Three days after his heart stopped, Geshe Lhundub Sopa was leaned upright against a wall, his odorless body perfectly poised, his skin fresh as baked bread. He looked like he was meditating, remembers Richard Davidson, a prominent neuroscientist and friend of the late Buddhist monk.

Sopa, a tutor of the Dalai Lama’s in Tibet, moved in 1967 to Wisconsin, where he co-founded the Deer Park Buddhist Center and taught South Asian Studies at the University of Wisconsin. 

By conventional Western standards, Sopa died on August 28, 2014. Five days later, and two days after Davidson’s initial visit, the neuroscientist returned to Deer Park and observed his friend’s body a second time. “There was absolutely no change. It was really quite remarkable,” he said.

By the standards of conventional Western medicine, Sopa was dead, though with a strangely preserved corpse. By the traditions of Tibetan Buddhism, Sopa’s body harbored a mind that remained very much alive. Like other accomplished Buddhists, Sopa was believed to have entered a meditative state known as thukdam, during which his consciousness would wisp away into a spare, luminous awareness. 

Thukdam, or thugs dam, in Tibetan, is an honorific meaning “one engaged in meditation.” For Sopa, this meditation, also known as “clear light,” lasted seven days before his body began to decay and was cremated, according to his obituary on Deer Park’s website

Reports of thukdam—often accompanied by lurid, Night of the Living Dead-type headlines—Shocking! 200-year-old Mongolian Monk Mummy Still Alive”—regularly arrive from the Tibetan diaspora, originating in Indian monasteries and Buddhist centers from New Zealand to rural Wisconsin. Thukdam typically lasts much shorter than two centuries, more like two or three weeks. As with other faiths, the lack of post-mortem decay is seen as a sign of spiritual attainment. (The Dalai Lama hinted recently that it could also betray an unhealthy attachment to the world.)

Whatever is going on inside thukdam meditators, His Holiness would dearly like to know. He’s been asking scientists to study the mysterious state for nearly 20 years, with little apparent success—until recently, when his friend Davidson and other researchers at University of Wisconsin-Madison’s Center for Healthy Minds created “The Thukdam Project.” 

Enlisting Davidson, one of the nation’s leading neuroscientists, was a coup for the Dalai Lama, a result of their long friendship and a marker of the growing collaboration between cognitive scientists and contemplatives. Davidson, the William James and Vilas Professor of Psychology and Psychiatry, has been at the forefront of an explosion of research—and popular interest—in mindfulness and the neural basis of healthy emotions, publishing nearly 400 articles and founding the Center for Healthy Minds. 

Described as rigorous and long-term, the Thukdam Project combines the brain power of neuroscientists, forensic anthropologists, doctors, psychologists, philosophers, and teams of monk-researchers in India. An inaugural report, which Davidson describes as the first-ever scientific study into thukdam, was published this January in the journal Frontiers in Psychology. The takeaway: A negative finding. 

Davidson and his colleagues had hypothesized that an electroencephalogram might detect residual brain activity in thukdam practitioners. But, as best as the researchers could tell, none of 13 thukdam subjects in the study, all of whom had been medically dead for at least 26 hours, demonstrated any discernible brainwaves. 

After the study was published this winter, Davidson said, a few colleagues politely suggested studying thukdam was a waste of time. But he calls the report a first step, not a last. 

“We’re going to keep going,” he said. “The skeptics just fuel my fire.” 

Evan Thompson, a philosopher who discussed thukdam with Davidson but was not part of the study, said it’s premature to declare the subject DOA. 

“If the thinking was that thukdam is something we can measure in the brain, this study suggests that’s not the right place to look,” said Thompson, a professor of philosophy at the University of British Columbia in Vancouver. “But that doesn’t prove we cannot measure it at all.”  

Researchers from Moscow State University and the Human Brain Institute in St. Petersburg told the Dalai Lama in May that they have examined 104 monks who are simulating meditation states thought to resemble thukdam. This past year, the Dalai Lama requested the Russian team and the Center for Healthy Minds to collaborate in their study of thukdam. The collaborative team, including their long-time Tibetan team colleagues at Delek Hospital and Men-Tsee-Khang, investigated a thukdam case at Gyutö Monastery who reportedly remained in the state for 37 days.

