How do we perceive faces? With some balloons, newspaper, some paste for paper mâché, and paints, you can create a hollow mask that appears to follow you as you move back and forth around the room. Rachel and her children Eva and Daniel investigate the illusion in this video from The Royal Institution‘s ExpeRimental series, a resource that can help parents set up fun, easy, and cheap science experiments at home.

This classic illusion can baffle brains of all ages. Making the masks can help us explore why it works (or doesn’t work), and why our brains can be so easily tricked. Here’s the Einstein mask in video form:

This series of ExpeRimental is supported by The British Psychological Society. To avoid any spoilers/test conclusions, pause the video at 3m50s. Find the full instruction sheet here (pdf).

Watch more experiment videos and demonstration videos on this site, including more DIY science from Ri.

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