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The Fabulous Adventure of the Brain
(October 8, 2004) -
Brain studies and neuroscience are among the most exciting and
promising research fields today. On Wednesday three top scientists
in the field gave us a glimpse of their work.
More is now known about the mechanisms of the brain.
Magnetic resonance imaging (MRI) has made it possible to pinpoint
the areas stimulated during an activity. Meanwhile PET (positron
emission tomography) scans can reveal how different regions interact
during a cerebral process.
Ravi Menon, a Professor of Neuroscience at the Robarts
Research Laboratory, said that with these tools, one thing we
can do is identify two visual pathways: perception and action.
If a region of someone’s brain has been damaged in an accident,
for example, they can identify a car yet fail to recognize a drawing
of the same car. The perception area remains inactive. The brain
can plan and anticipate a movement without the hand then moving.
Perception is therefore dissociated from action. In the future,
brain scans might explain more about how the minds of paralyzed
persons or victims of Lou Gehrig’s disease function.
According to Oakley Ray, a Professor of Psychiatry
and Psychology at the Vanderbilt Brain Institute in Nashville,
MRI is also very useful for determining the mechanisms of pain.
In 35% of cases, the placebo is more powerful than the drug. This
confirms the power of the mind, even from a negative standpoint:
some cancer victims convinced they would lose their hair did so
even though they were taking a placebo!
Finally, Rémi Quirion, Scientific Director
of the Douglas Hospital Research Centre in Montreal, said brain
scans could have a considerable impact on people’s lives.
Employers, insurers and immigration officers could require an
MRI before hiring an employee, issuing a policy or approving a
newcomer. Court decisions might even be influenced. Neuroethics
promises to raise numerous questions.
Valérie Martin
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