Sleights Of Mind Part 5

And it gets stranger. Sometimes a feature that was confabulated during one act of remembering gets reremembered during the next act. In the process, the confabulation can become a permanent feature of the memory. It becomes indistinguishable from the original.

Your memory isn't a partial sketch of the past, it's a sketch of a sketch of a sketch of a sketch of a sketch of a sketch...and with every new rendition, more errors can be introduced. Our colleague Joseph LeDoux, a neuroscientist at New York University who studies memory and emotions, says that he used to think a memory was something stored in the brain and accessed when needed. But a researcher in his lab, Karim Nader, convinced him otherwise. Nader demonstrated that each time a memory is used, it has to be re-stored as a new memory in order to be accessed later. The old memory is either gone or inaccessible. Thus your memory about something is only as good as your last memory about it. This is why people who witness crimes testify about what they read in the paper rather than what they witnessed.

Being an expert on the pliability of memory has not prevented Karim Nader from experiencing a memory source confusion shared by millions of other people. Nader, now a laboratory director at McGill University in Montreal, recalls seeing, on September 11, 2001, television footage of the first plane crashing into the north tower of the World Trade Center. But the footage of the first collision aired for the first time the day after the attacks. A 2003 study found that a staggering 73 percent of college students tested similarly misremembered the event. "Flashbulb memories"-that is, our seemingly vivid high-definition snapshot memories of traumatic or defining biographical events-are recalled over and over again. Nader's research indicates that the very act of recalling such flashbulb memories can fundamentally alter them.

Memory and the Media.

On February 23, 1981, two hundred armed officers of the Guardia Civil led by Lieutenant Colonel Antonio Tejero burst into the Spanish Congress of Deputies during the process of electing the new prime minister and held the democratically elected government at gunpoint for eighteen hours. The attempted coup d'etat ended on the following day, but ask any Spaniard older than thirty-five what he or she was doing at the time of the events and they will be able to tell you right to the smallest detail. The nerve-racking evening and the long night that followed are permanently engraved in their memories.

Or are they? As it turns out, many people remember having seen the start of the coup live on TV, as it happened. Not true. Although the coup was broadcast live on the radio, the videotaped images were not shown on TV until the next day, long after the coup attempt had collapsed and the hostages were freed.

Spanish writer Javier Cercas writes about this specific memory source confusion in his book Anatomy of a Moment: "We all resist the extirpation of our memories, which are the holders of ident.i.ty, and some prefer what they remember to what happened, so they keep on remembering that they saw the coup live."

Memory source confusion occurs because people are poor at determining the source of information. Remember when the shuttle Challenger exploded, killing all astronauts on board, including teacher Christa McAuliffe? Where did you first see the image of those two booster rocket nacelles, flying in lazy figure eights? You remember the image. Who could forget? But did you see it first in the New York Times? The Wall Street Journal? On the Today show? CNN? Was it on TV or did you see it first in the paper? Perhaps it was described to you on the radio? It's difficult to remember, because we don't concern ourselves as much with the source of our information as with the content.

This is why advertising is so effective when it tells us that the product being sold is the best available. Obviously, the source is biased (the company who produces the product paid for the ad). But if we hear it enough, over and over, we eventually begin to believe it. This is one of the reasons that political campaign funding reform is such a hot item: biased advertis.e.m.e.nts play a huge role in forming our opinions, whether we like it or not, so well-funded candidates have a huge advantage.

At our invitation, Magic Tony is giving a lecture on magic and psychology to some of our fellow researchers at the Barrow Neurological Inst.i.tute in Phoenix. He has decided that today he will mess with their memories. He will demonstrate how to create a memory illusion by implanting source confusion in an audience.

Tony calls two people, Hector and Esther, to join him in front of the group. He explains that before the lecture started he solicited their help with a trick. He asked Hector to think of a card and to keep thinking of that card throughout the lecture-to simply hold the card in his mind. And he gave Esther a deck of cards and asked her to remove a card and put it in her pocket, without looking at it. So now Hector is thinking of a card, and Esther holds a card but does not know what it is.

The moment of truth. "Hector, what was your card?"

"The jack of spades."

"Esther, look in your pocket. What is the card?"

She pulls out a card: the jack of spades.

Applause. Hector and Esther have astonished looks on their faces. How did Tony do that?

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

"One of the lovely things about being a magician," he says, "is that you realize words have strong consequences. And this trick is the perfect example of how a magician can use language to create an effect that was not really there in the first place."

