How to Win the World Memory Championship

Some contestants can recall the order of a deck of cards after looking at it for 60 seconds. Learn their tricks.

By Joshua Foer|Sunday, April 02, 2006

Try this memory test: Study each face and compose a vivid image for the person's first and last name. Rose Leo, for example, could be a rosebud and a lion. Fill in the blanks on the next page.

The Examinations School at Oxford University is an austere building of oak-paneled rooms, large Gothic windows, and looming portraits of eminent dukes and earls. It is where generations of Oxford students have tested their memory on final exams, and it is where, last August, 34 contestants gathered at the World Memory Championships to be examined in an entirely different manner. In timed trials, contestants were challenged to look at and then recite a two-page poem, memorize rows of 40-digit numbers, recall the names of 110 people after looking at their photographs, and perform seven other feats of extraordinary retention. Some tests took just a few minutes; others lasted hours.

In the final and most dramatic of the events, contestants sat behind a table in front of a large digital stopwatch. Each was given a shuffled pack of playing cards. A judge announced, "Neurons at the ready—go!" Contestants then began riffling through the cards, memorizing. As contestants finished, they smacked a timer, then closed their eyes and put their heads down on the table. Five minutes after the event had begun, each contestant received a fresh, unshuffled pack to reorder so that it matched the first deck.

In the 14 years since the World Memory Championships was founded, no one has memorized the order of a shuffled deck of playing cards in less than 30 seconds. That nice round number has become the four-minute mile of competitive memory, a benchmark that the world's best "mental athletes," as some of them like to be called, are closing in on. Earlier this year, a 29-year-old British accountant and former world champion named Ben Pridmore hit 32.13 seconds at a competition in Germany.

The youngest competitor was 12. Most were under 40, and two-thirds were men. Gunther Karsten, a 43-year-old patent translator and seven-time German memory champion, showed up in his distraction-minimizing uniform: earmuffs and sunglasses with the lenses taped over except for two small pinholes.

Most contestants claim to have just average memories, and scientific testing confirms that they're not just being modest. Their feats are based on tricks that capitalize on how the human brain encodes information. Anyone can learn them.

Psychologists Elizabeth Valentine and John Wilding, authors of the monograph Superior Memory, recently teamed up with Eleanor Maguire, a neuroscientist at University College London to study eight people, including Karsten, who had finished near the top of the World Memory Championships. They wondered if the contestants' brains were different in some way.

The researchers put the competitors and a group of control subjects into an MRI machine and asked them to perform several different memory tests while their brains were being scanned. When it came to memorizing sequences of three-digit numbers, the difference between the memory contestants and the control subjects was, as expected, immense. However, when they were shown photographs of magnified snowflakes, images that the competitors had never tried to memorize before, the champions did no better than the control group.

When the researchers analyzed the brain scans, they found that the memory champs were activating some brain regions that were different from those the control subjects were using. These regions, which included the right posterior hippocampus, are known to be involved in visual memory and spatial navigation.

It might seem odd that the memory contestants would use visual imagery and spatial navigation to remember numbers, but the activity makes sense when their techniques are revealed. The night before the World Memory Championships, Ed Cooke took me to the Lamb and Flag, the storied five-century-old pub where he spent many nights as an Oxford undergraduate. Cooke, a 23-year-old cognitive-science graduate student with a shoulder-length mop of curly hair, is a grand master of brain storage. He can memorize the order of 10 decks of playing cards in less than an hour, or one deck of cards in less than a minute. He is closing in on the 30-second deck.

In the Lamb and Flag, Cooke pulled out a deck of cards and shuffled it. He held up three cards—the 7 of spades, the queen of clubs, and the 10 of spades. He pointed at a fireplace and said, "Destiny's Child is whacking Franz Schubert with handbags." The next three cards were the king of hearts, the king of spades, and the jack of clubs. He ran over to the bar and announced, "Admiral Lord Nelson is holding a guitar upside down over there." By now, everyone in the pub had begun to gawk. Forty-six cards and a few minutes later, Cooke ended up outside the Lamb and Flag, where he proceeded to reel off the deck's order flawlessly.

