Meditation Changes Brain Physical Structure
As the spiritual leader of Tibetan Buddhism, the Dalai Lama was intrigued that scientists had found evidence that some parts of the brain might renew themselves throughout life. The discovery seemed to fit well with the Buddhist view that meditation can reshape and expand the mind to foster happiness and cultivate compassion. In a November speech, the Dalai Lama made the connection between neuroscientists' research into brain mechanisms associated with attention and emotion and Buddhist meditation that is performed to heighten powers of attention and regulate emotion.
"I feel there might be great potential for collaborative research between the Buddhist contemplative tradition and neuroscience" he said at the Society for Neuroscience annual meeting. People have studied the connections between meditation and brain physiology for years. Can science identify a physical signature of that effort somewhere in the vast landscape of the brain? Only recently has research been rigorously performed, fueled by two developments. One is neuroscientist Fred Gage's 1998 discovery, subsequently confirmed and extended, that new cells can, in fact, grow in the adult hippocampus, an area of the brain associated with learning, memory and emotion.
It had long been thought that cell growth stopped in the adult brain. The other is the continual refinement of technology used to image and measure changes in the brain. In the early 1990s, American scientist Richard Davidson traveled to India at the request of the Dalai Lama to meet with Buddhist monks who devote their lives to meditation. A Harvard-educated researcher at the University of Wisconsin, Davidson has since brought Buddhist monks to his lab. There he has hooked them up to an electroencephalograph, or EEG, that measures changes in the electrical activity of the brain.
Brain cells communicate by producing tiny electrical impulses. During EEG studies, researchers place several electrodes on a subject's scalp to detect and record patterns of electrical activity in the brain. In his studies on monks, Davidson found that electrical activity was heightened during meditation in an area of the brain called the left prefrontal cortex, just behind the forehead. Scientists have associated activity in this region with positive emotions, as opposed to the right prefrontal cortex, where increases are associated with negative feelings.
More recently, Davidson has found that longtime Buddhist practitioners of meditation can induce a heightened pattern of electrical signals called gamma-band oscillations, associated with concentration and emotional control, that are not seen in control groups. These changes are sustained even after meditating. Sara W. Lazar is a neuroscientist and meditator. You don't often hear those in the same sentence. But the life of this one-time Ph.D. student in molecular biology changed course when she discovered yoga and meditation while recovering from a running injury.
That was 12 years ago and now she is a cutting edge researcher in the field of neuroscience. She's focusing on the effects of meditation on the brain. "While in grad school I started practicing yoga and meditation, and found it to be incredibly helpful. I was less stressed, more focused and it really changed my perspective on a lot of things. I decided I would rather do research on meditation than on bacteria so, after I got my Ph.D., I found a lab that was willing to train me in neuroscience and let me do a small meditation study." That lab happened to be in the Psychiatry Department at Massachusetts General Hospital. The focus of her research is the neurobiology of meditation. She uses functional magnetic resonance imaging (fMRI) to investigate the neural correlates of changes in autonomic function during the practice of meditation.
Dr. Lazar goes on to explain, "MRI is a special way of using a MRI scanner to look at how the brain works. Normal MRI takes one really nice picture of your brain, with lots of details that are easy to see. fMRI is sort of like a movie - it takes special pictures of blood flow in the brain. The parts of the brain that are most active at any point will have the most blood flow, so we take pictures of the person meditating and resting, and then use a computer to determine where in the brain there is the most blood flow during meditation compared to rest."
Dr. Lazar explains that an MRI scanner is sort of like an X-ray, but it allows us to take pictures of the brain. Unlike Tibetan Buddhist monks, who have devoted their lives to the practice of meditation and their religion, meditation practitioners in the U.S. usually meditate just 20 to 60 minutes per day and incorporate their practice into a daily routine involving career, family, friends, and other outside interests, according to Lazar. Additionally, many American meditation students view meditation as a source of stress-reduction, mental exercise or personal growth, and do not necessarily incorporate traditional eastern religious elements into their practice.