Tony asks the audience to think about semantics, ambiguity, and how a sentence can have two different meanings based on context. Consider these two sentences: I asked him to think of a card. I showed him a card and asked him to keep thinking of it. They describe the same outcome, except the first sentence implies more freedom, says Tony.

When Tony brought Hector to the front of the group, he used the first sentence to describe what happened. He implanted that lie in everyone's memory. For Hector, who was there for the original event, the misinformation induced a source confusion. He would later remember that he himself chose the card freely. But, in fact, Tony had a different, earlier interaction with Hector. He had fanned a deck of cards and told Hector to stop when he felt the urge to choose one. Once Hector chose a card, Tony told him to keep thinking of it during the lecture. But, as you may suspect, Hector did not freely choose the card. Tony forced the jack of spades. We'll get to forcing techniques in the next chapter. For now, keep in mind that Hector was set up.

Next up, Esther. Consider two sentences: I handed her a deck of cards and asked her to remove one and put it in her right pocket, and to put the rest of the deck in her left pocket. Or, I asked her to pick a card and put it in her pocket. Again, the first sentence implies a lot more freedom-she has control of the cards-but, says Tony, that is not what happened. He fanned the cards and asked her to select one but, again, her choice was not free. Once again, he forced the jack of spades on her. She was set up, too.

"This is a lame trick," confesses Tony, "but by just using language, it is amplified into a miracle. Hector and Esther each have a false memory simply because of the words I used. By a.s.similating their memories to match my words, they helped lead the audience straight into a memory illusion and the experience of magic."

END OF SPOILER ALERT.

Crimes of Memory.

In 1975 an Australian eyewitness expert, Donald Thompson, appeared on a live TV discussion about the unreliability of eyewitness memory. He was later arrested, placed in a lineup, and identified by a victim as the man who had raped her. The police charged Thompson even though the rape had occurred during the time he was on TV. They dismissed his alibi that he was in plain view of a large audience and in the company of other guests on the show, including an a.s.sistant commissioner of police. The policeman taking his statement sneered, "Yes, I suppose you've got Jesus Christ, and the Queen of England, too." Eventually, the investigators discovered that the rapist had attacked the woman as she was watching TV-the very program on which Thompson had appeared. The woman had confused the rapist's face with the face she had seen on TV. Thompson was cleared.

In another ill.u.s.trious case, the earliest childhood memory of Jean Piaget, the famous child psychologist, was of nearly being kidnapped when he was two years old. He remembered details-being strapped into his pram, watching his nurse defend herself against the kidnapper, scratches on the nurse's face, and a police officer with a short cloak and white baton chasing the kidnapper away. But it never happened. Thirteen years after the alleged kidnapping attempt, Piaget's former nurse confessed that she had made the whole thing up. Piaget eventually realized that his strong visual memories of the episode were fabricated, based on having heard the story told many times by his family.

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

Magicians plant false memories in many tricks. One notable example is the twisting arm illusion. The magician places his palm on a flat surface and begins twisting it in an impossible 360-degree arc. Then he gives it a second spin. The trick is based on the fact that the magician has twisted his entire arm under his long coat sleeve, which no one can see.30 After the first revolution, the magician asks the spectator to do the same. During this effort, he resets his arm for one more revolution. The audience never remembers the magician removing his arm from the table because they are so wrapped up in the illusion. They remember that his palm spun around twice without lifting from the table, a case of misdirection plus false memory.

END OF SPOILER ALERT.

Memory illusions stem from your need to make sense of the world. If you see a bunch of oranges on the floor and then a picture of a probable cause such as someone reaching for an orange on the bottom of a big pyramid of oranges, you are likely to remember seeing the person grabbing the bottom orange even when you did not. You imagine the event and fill in the details as needed. You can remember events differently from the way they occurred or even remember events that never took place at all.

The crew for the Discovery Channel science show Daily Planet on Canadian television had wrapped its visit to our labs, and now the two of us were taking Apollo Robbins to the Phoenix Sky Harbor Airport for his flight back to Vegas. Apollo had come down to our inst.i.tute for the doc.u.mentary shoot so we could scan his brain using functional magnetic resonance imaging and also measure the eye movements of people in the audience as he pickpocketed watches and other personal belongings, all for the cameras.31 We arrived early for his flight and retired to enjoy some of the best pot stickers in town, at Flo's Shanghai in the shopping concourse of terminal 4 of PHX, and to discuss how magicians not only manipulate the memory of spectators but also use mnemonics to enhance their own memory skills to create magical effects.

