Meditation
Gives Brain a Charge, Study Finds
By Marc
Kaufman
Washington Post Staff Writer
Monday, January 3, 2005; Page A05
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."
©
2005 The Washington Post Company