Magic Trick Sheds Light on Neuroscience with 'Cup and Balls' Experiment

A magic trick may help shed a bit of light on human attention and visual systems, according to neuroscientists. A new study examined an old magic trick in order to better understand how people keep track of their surroundings.

Teaming up with Teller of Penne and Teller, researchers at the Barrow Neurological Institute examined the magician's "cup and balls" routine, a trick that dates back thousands of years. The routine involves balls appearing and disappearing under the cover of cups. Their ultimate goal, of course, was to find out what exactly distracts a person while the illusion is being performed.

The researchers used seven volunteers and tracked their eye movements as they watched a tape of Teller performing his illusion. They were then given a remote and told to press one button every time the ball was removed from the cup and another button when the ball was replaced. In all, the viewers watched the magician perform the trick in 48 different ways--sometimes the cups would be clear instead of solid and other times the ball would be dropped or stuck to the cup, or not in the cup at all.

After the experiments were performed, the researchers examined the results. They found that the common belief held by magicians that facial cues direct attention was wrong. Covering the face of the magician, for example, had no effect on where participants thought the ball actually was. And eye movements didn't accurately track what people were actually paying attention to, either.

So what does this mean for scientists? It allows them to learn how people pay attention to others and objects by means of eye-gazing, pointing or other verbal and non-verbal signals. In fact, it could allow neuroscientists to better understand people with conditions such as autism that have problems with maintaining this kind of attention.

The study was published in the inaugural issue of the journal PeerJ.