The vision thing: how babies colour in the world

We know that babies don't just see in black and white. But what colours can they see - and how key is it to their development?

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Sitting in a padded car seat, a small black and white bullseye stuck to his cheek, four-month-old Teo Bosten-Lam gazes at a computer. The screen is a mottled grey, like the snow on a old-fashioned television, but in the top right-hand corner is a deep blue circle. Teo has spotted it. He glances at the circle and, as he does so, it morphs into a smiley face and a triumphant jingle fills the darkened room. Buoyed by the reaction, he looks around. Suddenly a black and white spinning disc appears on the screen, issuing a sound that can only be described as "boing".

"Babies can't resist the black and white swirl things," says researcher Alice Skelton. "When they look away we play it and it brings them back to the screen." A PhD student in the baby lab at the University of Sussex, Skelton is attempting to unpick a conundrum that has fascinated parents and scientists alike: when it comes to colour, exactly what can babies can see?