Sleights Of Mind Part 4

But what makes the dinner roll trick really interesting is a twist performed by the magician Jay Marshall. He put an extra delay between the sound of the roll hitting the floor and its bounce back up. It's as if the roll dropped down below the floor before it hit and bounced back up. This maneuver heightens the illusion, and n.o.body notices the discrepancy.

END OF SPOILER ALERT.

In movies, technicians called Foley artists artificially exaggerate everyday sounds to make them more realistic. For example, they might recreate the sound of walking in the mud by rhythmically squeezing a wet newspaper in time with the screen actor's footsteps. A recent study showed that listeners deem such modified sounds more realistic than recordings of the actual event more than 70 percent of the time. Susana witnessed this when she joined a gym to practice tae kwon do (a Korean martial art) at the age of fifteen. On her first day she was surprised to find out that unlike punches in action movies a real-life punch doesn't make much noise.

Another multisensory trick popular with dinner table magicians involves a disappearing saltshaker. Again seated across the table from you, the magician puts a quarter on the table and says, "Would you like to see me make this coin go through the table?" Of course you would. The magician explains that he'll need a bit of help moving the coin. He takes the saltshaker, wraps it snugly in a dinner napkin, and taps the coin. Tap tap. He moves the napkin-clad shaker back toward his body. Nothing happens. The coin is still there. He repeats the tap tap and movement of the shaker. The coin has not moved. He does this a third time, saying, "Oh, my, this is difficult," and leaves the shaker on top of the coin. Then he takes his hand and wham, he slams the saltshaker right through the table. At least that is what it looks like. The saltshaker is gone. The napkin is flat and the quarter is still on the table.

SPOILER ALERT! THE FOLLOWING SECTION DESCRIBES MAGIC SECRETS AND THEIR BRAIN MECHANISMS!.

This trick, too, is simple. The second time the magician pulls the saltshaker back toward his body, he deftly takes it to the edge of the table and drops it into his lap. Because the napkin retains the shape of the shaker, you a.s.sume it is still in his hand, within the napkin shroud. Meanwhile, the magician uses his free hand to move the actual saltshaker under the tabletop to the position directly below the coin. He makes a third tap tap tap motion with the napkin, but this time the sound actually comes from below. When the magician slams the empty shaker-shaped napkin flat, your sense of vision and hearing together create the perception that the saltshaker has pa.s.sed through the table. It's a profoundly convincing combination.

END OF SPOILER ALERT.

These two tricks reveal a fundamental property of your brain: your propensity to integrate information from multiple senses as you interact with the world. When you simultaneously see a bright light and hear a loud sound, your brain figures they are related. Recall that illusions occur when the physical reality does not match the perception. If you see cymbals banged together and hear the resultant crash, it's not an illusion. But if you're in Boston for the Fourth of July celebration and you see the Boston Pops cymbals banged and hear only the howitzers firing during Sousa's crescendo, it's an illusion.

The fact that your brain combines sights and sounds into single perceptions seems patently obvious, but for neuroscientists the phenomenon is surprisingly complicated. From Aristotle on, researchers have tended to study senses-sight, hearing, touch, smell, taste, balance, self-motion, and feelings from the body-in isolation. Magicians, on the other hand, have learned to manipulate perception by understanding when and where the senses don't mix accurately.

Are senses really separate? When you encounter the world, your experience is not disjointed. When you perceive a barking dog, you don't feel you are seeing it with one channel of your brain and hearing it with another. In general, when combinations of sounds, smells, tastes, lights, and touches occur simultaneously, you perceive a coherent multisensory world.

Senses not only interact, they enhance one another. For example, what a food sounds like can determine how it tastes. Potato chips are yummier if they make more noise when you bite into them. Bacon and egg ice cream (sorry, the experimenters are British) tastes more bacony if you hear the sound of bacon sizzling in a pan, more eggy if you hear chickens clucking in a farmyard. Oysters taste better when you listen to seagulls and cras.h.i.+ng ocean waves.

