X-Message-Number: 3955 From: (Thomas Donaldson) Subject: Re: CryoNet #3903 - #3907 Date: Sun, 5 Mar 1995 22:45:44 -0800 (PST) Hi again! This will probably be my last message tonight (I have other things to get done). Some will cheer and others will weep, no doubt. But about symbol manipulation, computing, and uploading: unlike what Ettinger says, even when we think we are NOT manipulating symbols. I say this because if you think about the issue even a little bit, it becomes clear that at some level you must leave off dealing with symbols. It's what the symbols MEAN that is important, and working with that is what we are trying to do. Take it to a very basic level: flatworms can show very primitive learning. When they learn to turn left or right in a T-maze, are they manipulating symbols? I'm not talking about feeling at all, but about how symbols work. We build our computers to manipulate symbols for us. Sometimes they can do it much better than we. But the MEANING of their results and their inputs comes entirely from us. Even if we design the computer to take actions depending on its results, those actions ultimately come from us. A bit of thought will show that if we did nothing but manipulate symbols when we thought then we'd quickly find ourselves in an infinite regress or (perhaps) chasing our tail around and around. We can't find out the meaning of words from a dictionary alone, whether or not it is encoded in our brain. If we find one word, it will be defined only in terms of others (all symbols). When we as human beings learn to speak and think, we learn words by associating them with incidents and things in the real world. Ultimately that association cannot be a matter of symbols but of real, concrete acts. Moreover its very doubtful by now that we have memories in the sense that computers do. We are shaped by our learning and our environment, plus our basic physical type (including our brain) to respond to incidents and events in the world, not responding to symbols but to reality. That shaping is dynamic;but if we were to look at it at any instant, it would be much more as if our responses came out of our design. A can opener, for instance, has been designed to open cans, and no amount of symbolic manipulation will open a can of soup. We are far more complex, and can change much more, but we work like the can opener and not like a computer (in the contemporary sense of computer). Does the can opener have a memory? It's noteworthy here that neural nets also show some of these properties. Their responses depend on how they are connected up, not on an ordinary computer memory. Certainly we might use a computer to simulate them, but a real neural net (say, using Intel neural net chips (yes, Intel makes chips for that purpose) won't be a simulation. It will, in its own way, be more like the can opener (or our brains) than like a computer. The difference between our brains and the physical neural nets various scientists and engineers have constructed (and which are now finding more and more use, in a way just like Robin mentioned!) is that our brains also have special properties that make the wiring far more dynamic. Such processes, among other things, involve the use of short term chemical changes to preserve an association while behind those changes other physical rewiring (involving protein synthesis) can go on. Long long life, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=3955