The unique genetic mutation and the amazing intricacies of the brain make Concette Antico different from any other artist on Earth. When Concetta Antico sees a leaf, she sees not only green. “On the edge I see orange, red or purple in the shade; you see dark green, but I will see purple, turquoise, blue, she says. “Such a mosaic of color.”
Antico perceives colors in the same way, not only because she is an artist working in the style of impressionism. She is also tetrachromate, which means she has more receptors in her eyes that absorb colors. The difference lies in the Antico cones, the structures of the eye, which absorb certain wavelengths of light and transmit them to the brain. An ordinary person has three types of cones, which allow him to distinguish approximately a million colors. But Antico has four types, and her eyes can see the nuances of color - about 100 million of them - which is inaccessible to the ordinary person. “It shocks me how few colors people can distinguish,” says the artist.
Although tetrachromates have more receptors in the eyes, their brains are arranged in the same way as people with ordinary vision. How has Antico's brain changed to perceive more colors? As in any other business, experience is the best teacher - even if it comes to neural paths.
For many years, scientists were not sure about the existence of tetrachromats. If they existed, they said, they would be people with two X chromosomes. It's all about the genes behind the color vision. People with normal color vision have three types of cones, tuned to wavelengths of red, green, and blue. They are connected to X chromosomes - for most men it is one, for most women it is two. Mutations in the X-chromosome lead to the fact that a person perceives more or less color, so men are more likely to have congenital color blindness than women (if their X-chromosome alone has undergone a mutation). According to the theory, it was believed that if a person receives two mutated X chromosomes, she (most likely, a woman) will have four types of cones, not three.
This is what happened to Antico; Scientists confirmed that she tetrahromat, in 2012. It is believed that one percent of the planet’s population is tetrachromat, but it is not easy to test empirically. “The difference between the [color resolution perceived] by the tetrachromat and someone with normal vision is not as great as the difference between people with color blindness and ordinary sight,” says Kimberly Jameson, a cognitive scientist at the University of California Irvine’s Institute for Mathematical Behavioral Sciences . Together with colleague Alyssa Winkler of the University of Nevada at Reno, she studied Antico for over a year to better understand tetrahromatism. The difference in color perception is difficult to detect, partly because it is small, Jamison says, and partly because existing tests are designed mostly for three pigments: red, green and blue.
Based on the genes, Antico Jamison determined that Antico’s fourth wand absorbs the wavelengths responsible for “reddish-orange-yellow, but how this looks for Concetta is not clear.” Since tests are not calibrated for this wavelength, empirical demonstration of tetrachromatism is quite a difficult task.
Jamison and Winkler “hunt” tetrachromat to better understand how their brains work. Jamison is fascinated by how people develop communicative concepts, especially when they can perceive the world around them more widely than usual. “If you have an additional type of cones in the retina, this greatly complicates the forms that a signal can receive through it. We want to understand how this happens, ”she says. First of all, it is connected with how the brain builds its plexuses, when it receives certain signals quite often over time - this concept calls neuroplasticity. Many studies on the subject of neuroplasticity in animals, as well as people, have shown that two individuals with the same visual perception abilities can acquire completely different vision later in life due to some early influences. Scientists still do not really know what the reason. "There is a possibility that the system is learning to use these signals - wired connections create the necessary code so that the signals can be learned by the cerebral cortex."
So even if there can be much more tetrachromats in the world, they may simply not have an exceptional perception of color, since they have “not taught” their brains to pay attention to additional signals. Antico in this case is a rare exception. “I was different from the usual five-year-old children - and started painting at the age of seven, I was fascinated by flowers,” she says. For many years, she paid attention to the expanded color spectrum, so her brain was "tuned in" to use tetrachromacy.
Antico is personally interested in the continuation of tetrachromatic research. Five years ago, when Antico’s daughter was seven years old, the family discovered her color-blindness. Antico believes that her daughter's color blindness is associated with her own mutation. The more she helps scientists to study tetrachromatia, she believes, the more opportunities they will have to help people like her daughter. “If we understand the genetic potential of tetrachromatia and the difference in perception, we will learn quite a lot about the visual processing of colors, which we don’t know yet,” Jamison agrees.
In addition, Antico may have found another way to help people with limited color vision. She is a professional artist who has been teaching painting for over 20 years, and she has a number of students with color blindness. “Observing their work, I noted that they have a good perception of color, unlike other individuals who have a typical perception of colors,” Jamison says. “It is quite possible that, tune in to the perception of the difference between colors from early childhood, Antico gained some understanding of how to help them expand opportunities.” This hypothesis also has to be tested empirically, of course, but Jamison is intrigued by the prospect of improving the color perception of people through training, which neuroplasticity allows.
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