The same goes for skin and sound. When you say a word that begins with the letter p, t, or k, you produce a puff of air that is sensed by mechanoreceptors in human skin. The puff of air helps you and others perceive the sounds correctly. This rather amazing fact was revealed in a recent series of experiments. If you were a partic.i.p.ant, you would sit in a chair while researchers delivered tiny puffs of air to your ankle and played the sounds pa and ta. You would hear pa and ta. But when they played pa and ta without the puff of air, you would more likely hear ba and da.25 Your eyes can fool your ears. Check out the McGurk effect.26 In this auditory-visual illusion you will see a film clip of a man saying "da da da." But if you close your eyes, you will hear him saying "ba ba ba." Then if you mute the sound and just watch his lips, you will clearly see that he is saying "ga ga ga." The effect is amazing. It happens because your brain does its best to reconcile mismatching information whenever it can. Sometimes your brain's best is not good enough to be accurate. But then again, it is very unlikely that you will ever see "ga ga ga" and simultaneously hear "ba ba ba" in nature. The reason these effects work is that your brain takes shortcuts to make likely interpretations of perceptions occur faster. Thus, although the resultant perception may not be accurate (it's an illusion because the perception does not match the physical reality), the illusion is accurate enough and has helped humans to survive by saving brain processing time and effort as, for instance, your ancestors listened for leopards prowling in the nearby bushes.

Your ears can also fool your eyes. If you look at a single flash of light while hearing multiple beeps, you may see multiple flashes. In the same vein, what you hear influences what you feel. In the parchment skin illusion, you rub your palms together while listening to different sounds. Higher frequencies will make you feel as if your hands are rough. Lower frequencies give you the impression of your hands being smooth, although nothing about them has changed.

How you feel the world can actually change how you see it and vice versa. Remember the waterfall illusion from chapter 1? If you stare at the downward motion of a waterfall for some period of time, adjacent stationary objects such as rocks appear to drift upward. But if you feel an up or down sweep on your fingertip as you watch the waterfall, the perceived direction of water flow switches. Touch alters vision.

And then there is the rubber hand illusion, which you can try at home. First you need to buy one of those creepy rubber hands from a Halloween store. Let's a.s.sume it's a right hand. Sit at a table and place the hand on the table where you can see it while putting your own right hand in your lap, out of sight. Ask a friend to take two soft paintbrushes and simultaneously stroke your real hand and the rubber hand with the same rhythm. If you are like many people, you will soon feel that the dummy hand is your own. If your friend smashes the rubber hand with a hammer, you may scream Ouch!27 With the proper equipment, including a virtual reality headset, you can even induce an entire out-of-body experience based on this illusion.28 A surprising number of people experience unusual multisensory perceptions because of the way their brains are wired. One sensation, such as music, triggers another type of sensation, such as taste. Senses are cross-activated. For example, some people perceive letters or numbers as having color. For one person A is always red, B is always turquoise. For another person, 7 is always yellow, 4 is always orange. Days of the week can possess personalities: Tuesday is sad, Wednesday is happy. These a.s.sociations are idiosyncratic and automatic, lasting a lifetime. The phenomenon is called synesthesia.

Neuroscientists have identified at least fifty-four varieties of synesthesia, including some that are quite common. People with auditory synesthesia hear sounds such as tapping, beeping, or whirring when they see things move or flash. This trait was discovered accidentally when a student partic.i.p.ating in a study of visual motion reported hearing sounds when observing a scene similar to the opening of Star Wars, when the stars fly out at you, but in this case there was no sound track. Researchers soon identified many other students with the same cross-sensory perceptions. It seems that some people have an enhanced sound track to life, which makes sense when you consider that in the natural world many moving things (say, a bee) make sounds when they move (buzz).

In time-s.p.a.ce synesthesia, a visual experience can be triggered by thinking about time. Like Kurt Vonnegut's Tralfamadorians in Slaughterhouse-Five, some people can literally see time. For example, some say they view a year's time like a circular track with them standing in the middle. They can see the days and months unfolding all at once.

In mirror touch synesthesia, which is rare, people experience sensations of touch on their own bodies when they see other people being touched. They sense a slap on their shoulder when they see another person get slapped on the shoulder. Same goes for a kiss.

Synesthesia runs in families, suggesting a genetic origin to the condition. It is common for family members to experience different types of synesthesia and for the trait to skip generations. Research shows that synesthesia is caused by increased cross talk between various brain regions as well as extra connective pathways linking them.

As for the rest of us, synesthesia offers insights into our everyday perceptions. All of us have our sensory wires crossed to some extent, if only to process multisensory inputs. Look at the two shapes on the following page. Which one would you call bouba and which kiki? If you are like the vast majority of people tested from a wide variety of language groups, you will identify the rounded shape as bouba, maybe because your mouth makes a more rounded shape to produce the sound. When you articulate kiki, your mouth is more angular with the harder sound of k. Such synesthesia-like mappings may be the neurological basis of how sounds are mapped to objects and actions in the world.

