Friday, July 20, 2007

Life Beyond Brain Death

A Newsweek
article covers the changing definitions of death. It used to be that
when you reached "clinical death", that was it. Then it became possible
to restart the heart. Doctors moved on to declaring "brain death", when
cerebral function stopped. But it seems that even after the brain stops
working, all the information is still there and, provided
cellular death can be stopped or reversed in time, it's possible to boot
the brain back up. Normally, unrecoverable brain damage occurs within
five minutes but by lowering the body temperature,
doctors can significantly extend that time. More interestingly,
apoptosis and necrosis take time to destroy the information in the
brain, during which it may be possible to reverse the process or
cryogenically preserve the information
making up the mind and transfer it to a new receptacle; perhaps a
cloned brain or a robot. This leads to a new term: "information-theoretic
death" is the point at which the
physical structure of the brain succumbs to entropy and the mind can no
longer be reconstituted. This moral uncertitude as to when death occurs
is interesting in light of recent
suggestions that organ donation should be mandatory or done on an
"opt-out" scheme. Another
article suggests individuals be allowed to accept the legal
definition of death or define their own meaning. To
learn more about the endovascular temperature modulation techniques
described, see the Medical News
Today article on the subject.


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