Download Read More - Bruce Lieberman

April 5, 2006
Buddhism and the art of brain science
Dalai Lama and researchers collaborate in mix
of meditation and neuroscience
By Bruce Lieberman
Staff Writer
The San Diego Union-Tribune
In October 2004, neuroscientist
Fred Gage took a leap of faith and flew to
India to present a lecture to Tenzin
Gyatso, the current Dalai Lama.
The religious leader had asked him
to participate in a workshop on brain
science at his compound in Dharamsala,
in the foothills of the Himalayas.
The Dalai Lama wanted to learn
more about Gage's explorations at the
Salk Institute in La Jolla into the adult
brain's ability to generate new cells.
As the spiritual leader of
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.
Could science identify a physical
signature of that effort somewhere in the
vast landscape of the brain?
Gage was wary. His colleagues had
urged him to embrace the Dalai Lama's
invitation, but he flew to India with
unsettled questions.
"One of the concerns was that a
religious leader would have preconceived
notions, and then whatever you said they
would just use your words to further
support their already established belief
systems," Gage said.
After a week in Dharamsala, he
was pleasantly surprised. "There was
clearly an interest in dialogue," Gage said.
"He was really quite open to
learning new things, and incorporating
scientific
knowledge
into
their
philosophy."
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.
The two obviously come from
two very different perspectives, explained
R. Adam Engle, co-founder of the Mind
& Life Institute in Colorado, which
studies connections between Buddhist
traditions and modern science.
Until recently, brain science in the
West has been significantly geared toward
studying what can go wrong. "Research
has been focused on creating a mythical
state of normalcy defined by absence of
disease symptoms, Engle said. "There's
been very little effort into (studying) what
a truly healthy mind is, and how one
creates and maintains that."
Aided by the interest of the Dalai
Lama, that may be slowly changing.
Studies are tackling questions such as:
What do measurements of brain changes
mean? How does meditation affect sleep,
attention and memory? What are the
benefits of meditation, and how can
scientists begin to understand and
measure them?
Positive emotion
People
have
studied
the
connections between meditation and brain
physiology for years. Hundreds of studies
of
Transcendental
Meditation,
popularized by The Beatles, were
conducted throughout the 1970s, but
1
many were flawed, explained Sara Lazar, a
Harvard Medical School neuroscientist.
Only recently has research been
rigorously performed, fueled by two
developments. One is Gage's 1998
discovery and subsequent studies 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
cellular 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 Harvardeducated researcher at the University of
Wisconsin, Davidson has since brought
Buddhist monks to his lab. There he has
hooked
them
up
to
an
electroencephalogram, 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 of 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 -- which
are associated with concentration and
emotional control -- not seen in control
groups. These changes are sustained even
after meditating.
"It remains for future studies to
show that these EEG signatures are
caused by long-term training itself and not
individual differences before training,"
Davidson and his colleagues wrote in their
2004 study in the Proceedings of the
National Academy of Sciences.
Understanding differences in
EEG activity is problematic for the simple
fact that neuroscientists do not yet
understand what they mean.
"What on earth is the relation
between what we're seeing at the EEG
level (with) these various rhythms and
what is going on at the cellular level?
We don't know," said Patricia
Churchland, a cognitive neuroscientist at
UC San Diego who studies the nature of
consciousness.
Thickening the brain
At Harvard, Lazar has found that
people who incorporate meditation into
their daily lives have thicker brain tissue in
regions associated with attention and
sensory processing. Her results, published
in November in NeuroReport, showed
that those regions were 20 percent larger
than in control groups. Practicing
meditation regularly may slow age-related
thinning of the frontal cortex, her study
suggests.
Of the 20 subjects studied, two
were full-time meditation teachers and
three were part-time yoga or meditation
teachers. The rest were professionals in
other fields who meditated an average of
once a day for 40 minutes.
"A lot of studies of meditation
look at EEG. They sit there and start
meditating and something happens,"
Lazar said. "That's nice, but the reason
people meditate is because it affects every
aspect of your life -- at least that's what
meditators claim. So this was the first time
we were able to show something really
concrete, a measure of something that
2
changes permanently."
Many questions remain, however.
