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! Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=3464