How did he do it? Cooke has already memorized a specific person, verb, and object that he associates with each card in the deck. For example, for the 7 of spades, the person (or, in this case, persons) is always the singing group Destiny's Child, the action is surviving a storm, and the image is a dinghy. The queen of clubs is always his friend Henrietta, the action is thwacking with a handbag, and the image is of wardrobes filled with designer clothes. When Cooke commits a deck to memory, he does it three cards at a time. Every three-card group forms a single image of a person doing something to an object. The first card in the triplet becomes the person, the second the verb, the third the object. He then places those images along a specific familiar route, such as the one he took through the Lamb and Flag. In competitions, he uses an imaginary route that he has designed to be as smooth and downhill as possible. When it comes time to recall, Cooke takes a mental walk along his route and translates the images into cards. That's why the MRIs of the memory contestants showed activation in the brain areas associated with visual imagery and spatial navigation.

When Cooke memorizes a long string of numbers, he modifies the technique to convert the sequence into a string of images. To do this, he has memorized a repertoire of images for any combination of three digits between 000 and 999. To Cooke, the number 227 is the mathematician Kurt Gödel starving himself to death. The number 115 is Psmith, a character in several P. G. Wodehouse books. It also stands for the action of giving away someone else's umbrella and the image of a young lady stranded in the rain. The number 614 has become Bill Clinton smoking (but not inhaling, Cooke notes) marijuana. When Cooke sees the number 227115614, he divides it into three parts and conjures up the images he has memorized for each triplet—"Kurt Gödel offering someone else's umbrella to a cloud of marijuana smoke."


The more resonant the images are, the more difficult they are to forget. But even meaningful information is hard to remember when there's a lot of it. That's why competitive memorizers place their images along an imaginary route. That technique, known as the loci method, reportedly originated in 477 B.C. with the Greek poet Simonides of Ceos. Simonides was the sole survivor of a roof collapse that killed all the other guests at a royal banquet. The bodies were mangled beyond recognition, but Simonides was able to reconstruct the guest list by closing his eyes and recalling each individual around the dinner table. What he had discovered was that our brains are exceptionally good at remembering images and spatial information. Evolutionary psychologists have offered an explanation: Presumably our ancestors found it important to recall where they found their last meal or the way back to the cave.

After Simonides' discovery, the loci method became popular across ancient Greece as a trick for memorizing speeches and texts. Aristotle wrote about it, and later a number of treatises on the art of memory were published in Rome. Before printed books, the art of memory was considered a staple of classical education, on a par with grammar, logic, and rhetoric.

Today external aids supplant natural memory: PalmPilots track schedules, cell phones store phone numbers, and Internet searches turn up a bonanza of information. About the only place in modern society where you'll find people still using the loci method is at the World Memory Championships.

Gunther Karsten used to wake up in a cold sweat, worrying that someone with a photographic memory would show up at the competition and blow everyone out of the water. Most scientists say that's not likely to happen. Although some people claim to have a photographic memory, there is no evidence that anyone can actually store mental snapshots and recall them with perfect fidelity.

If photographic memory is a myth, might there be some other form of innately superior memory? John Wilding and Elizabeth Valentine think so. They divide people with superior memories into two classes—strategists and naturals. Strategists, like Karsten, Cooke, and most of the other competitors in memory contests, employ techniques that convert meaningless information into a form the brain can organize and retain. Strategists tend to be exceptional at memorizing only a few types of things. Naturals, on the other hand, show strong memory across a wide variety of tasks and tend to have an easier time holding on to those memories.

The most famous of the naturals was the Russian journalist S. V. Shereshevski, who could recall long lists of numbers memorized decades earlier, as well as poems, strings of nonsense syllables, and just about anything else he was asked to remember. "The capacity of his memory had no distinct limits," wrote Alexander Luria, the Russian psychologist who studied Shereshevski from the 1920s to the 1950s.

Shereshevski also had synesthesia, a rare condition in which the senses become intertwined. For example, every number may be associated with a color or every word with a taste. Synesthetic reactions evoke a response in more areas of the brain, making memory easier. They also create problems. "If I read when I eat, I have a hard time understanding what I'm reading—the taste of the food drowns out the sense," Shereshevski told Luria.

Shereshevski's greatest challenge was learning to forget. He tried writing things down in hopes of discharging their memory. When that didn't work, he tried burning the pieces of paper, but he could still see numbers hovering among the embers. Eventually, he discovered that he could forget information if he convinced himself it was meaningless. "If I don't want the chart to show up, it won't!" he exclaimed. "And all it took was for me to realize this!"

K. Anders Ericsson, a Swedish-born psychologist at Florida State University, thinks anyone can acquire Shereshevski's skills. He cites an experiment with S. F., an undergraduate who was paid to take a standard test of memory called the digit span for one hour a day, two or three days a week. When he started, he could hold, like most people, only about seven digits in his head at any given time (conveniently, the length of a phone number).