The bouba kiki effect was first described in 1929 by Wolfgang Kohler. The vast majority of people identify kiki with the angular figure and bouba with the rounded one.

Magicians intuitively know that your senses interact. They know they can fool you by the sound of the dinner roll hitting the floor and the sight of it bouncing back up into the air. When the magician pretends to throw the bun on the floor, you hear a thunk and perceive the act as having happened. Your brain integrates the sight and sound of the bun into a single perception: it landed and bounced. It is a multisensory illusion. By adding a delay, magicians discovered how to make the roll into what scientists call a superstimulus. They are live-action Foley artists. Similarly, when you see the saltshaker-shaped napkin tap the table and hear the sound of tapping, your brain integrates the sight and sound, leading to an auditory-visual illusion.

A superstimulus is a supersalient object or event that evokes a stronger neural and behavioral response than the normal stimulus for which the response evolved in the first place. It's supersized fries when you're hungry. It's an ice-cold pint of beer when you're thirsty. It's the extreme curviness and abnormally large b.r.e.a.s.t.s of the prehistoric Venus of Willendorf. It's mascara and lip gloss on a s.e.xy female face (remember from chapter 3 that increasing the contrast of eyes and lips produces the illusion of making a face look more feminine). Super-stimuli invite attentional focus. Jay Marshall realized that the timing of the roll hitting the floor was the key to the illusion. By increasing the delay enough to engage interest, but not enough to generate an in congruity, he made the bounce of the dinner roll seem more magical.

Multisensory integration is an ongoing and dynamic property of your brain that occurs outside conscious awareness. So, where in your brain does the cacophony of sensory information come together? Your senses are separate, in that your eyes, ears, nose, skin, and tongue are located on different parts of your body. But your experience is coherent, integrated, and usually unambiguous.

The Venus of Willendorf is a female superstimulus from more than twenty thousand years ago.

Part of the answer is that you possess multisensory neurons. Just as you have neurons that specialize exclusively in vision, hearing, or touch, you have neurons that fire in response to simultaneously occurring sights and sounds, touches and sounds, touches and sight, and so on for all aspects of sensory processing (including balance and pain and the location of your body in s.p.a.ce).

Multisensory neurons are found throughout your cortex, even in areas thought to specialize in a single sense. For example, several brain regions traditionally thought to be visual areas have multisensory neurons that fire in response to sounds and/or touch. And a midbrain region called the superior colliculus is densely packed with multisensory neurons that map out your brain's responses to all of these senses. Superior colliculus neurons extract clues from multiple sources, including multisensory neurons in your higher cortex, and help you orient your head and body to what's important in the world at any given moment.

Have you ever driven a cat crazy with a laser pointer? The cat will chase the little red spot up a wall, under a rug, behind a couch, or wherever you point the thing. It's great fun for feline and human alike. Researchers recently borrowed this game to run a multisensory experiment. Cats were trained to look straight ahead and then approach a very low intensity light, which was a very demanding task. But when the scientists added a brief, low-intensity burst of noise from the same location as the light, the cats performed brilliantly. When the researchers added a soft sound from another location, the cats failed miserably.

Now imagine a cat hunting mice in the dark. The rodents make soft skritching noises while the cat's sensory whiskers sweep the environment. For a cat, whiskers are better than eyes. By combining sound with whisker motion, the cat triumphs. The lesson for mice: keep silent.

But a deeper question remains. While multisensory neurons can combine inputs from your different senses, they are still widely located throughout your brain. It's not plausible that every multisensory neuron is directly wired to every other multisensory neuron. So how do they fire in concert? Objects have different features such as color, shape, sound, or smell. How does your brain figure out which features belong to the same object? How are unified conscious experiences bound in your brain? How does your brain connect the sight and sound of Marshall's bun?

Called the binding problem, the question has many proposed solutions but no definitive answer to date. People might possess a single neuron for each possible combination of features, but that is unlikely given the sheer number of combinations. One solution, called feature integration theory, posits that binding is accomplished by an act of selective attention. It occurs within your spotlight of attention when your brain's circuits combine different types of features of an object such as its color and brightness or shape and sound. The integration of two or more features speeds up the detection process and helps you to quickly adjust your attention to focus on the task you are performing. While neuroscientists have not settled on a solution to the binding problem, magicians merrily exploit the fact that attention-grabbing information from one sensory system leads to enhancement of attention in another. Thus a magician's rapid-fire patter serves to increase how intently you stare at the actions he wants you to look at. The tapping of the saltshaker under the tabletop right before it appears to sink through the table forces your brain to pay attention and visualize the false event.

