Optical illusions show how past experience dramatically influences perception

‘I’ll never trust another trapezoid.’

Part of a series of educational films produced by Bell Laboratories between 1956 and 1964, Gateways to the Mind (1958) explored human senses and perception using animations, demonstrations and in-the-lab sequences. In this brief excerpt, the US English professor and public educator Frank C Baxter walks the audience through three experiments carried out at Princeton University’s Perception Demonstration Center, each highlighting the powerful relationship between perception and past experience.