Apollo explained that by mentally a.s.sociating mundane numbers and objects (or people, places, things, activities, concepts, and so forth) with imagined wild caricatures of those things, he could retain the memory of a large number of those a.s.sociations for an incredibly long time. So long that it didn't seem like memory at all, it seemed magical. He demonstrated by asking Susana to write a list of fifteen items, in random order and hidden from his view, and to call them out as she proceeded. "Number 6: wolf; number 11: market; number 2: roulette..." She wrote her list in black pen on one of Flo's white-hibiscus-embossed paper napkins, slightly used, with a Steve's-lower-lip-shaped soy sauce stain on its backside. Here's her complete list.

tennis ball.

roulette.

bus.

cookie attic wolf lamp giant fan fingers market hot dog escalator.

column.

mirror.

Apollo listened but did not appear to be concentrating particularly carefully. At the end of the list, Apollo said, "Okay, now I'll say them back to you in order. Please check them against your list." Susana ensured that Apollo could not see her written list as he proceeded to read them off from his own mental list as promised: "Number one: tennis ball; number two: roulette..." He got them all perfectly. He then recited the list backward. Next he asked Susana to cross out seven of the items from the list in random order and to state, out loud, just the number of each entry as it was crossed out. The list remained hidden from Apollo's view as Susana crossed out her selections. Apollo then reported the remaining undeleted items, in numerical order.

Apollo's performance was a straightforward and extremely impressive display of mnemonic power. We reeled under its implications. "How did you do that?" Apollo explained that it was an easy trick that served to boost human memory capacity immensely. "All I did was to a.s.sociate each number-object pair with an imagined caricature of each object. But the real trick is that I have a list of standard objects that I use to represent each number. It's based on similar-sounding objects, or number h.o.m.onyms. For example, the number one sounds like 'wand,' so when I make the a.s.sociation between the object and the number, I'm really a.s.sociating a wand with the chosen object. In this case I burned the image of a tennis ball holding a wand into my memory. Then when the time comes to recite the list, I take each number in turn (backward or forward), recall the a.s.sociated number-h.o.m.onym that I always use for that number, and then use that to jog my memory as to the a.s.sociated object from Susana's list. To delete an item from the list, I imagine each object-number pair being destroyed graphically as Susana crosses it from her list. In the case of the wand-wielding tennis ball, I imagined the pair on fire and then the tennis ball exploding from the internal pressure. I did this for each of the deletions, and then when I went through the entire list in my normal fashion, it was easy to see which numbers had been deleted because I had destroyed them in various ways in my imagination."

As we drove home from the airport, we couldn't believe that we hadn't been trained to do this as neuroscientists. Why weren't we using this technique to give seamless scientific talks, or at least to remember the names of people we met at parties? Why weren't children taught this technique to learn their multiplication tables or other lists of facts? If neurologists could harness these techniques, maybe they could teach Alzheimer's patients to remember better the order in which to don their clothing each morning, maybe enable them to live in their own homes for one more year. It could be a great advance in the treatment of patients with cognitive decline.

We later learned that Apollo used what is called a peg system, a form of linking any number of items to a particular digit. Numbers or digits are represented by a word-wand for one, hive for five, hen for ten, and so forth. Then you a.s.sociate your number word to a vivid visual image. The linking elements are more easily remembered if they interact, are unusual, and tap into your emotions, making you laugh, feel disgust, or perhaps sense danger. Your imagination is what drives the power of the a.s.sociations. You can also link items without using numbers by a.s.sociating each word to the next one on your list. For Susana's list, you could think of a giant polka dot tennis ball ricocheting off a roulette wheel and the roulette wheel serving as the steering wheel on the bus, and so on.

These memory systems work because your brain's short-term memory, without some form of a.s.sistance, is capable of remembering only seven units (plus or minus two) of anything at a time. After seven items, you begin to forget so as to make room for new items. Or you "chunk" items, as when you remember the seven digits of a phone number (prefix plus four) and an area code. A line of poetry that contains more than around seven beats needs to be broken into two lines.

Another mnenomic strategy called the method of loci (the plural of locus, which means location, or place), also known as the memory palace, has been around for centuries. It's based on the a.s.sumption that you can best remember places that you are familiar with, so if you can link something you need to remember with a place that you know very well, the location will serve as a clue that will help you to remember.

