Professor Bruce Hood shows an illusion which involves a sculpted face, but instead of the usual convex human face of a sculpture, the sculpture is flipped and we're shown the inside of the face but human brains find it hard to recognise it is convex until the head starts turning around.

This clip is part of the Christmas Lectures 2011 presented by Professor Bruce Hood - Lecture Three: Are you thinking what I'm thinking?

View the full Lectures on the Ri Channel:
www.richannel.org/christmas-lectures/2011/meet-your-brain