Next time you log on to the Internet, go to YouTube and type in "Terry Fator." You won't be disappointed. Fator won first prize in the 2007 America's Got Talent compet.i.tion with his ventriloquism act. His puppets impersonate famous singers-Roy Orbison, Elvis Presley, Marvin Gaye, and many more-while Fator's lips never seem to move. The judges swooned. The audience screamed with delight. The Mirage Hotel in Las Vegas saw a good thing. Fator now has a five-year multimillion-dollar contract and his own theater to bring ventriloquism, an ossified art, into the twenty-first century.

Ventriloquism is the feat of s.h.i.+fting sound toward a visual target. It is a cla.s.sic multisensory illusion with deep historical roots. In many preagricultural societies, shamans used ventriloquism to speak with the spirit world. Inuits would descend into a netherland full of growly voices and appear to use a harpoon in battle. They "emerged" covered in blood (thanks to a bladder of blood stashed under their parkas) to reveal truth and wisdom. In Greece, at the Temple of Apollo at Delphi, "belly speakers"-"ventriloquism" means "speaking from the stomach"-gave voice to divine revelations and prophecy emanating from the dead. When you think about the world before the invention of recorded sound, you can appreciate the wonderment elicited by ventriloquists. Today we are accustomed to sounds coming at us from all directions, in elevators, shopping malls, restaurants, and so forth. But before Victrolas and, much later, iPods, a voice coming from above the ceiling or from beneath the floor (a favorite ventriloquist trick) could be terrifying. It was black magic.

During the Enlightenment, ventriloquism lost its reputation as black magic when magicians stepped forward to demonstrate the art of "throwing one's voice" and essentially demystified it. They described it for what it is: a multisensory illusion, one that takes an enormous amount of practice to make convincing.

Try saying "big love" without moving your lips. Or "mama papa." When you look at Fator's mouth, you'll notice that his lips scarcely move. His throat moves, but he hides it behind a goatee and a microphone. Like all ventriloquists, Fator employs a set of acoustic approximations and articulatory tricks. Sounds made with the lips-p, b, and m-are acoustically similar to sounds made by the tongue on the soft palate-k, g, and (soft) ng. He can subst.i.tute the latter for the former. By forcing air through his slightly parted mouth, Fator can make the sounds f and v without using his lips. All other sounds in English can be made with duplications inside the mouth.

In the early twentieth century, ventriloquists such as Edgar Bergen (and his dummy partner Charlie McCarthy) were enormously popular. Bergen danced with his dummies, made silly jokes, and brought vivid characters like Mortimer Snerd to life. But when another source of multisensory illusion-talking pictures-arrived, ventriloquist acts like Bergen's were doomed, displaced by the silver screen. For sheer entertainment there was no compet.i.tion.

Next time you go to a movie theater, consider the fact that films are a form of ventriloquism in that speech is not coming from the actors' lips. Sound is being piped into speakers far removed from their actions. Your brain creates the illusion of actors talking to one another, thanks to your multisensory brain. Moreover, images appear to be stable when in fact they are flickering. The steady appearance of a flickering light source-such as a fluorescent light, display screen, movie, or television set-is known as flicker fusion. It occurs when the rate of flicker is higher than a critical threshold, which for motion pictures is 24 frames per second.

Flicker fusion is thought to occur due to a process called persistence of vision. The concept was first presented to the Royal Society of London in 1824 by Peter Mark Roget (who also wrote the famous thesaurus) as the ability of your retina to retain an image of an object for between one-twentieth and one-fifth of a second after it is removed from your field of vision. Johnny Thompson exploited this fact in his red dress trick.

Max Wertheimer, the founder of the famous Gestalt school of psychology mentioned in chapter 2, and Hugo Munsterberg discovered a second principle-the phi phenomenon or stroboscopic effect, which is closely related to flicker fusion. You can perceptually bridge the temporal gap between two consecutive displays so that you perceive a series of static images in a continuous movement. Add this visual illusion to a nearby sound source and your brain does the rest: you are seamlessly transported to wondrous fictional worlds (unless of course you are watching a poorly dubbed foreign film!). The interconnection between our senses also plays a role in magic tricks involving memory, which is the subject of the next chapter. Consider this story.

