| Neurophysiology
of Meditation
Knowledge of the neurophysiology of meditation is changing
rapidly. Recent advances in medical imaging, such as
rCBF (regional Cerebral Blood Flow), real time MRI (Magnetic
Resonance Imaging), MEG (magnetoencephalography), and
improved EEG (electoencephalography) allow detailed studies
that are reshaping our understanding of the effects of
meditation on neural behavior. Already there are several
basic effects that have been discovered through scientific
research in the recent past which demonstrate the profound
influence meditation has on neurophysiology.
Andrew Newberg,MD has been conducting high-tech investigations
of the brains of meditating Buddhists and Franciscan
nuns at prayer in order to illuminate the chain of neurological
events that are triggered by intensely focused spiritual
contemplation. In collaboration with the Departments
of Neurology and Psychiatry at the University of Pennsylvania
Medical Center, he had an advanced Tibetan Buddhist meditator
engage in meditation while hooked up to an IV. When he
approached the transcendent peak of his meditative state,
he tugged on a string. Dr. Newberg was at the other end
and when he felt the pull, he released a radioactive
dye into the IV line. Then the mediator was whisked into
a SPECT (single photon emission computed tomography)
brain-imaging machine to determine which areas are active
by measuring blood flow.
Dr. Newberg found that the front part of the brain,
which is usually involved in focusing attention and concentration,
is more active during meditation, but there was greatly
decreased activity in the parietal lobe. See his pictures
on:
 The
Effect of Meditation on the Brain activity of Tibetan
Meditators
The parietal area of the brain is responsible for giving
us a sense of our orientation in space and time. He hypothesized
that blocking all sensory and cognitive input into this
area during meditation results in the sense of no space
and no time. When this part of the brain, which weaves
sensory data into a feeling of where the self ends, is
deprived of sensory input through the meditator's focus
on inward concentration, it cannot do it its job of finding
the border between the self and the world. Dr. Newberg
described how this affects consciousness:
The brain had no choice. It perceived the self to
be endless, as one with all of creation. And this felt
utterly real. The absorption of the self into something
larger [is] not the result of emotional fabrication
or wishful thinking. It springs from neurological events,
as when the orientation area goes dark.
Why
God Won't Go Away : Brain Science and the Biology of Belief by
Andrew Newberg M.D
Neuroelectrical
Effects
Early scientific studies on the neurophysiology of meditation
focused on changes in brain wave (EEG) patterns, and
differences in brain wave patterns between meditators
and non-meditators. In summary, mediation was shown to
 increase
Alpha (8-13 Hz or cycles per second) production
increase Theta (4-7
Hz) production
increase high Beta
(20-40 Hz) activity (with experienced meditators)
Alpha patterns are associated with calm and focused
attention; Theta patterns are associated with reverie,
imagery, and creativity; high Beta activity is associated
with highly focused concentration. It was therefore argued
that meditation contributed to a calm, creative, and
focused pattern of brain activity which resulted in a
person with these same qualities. Other early research
indicated that meditation produced an increased hemispheric
synchrony, which was correlated with creativity, and
decreased habituation, which was claimed to indicate
a "freshness of perception," although studies
on these last two areas provided mixed results.
QUIZ EXERCISE 13:
Which best describes the relation between alpha brain states and meditation? ...
a) The alpha state is the best indicator of successful meditation b) Meditation harmonizes the alpha state, and balances the brain c) Alpha brain wave activity is increased by meditation practice d) the alpha state is the goal of meditation
Record your answers for later insertion into the Quiz. |
Neurochemical
Effects
More recent studies have looked at the neurochemistry
of meditation. Meditation has been shown to increase
serotonin production. Serotonin is
an important neurotransmitter and neuropeptide that influences
mood and behavior in many ways. Its importance is demonstrated
by the recent explosion in use of fluvoxamine, a " selective
serotonin re-uptake inhibitor" like Prozac, Paxil, and
Zoloftsuch, for treating depression-related emotional
disorders. Low levels of serotonin have been linked to
a variety of disorders. For example, conditions associated
with low serotonin levels include: depression,
obesity, insomnia, narcolepsy, sleep apnea, migraine
headaches, premenstrual syndrome, and fibromyalgia.
QUIZ EXERCISE 14:
In what way is meditation related to Prozac? ...
a) Prozac is an effortless meditation b) They both increase the available serotonin in the brain c) They both have significant negative side-effects d) Meditation is a cheaper version of Prozac
Record your answers for later insertion into the Quiz. |
Meditation has also been associated with increased
melatonin availability. Melatonin is also an important
neurotransmitter and neuropeptide that influences mood
and behavior. It is derived from serotonin. Melatonin
has been linked to regulation of sleep, and early research
indicates it may have anti-carcinogen and immune system
enhancing effects.
QUIZ EXERCISE 15:
How does meditation influence the neurochemistry of depression? ...
a) Meditation increases available serotonin and melatonin to the brain b) Meditation increases the alpha state, and balances brain chemistry c) Meditation doesn't have a specific effect, so it can't directly influence anything d) Depression is due to excess serotonin which meditation reduces.
Record your answers for later insertion into the Quiz. |
These early studies on the neurochemical effects of
meditation on serotonin and melatonin, coupled with the
established research on the neuroelectrical effects of
meditation, indicate the profound and wide-ranging neurophysiological
consequences that a regular practice of meditation may
provide. They also hint at the neurophysiological basis
for the numerous health benefits that are attributed
to meditation, as well as the difficulty in attributing
a specific causal chain to meditation as a treatment
effect. Because of these numerous, system-wide influences,
meditation may remain a captive of "non-specific
effects" within experimental psychology, even as
the neurosciences demonstrate the effectiveness and importance
that a meditation practice offers for personal health.
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