AsianScientist (Feb. 28, 2015) – 12:30 pm, Friday. Most definitely blue and black, I thought dismissively, already clicking on another link and shoving the rest of my lunch into my mouth. How could anyone think otherwise?
A few hours later, I watched in disbelief as my phone buzzed with messages from friends who could only see white and gold. Disturbed, I polled my family. Blue, said my brother. Phew. Lilac [smiley face], said my dad, off on a tangent as usual. Discolored white, hedged my mom. It didn’t help when we discovered that Asian Scientist editors and columnists were split right down the middle.
I suppose going through a tiny existential crisis once in a while is probably good for the soul. While the dust settles and we try to recover some faith in our own sanity, neuroscientists and vision experts have weighed in on the science behind why no one can agree on the color of that darned dress.
But first, some neuroscience
If there is one thing to take away from the Great Dress Divide of February 2015, it is that color is very much a mental phenomenon instead of a physical one. Very simply put, light of varying wavelengths is reflected off objects and enters the eye. The light hits the retina, where light-sensitive cells transmit signals to the visual cortex of the brain. The brain then processes and interprets this visual information to arrive at a conclusion—this apple is red, the grass is green, and—in my case—that dress is blue.
But ambient light also varies in color—think of how sunlight goes from reddish-yellow in the morning to white at midday and back to red in the evening, or of how indoor fluorescent lighting compares with natural light. The light that objects reflect into our eyes is thus a mixture of information about the color of the objects themselves, and of the light illuminating them.
Yet for the most part, things don’t change their basic color even as light conditions change—we would describe grass as green no matter what time of day it is. This is because our brains are able to maintain some level of what is known as color constancy—in essence, calibrating the color of the object to account for the color of the light.
One of the ways the brain does this is by using contextual clues as reference points. For example, imagine you are taking your white pet dog out for a walk at sunrise (if you hate dogs, imagine that you are wearing a white shirt). Since you know your dog is white, your brain can then subtract some of the early morning reddish hue from your mental picture of the world.
Seeing is believing
OK, so what about that dress? The dress, or more accurately the photo of the dress, seems to have hit, purely by chance, some kind of perceptual boundary where small differences in how we do this calibration result in a big difference in the color our brains finally spit out.
A key feature of the photo is its lack of contextual cues. It’s a disembodied dress—there are no human faces (or even human skin) and no white areas for our brains to use as a reference. Add to that the weird colored lighting (it looks like artificial lighting to me) and overexposure, and there is plenty of room for different interpretations. The brains of people on Team White-and-Gold likely subtracted blue, while Team Blue-and-Black (go team!) subtracted yellow.
Even more disturbingly, some have reported the color of the dress changing upon a second (or third, or one hundredth…) look. Because the brain is always fine-tuning the color constancy calculation according to the multiple inputs it receives, factors such as taking into account the opinions of others may eventually tilt the balance in the other direction.
So what?
While this debate has captivated millions, there are those who have been saying: Who cares? It’s just a bad photo of a dress. Can’t we move on to something else already?
But think of it this way—because a woman on a tiny Scottish island decided to post a strange photo to Tumblr, I (and probably millions of people the world over) learned about color constancy, this amazing adaptive calculation we didn’t even notice our brains are doing every second of every day. That, even for today’s jaded, cynical Internet, is pretty cool.
This article is from a monthly column called The Bug Report. Click here to see the other articles in this series.
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Copyright: Asian Scientist Magazine; Photo: Trace Dominguez/Flickr/CC.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.
