Remember that dress the mother of a bride wore in Scotland that launched a million disagreements in 2015, with some people swearing it was white and gold while others bet it was blue and black? A neuroscientist may have an answer to the puzzle; it may be a game of shadows.Depending on what kind of light you thought the dress was photographed in, your brain made the necessary adjustments and informed you of the colour of the dress.“The original image was overexposed, rendering the illumination source uncertain,” neuroscientist Pascal Wallisch, an assistant professor in New York University’s Department of Psychology, said. “As a result, we make assumptions about how the dress was illuminated, which affects the colours we see.”Debates about the colours of the dress worn by the mother of a bride in Scotland almost broke the internet two years ago. It even has a Wikipedia page of its own. A few preliminary attempts were made to solve the riddle when the photograph went viral, but these were mere conjectures, that did not investigate perceptions about that particular dress.An MIT study also proposed that it was a difference between what kind of light people are usually exposed to, but it took into account responses from only 1,400 individuals.While the question may have faded from the minds of others, it sparked interest for Wallisch, who published his findings last week in the Journal of Vision. His work is based on an online survey of about 13,000 people, who had seen the dress and were asked a few questions pertaining to it. Read | MIT scientists decode mystery of the dress that split the internetOne of the questions was whether or not they believed the dress was in a shadow.“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,” Wallisch explained in a release. “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.”It may seem incredible given the amount of information that our brain processes every moment but it also performs the function of colour correction for all the visual input it receives. It is a basic cognitive function, according to the neuroscientist.Taking his theory forward the scientist also tried to determine what kind of people were likely to see the dress as white and gold and who was more likely to see it as blue and black, According to his hypothesis the colours you saw depended on whether you are an owl or a lark, or someone who starts their day late and sleeps late or an early bird. “This suggests that whatever kind of light one is typically exposed to influences how one perceives colour,” Wallisch said.So night owls are conditioned to see the world largely in long-wavelength artificial light while morning people see their world mostly illuminated by sunlight. Larks are more likely to see the dress as white and gold, while night people as blue and black.The controversy harks back to a more fundamental question: Do we all see the world in the same colours? There is still no black and white answer to that.