The debate about the color of the white-blue-gold-black dress that once exploded on the Internet has raised new questions about the relationship between perception and consciousness.
Now scientists have finally explained why people couldn’t agree on the colour of “that dress’.
When the dress went viral in 2015, millions of people – including fashionistas Taylor Swift and Gigi Hadid – were divided whether its true colours were gold and white or black and blue.
Now, in a new study, neuroscientist Doctor Pascal Wallisch concludes that the differences in perception are down to our assumptions about how the dress was illuminated.
Those who thought that the dress, worn by the mother of a bride at a wedding in Scotland, was photographed in a shadow most likely saw the garment as gold and white.
But those who thought it was illuminated by artificial light were more likely to see it as black and blue.
He suggested these differing perceptions could be linked to a person’s exposure to daylight.
People who get up and go to bed early, and spend many of their waking hours in sunlight are more likely to see the dress as white and gold than night owls, whose world is illuminated not by the sun, but artificial light.
Dr Wallisch, clinical assistant professor in New York University’s Department of Psychology, said: “The original image was overexposed, rendering the illumination source uncertain.
“As a result, we make assumptions about how the dress was illuminated, which affects the colours we see.
“Shadows are blue, so we mentally subtract the blue light in order to view the image, which then appears in bright colours – gold and white.
“However, artificial light tends to be yellowish, so if we see it brightened in this fashion, we factor out this colour, leaving us with a dress that we see as black and blue.
“This is a basic cognitive function: to appreciate the colour on an object, the illumination source has to be taken into account, which the brain does continuously.”
The findings, based on an online study involving more than 13,000 participants, was published in the Journal of Vision.
The study’s participants, who had previously seen the dress, were asked whether or not they believed it was in a shadow.
These beliefs – about whether or not the dress was in a shadow – strongly affected the “perceptual experience” of the dress.
Among those who saw it in a shadow, four out of five participants believed it to be white and gold; by contrast, only about half of the participants who didn’t see it in a shadow saw the garment bearing these colours.
