You see are certain amount of conversation in futurist circles about the idea of people living forever by uploading their brains into a computer. The idea is that if the brain is “simply” a collection of (albeit very complex) circuits sending signals to each other (these circuits are the neurons and collections of neurons linked in the brain) then we should be able to map out a person’s neural circuitry and replicate it with virtual circuitry in a computer. The makes sense if you believe that your self— your personality/character –– is a result of the specific structure of your neural connections (and there’s a lot of evidence to support that view.) The virtual circuitry of the computer brain would not decay the way our human “meat circuitry” does and thus people could live forever.

The problem I’ve always had with this theory is that it sounds more like cloning than uploading consciousness. I could be sitting here in my body and maybe you duplicate all the complex circuitry of my brain but you end up only with a virtual brain that thinks exactly like me. My consciousness is still stuck here in my decaying (though quite beautiful) body.

However, I was recently musing on a thought experiment described in Steven Pinker’s “How the Mind Works.” Let’s say you have a functioning conscious brain sitting around somewhere. Let’s say you replace one neuron in that brain with a metal wire that sends electrical signals in the same way as the neuron it’s replacing (this may be an impossibility right off the bat but stick with me here.) Then you replace a 100 more neurons in the same way. Then a 1000 more etc. until you’ve replaced all the brain neurons with wire counterparts. Would during this process the brain’s consciousness move from meat circuitry to wire? Or would it get lost in the process?

I don’t know and nobody does. But it might work.

However I suspect one error here is the idea of thinking of consciousness as a force or spirit that can be transferred from one shell (e.g. brain or set of circuits) to another. We are presuming that our own consciousness or self is, at the very least, continuously inhabiting our own brains (at least until we go to sleep or get knocked out.) But I wonder if it’s more a situation where our consciousness continually rises out of our current brain state from moment to moment and because we have access to memories we have a sense of a continuing self? In which case that self is something of an illusion. (This is certainly not my idea; it’s the crux of the book “The User Illusion.”)

In effect I’m saying, not only can we not move our consciousness from one shell to another, we can’t even maintain it in a single shell. It’s only because if the fact that our consciousness semi-reliably arises out of our brain in a familiar condition that we have the sense of continuity.

I dunno. This gives me a headache.