Category Archives: Color Vision

The Neuroscience of #TheDress

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#TheDress #WhiteandGod #BlackandBlue

#TheDress #WhiteandGod #BlackandBlue

Color perception is as relative as human perception in general, and it is easy to understand this statement if we use price as an example. The dress in question costs 77 dollars. This is expensive or cheap? It Depends. It is nothing to a Hollywood actress, but expensive for a beggar anywhere in the world.

What the price has to do with the color? Just as expensive and cheap depends on the bank account of each owner, the color of the dress also depends on how each person’s brain works. In the case of #TheDress, people are divided into two main categories, #whiteandgold or #blackandblue. The color of the original dress is black and blue, but what matters is the photo that generated a different dress (pictured above) and observers are divided between #whiteandgold or #blackandblue. Who is right? Everyone.

#TheDress

What is this for? Perceptual constancy brings some stability to our lives already so troubled. In the specific case of color, constancy is a mechanism that is constantly discounting changes in lighting so that the color of objects remains stable. Without the color constancy, we would perceive objects changing color almost all the time because the light emitted by objects – in fact – changes according to the change in lighting, whether natural or artificial. In other words, we see differences where they exist and therefore “we do not see the world as it is, but how it can be useful to us” as stated Beau Lotto.

Some brains assume that the lighting is yellowish, discounting the yellow and perceiving a #blackandblue dress while others assume that the lighting is blueish, discounting the blue and perceiving a #whiteandgold dress. The simulation below is the one that best illustrates the difference between those who discounts blue lighting (left) and those who discounts the yellow lighting (right).

Decodificando o desconto da iluminação! https://xkcd.com/1492/

Decodificando o desconto da iluminação! https://xkcd.com/1492/

If the brain’s task was deciding between a green or blue lighting, #TheDress would never gone viral. Blue and green colors are not opponents and the differences would have passed unnoticed. Discounting blue creates a perception predominantly yellow and discounting green creates a perception predominantly red. Yellow and red are two different colors but between them there is a wide variety of yellowish-red, orangish-red, and many other similar descriptions that we are used to and it would never cause a huge controversy.

The same cannot be said in the case of blue and yellow. They are opponents in the human color space and the perceptual result differs completely. Discounting blue creates a perception predominantly yellow and then people perceive #whiteandgold while discounting yellow creates a perception predominantly blue and people perceive #blackandblue. Between blue and yellow there is no intermediary color because there are no blueish-yellow or yellowish-blue and, therefore, either we name it yellow or gold or any other name that does not contain any blue or we name blue or any other name that does not contains anything about yellow – the reason for the stark difference.

Human Color Space

Human Color Space

What makes a person see #whiteandgold and another person see #blackandblue? In my research, 50% perceive #whiteandgold and 50% perceive #blackandblue. If this result is confirmed, the choice between seeing one or another may be merely the result of chance orchestrating our brains as getting heads or tails is also a matter of randomness. If my sample is not confirmed, the answer live somewhere else and Drummond was right because “each chose as his whimsy, his illusion, his myopia.” In this case, further research could help us understand what differs those who perceive #whiteandgold and those who perceive #blackandblue. One way or another, everyone is right because our minds were designed to see a bit but not much and it varies from brain to brain.

Color is often thought of as a quality of the object or light, but this is not true. The color is a mental phenomenon determined by neuronal processes and the light is just the beginning of this process that ends with the perception of one or more colors. Experiencing blue or gold or any other color is a mental construction.

Claudia Feitosa-Santana is a neuroscientist with Masters in Experimental Psychology and PhD in Neuroscience and Behavior from the University of Sao Paulo, and a Postdoctoral in Integrative Neuroscience from The University of Chicago. She lives in Chicago where she is an Adjunct Professor at The School of The Art Institute of Chicago and at the Roosevelt University.

Museum of Science and Industry, Chicago: Review

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Chicago Museum of Science presents a Wrong Color Definition

Chicago Museum of Science Color Mistake

According to the Museum of Science and Industry (Chicago, IL) “the color of an object is determined by the specific wavelengths of lights that it absorbs and reflects” but THIS IS NOT TRUE. This wrong definition is presented in the Color Booth and situated in the Science Storm Exhibition. Here are some explanations about why color is NOT determined by the specific wavelengths of lights that it absorbs and reflects:

“Many people believe that color is a defining and essential property of objects, one depending entirely on the specific wavelengths of light reflected from them. But this belief is mistaken. Color is a sensation created in the brain. If the colors we perceived depended only on the wavelength of reflected light, an object’s color would appear to change dramatically with variations in illumination through- out the day and in shadows. Instead patterns of activity in the brain render an object’s color relatively stable despite changes in its environment.” – by John Werner, Ph.D.: UC Davis, Center for Neuroscience.

“While color of an isolated light is closely related to the light’s physical properties — its energy and wavelengths — this is a misleading fact for understanding normal viewing. Color is not in light. What we see depends directly on a pattern of neural responses, not on the wavelength or energy of light that enters the eye. The simple relation between a physical stimulus and how we perceive it breaks down when the light is part of a complex scene. In natural viewing, the whole visual stimulus is a patchwork of different lights from many objects. The neural response to a particular light, and therefore our perception of it, is affected by the context of the other lights also in view.” – by Steve Shevell, Ph.D.: University of Chicago, Institute for Mind and Biology.

