On 20/08/07, Aleksei Riikonen <[EMAIL PROTECTED]> wrote: > On 8/20/07, Matt Mahoney <[EMAIL PROTECTED]> wrote: > > --- Samantha Atkins <[EMAIL PROTECTED]> wrote: > > >> Huh? Are you conscious? > > > > I believe that I am, in the sense that I am not a p-zombie. > > http://en.wikipedia.org/wiki/Philosophical_zombie > > > > I also believe that the human brain can be simulated by a computer, which > > has > > no need for a consciousness in this sense. > > > > I realize these beliefs are contradictory, but I just leave it at that. > > They are not contradictory, until it is demonstrated that a perfect > simulation/copy of a human brain *isn't* conscious. For the time > being, it is certainly rational to expect such a copy to be conscious, > since we the original copies are conscious. > > It does seem that consciousness is not necessary to produce an equally > capable information processing mechanism as the human brain, but > through introspection it obvious that these particular information > processing mechanisms that we are are indeed conscious, and hence it > is rational to expect a perfect enough copy to be conscious too.
Suppose a part of your brain were replaced with a cyborg implant that exactly emulated the behaviour of the missing neural tissue: accepted inputs from the surrounding neurons, computed all the biochemical reactions that would occur had the implant not been in place, and sent outputs to the surrounding neurons. This would have to be possible, even if it presented insurmountable practical difficulties, given that brain chemistry is computable, and there is no reason to think that it isn't. Say this implant involves a large part of your visual cortex. Someone holds up their hand and asks, "How many fingers"? Without the implant, you would have said, "Three". With the implant, therefore, you say, "three": same external behaviour because the implant perfectly simulates the missing brain tissue, by our original assumption. Now, suppose that the implant *isn't conscious but only behaves as if it's conscious*. In other words, you now have a zombie visual cortex which sends impulses to your motor cortex making you say you see three fingers when in fact you are thinking, "Oh my God I've gone blind!". What's worse, you can't scream or shake your head or even increase your heart rate because (remember) your zombie implant perfectly simulates the external behaviour of the original brain, and screaming and shaking your head and increasing your heart rate are certainly external behaviours. The conclusion would then have to be that either replacing enough neurons for you to notice that they are missing would cause a bizarre and nightmarish decoupling between consciousness and external behaviour, or else a cyborg replacement that was functionally equivalent to the original brain would also have to result in equivalent consciousness. This is an account of David Chalmer's "fading qualia" argument in favour of computationalism. -- Stathis Papaioannou ----- This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?member_id=4007604&id_secret=33563088-082508