According to Cicero, the Roman philosopher, the method was developed around 500 BC by Simonides of Ceos, a Greek poet who was the only survivor of a banquet hall collapse in Thessaly (he had stepped outside). He was able to identify the dead, who were crushed beyond recognition, by remembering their faces based on that day's seating arrangement. Simonides soon realized that he could remember any number of items by setting up walking routes in his mind's eye and visualizing items at various spots along the way. When it came time to remember, he simply retraced the familiar route and easily recalled each item. Unlike linking, loci involves placing a strong visual representation of each item in a geo graphical s.p.a.ce. The nice thing about the method is that, if you forget an item, you can keep "walking in your mind's eye" through the s.p.a.ce and pick up the next thing to be remembered.

The method was taken to China in 1583 by an Italian Jesuit priest, Matteo Ricci, who hoped to spread Catholicism but first had to demonstrate the "superiority" of Western culture. Ricci did so by teaching the method of loci to young Confucian scholars who had to learn countless laws and rituals by heart.32 You can try this yourself. Make a list of items you want to memorize, perhaps a shopping list-ice cream, bread, cat food, mayo, chicken b.r.e.a.s.t.s, and so on. Now imagine walking through your house or apartment. Start at the front door and make your way through several rooms. (If you live in a one-room apartment, divide the s.p.a.ce into distinct areas.) In your imagination, place each item on your shopping list at a single location along your route. Your front door is smeared with Cherry Garcia ice cream. Your living room couch is now a loaf of French bread. The door to your kitchen is shaped like a cat. Your dining room table has dissolved into a ma.s.s of mayo. Your bathroom floor is tiled with chicken b.r.e.a.s.t.s.

When you want to remember your shopping list, all you have to do is visualize your front door. You will instantly see the ice cream. As you enter the living room, the French bread will come to mind, and so on. Memory experts say you should make the images as weird and outrageous as possible.

You can also place more than one item in any location. If you have a list of forty grocery items to remember, you could place four items at each of ten locations. Each of these four items should interact at its location. As you open your front door, a gob of Cherry Garcia melts in a loaf of French bread with mayo icing and Meow Mix topping.

The Perils of Total Recall.

Most of us wish we had better memories. But is there such a thing as a memory that is too good? Few individuals (so far as we know) possess near total recall of their autobiographical memories, though no one has yet figured out why. For example, Jill Price, author of a 2008 memoir, The Woman Who Can't Forget, says that the days of her life ceaselessly replay themselves in her mind, like a movie running in her head. Give her any date in the past and she can recall what day of the week it was, what the weather was like, what happened to her that day, and the major news events on that date. But she admits that her perfect memory is more of a burden than a gift. She hates change. She cannot forgive herself (or forget) the bad choices she has made in life.

Rick Baron, who also remembers every single thing that ever happened to him, describes his days as "empty." The fifty-year-old has never married and never held a full-time job, but he does compete in occasional trivia contests.

Brad Williams, a news reporter for a family of radio stations in La Crosse, Wisconsin, can also tell you what happened on any date for most of his life. But he, too, talks about the frustrations of having a memory that never lets up.

We, like most married couples, can attest that one of the secrets to a happy long-term relationship is a short memory.

Memory contest champions and many of the world's best magicians use the method of loci. The three-time winner of the World Memory Championship, Andi Bell, can memorize ten randomly shuffled decks of cards in the time it takes him to scroll through them. That's five hundred and twenty cards. Then he can answer any question: What is the thirteenth card in the fourth deck? What is the twenty-second card in the eighth deck? and so on. He never misses a card. Bell's memory palace is a walk around London with specific landmarks. The route and the landmarks-streets, buildings, doorways, traffic lights, mailboxes, and the like-never change. They are fixed in his imagination. Each card has an icon. The jack of clubs is a bear. The nine of diamonds is a saw. The three of clubs is a pineapple, and so on for all fifty-two cards. To memorize a random deck of cards, Bell places an icon at each landmark along the route in his mind's eye. Then he can easily reconstruct the order of the cards by visualizing each icon as he walks through his memory palace.

In an article for Slate magazine, the journalist Joshua Foer describes how he entered the USA Memory Championship just to see how he could do. He says compet.i.tors insist they are not naturally gifted. They just use mnemonic techniques to help them recall three-hundred-digit binary numbers and to match hundreds of faces with names in twenty minutes.