As a reporter in the 1920s Soviet Union, Solomon Sherashevsky was able to remember names, dates, directions, sources, and other newshound essentials-without ever writing anything down. His editor thought Sherashevsky was being lazy in staff meetings, since he didn't take notes of his a.s.signments, and one day he asked the reporter to repeat every word of what had been said at that morning's briefing. Sherashevsky did so, flawlessly-somewhat amazed, we are told, that his talent was considered unusual. The dumbstruck editor sent Sherashevsky to the laboratory of Russian psychologist Aleksandr Romanovich Luria "to have some studies done on his memory." In the years that followed, Luria studied "the man with the vast memory," noting that his talent stemmed from a form of synesthesia. Sherashevsky saw vivid images-such as splashes of color or puffs of smoke-with every word, number, and syllable. Whenever he wanted to recall numbers, syllables, words, or events, he would conjure up the combinations of images in his mind's eye and report what he saw. In this way, he could remember almost everything he encountered. As we've seen, magicians, even if they don't have synesthesia, can capitalize on the mingling of the senses.

The Indian Rope Trick.

Memory Illusions.

The 1890s are remembered as an age of exuberant invention, when steam age engineers developed early precursors of the airplane, automobile, and cinema. Wilhelm Roentgen identified X-rays, Marie and Pierre Curie discovered radioactivity, and William James described the principles of psychology. Readers were enraptured by Sherlock Holmes, Dracula, and Rudyard Kipling's The Jungle Book. But for millions of people immersed in contemporary spiritualism-replete with seances, psychic lights, voices of the dead, and dark secrets from the Orient-the best new thing may have been a breathtaking magic act called the Indian rope trick.

On August 8, 1890, the Chicago Tribune carried the first officially recorded account of the trick. Two Yale graduates, an artist and a photographer, were traveling in India when they saw a street fakir pull a ball of gray twine from under his knee, hold the loose end in his teeth, and toss the ball toward the sky. The twine unrolled until the other end was out of sight. A small boy, "about six years old," then climbed the twine. When the lad was thirty or forty feet in the air, he vanished. Kapoof. This happened outside in daylight; no hidden wires or supporting gizmos could be concealed from view. The artist sketched the event. The photographer took snapshots. But when the photos were developed, they revealed no twine, no boy. There was only the fakir seated on the ground. The anonymous author proffered an explanation: the fakir had ma.s.s hypnotized the entire crowd, but he could not hypnotize the camera.

According to Teller, who wrote about the trick several years ago, the story's genius is that it allowed many readers to wallow in Oriental mystery while maintaining the pose of modernity. Hypnotism was to the Victorians what energy is to the New Age: a catchall explanation for crackpot beliefs. By describing a thrilling, gravity-defying miracle, then discrediting it as the result of hypnotism-something equally cryptic but with a Western, scientific ring-the Tribune allowed its readers to have their mystery and debunk it too.

Four months after the article appeared, the editor of a British weekly wrote to the Tribune asking to speak with one of the Yale graduates. He received an apologetic note from the author of the article: "I am led to believe that the little story attracted more attention than I dreamed it could, and that many accepted it as perfectly true. I am sorry that anyone should have been deluded."

In other words, it was a hoax. The trick is impossible. It does not exist nor has it ever existed. Historians of magic say it is fitting that the author of the article was John Elbert Wilke, a gifted liar who later became the first director of the United States Secret Service, famous for his skulduggery and Machiavellian scheming. He wrote the story simply to increase the newspaper's circulation. Wilke then printed a retraction, noting that the story had been "written for the purpose of presenting a theory in an entertaining form." The byline of the retraction was Fred S. Ellmore (as in sell more papers).

But Wilke's retraction came too late. The story had already gone viral. Long before the Internet made the spread of information instantaneous, news of the Indian rope trick flashed worldwide-it just took months rather than minutes. The story was picked up by newspapers throughout the United States and Europe, was translated into nearly every European language, and also reached India, where it was met with surprise. What rope trick?

