In February the internet split humanity in two… with a dress. People fought to the death to defend their perception of the dress as either blue/black or white/gold (I just made that up… but it was almost that remarkable!). But seriously, people felt strongly about how clear their perception was on this point, and what actually is remarkable was that so many people felt so very differently. For this reason—and perhaps because some of the arguments were between A-list superstars—the dress went viral in a way that visual illusions rarely do. We covered that explosion of interest in a previous post… and we will cover it again in an upcoming in-depth article in our Sept-Oct Illusions column in Scientific American: Mind due out in mid-August.

The Dress

One of the remarkable scientific aftershocks from the dress was that it has inspired dozens of visual science labs into action. They began conducting new experiments to understand the dress better instantly. The scientific mystery is that no previous color illusion has been ambiguous, to two people viewing the same image, until The Dress. Oh there have been color illusions in which colors change, sure (see the Rubik’s cube illusion here by Lotto & Purves)… but in these and all other pre-Dress color illusions, the color changes were the same for everybody. The Dress is the very first color illusion in which different people from the neurotypical population—those people with no known differences between their brains—experience the same colored surfaces as drastically different colors.

Credit: Beau Lotto (Unv. College London) & Dale Purves (Duke Univ)
A demonstration of color contrast. Panels A & B: The blue chips in panel A are physically identical to the yellow chips in panel B. Panels C & D: Same as panel A & B except colors on cube removed. Note that the same chips we already discussed now appear gray, if surrounded by white. This makes clear that color perception is always a figment of your imagination based on your brains estimates of surface reflection properties and the nature of the light illuminating that surface.

This week the first wave of research from scientific journals has begun to be published; Current Biology has posted a trio of papers by three different prominent competing color vision labs, each describing their initial studies of The Dress. More will come, but the field is already off to a good start. So in celebration of the scientific enterprise and its surprise boost from the world of fashion: here is a summary of those first three studies for reading pleasure.

The aggregate bottom line from all three studies, in my opinion, is that the colors yellow and blue enjoy privileged processing by the brain, presumably to effect color constancy of objects in the sunlight versus in the shade. Blue, especially, is processed differently from other colors. Perhaps (I wonder) the neural differences between the world’s blue/black versus white/gold populations will have something interesting about what underlies the individual differences in how we see the color blue, in general. These are certainly not the only effects that are occurring with The Dress—other factors such as viewing conditions, and many others, bias how we see color. But these studies show us the cutting edge new findings that come from The Dress.

I hope you enjoy them and have a chance to go read them for yourself!

Paper # 1: Striking individual differences in color perception uncovered by ‘the dress’ photograph

By Rosa Lafer-SousaKatherine L. HermannBevil R. Conway

Link to study

This large study examined perception of the Dress in an impressive 1401 subjects. They found that the colors perceived were widespread and generally grouped into three groups: blue/black, white/gold, and blue/brown. Women were more likely than men to report white/gold (and same with older people compared to younger people).

Asymmetries in blue–yellow color perception and in the color of ‘the dress’

Alissa D. WinklerLothar SpillmannJohn S. WernerMichael A. Webster

Link to study

The study finds that blue is much more likely than yellow to be perceived as achromatic (white or gray), despite having the same luminance levels. This suggests that blue has special perceived ambiguities that have serendipitously only become apparent due to The Dress.

The many colours of ‘the dress’

Karl R. GegenfurtnerMarina BlojMatteo Toscani

Link to study

This study finds that subjects tend to see the colors specifically within the daylight wavelength distribution of light, reinforcing previous research by the Conway group that suggested that color constancy perception developed in a daylight environment.