Contemplating Oneness: The Neuroscience of Meditation

Eastern practices meet Western studies

To learn about the default network and its interplay with the external, Josipovic and Heeger are beginning to piece together a slew of images collected from scanning the brains of Buddhist monks as well as secular meditators from around the Tri-State area. The pair is planning to extend their study to Christian monks, nuns and Jewish contemplatives.

One of the practitioners of nondualism, or “oneness” meditation, in the study is 31-year-old Karma Drodhul. He became a Lama, or trained Tibetan Buddhist, through spending about seven years in meditation retreats. The brain scans do not prevent Lama Drodhul from entering a state of oneness. “In Buddhism, we are used to meditating through distractions,” he says after a recent fMRI session. “It was fun.”

For each scan session, participants lie with their heads in the fMRI machine, which emits a magnetic field about twice as strong as a hospital MRI. As blood flows to active areas of the brain, it carries oxygen that changes the magnetism of that area. A computer attached to the machine captures a picture of the brain, based on differences in magnetism, about every two seconds. After scanning a participant’s brain, Josipovic typically ends up with hundreds of images. Some of the images reflect the brain activity as subjects see flashing photos of a face or houses or a landscape on a projector screen viewed on a mirror in front of their faces. Each of these types of objects is associated with activation of a different, precise area of the brain, so the resulting images serve as a point of reference for the rest of the images.

Josipovic already has some early revelations about the networks. For normal nonmeditators, Josipovic’s saw the same interplay as other scientists: When the activity of the external network is up, the default is down and vice versa. But the story is different when it comes to experienced meditators. The activity of the two networks for them is not as sharply opposed, perhaps indicating that there is brain activity accompanying the experience of harmony between internal and external perspectives in nondualism meditation.

The default network’s broader implications

Understanding the default network may eventually elucidate information about the mental diseases that seem to target it, including Alzheimer’s, autism and depression. While the activity of the external network is sometimes also affected in these diseases, it is “not nearly as broken,” says Jessica Andrews-Hanna, who recently completed her graduate studies in the laboratory of Randy Buckner at Harvard University on the default networks of aging people.

The diseases that involve the default network are varied but, for all of them, the network does not seem to turn off when it should. Perhaps because it loses that “push-pull” relationship with the external network in patients with severe Alzheimer’s and other cognitive problems, it remains perpetually “on.” Within the default network, activity is disorganized and connections are deteriorated. Its activity also does not seem to wane in studies of autistic people when they perform goal-related tasks, or of depressed people during rest.

All these studies suggest that there could be a striking similarity between the brains of meditators and those of people with dementia or depression. According to Andrews-Hanna, if it’s true that meditators maintain their two networks operating at the same time, their brain scans would be reminiscent of those of the mentally ill. “Presumably, in the meditators’ case, maybe it’s all cognitive; maybe they have the ability to say, ‘Now I want to control these two [networks] together,’” says Andrews-Hanna. “If you can turn the brain regions on and off when you want, that’s great.”

For now, neuroscientists are waiting to learn what Josipovic and Heeger find from their studies of meditators, which they hope will offer unique insight about the default network. The first step is to see if nondual contemplation — combining the external and subjective experiences — does correspond to differences in the default network. If it does, these studies will open up a new way to explore what was before a completely elusive network.

*Correction (August 17, 2009): This sentence originally read: “The researchers are interested in a special type of meditation in which the practitioners try to merge the external world with their own internal, personal thoughts, explains Josipovic, who is a Tibetan Buddhist as well as research associate in Heeger’s neuroscience lab.”

**Correction (August 17, 2009): This sentence originally read: “While scientists first thought this area might just be active when the brain had no task to focus on, a growing camp of brain researchers, including Josipovic and Heeger, believe that it is the seat of self-related thinking.”

***Correction (August 17, 2009): Sentence added: “In nondual meditation, practitioners are cognizant of awareness which is both the nature of mind and the context of internal and external experiences.”

Related on Scienceline:

A brain imaging tool that may open up new ways to visualize the brain.

Is lie detection a reliable way to use fMRI?

How extreme athletes focus on the the moment.