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United States - Brain research
is beginning to produce concrete evidence for something that Buddhist
practitioners of meditation have maintained for centuries: Mental
discipline and meditative practice can change the workings of the
brain and allow people to achieve different levels of awareness.
Those transformed states have traditionally
been understood in transcendent terms, as something outside the
world of physical measurement and objective evaluation. But over
the past few years, researchers at the University of Wisconsin working
with Tibetan monks have been able to translate those mental experiences
into the scientific language of high-frequency gamma waves and brain
synchrony, or coordination. And they have pinpointed the left prefrontal
cortex, an area just behind the left forehead, as the place where
brain activity associated with meditation is especially intense.
"What we found is that the longtime
practitioners showed brain activation on a scale we have never seen
before," said Richard Davidson, a neuroscientist at the university's
new $10 million W. M. Keck Laboratory for Functional Brain Imaging
and Behavior. "Their mental practice is having an effect on
the brain in the same way golf or tennis practice will enhance performance."
It demonstrates, he said, that the brain is capable of being trained
and physically modified in ways few people can imagine.
Scientists used to believe the opposite
- that connections among brain nerve cells were fixed early in life
and did not change in adulthood. But that assumption was disproved
over the past decade with the help of advances in brain imaging
and other techniques, and in its place, scientists have embraced
the concept of ongoing brain development and "neuroplasticity."
Davidson says his newest results from
the meditation study, published in the Proceedings of the National
Academy of Sciences in November, take the concept of neuroplasticity
a step further by showing that mental training through meditation
(and presumably other disciplines) can itself change the inner workings
and circuitry of the brain.
The new findings are the result of
a long, if unlikely, collaboration between Davidson and Tibet's
Dalai Lama, the world's best-known practitioner of Buddhism. The
Dalai Lama first invited Davidson to his home in Dharamsala, India,
in 1992 after learning about Davidson's innovative research into
the neuroscience of emotions. The Tibetans have a centuries-old
tradition of intensive meditation and, from the start, the Dalai
Lama was interested in having Davidson scientifically explore the
workings of his monks' meditating minds. Three years ago, the Dalai
Lama spent two days visiting Davidson's lab.
The Dalai Lama ultimately dispatched
eight of his most accomplished practitioners to Davidson's lab to
have them hooked up for electroencephalograph (EEG) testing and
brain scanning. The Buddhist practitioners in the experiment had
undergone training in the Tibetan Nyingmapa and Kagyupa traditions
of meditation for an estimated 10,000 to 50,000 hours, over time
periods of 15 to 40 years. As a control, 10 student volunteers with
no previous meditation experience were also tested after one week
of training.
The monks and volunteers were fitted
with a net of 256 electrical sensors and asked to meditate for short
periods. Thinking and other mental activity are known to produce
slight, but detectable, bursts of electrical activity as large groupings
of neurons send messages to each other, and that's what the sensors
picked up. Davidson was especially interested in measuring gamma
waves, some of the highest-frequency and most important electrical
brain impulses.
Both groups were asked to meditate,
specifically on unconditional compassion. Buddhist teaching describes
that state, which is at the heart of the Dalai Lama's teaching,
as the "unrestricted readiness and availability to help living
beings." The researchers chose that focus because it does not
require concentrating on particular objects, memories or images,
and cultivates instead a transformed state of being.
Davidson said that the results unambiguously
showed that meditation activated the trained minds of the monks
in significantly different ways from those of the volunteers. Most
important, the electrodes picked up much greater activation of fast-moving
and unusually powerful gamma waves in the monks, and found that
the movement of the waves through the brain was far better organized
and coordinated than in the students. The meditation novices showed
only a slight increase in gamma wave activity while meditating,
but some of the monks produced gamma wave activity more powerful
than any previously reported in a healthy person, Davidson said.
The monks who had spent the most years
meditating had the highest levels of gamma waves, he added. This
"dose response" -- where higher levels of a drug or activity
have greater effect than lower levels -- is what researchers look
for to assess cause and effect.
In previous studies, mental activities
such as focus, memory, learning and consciousness were associated
with the kind of enhanced neural coordination found in the monks.
The intense gamma waves found in the monks have also been associated
with knitting together disparate brain circuits, and so are connected
to higher mental activity and heightened awareness, as well.
Davidson's research is consistent
with his earlier work that pinpointed the left prefrontal cortex
as a brain region associated with happiness and positive thoughts
and emotions. Using functional magnetic resonance imagining (fMRI)
on the meditating monks, Davidson found that their brain activity
-- as measured by the EEG -- was especially high in this area.
Davidson concludes from the research
that meditation not only changes the workings of the brain in the
short term, but also quite possibly produces permanent changes.
That finding, he said, is based on the fact that the monks had considerably
more gamma wave activity than the control group even before they
started meditating. A researcher at the University of Massachusetts,
Jon Kabat-Zinn, came to a similar conclusion several years ago.
Researchers at Harvard and Princeton
universities are now testing some of the same monks on different
aspects of their meditation practice: their ability to visualize
images and control their thinking. Davidson is also planning further
research.
"What we found is that the trained
mind, or brain, is physically different from the untrained one,"
he said. In time, "we'll be able to better understand the potential
importance of this kind of mental training and increase the likelihood
that it will be taken seriously." [WASHINGTON POST]
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