"Greg Egan - The Extra (2)" - читать интересную книгу автора (Egan Greg)

stood back and watched.
But . . . had they merely swapped places, he wondered, or had they swapped
bodies? His dreamer's point of view told him nothing - he saw all three bodies
from the outside - but the lean young man who watched bore Gray's own
characteristic jaded expression, and the middle-aged man in Sarah's embrace
moaned and twitched and shuddered, exactly as the Extra had done.
Gray was elated. He still knew that he was only dreaming, but he couldn't
suppress his delight at the inspired idea of keeping his old body alive with the
Extra's brain, rather than consigning it to flames. What could be more
controversial, more outrageous, than having not just his Extras, but his own
discarded corpse, walking the grounds of his estate? He resolved at once to do
this, to abandon his long-held desire for a symbolic cremation. His friends
would be shocked into the purest admiration - as would the fanatics, in their
own way. True infamy had proved elusive; people had talked about his last stunt
for a week or two, and then forgotten it - but the midsummer party at which the
guest of honour was Daniel Gray's old body would be remembered for the rest of
his vastly prolonged life.
Over the next few years, the medical research division of Gray's vast corporate
empire began to make significant progress on the brain transplant problem.
Transplants between newborn Extras had been successful for decades. With
identical genes, and having just emerged from the very same womb (or from the
anatomically and biochemically indistinguishable wombs of two clone-sister
Extras), any differences between donor and recipient were small enough to be
overcome by a young, flexible brain.
However, older Extras - even those raised identically - had shown remarkable
divergences in many neural structures, and whole-brain transplants between them
had been found to result in paralysis, sensory dysfunction, and sometimes even
death. Gray was no neuroscientist, but he could understand roughly what the
problem was: Brain and body grow and change together throughout life, becoming
increasingly reliant on each other's idiosyncrasies, in a feed-back process
riddled with chaotic attractors - hence the unavoidable differences, even
between clones. In the body of a human (or an Extra), there are thousands of
sophisticated control systems which may include the brain, but are certainly not
contained within it, involving everything from the spinal cord and the
peripheral nervous system, to hormonal feedback loops, the immune system, and,
ultimately, almost every organ in the body. Over time, all of these elements
adapt in some degree to the particular demands placed upon them - and the brain
grows to rely upon the specific characteristics that these external systems
acquire. A brain transplant throws this complex interdependence into disarray -
at least as badly as a massive stroke, or an extreme somatic trauma.
Sometimes, two or three years of extensive physiotherapy could enable the
transplanted brain and body to adjust to each other - but only between clones of
equal age and indistinguishable lifestyles. When the brain donor was a model of
a likely human candidate - an intentionally overfed, under-exercised,
drug-wrecked Extra, twenty or thirty years older than the body donor - the
result was always death or coma.
The theoretical solution, if not the detailed means of achieving it, was
obvious. Those portions of the brain responsible for motor control, the
endocrine system, the low-level processing of sensory data, and so on, had to be
retained in the body in which they had matured. Why struggle to make the donor