[hgomersall]

There's an interesting thought experiment that goes the other way. What if we replace a single neuron in a conscious person's brain by a properly connected real-time neuron simulator? Would that affect the person's consciousness? What about two neurons? Etc etc. At what point, if ever, would a progressively more simulated brain no longer be the original consciousness?

[hoseja]

This may be a little deceptive depending on how you define "a properly connected real-time neuron simulator". Can it form new connections? Can it grow? Does it metabolize? Can it die? Etc...

[kertoip_1]

But does it really matter? If we can just replace, one-by-one all neurons in brain with artificial ones and that would not affect consciousness of the user, then we've just proved it's possible to have a thinking machine

[hoseja]

What if you replace all the neurons and the person is suddenly stuck with no short-term memory and aphasia? Clearly your replacement neurons are defective. At which point are they not? Is that point distinguishable from normal neurons?

[sudosysgen]

What is this counterfactual? We're talking about replacing the neurons one by one, slowly. When would the loss of memory happen?

[criddell]

Is a person with no short-term memory and aphasia still conscious?

[hgomersall]

These are all good questions and probably allow our realised thought experiment to gain more insight into what aspects are necessary for consciousness and what are just biological baggage.

[hoseja]

I suspect the line is very blurry indeed.