On the one hand, a main theme here is theories of consciousness. On the other hand, it’s been almost eight years blogging, and I’ve covered my views pretty well in numerous posts and comment threads. Our understanding of consciousness currently seems stuck pending new discoveries, either in answering hard questions, or in providing entirely new paths.
A while back I determined to step away from debates (even blogs) that center on topics with no resolution. Religion is a big one, but theories of mind is another. Your view depends on your axioms. Unless (or until) science provides objective answers, everyone is just guessing.
But it’s been three-and-a-half years, and, well,… I have some notes…
Over the last few weeks I’ve written a series of posts leading up to the idea of human consciousness in a machine. In particular, I focused on the difference between a physical model and a software model, and especially on the requirements of the software model.
The series is over, I have nothing particularly new to add, but I’d like to try to summarize my points and provide an index to the posts in this series. It seems I may have given readers a bit of information overload — too much information to process.
Hopefully I can achieve better clarity and brevity here!
Over the past few weeks we’ve explored background topics regarding calculation, code, and computers. That led to an exploration of software models — in particular a software model of the human brain.
The underlying question all along is whether a software model of a brain — in contrast to a physical model — can be conscious. A related, but separate, question is whether some algorithm (aka Turing Machine) functionally reproduces human consciousness without regard to the brain’s physical structure.
Now we focus on why a software model isn’t what it models!
Last time I introduced four levels of possibility regarding how mind is related to brain. Behind Door #1 is a Holy Grail of AI research, a fully algorithmic implementation of a human mind. Behind Door #4 is an ineffable metaphysical mind no machine can duplicate.
The two doors between lead to physical models that recapitulate the structure of the human brain. Behind Door #3 is the biology of the brain, a model we know creates mind. Behind Door #2 is the network of the brain, which we presume encodes the mind regardless of its physical construction.
This time we’ll look more closely at some distinguishing details.
Last week we took a look at a simple computer software model of a human brain. (We discovered that it was big, requiring dozens of petabytes!) One goal of such models is replicating consciousness — a human mind. That can involve creating a (potentially superior) new mind or uploading an existing human mind (a very different goal).
Now that we’ve explored the basics of calculation, code (software), computers, and (computer software) models, we’re ready to explore what’s involved in attempting to model a (human) mind.
I’m dividing the possibilities into four basic levels.
Last time we looked at the basic requirements for a software model of a computer and put a rough estimate on the size of such a model (about 2.5 terabytes). This time we’ll consider a software model of a human brain. Admittedly, there’s much we don’t know, and probably need for a decent model, but we can make some rough guesses as a reference point.
We’ll start with a few basic facts — number of neurons, number of synapses — and try to figure out some minimal requirements. The architecture of a viable software brain model is likely to be much more complicated. This is just a sketch, a Tinkertoy® or LEGO® version.
Even so, we’re gonna need a lot of memory!
The computer what? Connectome. The computer’s wiring diagram. The road map of how all the parts are connected.
Okay, granted, the term, connectome, usually applies to the neural wiring of a biological organism’s brain, particularly to the human brain. But the whole point of this series of posts is to compare a human brain with a computer so that we can think about how we might implement a human mind with a computer. As such, “connectome” seems apropos.
Today we’ll try to figure out what’s involved in modeling one in software.
The ultimate goal is a consideration of how to create a working model of the human mind using a computer. Since no one knows how to do that yet (or if it’s even possible to do), there’s a lot of guesswork involved, and our best result can only be a very rough estimate. Perhaps all we can really do is figure out some minimal requirements.
Given the difficulty we’ll start with some simpler software models. In particular, we’ll look at (perhaps seeming oddity of) using a computer to model a computer (possibly even itself).
The goal today is to understand what a software model is and does.