The argument that if a neuron simulation calculated the proper state 1000 times too slow or too fast it wouldn't "work" with other neurons is both trivial and obvious.
Coupling.
If the whole thing is simulated, time in our frame is no longer relevant -- only time in the simulation. Church-Turing is correct.
If only part is simulated, then time in the simulation must couple correctly with time in our frame. Obviously this requires something in addition to a "Turing machine" just like any two systems require an interface in order to interact with each other.
Durr.
Thats why I was careful to say "and a suitable interface" in every relevant statement of that post.
Try reading, westprog. It helps.
Well Al Bell said so, and you jumped in.
You contend that if we replaced a single neuron with a simulated one + interface, the brain would cease to be conscious?
What I don't get here is that you keep skimming over the point that a Turing machine + suitable interface
doesn't work.
Can't work. It won't be a Turing machine any more. It will be a different device altogether.
I know that you keep coming up with ways to avoid this. Yes, a perfect implementation of a Turing machine isn't possible in the real world. So what? The same applies to
any design or concept. If we were to use that as an approach, we wouldn't be able to reason about
any system.
What makes the concept of the Turing machine useful is that we can make predictions about computations. These predictions are of great practical value. We know that we can launch our Pascal computations into the time-sharing computer, and not worry about implementation details or interaction with the world - and be sure that the program which takes an hour will give exactly the same result as one that take a millisecond.
This is clearly not the case with the replacement neuron. To talk blithely about coupling is to miss the point that a coupled Turing machine is not a Turing machine, and the reasoning we use about Turing machines no longer applies. A Turing machine is, by definition, a closed, non-interacting system. The people who design computers and operating systems have to go to great lengths to provide environments where programs could operate as if they were Turing machines. In almost every case, the computer and operating system which runs the programs has to use a different model, because the Turing model isn't appropriate for running a computer. I gave a link to a paper describing the issues involved in coping with these issues.
So when describing a device which can replace a neuron in a human body, the Turing model is simply irrelevant. Turing-style programs are designed to work as closed systems. The neuron is designed to be open, time-dependent, asynchronous, reactive. The Turing model is of no help in understanding or replacing neuron behaviour.