The Science Behind Sleight Of Hand Now you see it, now you don't. Susana Martinez-Conde, a neuroscientist at the Barrow Neurological Institute, discusses techniques used by magicians. Essentially, she says, magicians manipulate the audience's attention.

The Science Behind Sleight Of Hand

The Science Behind Sleight Of Hand

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Now you see it, now you don't. Susana Martinez-Conde, a neuroscientist at the Barrow Neurological Institute, discusses techniques used by magicians. Essentially, she says, magicians manipulate the audience's attention.


Magicians also earn their living by convincing us that the fantastic is possible. But when you clear out all the smoke mirrors and occasional fireworks, at the heart of magic is the ability to make people see something that's not really there or miss something that really is. Psychologists and neurologists have been looking into how magicians manipulate our perceptions in any case, and one of those researchers is Susana Martinez-Conde of the Barrow Neurological Institute. She and her co-authors, including five internationally-known magicians, recently published a paper on the topic in the journal Nature Reviews Neuroscience. Professor Martinez-Conde joins us from member station KJZZ in Phoenix. Thanks so much.

Professor SUSANA MARTINEZ-CONDE (Director, Laboratory of Visual Neuroscience, Barrow Neurological Institute): Thank you. My pleasure.

SIMON: And why was this important to find out? What made you decide to look into this, professor?

Professor MARTINEZ-CONDE: As committed neuroscientists, we realized that we had a very good and previously untapped resource which was the magicians. We find that a number of the principles that we take advantage of in the laboratory and visual illusions that we use to understand what the brain is doing, in many occasions these have not been discovered by scientists but have been discovered by artists such as painters, for instance. Magicians are these artists of awareness and cognition. These are expert manipulators of attentional levels.

SIMON: So how, for example, do they pull off a coin trick?

Professor MARTINEZ-CONDE: To make a coin disappear, or a coin appear, or a coin to change positions, you may have a number of techniques that magicians use. They may pretend to change the position of the coin, but the coin has always been in their hand, or they may use a duplicate. What's interesting from a scientific point of view is how it is that we miss the maneuver.

SIMON: How do we miss it?

Professor MARTINEZ-CONDE: Basically, we don't pay attention to it. Magicians not only manipulate attention in space - that is they don't only manipulate where you pay attention to within the visual scene - but also they manipulate at what point in time you pay attention to. So very often when we're witnessing a magic trick, what we think is the most important part of the action is not so, and the magic trick itself has already happened, or perhaps it hasn't even started. So...

SIMON: So we're watching the - we're watching exactly the wrong place because they distract our attention to it, if you please.

Professor MARTINEZ-CONDE: Exactly. The wrong place and the wrong time. Say that a magician gives you a coin and asks you to place it yourself in your pocket. You're absolutely sure that you have put it in your pocket. Now the magician says, OK, now I'm going to take it out of your pocket without you noticing, and they may produce a coin. Now you think this is the coin out of your pocket, but it's not. It's a duplicate. Now the coin is still in your pocket at that time. But while you're distracted watching the coin that the magician had just produced, it may be that now after the trick appears to be over, he steals the coin from your pocket.

SIMON: The weasel! Are magic shows less fun for you now because you know what to look for?

Professor MARTINEZ-CONDE: Well, first off, I don't know what to look for. These techniques are so powerful and so sophisticated that it's very difficult even if you have some idea of what the general brain principles are maybe involved. It's very hard to catch the trick. And the fact is that this is what makes magic such a powerful form of entertainment. Part of the fun is trying to figure out all the time how the tricks are being done, and after the show, to think about it and try to reconstruct how the trick happened. And most often, you are going to fail at that.

SIMON: Now you see it, now you don't.

Professor MARTINEZ-CONDE: That's right.

SIMON: Susan Martinez-Conde is director of the Laboratory of Visual Neuroscience at the Barrow Neurological Institute, joining us from Phoenix. Thanks, professor.

Professor MARTINEZ-CONDE: Thank you.

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