“Color is often thought to be a quality of light but this is not so. For example, the expression the ocean is blue uses a perceptual experience of blueness to describe the physical light. Color itself is not in the light. Color is a perceptual phenomenon determined by neural processes in the brain. The region of the electromagnetic spectrum that is visible to humans is from about 400 nm to 700 nm, but no wavelength is endowed with a color. Instead, a particular wavelength, say a wavelength near 470 nm or 580 nm, is perceived as blue or yellow, respectively, only because these wavelengths stimulate the photoreceptors in the human eye that are responsible for the transduction of physical light into neural responses. Those neural responses go through a series of processing stages in the brain. The experience of blue or yellow, as well as all other colors, is a mental construction. The experience of a color is like the understanding of language. There is no meaning in the physical sound (the brain must interpret it) just as there is no blue or yellow in the wavelengths of light. Color is a percept that humans are able to experience through sensory neural processes.” – by Claudia Feitosa-Santana, Ph.D.: Roosevelt University, Psychology Department.

This is very old news:

Isaac Newton (1642, 1727) brilliantly wrote about in his book “Opticks“, first published in 1704: “And if at any time I speak of light and rays as coloured or endowed with colours, I would be understood to speak not philosophically and properly, but grossly, and accordingly to such conceptions as vulgar people in seeing all these experiments would be apt to frame. For the rays to speak properly are not coloured. In them there is nothing else then a certain power and disposition to stir up a sensation of this or that colour.”

Later, W. D. Wright was inspired by Newton’s words and published a book named “The Rays are not Coloured” in 1967, stating that “our perception of colour are within us and colours cannot exist unless there is an observer to perceive them. Colour does not exist even in the chain of events between the retinal receptors and the visual cortex, but only when information is finally interpreted in the consciousness of the observer.” – by W. D. Wright, Imperial College of Science and Technology, London

First published by Adam Hilger LTD, London - 1967

First published by Adam Hilger LTD, London – 1967

Therefore, if you go to this museum eager for your kids to learn science, it is better to readjust your expectations. It can be fun but not educational. Most of time you will not find an employee or a volunteer to answer your question, and if you find them it does not mean that they will give you the right answer.

Their uniforms are very misleading. They have two types: employees that are not scientists 99% of the time wear an uniform that says “Scientist”, and volunteers wear an uniform that says “Volunteer” that, although are often retiree from many different areas not related to science, you will have better chances to find a science student among them.

More alarming and very scary is the fact that they offer a “Teacher Workshop” and “Center for the Advancement of Science Education”. According to their own words, the “Teacher Workshop is designed to increase your knowledge of science, improve teaching skills and demonstrate how to use Museum programs and exhibits to enhance science curriculum.” The “Center for the Advancement of Science Education” offers an enormous list of activities like Field Trips, Science Minors, Learning Lab, etc. It would be fantastic if the museum was taking science seriously and updated but this is definitely not the case.

OBS: Before writing this review, I have contacted the museum requesting that the panel with the color definition should be fixed. The answer was NO and the explanation was once more a proof that the MSI Chicago does not have scientists enough and/or no respect for Science.

Color is in the Brain

The Eskimo Snow Vocabulary Hoax

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It is well known that humans have an eagerness to embrace exotic facts, and here we have an old hoax that is still believed to be true by many of us: the Eskimos and their dozens or even hundreds of different grades of snow. Some people still believe that Eskimos are able to perceive more types of snow compared to us. Some people still believe that Eskimos have a super rich vocabulary for the different types of snow.

The anthropologist Laura Martin spent some of her research time during the 1980s trying to slay the trot about the Eskimos, and after years of struggle she published “Eskimos Words for Snow” (Martin, 1986). This ought to have been enough for the news to get out our lives but no, and Martin later cited the number of Eskimo snow terms given as “nine” in a trivia encyclopedia (Adams 1984), “one hundred” in a New York Times editorial (February 9 1984), and “two hundred” in a Cleveland TV weather forecast (Pullum, 1989).

Interior designers have different names to different shades of beige, and hairdressers have different names to different shades of brown and black – fair enough! But according to the linguist Geoffrey K. Pullum – who worked very hard to destroy The Great Eskimo Vocabulary Hoax, Eskimos aren’t really that interested in snow. For the Eskimos, snow is a constant background, like sand on the beach. And even surfers or beach lovers have only one word for sand.

In 1911, the linguist Franz Boas compared the English terms for water to Eskimo terms for snow, stating 4 names for the Eskimos’ vocabulary for snow. Recently, in 2003, Larry Kaplan claimed a little more in “Inuit Snow Terms“. For Pullum and Martin, we have to be aware that the Dictionary of the West Greenlandic Eskimo Language (Schultz-Lorentzen, 1927) gives just two possible relevant roots for the Eskimos’ vocabulary for the types of snow: qanik – meaning snow in the air (snowflake), and aput – meaning snow on the ground. All the other names are derivative. That is all.

The Great Eskimo Vocabulary Hoax

The Great Eskimo Vocabulary Hoax

Color is in the Brain

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Color is Mental Construction

Color is often thought to be a quality of light but this is not so. For example, the expression the ocean is blue uses a perceptual experience of blueness to describe the physical light. Color itself is not in the light. Color is a perceptual phenomenon determined by neural processes in the brain. The region of the electromagnetic spectrum that is visible to humans is from about 400 nm to 700 nm, but no wavelength is endowed with a color. Instead, a particular wavelength, say a wavelength near 470 nm or 580 nm, is perceived as blue or yellow, respectively, only because these wavelengths stimulate the photoreceptors in the human eye that are responsible for the transduction of physical light into neural responses. Those neural responses go through a series of processing stages in the brain. The experience of blue or yellow, as well as all other colors, is a mental construction. The experience of a color is like the understanding of language. There is no meaning in the physical sound (the brain must interpret it) just as there is no blue or yellow in the wavelengths of light. Color is a percept that humans are able to experience through sensory neural processes.

More at www.feitosa-santana.com