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

Magicians and card sharps often use the loci method to stack a deck of cards. A stacked deck, as the name implies, is simply a deck with the cards set up in a predetermined order. It is never shuffled honestly, so that the magician, knowing the position of one card, can always calculate the position of every other card. To memorize a stacked deck, a magician starts with randomly shuffled cards. If you examined them, you would not see anything suspicious. Then the magician creates a personal memory palace to remember the exact order in this particular deck. From then on, he does not shuffle them. He only pretends to mix the cards using a variety of so-called false shuffles. By peeking at the bottom card of the deck as he carries out tricks, the magician can always know the exact order of all the cards by invoking his memory palace.

Stacked decks can also be cyclical and, once you see how they are put together, diabolical. One of the most famous is the Si Stebbins stacking system, originally published around 1898 by William Coffrin, alias Si Stebbins, in a booklet t.i.tled Si Stebbins' Card Tricks and the Way He Performs Them. To create a Si Stebbins stack, you first organize each playing suit in order. Take all the spades and place them ace, two, three, and so on up to king. Do the same with the diamonds, hearts, and clubs. Then lay these four mini-stacks side by side in the following order: clubs, hearts, spades, diamonds. The mnemonic for this is CHaSeD. Now for the stacking. In the stack of clubs, put the ace on top. In the stack of hearts, put the ace, two, three, and four on top. For spades, put the ace through the seven on top. For diamonds, put the ace through the ten on top. Then make a full stack by piling the little stacks of clubs, hearts, spades, and diamonds. You now have a stacked deck. You can cut the cards any number of times, and by looking at the bottom card you can always know the card on top. How? By counting. The stacking results in the fact that every card is three values higher than the preceding card.

Hot Reading.

Some corporate magicians use amazing memory feats to appear to read minds. For example, when they receive a list of people attending a seminar at a given company, they can Google the names to find a subset with photos posted online. Then they memorize the face and name of each one along with any personal information they can gather. (Before Google, such magicians could look up people in newspaper archives at the library, or even send accomplices to discover information at the company office.) The amount of data collected can be quite large. During the corporate seminar, the illusionist can then claim mentalist powers and "read the minds" of various people by providing their names, work and home addresses, office and home phone numbers, children's names, pets' names, genealogical information, etc. The goal is to provide so much detailed information that it seems impossible that the magician could know it all in advance, and that the only solution must be that he's reading the mind of the client in real time. In the world of magic, such subterfuge is called a hot reading. But the real feat is that the magician did indeed remember all that information, and was able to conjure it as if by magic during the seminar.

We saw another type of stacked deck in action at the Magic Olympics in Beijing. Juan Tamariz, the famous Spanish magician, called a volunteer from the audience and, after much joking, prompted him to "pick a card, any card." The deck looked normal, but it really contained only six cards-the three of hearts, the nine of clubs, the seven of clubs, the jack of diamonds, the two of spades, and the ace of hearts-repeated in order over and over. Tamariz fanned the cards in front of the volunteer and noted the exact position of the card that was selected. By counting down the line of cards, Tamariz was able to identify and then surrept.i.tiously lift an identical card from the stacked deck. While the magician did not know the ident.i.ty of the chosen card, he now had an exact copy of it in his possession and was able to produce it, as if by magic, at the end of the trick.

END OF SPOILER ALERT.

A little later, Tamariz demonstrated a two-part trick involving memory that stunned the a.s.sembled experts. By now you probably realize that it is extremely difficult to fool a magician. They know every sleight of hand in the book and are constantly on the lookout for misdirection, fake shuffles, clever props, and the like. One false move and they're on to you. Tamariz began his trick with an incredibly corny routine. He announced he would teach us some comedy. Pacing the stage and wringing his hands, he asked everyone in the audience to touch their two index fingers together, making a horizontal line in front of their eyes, and then stare into the distance. "You see?" he said. "You've created a magic sausage floating in front of your eyes. And if you're really hungry, you can use six fingers to make three sausages."

The magicians in the enormous lecture hall were stumped. What was Tamariz talking about? Sausages? Fingers? Just then, Tamariz jumped into the audience and corrected the finger position of a guy in the front row. "You're doing it all wrong!" he screamed. Then he praised the man in the next seat over. "That's perfect! It's so good you can slice them up and share." With that, Tamariz did a karate chop in the air, through the perfect finger sausages, and produced a string of three large kielbasa.