Over two years, S. F. completed 250 hours of testing. By then, he had stretched his digit span from 7 to more than 80. He had developed his own strategy for remembering based on his own experience as a competitive runner: He associated strings of random numbers with track times. For example 3,492 was remembered as "3 minutes and 49 point 2 seconds, near world-record mile time."

The study of S. F. led Ericsson to believe that innately superior memory doesn't exist at all. When he reviewed original case studies of naturals, he found that exceptional memorizers were using techniques—sometimes without realizing it—and lots of practice. Often, exceptional memory was only for a single type of material, like digits. "If we look at some of these memory tasks, they're the kind of thing most people don't even waste one hour practicing, but if they wasted 50 hours, they'd be exceptional at it," Ericsson says. It would be remarkable, he adds, to find a "person who is exceptional across a number of tasks. I don't think that there's any compelling evidence that there are such people."

Ericsson contends that Shereshevski must have developed his extraordinary memory through practice using a system that sounds very similar to the loci technique. He cites Luria's description of how Shereshevski remembered lists of random words: "When Shereshevski read through a long series of words, each word would elicit a graphic image. And since the series was fairly long, he had to find some way of distributing these images of his in a mental row or sequence. Most often . . . he would 'distribute' them along some roadway or street he visualized in his mind."

Shereshevski died long before Ericsson began his research, but the psychologist was able to vet the extraordinary memory of another supposed natural, Rajan Mahadevan, who was believed to have a baseline digit span of about 15. Born in India in 1957, Mahadevan could memorize parking lots full of license plates by age 5. For a time, he was listed in Guinness World Records for flawlessly memorizing the first 31,811 digits of the mathematical constant pi (the record now stands at more than 80,000 digits).

In 1987 Mahadevan enrolled as a graduate student in psychology at Kansas State University, where he was employed as a participant in memory experiments. Six years later, Charles Thompson, Thaddeus Cowan, and Jerome Frieman, psychologists at Kansas State, published Memory Search by a Memorist, a book about Mahadevan that concluded, "He seems to rely on raw memory power."

Not long before the book was published, Mahadevan left Kansas State and went to the University of Colorado, where Ericsson was based. While Mahadevan continued to pursue his Ph.D. in Ericsson's lab, he and the psychologist collaborated on more studies of his apparently unique memory. Last year, they coauthored a paper in which they argue that the 1993 book on Mahadevan was wrong. His impressive memory did not derive from any ability but rather from skills developed during the 1,000 hours he had spent reviewing the digits of pi for his Guinness world-record run.

"It would be nice to say that I just have a talent to do it," says Mahadevan. But knowing that his superior memory is an acquired skill is in some ways more important to him. Memory, he says, is "a level playing field, and I prevail under those circumstances. My view is that it does not in any way diminish my achievements."

By the third day of the World Memory Championships, 19-year-old Clemens Mayer from Germany held a commanding lead. He needed only a safe time of about one minute and 30 seconds in the final card-memorizing event to become the first German world memory champion. Karsten was in second place. The other competitors jockeying for position behind them, including Ed Cooke and Ben Pridmore, were all gunning to do a 30-second deck.

Mayer is practically a poster child for Ericsson's ideas about how memory skills can be acquired. What is mysterious about people with exceptional memory, says Ericsson, is not their memory but their motivation. Not many people have the discipline and drive to practice memorizing for the several hours a week needed to compete in the World Memory Championships. Mayer, who had attended a sports academy in East Germany, had hoped to someday become an Olympic runner. Three years ago, he turned on the television and saw Gunther Karsten memorizing a deck of cards. He thought, "I can do that," and began applying the discipline that had made him one of Germany's top young runners. At first, he practiced for two hours a day. Now he spends closer to half an hour, still more than almost anyone else on the memory circuit.

Most memorizers have an Achilles' heel. The digit people are often bad at names and faces. The poem people are often bad at cards. Mayer has no such weak spots. He ranked near the top in every discipline and set a new world record of 198 digits in the spoken numbers event, in which contestants must recall 200 digits read aloud at the rate of one per second.

Mayer managed to memorize a deck in a safe 1:02.7. No one even came close to breaking the 30-second barrier. The best time belonged to Katharina Bunk, a 14-year-old German who was competing alongside her older brother. She managed 45.8 seconds. The 30-second deck would have to wait another year.
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