The Rubber Hand Illusion
Mentalism is based in part on building performances that take advantage of natural cognitive biases and illusions. This is the first in a series that will explore the inner workings of our minds.
In a study called “Rubber hands ‘feel’ touch that eyes see,” scientists Matthew Botvinick and Jonathan Cohen published an optical and sensory illusion that has found great acclaim with neuroscientists as well as mentalists. This was a huge step in the knowledge of how we bodily self-identify, and the original study can be found at https://webapps.pni.princeton.edu/ncc/publications/1998/BotvinickCohen1998Nature.pdf.
Essentially, one of the subject’s real arms was hidden behind a screen, while a life-size fake rubber hand was positioned directly in front of the subject. 2 paintbrushes were then used to stroke the fake hand and the real (hidden) hand in sync, wherein the visual information of seeing the rubber hand being stroked along with the tactile information of the synced touch created a compelling illusion that the rubber hand belonged to the participant.
This has led to compelling advances in virtual reality technology, as well as helping to relieve “phantom limb” neurological pain. Other experiments have taken a more lighthearted approach, such as https://www.youtube.com/watch?v=sxwn1w7MJvk where you can see the reaction when the fake hand is suddenly smashed with a hammer!
And psychological illusionist Derren Brown even performed a routine based on this idea in his 2011 television special Svengali.
When you have a chance, give it a shot with a friend. You’ll have fun and learn something in the process!
Kevin Viner
I’m a professional mentalist who travels the world performing. Beyond my profession, my interests include writing music, guitar, aviation, martial arts, and mathematics.
