The effects
of meditation on the brain.
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Aim: Examine differences in brain activity that
might have resulted from having engaged in meditation over a long period of
time.
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Participants: -12 experienced meditators 7/12 were
Asian.
- Untrained Caucasian that was interested
in trying to learn meditation.
- Control group
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Procedure: The participant’s brains were
scanned using fMRI while they concentrated on a red dot on a screen in front of
them, and while at rest with no concentration. Researchers played various noises
in an attempt to distract participants from meditation.
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Results: During meditation, attention related networks
in the brain and the visual cortex would be more active, than during rest
periods. Novice meditators found it more difficult than experts to sustain
their concentration. Experienced meditators showed a response to the disturbing
stimuli, not in terms of a change in attention away from the target of their
concentration meditation, but in terms of some kind of adjustment of
concentration, perhaps an active resistance to being disrupted.
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Conclusion: The experienced meditators showed
response to the disturbing stimuli, not in terms of a change in attention away
from the target of their concentration meditation, but in terms of some kind of
adjustment of concentration, perhaps an active resistance to being disrupted.
The differences are probably due to neuroplasticity, some kind of changes in
the brain that have occurred over time as a result of periods of sustained meditation.
Changes in
the brain after juggling training.
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Aim: Determine whether both functional and structural
changes could be detected in the human brain as a result of learning a new
motor skill.
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Participants: - 21 females
- 3 males
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Procedure: Half of the participants had 3
months to learn a basic juggling routine. Structural MRI scans were done before
and after the three months, and a third scan was made 3 months later. During
this time participants did not practice their skills.
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Result: While there was no significant group
differences in brain structure in the first scan (before training), two areas
of the brain were significantly different in size after training. The difference became smaller in the
third scan, when practice had ceased for three months. These differences were apparently
due to an increase in volume in the two regions of the juggler’s brain.
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Conclusion: The practice of watching balls moving
through the air repetitively and learning to move in response to this
strengthened the connections between neurons in the parts of the brain
responsible for this activity.
Changes in the
brains of experienced London taxi drivers.
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Aim: Determine if fully London Taxi drivers have
structural differences in their hippocampi as a result of being “on the
knowledge”
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Participants:
Fully licensed London Taxi drivers, with a range of experience years.
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Procedure: The researchers used MRI scans of the brains
of the Taxi drivers and compared them to scans of healthy males who did not
drive Taxis.
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Result: Researchers found that both the left and right hippocampi
were significantly higher in volume in the brains of the Taxi drivers, although
there were some parts of the Hippocampi that were smaller in the brain of Taxi
drivers. He researchers found a positive correlation that could not be
accounted for by age differences.
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Conclusion:
There has probably been a redistribution of grey matter in the hippocampi
as a result of intense development and use of spatial memory skills,
specifically those relating to learning and remembering routes through the
city.
PET
evaluation of bilingual language compensation following early childhood brain
damage.
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Aim: Can the fact that both of your parents are deaf
and that you have to use sign language from a young age, can this might have
had something to do with his ability to speak despite brain damage.
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Participants: Subject “MA” who suffered a lesion on
the left frontal lobe at the age of 6 weeks.
- 12 control subjects who were fluent in sign
language.
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Procedure: The researchers compared MA and 12
other control patients, using PET scan they compared them while the
participants produced narrative speech or signs. The participants also had to
do perform a set of motor control tasks.
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Result: The researchers found that MA’s right
hemisphere was more active than control subjects’ during the production of both
speech and sign language. MA seemed more anxious and agitated. He was judged
normal by independent observers of speech and sign language production and
neuropsychological tests. These findings suggest that language function seems
to have developed in the right hemisphere instead of the left hemisphere as a
form as adaption.
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Conclusion: MA’s language abilities may have
developed in the right hemisphere at the expense of visuo-spatial ability.