For the next fifty years, many hundreds if not thousands of people gave eyewitness accounts of having seen the Indian rope trick. In 1904, a young British gentleman, deemed trustworthy by virtue of his high breeding, told the Society for Psychical Research that he had seen the trick a few years earlier. After lengthy questioning, the society dismissed his testimony as ill.u.s.trating "once more the unreliability of memory." But reports continued to pop up, with embellishments: After the boy disappears into thin air, the fakir calls for him to return. Hearing no reply, the fakir grabs a knife, climbs the rope, and also disappears. Shouts ensue. Then pieces of the boy-leg, arm, torso, head-fall to the ground. The fakir climbs down and puts the pieces of the boy into a basket; after an incantation, the boy jumps out, whole and smiling. The fakir is covered in blood.

As the legend of the rope trick grew, so did its pedigree. Historians traced it to the ancient world with antecedents in Australia, Siberia, Germany, and China. Indian scholars referenced rope-climbing metaphors from the eighth century. Marco Polo was said to have encountered the trick.

Magicians stepped up to debunk the trick, which they knew to be impossible, and offered a reward to anyone who could actually perform it. But every time they managed to discredit a sighting-such as proving that the "rope" in question was really a pole-more first-person accounts poured in. Like the Loch Ness monster, Bigfoot, or UFOs, the Indian rope trick retained credibility despite the lunacy of it all.

If you've never heard of the legend, it's likely because its popularity peaked in the years just before the Second World War. Modern magicians occasionally try to mount a version of the trick but routinely fail to deliver. It was not firmly and decisively revealed as a hoax until 2005 when Peter Lamont, a research fellow at Edinburgh University, published the full story in his book The Rise and Fall of the Indian Rope Trick. Lamont explains that the trick is a cla.s.sic example of how memory illusions take root within the human mind.

Were eyewitnesses lying? A lasting human foible, Lamont says, is that people will believe hoaxes and rumors to be true despite all evidence to the contrary, including denials by their originators, if a.s.sertions of truth are repeated often enough. In this regard, the Indian rope trick shares features with modern political "controversies," such as the claim that Iraq possessed weapons of ma.s.s destruction, that Barack Obama was not born in the United States, or that astronauts never set foot on the moon. Another persistent human foible is the exaggeration effect. According to Lamont, the longer the period between when the trick was seen and when it was reported, the more impressive the account of it. In other words, people tend to confabulate over time. Indian street magic includes acts in which children climb poles, hide in baskets, and appear to be mutilated-all potential sources of confusion in memory formation. The true secret, Lamont concludes, is the way supple human memory combines events seen with legends only heard. We reshape our memories with each retelling of them, which means that along with your willingness to be misdirected, your memory is an easy target for magicians to exploit in countless tricks of their trade.

Johnny Thompson-the Great Tomsoni of the red dress trick-is happy to demonstrate how he manipulates memory. He has the perfect audience: the hundred or so scientists at the Magic of Consciousness symposium. They are trained observers. Can he fool them?

Johnny asks the scientists if they believe in mind reading or psychic or paranormal abilities. He calls up a volunteer, whose name is Dan, and asks again, "Do you believe in mind reading?"

"No."

"Neither do I. I'm a faker, fraud, phony, and cheat." But then, says Johnny, "n.o.body's perfect." Only he is perfect-at fakery. The trick, he says, is based on psychology, behavior patterns, and "closing the doors" to all rational explanations for what we are about to see.

Johnny takes out his wallet and removes a $100 bill. He also takes out a small envelope and asks Dan to examine but not open it. The envelope, he says, contains a prediction. The money and envelope go back into the wallet, which then goes into Dan's breast pocket.29 Next, Johnny pulls out a "perfectly ordinary deck of cards," shuffles them, and asks Dan to cut the deck. From our angle, seated behind him, there is no apparent trickery going on. As far as we can tell, he doesn't put anything into his pockets or pull anything out. Then Johnny explains the challenge: there are fifty-two cards in the deck, and only one matches the card sealed in the envelope. All Dan has to do to win is pick one of the fifty-one cards that does not match. If he picks the card that matches, he loses.

After the cards are cut, Johnny asks Dan to turn them over slowly, one at a time, and stop whenever he "feels" a precognition that his chosen card will not match the one inside the envelope in his breast pocket. Dan stops at the nine of clubs. Johnny teases him. Is he sure of his choice? Doesn't he want to go one more card? Dan says no, he is happy with the nine of clubs. And lo and behold, when they open the envelope, inside is a nine of clubs. Also embossed on a plaque in the wallet, in gold letters, is this legend: YOU WILL CHOOSE THE NINE OF CLUBS. Johnny confiscates the wallet and the money.

After the applause dies down, Johnny helps "close all the doors" on this trick by going back over the apparent choices Dan made and the access he had to information about his decisions.

