by kadushka | 2025-04-16 17:41:59+00:00
We should clarify the definition of "uploading". I see two cases:

1. We gradually replace each neuron in-place - without any external connections. This means a biological brain slowly turns into a silicon brain (or whatever material used for new neurons)

2. We gradually replace each neuron with a connection to an external computational system which provides the signals that the original neuron would output. This is what I mean when I say "brain uploading".

The first case is more straightforward, and I'm not discussing it here - I expect it to be possible when the technology is ready.

The second case might have fundamental issues. The main issue is about preservation of consciousness - let's try to define it first. Consciousness is a property of a brain, which most likely depends on the signals between neurons, and which might or might not additionally depend on each neuron internal electrochemical state. When we change a brain we change its consciousness. If we change it too much, we might alter consciousness to the degree where it is not longer the same identity. This might be happening to a degree as a person grows, though I'd argue that the person would still be the same, in a sense that the person would consider himself to remain the same person over the years. For example, I remember myself 20 years ago, and even though I was somewhat different in terms of views, habits, drives, etc, I'm sure I was still me - I was not my neighbor Mike - I'm still the same captain of mostly the same ship. If we replace neurons as in case 1 above, I believe the continuity of consciousness can be preserved. But in case 2, I'm not so sure, because we are fundamentally changing the structure of the brain, not just individual components. Going back to my original example of just 3 neurons, replacing one neuron with a silicon based device in-place does not fundamentally change the overall structure of the 3-neuron brain. It's still just 3 neurons operating together as a whole. However, if we replace one neuron with a connection to an external computer, we no longer have the 3-neuron brain. We have 2 neurons which operate as before, because they still receive the same inputs from the third neuron as before, but the third neuron has fundamentally changed - it is now receiving external signals that the original third neuron did not receive, and therefore, the structure of the original brain is now different. I don't know if we can claim the consciousness of the original 3-neuron brain is preserved. The problem is that the other two neurons cannot adapt to this change, because from their point of view nothing has changed. Now if we consider that the brain has 100B neurons, and we replaced 50B neurons per case 2 - now I'm not sure what is happening to the consciousness because half of the brain is receiving external signals from some complex computational system. Does new consciousness extend to that external system? Why, or why not? If yes, how is it impacted?

Re: "emulating a mechanical watch in software". Can we upload the mechanical watch to the cloud? No, we can only replicate it. But that is not relevant to our discussion, because a mechanical watch has no consciousness which could change or be transferred.