(Simon & Schuster)

Let’s start with a number that many have come across in math class: pi, the ratio of a circle’s circumference to its diameter. It begins with 3.14159 . . . and carries on forever. It is infinite and irrational, never ending and never repeating, and people are drawn into its orbit.

To some, the attraction is spiritual; to others, the pull may be explained by the “because it’s there” reasoning of mountaineers. Memory athletes — so called because of their intensive training in games of the mind — in particular are drawn to the endlessness of pi.

Akira Haraguchi of Kisarazu, near Tokyo, recited pi to more than 100,000 digits in 2006, a feat that lasted more than 16 hours. To him, pi represents a religious quest for meaning.

“Reciting pi’s digits has the same meaning as chanting the Buddhist mantra and meditating,” Haraguchi, who is 72, says. He is widely recognized as the champion of pi, although Guinness World Records has not validated his recitation.

The official Guinness record holder is Rajveer Meena, 23, from Rajasthan, India. On March 21, 2015, Meena recited pi to 70,000 decimal places. (It took him 9 hours 7 minutes.) He said he wanted to show that despite a humble background, he could win the world’s toughest memory challenge.

Memory wizards have varying motivations and use different techniques, but they all essentially convert the exercise into a story. When they recite the numbers, they are telling themselves a tale in their head and rendering it into digits. Haraguchi uses a system based on the Japanese kana alphabet. Translated roughly into English, the first 50 digits of his translation reads: “Well, I, that fragile being who left my hometown to find a peace of mind, is going to die in the dark corners; it’s easy to die, but I stay positive.”


One hopes that in the rest of the 100,000 digits the story line picks up a bit.

Meena assigns numbers to certain words. He gave me an example. “I leave my house and meet Roger Federer, go to the park, grab a pair of jeans, get a cab for $50 to the office, where I earn $100.” This translates into the number 749099950100: I (74) leave my house and meet Roger Federer (90), go to the park, grab a pair of jeans (999), get a cab for $50 to the office, where I earn $100.

Memorizing the story for a sequence of 70,000 digits took him more than six years. Along with getting into Guinness, “it was a good way to increase patience and confidence,” Meena says, deadpan.

For Daniel Tammet, 39, the number sequences in pi have an aura. They have color, texture, shape and, even weirdly, emotion, he says. The number 4, for example, to Tammet is blue, but it’s also a timid number, one he feels close to because of his own shyness. Numbers can glow and wink on their own and perhaps even snarl when Tammet looks at or thinks about them, but strings of numbers form sentences of emotions and feelings.

Tammet is a best-selling author and translator. British-born but now living in Paris, he is a polyglot, speaking 10 languages, and he has synesthesia, a neurological condition that allows him to see colors in different words or numbers. “Three is green, five is yellow and nine is blue — very blue, a different blue to 4,” he says.

Tammet also has autistic savant syndrome, and an IQ that is well above average. He set the European record for the recitation of pi in 2005. It took him just over five hours to dictate a string of 22,514 places.

“I would look at the numbers and find emotions and shapes — it’s like a poem for me, like Baudelaire in French or Shakespeare in English,” he said “Pi is like a poem written in numbers. And the further I went into the numbers, the more sense it made.”

Tammet constructed a poem out of pi, and recited it in public. To find out how he did it, Daniel Bor and colleagues at the University of Cambridge’s department of psychology put Tammet through a variety of tests, including a brain scan, and found that his synesthesia appears to generate structured, “chunked” content that enhances recall.

Chunking — the grouping of smaller elements into units that are more easily memorized — is a technique commonly used by memory athletes. For example, the number 10271962 might be remembered as Oct. 27, 1962. Tammet’s autism and synesthesia seem to have aided him in memorizing pi. Tammet saw pi in synesthetic chunks that he associated with particular colors and emotions, and he knitted these chunks together into a story. “He used a mnemonic method, but one intimately connected to his synesthesia,” says Bor.

Memory athletes such as Tammet, Haraguchi and Meena use methods to encode information into a form that makes it more memorable to them.

Humans don’t learn well if we just stuff ourselves with raw information; we need to provide a framework that the brain can feel at home with, experts say. That’s because the part of the brain involved in processing short- and long-term memory, the hippocampus, is also involved in processing emotion and navigation.

While Tammet, Haraguchi and Meena all wove stories out of chunks of pi, you don’t have to have savant abilities or be aided by synesthesia to do this, it turns out. You just need to practice.

Martin Dresler, of the Donders Institute for Brain, Cognition and Behavior at Radboud University Medical Center in the Netherlands, has shown that anyone can use the techniques of memory athletes to become masters themselves.

Dresler put 23 of the world’s most successful memory athletes through a functional magnetic resonance image (fMRI) brain scanner. Most such athletes use a technique called method-of-loci, also known as the memory palace technique.

With this method, you imagine a place you know intimately, typically your house, and you populate a route through the house with items on the list of things you need to remember. The more unusual, startling, even unsettling the images, the more memorable they are. By tracing the route through your house in your head, you can pick up the items along the way and replicate the list.

For example, I might translate the beginning of pi — 3.1415 — into this walk through my house: “There are three bullet holes in the front door. I open it and find one dead horse in the doorway, its four feet standing straight in the air, and one elf sat at the foot of the stairs, waving five gold rings on his fingers.”

When Dresler’s team checked the results from the fMRI, they found no structural differences in the brains of the memory athletes compared with untrained people.

Dresler then put volunteers who were new to memory training through six weeks of instruction on using the memory palace technique.

After this, they had typically doubled their ability to remember words from a random list, and the activity patterns of their brains had started to converge with that seen in the champion memorizers. Anyone can try this. Dresler’s subjects used a Web-based training platform (you can find it at memocamp.com) to help them build and memorize routes through a palace and to learn lists of random words by placing the words along the routes.

Our potential memory is vast, but the key is to understand how it evolved and to play to its strengths. “There has hardly been an evolutionary pressure for our ancestors to store abstract information,” says Dresler, “whereas memory for visuospatial information — finding the way home, or to feeding or mating places — is crucial for most animals.”

It seems counterintuitive at first that to remember more information we need to encode data into bulkier shapes. We need to build palaces filled with penguins and space stations and Roger Federer; we need to create more information to remember less. That’s because our brains evolved to encode visuospatial information. We learn by listening to stories, and if we create stories, we can learn to remember.

All the memory athletes Dresler has worked with say they have no innate skill. Everything they do has been learned. Anyone, it seems, can become a memory superhuman.

This article has been adapted from “Superhuman: Life at the Extremes of Our Capacity” by Rowan Hooper. Hooper is managing editor of New Scientist magazine.