“Memristor minds: The future of artificial intelligence”

Ever the guardian of my intellectual development, Norm sent me a link to a New Scientist article on memristors, today. I’d never heard of them, but the article was interesting for both good and bad reasons, so I thought I’d share my impressions.

Here’s a short summary: The memristor is apparently a “missing component” in electronics, hypothesized by Leon Chua in 1971, to sit alongside the well known resistor, capacitor and inductor, but at the time it was unknown as a physical device. In the early years of this century, Stan Williams developed a nanoscale device that he believed fit the bill. And then Max di Ventra, a physicist at UCSD, linked this work with some research on a slime mould, which showed that they are capable of “predicting” a future state in a periodic environmental change. He suggested that this is a biophysical equivalent to a memristor. The article then goes on to suggest that neural synapses work the same way, and so this must surely be the big missing insight that has prevented us from understanding the brain and creating artificial intelligence.

But the article troubles me for a couple of reasons and I can’t help thinking there’s a serious problem with the way physicists and mathematicians tend to think about biology. Firstly, here’s a quote from the article:

“To Chua, this all points to a home truth. Despite years of effort, attempts to build an electronic intelligence that can mimic the awesome power of a brain have seen little success. And that might be simply because we were lacking the crucial electronic components – memristors.”

Hmm… So exactly what years of effort would that be, then? VERY few people have ever attempted to “build an electronic intelligence”. We simply don’t do that – we use computers! 

Sure, a computer is an electronic device, but the whole damned point of them is that they are machines that can emulate any other machine. So they can emulate memristors too. They don’t actually have to be MADE of them in order to do that – they simply simulate them in code, like they simulate everything else. And I’m sure I’ve many times written code that has a state memory like a memristor. I didn’t know there was a named physical device that works in the same way, and it’s very interesting that there is, because it might give us new analogies and insights. But if I needed something to behave like that I could have coded it any time I wanted to. It’s meaningless to say that we’ve been stuck because we lacked a new type of electronic component. Only a physicist would confuse hardware and software like that! It boggles my mind.

And then I’m a little perplexed about a missing electronic component we DO know about. Maybe someone can help me with this? Chua’s work apparently hypothesized the memristor as a fourth component to add the existing resistor, capacitor and inductor. But where’s the transistor? Isn’t that a fundamental component? It’s a resistor, after a fashion, but surely it’s a fundamental building block in its own right, because it has the ability to allow a voltage to modulate a current - without them almost no electronic circuits would do anything useful!

I hate to say it, but I wonder if that’s a comment on the minds of physicists, too? It’s the transistor (or vacuum tube) that makes the difference between a static circuit, for which the mathematics of physics works well, and a dynamic circuit, for which it doesn’t. The capacitor is a dynamic system too, but only for a moment and then it settles down into something nice and easy to write equations for. It’s only when you add transistors and their consequent ability to generate feedback that the system really starts to dance and sing, and then the equations stop being much use.

The real glaring insight that electronics gives us, in my not-always-terribly-humble opinion, is the realization that sometimes classical science has a bad habit of being obsessed with “quantities” and ignoring or even sometimes denying the existence of “qualities”. Two electronic systems might have precisely the same mass, complexity and constituent substances, for instance, but be wired up in a different arrangement, producing radically different results. The reductionism implicit in much of physics can’t “see” the difference between the two circuits – because it’s something purely qualitative, not quantitative.

It’s the same with the brain. The reason we don’t understand the brain has NOTHING of significance to do with some “missing component”. It has nothing to do with quantum uncertainty or any other reductionistic claptrap. The reason we don’t understand the brain is that we don’t understand the CIRCUIT. We don’t understand the system as a whole. Memories, thoughts, ideas and the Self are not properties of the brain’s components, they are properties of its organisation. It’s very hard to understand organisations – I could easily give you an electronic circuit diagram out of context and it might take you days or weeks to figure out how it works and exactly what it does. But you could know everything you need to know about the properties of its resistors, capacitors,  inductors and transistors, and even it’s memristors. You could weigh it and measure it all you liked and it would tell you nothing. Organization is not amenable to understanding using the tools of classical Physics.

Life and mind are qualitiative constructs. Looking for some special elixir vitae is completely missing the point. The article is very interesting and I plan to look up more information. Memristors may well provide a useful analogy that gives us some hints and insights about localised properties of brains, and that may steer us towards making more sense of the circuitry of intelligence. However, to suggest that we’ve got it all wrong because we didn’t have the right component in our toolbox for making our “electronic brains” is just nonsense. Electronic components are the province of physics, but electronic design is not. Synapses may be the province of physics too, but biology is not. Biology is a branch of cybernetics, which has a very different mindset (or did until physicists took it over and turned it into information theory).

P.S. I sort of see why transistors are missing now – at the mathematical level of description of Chua’s work, I guess a transistor is just a resistor, because both of them convert between voltage and current. Time only really enters into the equations as an integral, and the deeply nonlinear consequences of the transistor don’t really apply when you consider it as a single isolated component. But that was my point - once you wire them up into circuits all of this is pretty much irrelevant. It’s circuits that matter for intelligence. Minds are emergent properties of organisations. Looking for a “magic” component is just a modern-day form of vitalism.

Good to know we’re in such safe hands

Stark just sent me this link and I felt I had to share it with you in a post (because not everyone reads comments):

I don’t blame her personally - she’s a politician, so I’d hardly expect her to be smart or anything – but it’s her completely unquestioning confidence in her “fact” that’s the scary thing. She seems not to notice anything even remotely peculiar or troubling about the idea that the Earth is only 6,000 years old.

