[magusdei]

Can you specify what you mean by "emulate my brain within an acceptable margin of error"? What would this mean as an actual experiment? Depending on your answer, I think we can actually test your implicit proposition that no such algorithm exists.

[qsort]

I'm not actually claiming no such algorithm exists, as I have already stated, but simply that such a thing is not known to exist.

I'm not an expert in neurosciences so I can only give an informal description. Let's also remove "me" from the equation, let's talk about a randomly chosen human H. We know for a fact that there is nothing physically special about human brains, they are just ordinary organic matter. This matter forms a system subject to the laws of physics. With enough computational power and scientific knowledge (we have neither as of now, AFAIK), we could write a program for a quantum Turing machine that runs a 1:1 simulation of H's brain in software. Any quantum program can be emulated by a Turing machine equipped with sufficient random numbers with at most an exponential slowdown, making this program computable in exactly the classical sense.

My questions are (1) is it possible, even in principle, to make a program of this kind? (2) Would such a program be sufficiently predictive (with any statistical notion of that concept you prefer) of H's behavior?

If there exists a program that satisfies both (1) and (2), then I'm content with the notion that I am, myself, not significantly different from such a program.

[magusdei]

Hmm, this still doesn't quite answer my question at the level of concreteness I was looking for. But thank you for clarifying.

The thing is, you can only define predictive accuracy relative to some experimental design. Otherwise you can always claim that there is some unknown, unperformed experiment where the predictions of the model and your actual behaviour would diverge to a greater degree than is permissible by your accuracy threshold, no matter how many successful experiments have already been done in constrained conditions.

Imagine a task where you have to classify images as being of dogs or non-dogs. We can already train a model that can almost perfectly predict the choices you would make during the runs of such an experiment. But we obviously wouldn't call such a model a "model of your brain"!

My question is this: what would be a sufficient experimental design or empirical criterion to decide that some program is a model of you? The loosest criterion I could imagine would be something like "can successfully deceive your loved ones into believing they are you in a single text chat of unbounded duration with some extremely high success rate." Recent advances in NLP lead me to believe that we'll be able to reach at least this level of fidelity quite soon.

[mannykannot]

To be fair, qsort is not insisting on seeing an algorithm that is metaphysically identical with a human mind, nor claiming that such an algorithm would be a p-zombie, devoid of subjective experiences, which are both positions that you might find from dualist philosophers.