Um, what was that all about? The magicians squirmed with concern. Poor old Tamariz, he must be losing his touch. Of course, the s.e.xagenarian began prancing again and pulled off several gorgeous tricks flawlessly. Everyone forgot the sausage nonsense.

About forty-five minutes later, Tamariz invited a woman onto the stage and had her count out ten cards. He had her place a rubber band around them, carry them to a table across the stage, and return to his side. Next he invited a man to step up onto the stage next to the banded cards. The two volunteers were a good fifteen feet apart, and Tamariz never left the woman's side. Tamariz asked her to count out another ten cards onto a table and then hold them in her two hands. With much fanfare he proclaimed he would make some of the cards teleport across the stage. Once he was done, there should be thirteen cards in a stack on the other side of the stage. Tamariz magically waved his hands toward the woman and asked her to give him the cards so he could count them for all to see. Only nine cards remained. One was missing. He handed her the cards again and repeated the magical wave. Now he recounted, and two cards were missing. A third time...three cards were missing. "Let's see how I'm doing," he said, and asked the man to count out the cards next to him. The man did and said, softly, "Um, there are ten cards here."

Tamariz pretended to be crushed. "Ten? You only have ten? Are you sure? Could you count them again?" Yes, only ten and not thirteen. Tamariz was deep in thought. "Ummm, could you check your left pocket?" Nothing was there. "Your, umm, right pocket?" Nada. People started shifting in their seats. Everybody wanted to disappear. "Could you check your inside left breast jacket pocket?" Tamariz said. Still nothing.

Dejectedly, Tamariz said, "And your inner right jacket pocket?" The man's left hand entered his right inner jacket pocket and he looked up suddenly in surprise. He stopped cold. Hackles rose on one thousand necks. Slowly, the man removed his hand from the pocket. In it were three cards.

"Three cards!" screamed Tamariz. "Three cards! It's a miracle!"

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

Only you know it isn't. He planted the cards on this guy during the sausage trick, now a long-forgotten ruse. (The onstage volunteer was the same guy that Tamariz corrected right before pulling sausages out of the face of the man on the next seat.) And no one-neither the volunteer nor the world's best and brightest magicians-remembered that he had had that opportunity an hour earlier. Memory can play tricks on us all.

END OF SPOILER ALERT.

Expectation and a.s.sumption.

How Magicians Make a.s.ses of U and ME.

It's not easy to follow magic acts by the Great Tomsoni, Apollo, Teller, and James the Amaz!ng Randi. But Mac King, the last speaker at our 2007 Magic of Consciousness symposium in Las Vegas, is undaunted. Connoisseurs will tell you that Mac is one of the most influential magicians in the world. He is also one of the nicest and without a doubt funniest.

For his stage act-which he presents twice a day, five days a week, at Harrah's casino on the Las Vegas strip-Mac affects the persona of a country b.u.mpkin. The first words out of his mouth are "Howdy! I'm Mac King." The audience shouts back, "Howdy!" A bit of a Danny Kaye look-alike, Mac wears outrageously tasteless plaid suits that somehow accentuate his beak nose and reddish blond hair fashioned in a cla.s.sic bowl cut. He guffaws and giggles as he performs his routines. Mac is having such a great time you can't help but be drawn in.

Mac explains the source of his mirth. Each day, he calls new people up on stage to a.s.sist with a trick, and each time he finds something funny and spontaneous to say or do with them. In this way Mac never lets his act grow stale, which is undoubtedly why his show is one of the highest rated in Las Vegas.

Mac is also an inventor of new illusions. He often creates tricks for other magicians' shows and is always on the lookout for inspiration. His office is littered with props. You get a feeling for his devious sense of humor and inventiveness through a story he tells about a trick he pulled on his wife. Several years ago, Mac purchased two pencils with little hands on their ends instead of the usual erasers. The hands were about two inches long and rubbery with wires that could be used to oppose the fingers. "I thought they were funny," says Mac. One day, looking at the pencils on his desk, Mac had an inspiration. He called to his wife, who was in the bathroom. "Honey, could you please fill the sink with hot water? I want to shave." She obliged and then stepped into the shower. Mac came in after her in his bathrobe. He splashed the water, hid his hands in the sleeves of his robe, and stuck out the tiny rubber hands. Then Mac let out a bloodcurdling scream. When his wife looked out from the shower, she saw Mac standing there with the tiny shrunken hands over a hot steamy sink. "She freaked out," says Mac with a satisfied expression. This is not a trick he can take to the stage in Vegas but it ill.u.s.trates the way his mind works.

