reds that you've ever seen, and then stimulates a blue cone, and your whole field of vision is nothing but the most intense, truest blue imaginable, possibly even beyond the imagination. By stimulating the cones in succession, or in tandem, the cone artist creates his or her art.

Monkey mind, monkey eyes. My hold on the real world has always been tentative at best.