The Dalai Lama challenged scientists to test the visual memory of Buddhist monks (Image: Sipa Press/Rex Features)

If you’re going to challenge the Dalai Lama to a memory game, don’t do it just after he’s meditated. New research finds that meditation boosts visual memory, but only in the short term.

The findings counter the claims of some monks who say that years of practicing a meditation technique that centres on creating an elaborate mental picture of deities can offer long-lasting improvements in visual memory and processing.

“They claim they can do it all the time – they cannot,” says Maria Kozhevnikov, a neuroscientist at George Mason University in Fairfax, Virginia, who travelled to several monasteries in Nepal to test the Buddhist monks’ visual memory.


Holy challenge

In 2003, the Dalai Lama, who has a long-term interest in science and what he calls “the luminosity of being”, attended a neuroscience conference at the Massachusetts Institute of Technology. There he challenged Kozhevnikov’s then post-doctoral advisor, Stephen Kosslyn, to test the visual memory of Buddhist monks.

Kosslyn and most other neuroscientists claimed that working memory was too short to maintain an image for more than a few seconds. He found no difference in visual memory between moderately practiced monks and non-meditators who came to his Harvard lab.

The Dalai Lama suggested that Kosslyn test more experienced monks in Nepal, and Kozhevnikov took on the task while on sabbatical.

Her initial tests at Sechen Monastery in Kathmandu confirmed Kosslyn’s findings. She showed monks an array of six images – various animals, for instance – and then five seconds later another six images, five of which appeared in the first set and one new picture. Test subjects had to determine which image was new.

In another task, Kozhevnikov showed monks a three-dimensional shape next to a rotated version of the shape or its mirror image.

‘Unbelievable performance’

The Sechen monks proved no better at determining whether the second shape was identical to or the mirror image of the first shape, compared to people who don’t meditate. Their visual memories, too, seemed normal.

Then, by chance, Kozhevnikov tested a monk immediately after a meditation session. “He showed unbelievable performance. Suddenly, I realised that I need to give this test right after meditation,” she says.

On subsequent exams of 15 monks and experienced meditators in the US, she got the same results. Before meditation, they performed no better than anyone else. Yet after 20 minutes of meditation, their visual memory and spatial skills improved dramatically.

What’s more, only practitioners of a meditation style that emphasises visual imagery – called deity yoga – registered an improvement. Kozhevnikov also tested 14 people experienced in a form of meditation that does not focus on mental imagery – known as open presence meditation – and their visual memory and spatial skills saw no gains.

Artists too?

The team didn’t probe how long the improvement lasts after meditation, but Kozhevnikov suspects that it varies from person to person, depending on meditation experience, mood and the length of the meditation session.

She also speculates that heightened visual memory and processing isn’t unique to those who practice Buddhist meditation. Visual artists may also experience transient surges in visual awareness that allow them to maintain mental images for extended periods, Kozhevnikov says.

“I think that if she shows it’s not confined to these practitioners, but you find the same thing happening in these great visual artists that’s important,” says Jack Loomis, a neuroscientist at the University of California in Santa Barbara.

Their heightened mental images may not even be contained to two dimensions, Loomis speculates. Most people can maintain a coarse mental picture of their three-dimensional world and can roughly approximate different vantage points.

“What if these people have an incredibly dense representation of three-dimensional space,” he says. “That’s pretty amazing.”

Journal reference: Psychological Science (DOI: 10.1111/j.1467-9280.2009.02345.x)