X-Message-Number: 11798 From: Thomas Donaldson <> Subject: Answer to Mike Perry plus longer discussion for Daniel Crevier Date: Sat, 22 May 1999 23:30:32 +1000 (EST) For Mike Perry: My reason for saying that dreams are not the same as virtual consciousness is simple. They DO depend on previous consciousness, and persist for only a finite length of time. It isn't sufficient to keep a brain only TEMPORARILY isolated to make its thinking virtual. If I go into my room, lie down, and close my eyes to think about something, I am just as isolated, but that is hardly the same as the long term isolation of a "virtual person" (if such is possible) in a computer. There is, of course, also the simple point that it is only for unproved theoretical reasons that the behavior of a living brain can be imitated by a computer (highly parallel or not). And to say that these living brains occasionally pass through a period of virtual reality says nothing about whether or not a computer could do so. To Daniel Crevier: I have discussed this issue several times in PERIASTRON. I can send you precise bibliographic information once I look it up, but basically an article in the JOURNAL OF CHEMICAL NEUROANATOMY (I believe in 1998) showed how we can distinguish at least 5 different kinds of interneuron solely on the basis of whether or not they contained specific biochemical factors. In two cases, the distinction lay in the ratio between two such factors rather than any absolute level of containment. Such information needs to be developed a good deal further; even those studying such questions would agree. (I plan to report on several recent articles looking at chemical neuroanatomy in the coming PERIASTRON ... the 1 May issue, out towards the end of May). At its simplest level, such information means that electron micrographs alone are unlikely to provide enough information to decide whether or not a brain is revivable --- unless they show literally TOTAL destruction, which they do not. As I've said, I'll have to look up the exact issue and article, and can send that to you separately. Best and long long life to all, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=11798