Svyatoslav Medvedev, founder of the Institute of the Human Brain, told the Dalai Lama about a finding from the collaborative team in a dialogue posted online that from the forensic perspective, the bodies of meditators in thukdam are “quite different from the ordinary process of someone undergoing the normal process of death.”

During that dialogue, Medvedev asked His Holiness about the importance of studying thukdam, a relatively rare state experienced in its fullness only by spiritual masters. 

“I’m not sure about the value of studying it for humanity at large,” he said. “But this is an observable reality and we need a scientific explanation. Why are these bodies not decomposing?” 

The Dalai Lama later added that most of humanity’s problems are caused by our wayward minds, and we have a lot to learn about how our minds work, and studying thukdam can contribute to that. 

Other leaders of the Thukdam Project say studying thukdam raises questions from the profound (What is death?) to the pragmatic (When should we harvest organs?) Also up for discussion: Could there be a meditation practice that makes the body go into a state of metabolic suspension? And where, exactly, is consciousness located? 

“If we find some kind of post-mortem signal and can say, that’s consciousness, that would be earth-shattering,” said John Dunne, Chair in Contemplative Humanities at the University of Wisconsin-Madison, and a contributor to the project. “We would have to radically shift our idea of what consciousness is.” 

Western medicine should already shift its conventional definition of death, Dunne and Davidson argue. As Tibetan Buddhists have long believed, biological death is more like a process—or a journey through various states—than a simple on/off switch. 

As Thompson explains in his book, Waking, Dreaming, Being: Self and Consciousness in Neuroscience, Meditation, and Philosophy, Thukdam is part of Tibetan Buddhism’s larger, bardo-based explanations of how our minds meet death: 

What would ordinarily be considered the moment of death in a modern clinical setting — the cessation of breathing and other vital signs — corresponds to what Tibetan Buddhists regard as the end of the outer dissolution. What follows next is the inner dissolution, which consists in the gradual dawning of over more subtle levels of consciousness as the coarser levels of consciousness fall apart. Death occurs only with the rising of the clear light of pure awareness at the end of the inner dissolution, for this is the moment when the outer sensory consciousness and the inner mental consciousness have completely dissolved back into the ground luminosity of pure awareness or ultimate nature of mind. 

For most of us, Thompson explains, the experience—said to feel something like dawn spreading its light across a plain—lasts just a few seconds. But meditation masters can abide in thukdam for days or even weeks, a radical experience of nonduality that can eradicate ignorance at its roots, leading directly to buddhahood.

Attaining that rarefied state is one feat. Trying to measure thukdam’s physical energy, if any, after the practitioner has been dead for days is a massive challenge. 

“We’re looking through layers of bone, muscle, flesh, tissue, trying to find a tool sensitive enough to detect something that residual, but most of our instruments just aren’t that subtle,” said Tawni Tidwell, a biocultural anthropologist, Tibetan medical doctor, and member of the Thukdam Project. “But that doesn’t mean there’s nothing there.” 

Cultural sensitivities provide another set of complications, Tidwell said. Bodies are usually observed for three days to determine if thukdam will set in; and people believed to be in thukdam are rarely touched, for fear of disturbing the mind inside. The Thukdam Project is trying to obtain advanced permission from practitioners to test them upon death, but there’s a cultural reticence to talking about spiritual achievements, explained Tidwell.  “A lot of our great practitioners don’t want to claim that they will go into thukdam.”  

But Tidwell and others have some help. They’ve enlisted monk-researchers who, inspired by the Dalai Lama, studied Western medicine at places like Emory University and are now taking those tools back to their communities. “It’s not the Westerners who are doing the measuring and poking and prodding,” Tidwell said with a laugh. “It’s the monastics who trained at Emory.” 

Those monks may be very busy. Tidwell said the Thukdam Project is working on a study of how bodies decompose in different climatic conditions in India, and Dunne said he wants to look outside the brain for signs of post-mortem consciousness. 

“The phenomenon that we observe, the lack of bodily decay, is not something we would normally think about as ‘in the brain’ anyway,” he said. “We’re looking at some whole-body phenomenon. But it was nice to rule the brain out.”

This story has been updated to better reflect the dialogue between the Dalai Lama and Russian researchers.