At our science conference, Mac performs one of his favorite tricks from his show at Harrah's. But first he explains a cardinal rule in magic: never perform the same trick twice, at least for the same audience. "It's really hard," explains Mac, "because if you do a trick that really fools people, they'll say after it's over, 'That was the greatest thing. Do it again! Do it again!' You think to yourself, okay, why not? What's the harm in doing the same trick over?" He gives a conspiratorial smile. "Well, I'll tell you. If you see a trick a second time, there are lots of clues."

To demonstrate, Mac picks a guy from the audience to come onstage. His name is Marvin Chun. He's a famous visual science professor from Yale, but Mac doesn't know that. And Marvin certainly isn't the one teaching the lessons today. "Marvin," says Mac, "there's a surprise! You get a prize for helping. I keep the prize in my shoe. Let's see what I have for you today, Marvin." Mac removes his right shoe and a packet of honey falls to the floor. It's not a very appealing prize, and so everyone t.i.tters. "No, really, Marvin, you get my shoe," says Mac. "These are Rockports. Really nice shoes. You know how you tell a real Rockport shoe?" Mac tips his shoe over. "They have these big rocks in them."

An impossibly giant rock falls to the floor with a loud thud. Unlike the honey packet, the rock is a huge surprise. You have no idea where it came from and how it got into his shoe. "I had it in a secret hiding place," Mac says in answer to the unspoken question.

Mistakes.

From our angle onstage, behind the performers, we don't have a good view of the rock, but we learned of its existence during Teller's talk when Mac accidentally dropped the rock from his back pocket. It made a loud thud that everyone in the room must have heard, but only those of us at the dais realized what happened. We'll never forget the mirth and chagrin on Mac's face as he retrieved his rock unceremoniously, on all fours, and looked up at us as he groped under his chair. Even though no one in the audience saw the rock, you would think the loud noise, followed by Mac's undignified crawling around the stage, would have been a clue to whatever he was up to. But the sound seemed to fall on deaf ears. As far as we could tell, no one heard it, and no one seemed to remember seeing Mac crawl under his chair.

It occurred to us that magicians, like all of us in our jobs, must make mistakes all the time. But since a magician's mistakes involve unlikely objects and actions, most spectators do not realize their significance. Magicians know this, and it gives them the courage to simply keep going even in the face of glaring logical errors. Indeed, one of the hallmarks of a good magician is the ability to recover smoothly and seamlessly from unexpected mishaps. Mac told us a hilarious example of this from early in his career. One of his signature tricks involves pulling a live goldfish out of his mouth and dropping it into a gla.s.s of water held by a volunteer from the audience. Don't worry, he says, the fish is not in there very long-only a few seconds-or it could not survive the heat and saliva in his mouth. Anyway, the first time Mac did this trick onstage with a volunteer, he started choking as "that little fish decided to swim down my throat. I tried to hack it back up. Then I turned around and threw up bits of my sandwich from lunch and the fish into the suitcase I keep on stage. The guy next to me said 'Eeeee www!' but no one else reacted. I keep an extra fish in case of a fish accident and so I recovered and finished the trick." Mac's eyes widen. "Later, no one asked me 'Did you vomit onstage?' Everyone saw it. It's so weird. I don't know what's going on in people's minds."

The lesson here is to keep moving forward after everyday mistakes. Even though magicians make mistakes all the time, they put them behind them, keep moving forward, and the audience hardly ever notices. You should do the same. Just like a magician, continue to glide along as if nothing happened, and your mistake will go unnoticed most of the time, too. Don't get mad. Don't get embarra.s.sed. Just reset yourself as best you can and go tuck a fresh goldfish from your suitcase into your mouth.

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

The rock weighs about five pounds and is the size of a papaya. To demonstrate that doing the same trick twice is a mistake, Mac performs it again, exactly the same. This time you can see more clearly how he does it. Mac tips his shoe and the honey packet falls out. Cla.s.sic misdirection. But you are on to him. Instead of focusing your attention on the honey packet, you see him reach into his back pocket and slip the rock into his shoe. When the rock falls out with the loud thud, you are no longer surprised.