X-Message-Number: 3464
From:  (Thomas Donaldson)
Subject: SCI.CRYONICS: Individual Variation in Brain Connectivity
Date: Sun, 11 Dec 1994 07:34:59 -0800 (PST)

Hi again!

Brian Wowk may already know this, but he doesn't indicate it in his discussion,
so I will add the point myself: it is very unlikely that a map of the connect-
ions of MY brain will correspond to a map of the connections of YOUR brain.
Connections themselves aren't genetically determined (at least, this is the
strong consensus among neurobiologists. Theoretically they MIGHT be, but no
one believes that).

What we WILL have is generic resemblances. That is, on a gross scale (say at
over 1 cm) the connections in our brains will look similar. Below that scale,
differences will show up strongly. These differences will have resulted first

from chance events during embryonic development, and second from the effects of 
experience on the brain.

We can't therefore expect to get GENERAL insights about brains from such maps.
If we are attempting to revive a suspension patient, such a map may prove 
useful --- but note that even Ralph Merkle's methods involve destruction of
the original brain tissue. (If we read it into a computer --- RELIABLY ---
I would agree that such destruction doesn't really matter, although I remain
doubtful about whether it is wise for us to want to be revived AS computers of 
any kind other than brains).

As for workinng out the connections in brains at a resolution of 1 cm, we are
very close indeed to doing this. And it will tell us a good deal about how
our brains work, though nothing that relates to particular individuals.

			Long long life,
			  Thomas Donaldson

PS: Strictly speaking, you should hope that your brain is not the same as 
mine. As many cryonicists know, I had a brain tumor --- an astrocytoma, 
treated with radiation --- 5 going on 6 years ago. This will have disrupted
part of my brain and still affects me. And if you have the SAME structure as
I you should see your neurologist immediately!

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