"Now if you were to walk away right now, you might think that that was the cleverest card trick or feat of sleight of hand that you'd ever seen," says Johnny. "But it wasn't a card trick. Were the cards shuffled?"

"Yeah," answers Dan.

"Did you cut them?" asks Johnny.

"Yes."

"Did you deal them faceup and see that every card was different?"

"Yes."

"Did you stop on the card that you wanted to stop on?"

"Pure impulse," says Dan.

"And I saw that you stopped on the only losing card," confirms Johnny. "Did I not offer you a hundred dollars? I begged, implored, even told you to go one card further. If you had changed your mind, that wallet would still be in your hands, am I right?"

"Yes," laughs Dan.

SPOILER ALERT! THE FOLLOWING SECTION DESCRIBES MAGIC SECRETS AND THEIR BRAIN MECHANISMS!.

As you might suspect, Johnny's retelling of the procedure was actually a clever rewriting of history, one designed to slyly gloss over his suspicious actions. We don't know precisely how Johnny did this trick, because he elected to keep the methods secret. But we can extrapolate from our knowledge of magic to explain how he could have done it.

First, it was Johnny who "shuffled" the cards, not Dan. It is a common sleight of hand to make it appear that a deck of cards is shuffled. So were the cards really mixed up? Probably not.

Second, Dan may have cut the cards, but Johnny made sure Dan cut roughly from the middle. Of course, he omitted this detail from his retelling.

Third, after the cards were cut, Johnny took a furtive glance at the bottom card. This told him the exact order of every card in the deck. How? Because he had stacked it. A stacked deck is one in which the magician has carefully placed every card in a predetermined order and then memorized the order. When the deck is cut, the position of only two cards has changed; the rest of the order is preserved.

Fourth, Dan counted out the cards one at a time, starting at the top of the deck, and stopped on whichever card he wanted, right? Not really. Dan was standing in front of a crowd of hundreds of his peers. The possibility that he was going to count out fifty-one cards in the most tedious fas.h.i.+on imaginable was highly unlikely. Instead, Dan counted out seven cards before selecting one-which happened to be the nine of clubs. You can be sure that Johnny knew Dan would not choose the first card, nor would he count out very many cards before selecting. To count out more than about ten would be nerve-racking. Remember, Johnny knew the exact order of the cards in the deck, including the top ten. This means he knew pretty nearly which card was going to be selected, plus or minus five or so cards. Also note that even if Dan had behaved radically and counted out dozens of cards, Johnny could have simply recut the deck, or performed one of many other possible procedures, to force Dan to make the necessary selection in a different way. Since the audience doesn't know the trick, they have no way of knowing if additional procedures are strange or unnecessary. So Johnny was holding all the cards in more ways than one. He could ensure that the card Dan chose was one that Johnny had in his pocket.

Finally, Johnny did not retrieve the wallet containing the matching card and embossed plaque until after Dan had made his final selection and presented it publicly. This too was left out of the retelling of the trick.

The fact is that Johnny could have known ahead of time, before he even drove his Cadillac to the event, the narrow range of ten or so cards that were likely to be chosen. He could also force Dan to choose one of the ten cards in a seemingly magical way. If Johnny had ten wallets stored in his suit, all with different cards and embossed messages matching Dan's ten most likely selections, organized so that Johnny could grab the correct wallet in a natural fas.h.i.+on after Dan had made his choice, it would appear as though Johnny had precognition. And in a way he did. He knew exactly how Dan would behave, because Johnny is a master of human observation. Then, by recounting the entire trick slightly inaccurately, leaving out the suspicious bits and distorting certain details, he created false memories for the audience. The creation of such false memories is known in cognitive sciences as the misinformation effect-that is, the tendency for misleading information presented after the event to reduce one's memory accuracy for the original event. In Johnny's case, a confidently delivered, coherent-sounding story is much easier to remember than a quick series of subtle movements and visual impressions. In this way, Johnny effectively removed the possibility that the audience, or even Dan himself, could reconstruct the trick and work it out after the fact.

END OF SPOILER ALERT.

Johnny tells us, "When people see a wonderful piece of magic, they try to figure out how it's done. They have avenues of thought and logic. The magician, just before the denouement or finish, must close all those doors. The only solution is magic."

