X-Message-Number: 26297 Date: Tue, 7 Jun 2005 10:42:17 -0400 From: Thomas Donaldson <> Subject: computer simulation of brains Hi everyone! It will be very interesting indeed to see how well the Blue Brain Project actually works when it's implemented. The major question in my own mind about this project comes from the evidence of just how variable are brains are; most of such evidence came out in the last 15 years. Implementors of a brain model will need to implement changes in number and destination of synapses, and the production of new neurons, both. I do not know myself to what degree such variability will turn out to be important, but simply because of natural selection it seems very unlikely to me that we retain those features without using them a lot. It's even more interesting that production of new neurons by the subventricular system does not, at least in monkeys and very likely not in humans, make neurons which primarily migrate to the olfactory cortex. Given the differences between the architecture of Big Blue and that of our brain, implementors will clearly have to write a simulation of brains (and use more power and processors to run such a simulation). To some degree a simulation can use "new neurons" and "new connections", but they will likely become too many and cause problems long before real new neurons and connections would do so. I hope that the implementors of this idea tell us of their work in an ongoing way. They've started a very large project, perhaps too large for any fixed computer, and larger than they may think. If they get some good information from it about how our brains work that will be very nice, whether or not it actually fails in the end as a true simulation of a real brain. Best wishes and long long life to all, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=26297