Unprecedented insight into memory champion's brain reveals his tricks

Nelson Dellis holds his trophy after winning the annual USA Memory Championships in New York in 2011 DON EMMERT/AFP via Getty Images Nelson Dellis is a six-time US memory champion who once memorised the order of a shuffled deck of cards in 40.7 seconds and knows the first 10,000 digits of pi. Now, scientists have studied his brain in unprecedented detail, revealing how he achieved such feats and how we can acquire some of the same skills. Dellis claims he had an average memory until around 25 years old, when his grandmother’s decline from Alzheimer’s disease inspired him to start memory training for hours every day, including memorising numbers, names and words. “I still train my memory regularly,” he says. “It’s like a muscle; if you don’t use it, it fades.” Read more Specific cognitive training has 'astonishing' effect on dementia risk While memory impairment – like that which occurs with dementia – has been widely studied, less is known about people with extraordinary memory. To address this gap, researchers – including scientists at Washington University in St. Louis, Missouri – have turned to Dellis. Dellis had his brain extensively scanned for a total of around 13 hours in 2015 and 2021 while he rested and was tested on his memory. In one of the tests, Dellis was asked to repeatedly remember a set of four to seven words that each flashed on a screen for just over 1 second. He was told to use rote memorisation, a technique that involves repeating things over and over to make them stick. “You’re lying still in a scanner trying to memorise things, which is not exactly how I normally train, but it was really cool to be part of something that’s trying to bridge the gap between what memory athletes do and what science can measure,” says Dellis. His brain activity was then compared with that of two scientists, who acted as the controls and were deemed to have very good – but not extraordinary – memories. Free newsletter Sign up to Eight Weeks to a Healthier You Your science-backed guide to the easy habits that will help you sleep well, stress less, eat smarter and age better. Sign up to newsletter The Washington University in St. Louis researchers have now analysed this data, and found that Dellis and the controls had similar brain activity during the task. Across all three individuals, electrical signalling increased in their retrosplenial, extrastriate visual and dorsal frontal cortices, which are linked to navigation, visual information and working memory, respectively. But Dellis doesn’t generally use rote memorisation. “Rote memorisation is a terrible approach to memorising, but it’s what most people know how to do,” he says. To step things up, another task – which was done only by Dellis – involved him memorising the order of a shuffled deck of cards while his brain was scanned. This time, Dellis employed the method of loci, also known as a memory palace. This involves associating information with specific locations, such as within your hous