In 2007, then presidential candidate Hillary Clinton made headlines when she recounted an episode of flying into a United States military base in Bosnia in 1996. "I remember landing under sniper fire," she said. "There was supposed to be some kind of greeting ceremony at the airport, but instead we just ran with our heads down to get into the vehicles to get to our base." Then CBS news aired a video clip from the trip. There was no sniper fire. There was no greeting ceremony. The first lady and daughter Chelsea were seen strolling along, shaking hands, chatting and smiling. Many people had a good laugh at her expense, but Clinton was not lying. Her memory of this particular Bosnia trip had been revised, transformed, and reconsolidated with other memories about Bosnia within the normal circuits of her brain.

Magicians know that memory is fallible and that the more time has elapsed, the worse it is. They count on the fact that your poor memory will not allow you to accurately reconstruct what took place onstage after the fact. Know this about yourself, and keep records of important information and conversations immediately after they happen.

False memories can be devastating. Elizabeth Loftus, a psychologist at the University of California, Irvine, and an authority on the malleability of memory, is famous for having shown in the 1990s that some psychiatrists and other mental health professionals implanted so-called repressed (and later recovered) memories in the minds of their patients. For example, one woman, under hypnosis, became convinced that she had memories of being in a satanic cult, of eating babies, of being raped, of having s.e.x with animals, and of being forced to watch the murder of her eight-year-old friend. After later talking with other therapists and realizing that her doctor had manipulated her memory, she sued the psychiatrist for malpractice and won a large monetary settlement.

But for most of us, false memories are prosaic and for the most part harmless. You remember voting in elections you didn't vote in. You remember giving more to charity than you really did. You remember that your children walked and talked earlier than they did. You recall shaking hands with Bugs Bunny (a Warner Bros. character) at Disneyland.

Loftus's studies also explore the misinformation effect. In one example, partic.i.p.ants viewed a simulated automobile accident at an intersection with a stop sign. After the viewing, half the people were given the suggestion that the traffic sign was a yield sign. When asked later what kind of traffic sign they remembered seeing at the intersection, those who had been given the suggestion tended to claim that they had seen a yield sign. Those who had not received the phony information were much more accurate in their recollection of the traffic sign.

In another cla.s.sic experiment, Elizabeth Loftus and her colleague John Palmer asked observers to estimate the speed of a car hitting another, after watching a video recording of a car accident. Observers who were asked how fast the car was going when it hit the other car gave lower speed estimates than observers that were asked how fast the car was going when it smashed into the other car. Magicians' word choices in recounting the spectators' experiences have a similarly profound impact on their memories of the original events.

Misinformation can change your recollections in predictable and sometimes very powerful ways. You construct a false memory by combining an actual memory with the content of suggestions received from others. During this process, you forget the source of the information. This is a cla.s.sic example of source confusion-something magicians find quite useful.

Types of Memory.

Your memory feels like a single resource, but this is an illusion. It is composed of subsystems that work in concert to give you the sense of being whole and in command of your past life.

Procedural memory, sometimes known as muscle memory, is for physical skills: skiing, riding a bicycle, shuffling a deck of cards.

Declarative memory deals in facts, and is further divided into semantic memory and episodic memory.

Semantic memory encodes meanings, definitions, and concepts-facts that you know that aren't rooted in time or place: "A horse has four legs," "The capital of England is London."

Episodic or autobiographical memory encodes experiences from your unique personal past. This is what allows you to know and recall what has happened to you in your life. The time you discovered someone stole your laptop. The trip to the hospital when your son had an allergic reaction to nuts. Your first magic show.

At a deeper, biological level, all your memories are fallible. The act of remembering an event from your past is not like playing back a mental videotape in your mind's home theater system. It is more like retelling a s.h.a.ggy dog story that you once heard. You recall a few key phrases and junctures along with the story's overall gist, but you don't recall the exact order of words in the story. When you repeat the "same" story to another person, you reconstruct it in your own way. You freely embellish and fill in missing gaps to make the story flow smoothly. While you might repeat verbatim a few key bits of the original telling, most of the word choices are yours.

Similarly, when your brain lays down a new memory, what it actually encodes is a spa.r.s.e constellation of personal details and meaningful junctures. When your brain later retrieves the memory, it uses that constellation as a scaffold for reconstructing the original experience. As the memory plays out in your mind, you may have the strong impression that it's a high-fidelity record, but only a few of its contents are truly accurate. The rest of it is a bunch of props, backdrops, casting extras, and stock footage your mind furnishes on the fly in an unconscious process known as confabulation.