This is ARIZONA, for pity’s sake! Even if you want to believe that the entire Grand Canyon was carved out during Day Forty of Noah’s Flood, as all that water was mysteriously draining away through some plughole in the Pacific, you only have to stand on the edge of it for a few seconds to see that the vertical mile of very hard sediments it cuts through couldn’t conceviably, not by any stretch of even such a badly atrophied imagination, have been laid down in a mere forty days and forty nights. Or even 4,000 years, which is the most we could allow, even assuming the Flood finished on the Tuesday before Jesus was born. I mean, if all that solid rock was just silt from the Flood then it had to get there from somewhere uphill. The Rockies, presumably, so did they just erode into trillions of tons of dust during a wet weekend before the Deluge started in earnest? And the peculiar distribution of all those darned fossils in it ought to be a bit troubling, to say the least…

I really find it hard to believe than anyone can live in this 200 million to two billion year-old landscape for more than a week and not notice how utterly inconsistent it all is with the idea of a 6,000 year-old Earth. But then she lives in Phoenix and all that heat can addle one’s brain. Mercifully, up here in Flagstaff, where the air is clearer and our blood stays below boiling point, people seem rather more rational.

Anyway, she clearly has a damn good argument for opening a uranium mine. I’d trust her judgement, wouldn’t you?

Thanks, Stark!

Independence Day

I’ve been lucky enough to have lived with two very different women, both of them lovely people. I’m trying not to read too much into the fact that it was only after I left each of them that they really started to blossom, but yesterday I was able to mention Ann’s interview about her passion for science and her doctoral research, and today it’s Sara’s turn. She’s just finished writing a new book, so if you need a dose of her indomitable spirit and positive attitude, you’ll find it here. Good luck to both of them.

Independence Day Parade, Flagstaff

All that dentistry for nothing

Ok, I’m cunningly going to sidestep the question of what my new game is about one more time and hope you don’t notice.

That’s partly because my PC gave up the ghost this week, so I’m still in the middle of setting up a new one. It didn’t help that the first replacement I bought had a suicidal disk controller, and the second has a bug in the video driver that meant my DVI monitor would just go blank in the middle of installing Windows, leaving me without a clue what was going on and the computer baffled about why I wasn’t answering its questions.

But here’s pause for thought: my new PC (or Next Month’s Rent, as I like to call it) has four 64-bit CPUs, each running at 2.5GHz. It has 8GB of RAM and a one-terabyte hard drive. OH… MY… GOODNESS! Even the graphics card has 320 data execution paths and 512 MILLION transistors.

I still have the second computer I ever owned, from way back in 1979. It had one 8-bit CPU running at 4MHz, being fed by 640 bytes of memory and no disk drive. The first disk drive I owned had 360KB of storage.

So the processor clock is now 640 times faster, not to mention having four times as many cores, eight times as many bits and a lot more fancy gizmos like caches, FPUs and a separate GPU to do a lot of the work. Disk space has increased by a factor of 1.6 million, and memory has shot up by a factor of 13 million!

Just imagine if cars were 640 times faster than they were in 1980, capable of scooting along at up to ninety thousand miles per hour! (They’d be spacecraft, in fact, since escape velocity is only 17,500 mph.) What would it be like if your cupboards could hold 13 million times as much stuff before it all started to fall out every time you opened a door?

Isn’t technology wonderful? So how come robots haven’t taken over the world yet?

I got to thinking about this because I was talking about my first computer in an interview for FlagNews, a local TV and Web infotainment show that I like and seem to have become mysteriously drawn into. Tyrus, the producer and one of the presenters, is a really nice guy who works hard to bring only good news to the people of Flagstaff and environs, and to create a video archive of the local culture on a shoestring budget. Some weird kind of synchronicity brought us together and I’m delighted to have met a friend. I’ll probably end up helping out at the show in some capacity – making tea, coiling cables and interviewing local scientists; that sort of thing) and I’m looking forward to meeting the rest of the team. Anyway, my interview is up on their website today (7/3/09). Tyrus and Pez (the editor, who I met at the folk festival last weekend) have kindly managed to pull it together into something that sounds like I knew what I was talking about (I’m a bit rusty).

But here’s the thing: I always hated doing television and would turn down nine out of every ten requests, because if I ever plucked up the nerve to watch myself all I could ever see were my damn teeth – a random collection of great yellow things that stuck out at all angles. So about six months ago I had them fixed, and I felt so much better about myself. But there they are again! They’re disco-white and straight now, but they still dominate my face like Al Jolson’s lips in blackface makeup. Oh well.

I also did an interview for EuroGamer yesterday – by email. My teeth look so much better by email. With all this sudden attention I guess I’d better get on and DO something. More news on that in the next post. Probably.

P.S. And in a continuing flurry of interviews, Norm just pinged me to say that his recent interview with Ann (my first wife), about her research on Open Science and Public Engagement, is now up on the web at Machines Like Us. Hers has a lot more content in it than mine.

P.P.S. FlagNews really needs support, so if you happen to live in Northern Arizona and found my interview interesting (or not, for that matter), send ‘em a little cash, why don’t you? There’s a PayPal link on their website. The same goes for MachinesLikeUs. People do this stuff out of the kindness of their hearts and we should encourage that as much as we are able.