Sometimes it just seems like the whole world has gone crazy. Like when your colleagues, all serious people, cluster for precious minutes around a computer screen debating the color of a dress. And you see that, online, many other serious people are doing the same thing — say, at On Point or The New York Times.
So though I was curious about the science behind the recent viral phenomenon known as "The Dress," my first question for Boston-area neuropsychiatrist Dr. Jon Lieff was a more mundane "Why?" To quote one top Slate commenter, "How is this a thing?"
Not that it's a bad thing. The dress phenomenon "informs people that perception is not what it seems," Dr. Lieff says. "We think we see reality when in reality, what we see is what the brain wants us to see. And that leads us into philosophy..."
But let's not go into philosophy just yet. (And you can read Dr. Lieff's thoughts at more depth on his website, Searching for the Mind.) Let's talk instead about why this of all optical illusions swept the Internet.
His bottom line: "Our brain is correcting for an imagined light source. That's the problem."
And what's unusual about it: "This doesn't usually happen with an illusion: In any crowd, you have half the people saying one thing and the other half saying another thing. And because of the type of illusion it is, once it's fixed, your brain is going to keep you on the blue side or the white side. I'm sure you've seen other kinds of illusions where it flips back and forth. This is different. Once people choose their sides, they're saying, 'This is it, and I'm the right one and you're the wrong one.' So it's captured the imagination, but in truth there are hundreds of these occurring all day long, that people don't realize."
"An example: if you're watching a waterfall on the TV and your hand is on the desk, your hand thinks the desk is rising up.
If you have an orange drink but you color it red, you think it's cherry when you taste it. i can give you many examples like this. But there are a lot of reasons for it, and the reason this particular thing has captured the imagination is complicated; it involves at least four or five things that make it very complex from a scientific point of view."
A basic truth: Our brains are constantly adjusting for color. Dr. Lieff's example: "If you take a white piece of paper and you have it inside, you see it as white, and then you take it outside and you see it as the same white, but in truth, the actual color has changed because of the ambient light. But our brain adjusts for what we think is illuminating something, so that's part of the mystery of why this works."
So why might that be different for different people looking at the dress?
"There are a number of factors. One factor is that these particular colors are complicated colors, they're not just black or just gold...so you start with a complicated set of colors, and people may be sensitive more to one or the other."
"The second feature that's ambiguous is that you don't have any idea what the light source is. If it was obvious the light came from a regular light bulb or outside in the sun, the brain would then calculate, 'Well, this is the light source and this is what that color comes out to be.'" You also can't tell if there's a shadow or not. So there's a lot of ambiguity and as a result of that, the brain chooses one or the other."
Reaching far back to the 3-a.m. dorm rooms of my past, I asked whether all this echoes back to the old philosophical discussion about qualia — about our subjective perceptions, questions like "How do I know, as we look at this red sunset together, that you're seeing the same thing I am?"
Yes, Dr. Lieff kindly responded; it shows people that qualia are different in different people. And "this is a particularly stark example of the differences that people see."
Kind of an edifying reminder, I thought, to emerge from such an otherwise annoying Twitter trend...