Lazar does not yet know whether the
brain growth was due to increased
numbers of neurons, more support cells
or a growth in blood vessels feeding that
area.
It shouldn't be surprising that
meditation alters part of the brain
physiologically, scientists say. Musicians,
linguists and athletes have thicker brain
tissue in areas associated with their
strengths and talents.
"It makes sense that if you're using
part of your brain a lot, it's going to get
worked out and there's going to be more
stuff in that area to support increased
usage," Lazar said. "In a sense, that's all
we're seeing."
In follow-up studies, she plans to
study whether the increased thickness is
correlated with increased attention and
memory.
For the sleepy
Bruce O'Hara, from the University
of Kentucky, has been interested in claims
by Buddhist monks that dedicated
meditation can reduce the need for sleep.
If true, meditation might be of value to
people with sleep disorders or those
whose jobs leave them sleep-deprived.
During sleep, neurons fire with
more synchrony than during wakefulness.
In the deepest stage of non-REM sleep,
the dominate brain wave is called a delta
wave. During meditation, brain cells fire
with a different synchrony that produces
alpha waves.
The question is: Can alpha waves
be as restorative and therapeutic as delta
waves?
O'Hara first put subjects to a
psychomotor vigilance test, which is a
simple measure of reaction time. During
the test, subjects press a button as soon as
they see an LED clock display begin to
tick. Most alert people push the button
after about 200 milliseconds. The test
randomly repeats over 10 minutes, and a
subject's results are closely correlated with
how sleepy they are, going into the test.
Each subject, none of whom was
an experienced meditator, took the test
after spending 40 minutes in casual
conversation, reading, sleeping or
meditating. Only when the subjects
meditated prior to the test did their scores
improve.
"It was amazing how consistent it
was," O'Hara said. "Twelve out of 12 of
our first subjects all improved (on the test)
following meditation."
O'Hara also tested subjects who
deprived themselves of sleep the night
before. Those who meditated right before
the test performed better than those who
did not.
O'Hara next examined sleepdeprived subjects who took a nap right
before the test. They actually did worse
because it takes time to fully recover
alertness after a nap.
The biggest boost in performance
was short-lived, O'Hara found. Meditating
subjects, whether alert or sleep-deprived,
still performed better on the test an hour
after meditating, but their performance
did decline.
As for the question of whether
meditation can replace sleep among
practiced meditators, O'Hara said, "it
looks like there is a payback, but at best
it's that two hours of meditation equals
one hour of sleep."
In future studies, O'Hara plans to
use EEG tests to examine whether a
boost in alpha waves during meditation
correlates with a commensurate drop in
delta waves during sleep after meditating.
Such a measurement might provide
evidence that meditation does restore the
brain in a way that requires less sleep, he
said.
Peptide connection?
There are still many questions
about what exactly is changing in the brain
3
and what is behind the changes. UCSD's
Patricia Churchland said meditation may
alter production of peptides. More than
100 of the small-chain molecules populate
the brain, mixed among the brain's
billions
of
neurons,
glial
and
oligodendrocyte support cells and blood
vessels.
One of these peptides, called
oxytocin, has been associated with a
general feeling of well-being, even a sense
of trust in social situations.
"If you wanted a source of
speculative hypothesis, mine would be
that the real story is going to be found at
the level of the vast range of peptides that
are sloshing around," she said.
For Gage, at the Salk, using
neuroscience techniques to understand
meditation's effect on the brain may teach
scientists new things about human
biology. "It's a very serious opportunity to
use neuroscience and its knowledge to get
insight into very, very complex
behaviors," he said.
Some scientists disagree, however.
Last fall, before the Society for
Neuroscience
meeting, a
petition
protesting the society's invitation to the
Dalai Lama was posted on the Web.
"It is ironic for neuroscientists to
provide a forum for and, with it, implicit
endorsement of a religious leader whose
legitimacy relies on reincarnation, a
doctrine against the very foundation of
neuroscience," the petition read in part.
Gage said the decision to invite
the Dalai Lama was a good one, and that
neuroscience and Buddhist practitioners
of meditation can legitimately focus their
discussions on the brain and mind.
"It's a philosophy, and they're not
trying to promote anything," Gage said.
"There's an interest in sharing ideas, and I
think science has to be open to that."
-End-
4