|
| |
Scientific Research
A Course in Meditation,
2007
by Theodore K. Phelps ©
2007
-from Chapter 8 "The Naturals" pp. 227-230
|
Web readers please
note: this text is offered for your information, not as a replacement
for a course of instruction. The text is directly excerpted from the
book, and certain references do not make sense out of context.
The Science of Meditation
Meditation has a wide range of scientifically
measurable effects. In 1988 Michael Murphy and Steven Donovan, of the
Esalen Institute, published The Physical and Psychological Effects
of Meditation and reported 1,253 scientific and literary studies
on meditation going back to 1931. When they published a second edition
in 1996, they had added about 400 more studies. During those eight
years, they reported, growth in research had been "nothing short of
spectacular," with investigations moving beyond the gross physiology
to subtle changes in biochemistry and voluntary control of internal
states. The studies don’t all line up perfectly in support of
meditation’s effectiveness. They create debate and raise questions.
But, that is the way of science in every area it explores.
It takes a lot of money and time to study anything
at the level proper for professional publication. The amazing array of
studies visible even in the table of contents of Murphy and Donovan’s
book tells a significant story. There could not be such a rich set of
published studies had there not first been a long, persistent history
of meditation’s effects, felt outside of science, by people
practicing a wide variety of meditative styles. Each study began with
an intriguing suggestion springing out of direct experience.
Listing all that we now know or suspect happens
during a natural style meditation would be daunting. So, here are some
highlights that I enjoy:
Physiologically, the meditative function brings
reduced tension, greater blood flow, reduced blood pressure, slower
breathing, reduced consumption of oxygen (a measure of metabolic
level), increased brain activity in the frequencies associated with
relaxation and happiness (alpha and theta waves). Chemicals normally
associated with stress (blood lactate and the hormone cortisol) are
reduced, and calming hormones associated with wellbeing (melatonin and
serotonin) are increased.
Indeed, meditation seems to be uniquely capable of
processing the dangerously-common stress hormone, cortisol. One study
showed declines of 25% in long-term meditators during their sittings.
Short-term meditators showed small declines, and no change was seen in
the control groups doing rest and relaxation (Murphy and Donovan
1996:65). Cortisol is an adrenal hormone that is found in extremely
high levels in people with pain and is associated with the
fight-or-flight response, that stress-readiness condition urgently
needed during periods of acute physical danger. Cortisol is a damaging
chemical to leave lingering in the bloodstream. It can be cleared out
when the event that triggered it can be addressed directly with an
explosion of physical action (fighting or running away); otherwise, it
lingers and corrodes the body. Dharma Singh Khalsa, M.D., a previous
graduate student of Benson and author of Meditation as Medicine
says that the stress-induced overproduction of stimulating hormones,
such as cortisol and adrenaline, "accelerates the aging process, and
is a major risk factor not only in Alzheimer’s disease but also in the
far more common condition of age-associated memory disorder"
(2001:84,180). He also favors meditation as a way of clearing cortisol
from the bloodstream. |
Oxygen Consumption
Herbert Benson, then at the Harvard Medical School,
joined physiologist Robert Keith Wallace, Ph.D and others in the early 1970s
in studying the physiology of people practicing TM. In 1975 he reported on
this early research in the first of his several bestselling health and
wellness books, The Relaxation Response. Benson saw that there was a
coordinated deep restfulness during certain forms of meditation. Although
people who meditate knew that the body can become unusually quiet, it was
striking scientific news that meditation is producing significantly
deeper rest than sleep. This is determined by measuring how much oxygen
is consumed. In sleep, oxygen consumption gradually decreases about eight
percent over four or five hours. In meditation, it drops 10 to 20 percent in
the first three minutes (Benson 1975:64).
The amount of oxygen an animal consumes changes moment
from moment, being controlled by a complex process of the body called
metabolism. We can indirectly affect metabolism by changing the level of
physical activity—resting, running, eating, sleeping, or meditating—but we
cannot control it directly. We don’t lower our oxygen consumption when
holding the breath, because the tissues go right on consuming oxygen from
the bloodstream according to their need and at approximately the same rate.
So, this significant lowering of the consumption of oxygen in meditation
implies a deep, complex, and organized shift in what the body is up to. It
is especially significant considering that most meditators have no idea it
is happening.
Benson’s original work on oxygen consumption has held up
well. In 1996 Murphy and Donovan reported that over 40 studies have shown
reduction of oxygen and carbon dioxide elimination. They report that oxygen
consumption has been reduced by 55% and carbon dioxide elimination by 50%,
and that breath rates have been seen as low as one breath per minute.
Recalling the mapping of the Naturals in the first two
talks (Chapters 6 and 7), we could predict that only some methods of
meditation would produce these changes. And that is true. Citing 45 studies
between 1957 and 1991, Murphy and Donovan observed that, "Such quieting of
the organism, however, happens for the most part in quiet meditation of the
TM or zazen type, not in active, high-arousal practices such as Ananda Marga
Yoga" (1996:69). In my terms, it happens with the Naturals.
The Meditating Brain
Benson reported that certain electrical brain activity
(EEG alpha and theta waves) increases both in intensity and frequency during
meditation (1975:64). His early findings have held up well. Murphy and
Donovan cite 36 studies between 1955 and 1987 showing increasing alpha
rhythms using many types of meditation, including sessions with Zen masters
(see EEG described in Chapter 9).
Murphy and Donovan cite 25 studies between 1955 and 1984
showing an unusual "synchronization/coherence" of alpha activity among the
four quadrants of the brain, front, back, left, and right. They note that
this effect has been scientifically associated with creativity.
Synchronization of the various parts of the brain is particularly
significant because meditation is more than relaxation and peacefulness. It
opens the mind to a rich source of intelligence and creativity. In the next
talk, I will describe recent research on the brainwave patterns in highly
developed (enlightened) long-term meditators.
Our knowledge of the brain in meditation will become much richer in
coming years as researchers move beyond EEG to new, dynamic, 3-dimensional
imaging tools, such as computed tomography and magnetic resonance imaging.
These tools have already been used to show how areas of the brain shift
activity during meditation and to chart some lasting changes in brain
structure with long meditation practice.
|
|
