I’m not sure I understand why the 🌍 digital/analog distinction is relevant here …

Someone once tried to convince me the distinction doesn’t even make sense!

Ha, well, 😁 computationally it does, but perhaps it is better to speak of 🌍 discrete and continuous

Ok, now I’m even more confused …

Well, think of a analog and digital watches: both tell the same time, but in a different format

Sure, so you mean there is no difference?

I didn’t say that, but perhaps that they simply measure time in different ways, it is not time which is analog or digital, but the watch

Ah, ok. So in the case of information processing, it is not the brain or the computer that is analog or digital, but how we measure and describe it?

That’s exactly what I mean! We can describe a neuron in different ways and then compare it to a circuit or a flipflop.

So there is a similarity in the description, but not necessarily in the thing you are describing? 🤔                                                                       

That starts to sound very philosophical and abstract, but, yes, indeed. We can describe them in the same way.

So what did you mean with discrete and continuous?                                                                                               

Both brains and computers work with electricity, but in a computer the voltages are tightly controlled and used in a digital way: ones and zeroes

In a brain the voltage can vary continuously, but sometimes triggers a neuron to “fire”, and up to a point we can treat that as a “one” too

So continuous means that we measure what is happening as close as possible, discrete that we just count the neurons that fire

Aha, so by treating them as discrete units, we can then treat them as digital in our computational model 😊                                                                                        

Precisely! We’re not trying to copy the brain at all, only what we think is informationally relevant.

But Cho will tell you we are also ignoring a lot of stuff that happens in the brain to make that possible

And that we don’t really know which bits and pieces are relevant for the brain as a whole

Yep, I can tell you exactly how information flows through a computer or even a network, but we can’t trace it in the brain

Because in the brain medium and message, 🌍 vehicle and content aren’t clearly distinguishable.

So we can’t point at the brain and say “this process right here is this or that law of thought”. I think I get it!

Happy to have been of assistance!

Thank you so much! I’ll report back to John now

When we talk about computers, we tend to distinguish the machine and its programming: hardware and software

OK, yes, I think everyone is familiar with those terms                         

Great, but I’d like to point out how wrong that is, in some respects …

Where do we draw the line between those? Are they really that different? Doesn’t the design of the one determine the design of the other?

Whoa, those are tricky questions! 😅
Remarkably similar to the kind we ask about humans; is that what you’re after?

In a sense. We are so used to the hardware/software distinction, that we forget that somewhere they overlap and interact

Can you give me some examples? Otherwise, I fear our readers won’t all get it …😅

Sure: flip-flops are at the same time a hardware device and a software abstraction, a circuit and a one or zero

Right, so there is a level where the distinction is arbitrary: it is both a thing and information

Exactly! 😉 But then of course at other levels things are much more clear cut

But what did you mean with “wetware” then?                                       

Ah, yes, well as far as I know, the brain is like that all over: it is tremendously difficult to keep the hardware and software apart

Oooh, now I get what you mean: a classical computer architecture is completely different

Right, but if the brain is an information processor, you can try to just copy the informationally relevant bits

So like Smee you can capture the same informationally relevant relations in a different hardware?

Up to a point, of course. We can try to copy some of the structure of the brain, but only in software really

What do you mean? 🤔                                                                             

Well, most “artificial neural networks” (ANN) actually are software simulations that run on ordinary beige box computers

Aha, so as you said: a lot of simplification and abstraction 😊                

Correct! We still don’t know exactly how the brain does all its information processing or how to copy that efficiently

and then there’s the whole digital/analog problem …

I’m not sure it would qualify as an artificial neural network nowadays, but there was this doctor and metallurgist, working on electro-biology: Alfred Smee

He thought that all thought was based on electrical activity in the brain which we could use as a model for a machine

That’s amazing! 😁 I didn’t know that … 

It seems he conjectured you’d need an artificial neural network the size of London to model a whole human brain

Ha! 😅 He was probably right, early computers where absolutely massive, and supercomputers still are

With the technology of his time this could probably never have been built, he even guessed that the machine would self-destruct by using it …

It really is surprising how old some ideas are, and has to wait for technology to catch up so we can realize them!

But a lot of there machines were never built: Babbage’s analytical engine, for instance

Or Turing’s Machine, indeed, the idea was enough to prove that something was or wasn’t possible

That’s very interesting!  🤔                                                                       

Well, I guess that you could compare and contrast Smee and Babbage in that respect

Babbage did not consider his machine as a model for the mind, but developed his ideas from the technology that was available

Smee tried to design a machine based on what they then understood of the brain, but the technology wasn’t there yet

But now it is?                                                                                               

Not exactly, as I mentioned to Manuel, artificial neural netword can’t really compete with our organic brains

So the idea of copying the brain still can’t be realized?                       

With some extreme simplifications, maybe a little bit …

Tell me more! 😊                                                                                        

I think I need to make a few distinctions first, like between hardware, software, and … wetware

Wetware!? 🤔