Theories vs. Metaphors
I have said things like:
We should expect brain emulation to be feasible because brains function to process signals, and the decoupling of signal dimensions from other system dimensions is central to achieving the function of a signal processor.
Bryan Caplan says I make:
the Metaphorical Fallacy. Its general form:
1. X is metaphorically Y.
2. Y is literally Z.
3. Therefore, X is literally Z.
…. To take a not-so-random example, … Robin says many crazy things … like:
1. The human mind is a computer.
2. Computers’ data can be uploaded to another computer.
3. Therefore, the human mind can be uploaded to a computer.
No, I’m pretty sure that I’m saying that your mind is literally a signal processing system. Not just metaphorically; literally. That is, while minds have a great many features, a powerful theory, in fact our standard theory, to explain the mix of features we see associated with minds, is that minds fundamentally function to process signals, and that brains are the physical devices that achieve that function. And our standard theories of how physical devices achieve signal processing functions predicts that we can replicate, or “emulate”, the same signal processing functions in quite different physical devices. In fact, such theories tell us how to replicate such functions in other devices.
Of course you can, like Bryan, disagree with our standard theory that the main function of minds is to process signals. Or you could disagree with our standard theories of how that function is achieved by physical devices. Or you could note that since the brain is a signal processor of unparalleled complexity, we are a long way away from knowing how to replicate it in other physical hardware.
But given how rich and well developed are our standard theories of minds as signal processors, signal processors in general, and the implementation of signal processors in physical hardware, it hardly seems fair to reject my conclusion based on a mere “metaphor.”
"your mind is literally a signal processing system."
My previous post was out of line, I leaped before I looked, I have replaced it with this, for you consideration.
With apologies to physics, let's assume all forces are just different densities of the same thing. The strong forces and the weak forces for the sake of this discussion are different forms of gravity different densities of gravity
In other words "gravity" is also a kind of signal.
I think the problem you're experiencing has to do with how you define a signal. In a digital world the signal is electricity. A switch is either on or off. There's no middle ground. When you talk about coupling and decoupling you're talking about an absolute condition. When you talk about software you can talk about software as being close to or far from the machine – tightly bound or loosely bound to the machine.
That is at least until one sees that (digital) electrical switches are in fact pendulums as well.
So in essence a pendulum is a signal processor. The processing that takes place is Its movement along its trajectory. There is input and output here just not at the level of complexity of the discussion.
Rather than a brain that merely process a signal the brain itself is also a signal. The input and output merely a form of trajectory for an organic machine that is already in motion.
Respectfully,DWC
We should expect brain emulation to be feasible because brains function to process signals, and the decoupling of signal dimensions from other system dimensions is central to achieving the function of a signal processor... our standard theories of how physical devices achieve signal processing functions predicts that we can replicate, or “emulate”, the same signal processing functions in quite different physical devices.
Here's an attempt to clarify Bryan's argument. When I do, I find some virtue in it:
To have a perfect (or pure) signal processor, you must decouple signal dimensions from other system dimensions. A properly functioning computer is (while it is properly functioning) a pure signal processor.
Evolutionary pressure will make the brain an increasingly pure signal processor. But, it is unlikely that this process asymptotes at perfect signal processing, for two reasons:
1. The brain has other functions besides signal processing as well as nonfunctional constraints (such as size).
2.Evolution is limited by history: you can't reach every point in design space from where you are now by an evolutionary process.
Therefore, the fact that the brain is "mainly" (an excessively vague term) a signal processor doesn't imply that it can be emulated by a computer. The brain probably has impurities in its execution of signal processing which are essential to its functioning as a signal processor.
Which is to say, we should be able to emulate the signal processing functions of the brain, but we can't do it by emulating part of the brain, as no part of the brain is a pure signal processor.