You will have seen it

Tweeted over 10 million times, with everyone from Taylor Swift and Justin Bieber to David Duchovny and Ellen DeGeneres chiming in, you either saw it was blue and black (Jaden Smith, Demi Lovato) or white and gold (Anna Kendrick, Katy Perry) depending on… what exactly?

Some said it was the conditions you saw the photo in, others that it depended on the brightness of your screen.

But the real answer is… your brain.

You saw it as either blue and black or white and gold because you brain decided on one or the other and then wouldn’t let go. #thedress gave millions of people an insight into the complex world of colour perception and the incredibly lengths you brain goes to in order to make sense of the world around us. The tale of colour, and our perception of it, takes in emotion, culture, language, art, as well as neuroscience, and one group at Harvard Medical School in the U.S. has been at the forefront of the research into this fascinating subject.

Conway understands why, when presented with what should be an unambiguous decision, such as the colour of a dress, that the brain can get confused.