Science & Tech

#TheDress Shows the Quirks of Human Perception

A lone Roman Originals dress has threatened to ‘melt the Internet’ by sparking a ferocious debate about its color: Is it white and gold or blue and black? The world is divided into two camps with apparently equal backing.

If you see #TheDress as white and gold, you can’t fathom someone else seeing it as blue and black – and vice versa. Fueling the confusion is the fact that some people see blue and black one time, then see white and gold when they look at #TheDress in a slightly different way.

Can we trust our eyes?

While the debate is fun, it’s also somewhat unnerving. We think of our vision as an impartial purveyor of visual truth. We assume that we see the world exactly as it is. #TheDress phenomenon shakes our trust in our eyes.

But our visual system has never been as simple as we assume it is. Our eyes take in wavelengths of light, but our brains have to interpret what we see based on the context, our experience, and our assumptions.

A natural scene emits or reflects light to the retina that has color information based on the intrinsic wavelength of the light source transformed by the reflective properties of objects the light interacts with. However, the color information coming in can be ambiguous, and interpreted in different ways: for instance, white light reflecting off of a green object and green light reflecting off a white object send similar information to our eyes. But our brains know that the object must be either green or white. Using the clues available, the brain makes an absolute decision and sticks with it.

The classic checkerboard illusion.

A classic example of this fact is the checkerboard illusion. Squares A and B are the same color. But our brains don’t just look at the wavelengths. They look at the context and the structure of the image and decide that square B is lighter. Only by interrupting the scene can we see the colors as they truly are.

If vision is inherently subjective, the circumstances of #TheDress image are a perfect storm to make things even more uncertain. The image is a casual photograph from a device whose interpretation of color and light is unknown. The scene includes artificial lighting and ambiguous shadows. And the image can be reproduced much differently on a smartphone than on a high-resolution monitor.

Our brains at work

Faced with all these uncertainties, our quirky, clever brains go to work. We draw meaning from clues: Is it an overexposed shot in a department store or was it shot outside? Should we interpret the light as warm, natural sunlight or cold, harsh fluorescent light? Each person’s brain makes instant judgments about these questions and more. And based on those assumptions, each person can arrive at a very different decision – white and gold or blue and black.

As illustrated by #TheDress, sometimes our perceptual experience is completely different from the person sitting right next to us. What’s remarkable isn’t that we’re noticing it with The Dress. What’s remarkable is that we don’t notice it more often.

At Dolby, we care deeply about understanding how the brain interprets the world. By studying human perception, we create tools that creative artists use to convince us that we’re seeing something that’s not really there or hearing something completely new. That’s where so much of the magic of our entertainment comes from.

(By the way, if you’ve bet anyone that #TheDress is actually white and gold, I’ve got bad news for you: spectrophotometer measurements of the precise wavelengths of light reflected by those interleaved pieces of fabric show beyond all doubt that the material is blue and black. Sorry.)