Tuesday, November 25, 2008

Meditation May Protect Your Brain

By Michael Haederle, Miller-McCune.com. Posted November 22, 2008.

Research is confirming the medicinal effects that advocates have long claimed for meditation.

For thousands of years, Buddhist meditators have claimed that the simple act of sitting down and following their breath while letting go of intrusive thoughts can free one from the entanglements of neurotic suffering.

Now, scientists are using cutting-edge scanning technology to watch the meditating mind at work. They are finding that regular meditation has a measurable effect on a variety of brain structures related to attention -- an example of what is known as neuroplasticity, where the brain physically changes in response to an intentional exercise.

A team of Emory University scientists reported in early September that experienced Zen meditators were much better than control subjects at dropping extraneous thoughts and returning to the breath. The study, "'Thinking about Not-Thinking:' Neural Correlates of Conceptual Processing During Zen Meditation," published by the online research journal PLoS ONE, found that "meditative training may foster the ability to control the automatic cascade of semantic associations triggered by a stimulus and, by extension, to voluntarily regulate the flow of spontaneous mentation."

The same researchers reported last year that longtime meditators don't lose gray matter in their brains with age the way most people do, suggesting that meditation may have a neuro-protective effect. A rash of other studies in recent years meanwhile have found, for example, that practitioners of insight meditation have noticeably thicker tissue in the prefrontal cortex (the region responsible for attention and control) and that experienced Tibetan monks practicing compassion meditation generate unusually strong and coherent gamma waves in their brains.

"There are a lot of potential applications for this," said Milos Cekic, a member of the Emory research team and himself a longtime meditator. He suspects the simple practice of focusing attention on the breath could help patients suffering from depression, anxiety, post-traumatic stress and other conditions characterized by excessive rumination.

Meanwhile, a meditation-derived program developed at the University of Massachusetts called Mindfulness Based Stress Reduction (MBSR) is gaining popularity for treatment of anxiety and chronic illnesses at medical centers around the U.S.

As far back as the 1960s, Japanese scientists who used electroencephalograms (EEG) to measure the brain waves of Zen monks found characteristic patterns of activity. But the advent of functional magnetic resonance imaging (fMRI) in the 1990s gave researchers a chance to see brains functioning in real time. Functional MRIs measure the blood flow in different parts of the brain, which correlates with how active they are.

The Emory team, which also included Giuseppe Pagnoni and Ying Guo, wanted to see whether Zen meditators were indeed better than novices at controlling the flow of thought, as meditators themselves report. Cekic and Pagnoni asked a dozen seasoned Zen meditators -- including several monks -- and a dozen control subjects to perform a simple cognitive task while undergoing an fMRI scan. The Zen practitioners all had at least three years of daily practice experience, while the control group members had none.

Inside the scanner, the subjects were all asked to follow their breathing while looking at a screen on which words or wordlike combinations of letters were flashed at irregular intervals. Students had to decide whether they were seeing a real word or a made-up word and signal by pressing a button and then return to focusing on their breathing.

The random word or letter combinations engaged what is sometimes called the "default semantic network," a resting state in which words and thoughts arise spontaneously -- what we experience as mind wandering, Cekic said. Practitioners of zazen (seated Zen meditation) are taught to notice when the mind has started to wander and quickly return attention to the breath.

When the word or letter combinations flashed on the screen, the experienced meditators were quickly able to leave the default state and return to their breathing, Cekic says. "You have these extended reverberations in the semantic network after you give people a word," Cekic said. "The meditators pretty much turn it off as soon as it's physiologically possible, while the non-meditators don't."


See more stories tagged with: health, brain, wellness, meditation

Michael Haederle lives in New Mexico. He has written for the Los Angeles Times, People Magazine, Tricycle: The Buddhist Review and many other publications.

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