Mind & Brain / Memory, Emotions, & Decisions

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.

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."