Admittedly, we here behind UWMadScience passionately resisted viral postings about “the dress” as it percolated – and then exploded – across social media in the blink of an eye (people must have tired of the llamas). Does it really matter whether it’s black and blue, or white and gold?
Consequential or not, it turns out the divisiveness people feel over the color is firmly rooted in neuroscience. Your brain vs my brain, or something like that. And along with the neuroscience, the subject delves into the philosophical. But what color is it, really? The answer: context matters.
Bas Rokers is a professor in the Department of Psychology at UW-Madison, and while he can’t tell us how a silly dress can become a social media sensation, he can explain why some of us see one set of colors while the rest of us get it wrong.
“I am watching all this discussion on Reddit and people are very much disagreeing over what’s the fact of the matter and what people perceive,” Rokers said. “Really, all the dress is doing is reflecting light of a particular set of wavelengths.”
We have a photo of the dress but we don’t know anything about the light source that’s illuminating it, Rokers says. And this matters, a lot.
Light from a source, whether the sun or the sky or an LED lightbulb, hits an object, and the physical properties of that object determine what wavelengths of light are absorbed, and what wavelengths are reflected back to our eyes. The brain is tasked with subtracting out the color of the light that is illuminating the dress and interpreting only the light reflecting off of it.
“The brain only has access to the light that enters the eye and it’s the job of the brain to try and make a best guess about the properties of the light sources by looking across the entire scene,” Rokers says.
So, if a yellow source of light, like the sun, is illuminating the dress, your brain subtracts out more yellow light and you see the dress as blue. But if a more blue-tinted light is cast upon the dress, your brain gets rid of the blue in the surroundings and you perceive white.
It’s similar to knowing you have a piece of chocolate cake in your mouth, and trying to pick around that to figure out whether there is also cinnamon and maybe a hint of citrus.
“You’re making a judgement,” Rokers says. “Your brain makes the best guess about what’s going on, and when that’s wrong, you experience a visual illusion.”
These visual, or optical, illusions happen all the time. In fact, the National Geographic Channel has a series devoted to these kinds of Brain Games, and Rokers was featured in the show’s first episode back in 2011.
“It’s hard for people to imagine anyone could see anything else than what they’re seeing,” says Rokers. “We think we see the world as it is.”
This is where things tap into the philosophical dimension, into something Rokers refers to as the Qualia Problem.
A quale, or qualia, is a subjective experience that inherently reflects an individual’s awareness or interpretation of the world around them. We can each describe what something, like a dress, looks like to us, but we can never know exactly what it looks like to someone else.
“The philosophical questions is, is the red you perceive the same as the red I perceive?” says Rokers.
So we asked him, what if each and every one of us stood in the same room, looking at THE dress. Would we all see the same color?
“In a room, we would have much more visual information than in the picture and the colors people would perceive would be much more similar,” he says. While we may all perceive subtleties in shade or hue, chances are good, we would be in agreement about what general color we were seeing.
“Vision scientists are saying this is the most compelling display of what’s known as color constancy anybody’s ever seen,” Rokers says. “Since our brain gets it right so much of the time, we all start out thinking everyone must see things the same. But actually, our senses are fooling us all the time.”
So the dress, what color is it, really?