Thursday, 28 April 2005

Spindle Cells, Consciousness, and the Singularity

This one's a Brain post, and a half.

From a fact article in Asimov's SF Magazine, some quotes to ponder :
Here in the twenty-first century we like to view ourselves as ambulatory brains, plugged into meat-puppets that lug our precious grey matter from place to place. We tend to think of that grey matter as transcendently complex, and we think of it as being the bit that makes us us.

But brains aren’t that complex, Kurzweil says. Already, we’re starting to unravel their mysteries.

"We seem to have found one area of the brain closely associated with higher-level emotions, the spindle cells, deeply embedded in the brain. There are tens of thousands of them, spanning the whole brain (maybe eighty thousand in total), which is an incredibly small number. Babies don’t have any, most animals don’t have any, and they likely only evolved over the last million years or so. Some of the high-level emotions that are deeply human come from these.
Perhaps the definition of "intelligent life" might have to include all animals with spindle cells, and thus the capacity for love, hate, and so on.
Scanning resolution of human tissue–both spatial and temporal–is doubling every year, and so is our knowledge of the workings of the brain. The brain is not one big neural net, the brain is several hundred different regions, and we can understand each region, we can model the regions with mathematics, most of which have some nexus with chaos and self-organizing systems. This has already been done for a couple dozen regions out of the several hundred.
Recent - as in, within the last 20 years - advances in mathematics in the fields of Chaos Theory and Self-organising systems have been crucial in solving many problems, from the behaviour of flocks of birds and schools of fish, to turbulent flow out of a common household tap. We have tools now that enable us to undrestand much of what we could merely observe in the dim, dark and distant past of 1970.
"We have a good model of a dozen or so regions of the auditory and visual cortex, how we strip images down to very low-resolution movies based on pattern recognition. Interestingly, we don’t actually see things, we essentially hallucinate them in detail from what we see from these low resolution cues. Past the early phases of the visual cortex, detail doesn’t reach the brain.
Meanwhile, with Psychology and Psychiatry, most medical schools are still in the "Ju Ju and Witchdoctor" stage, doing the equivalent of bleeding the patients to remove evil humours. Most, but not all. And we now have an arsenal of psychotropic drugs whose effects may be extremely crude, but still effective. The equivalent of amputations to cure gangrene, rather than antispesis and antibiotics. Still more effective than making passes with relics of saints.
"We are getting exponentially more knowledge. We can get detailed scans of neurons working in vivo, and are beginning to understand the chaotic algorithms underlying human intelligence. In some cases, we are getting comparable performance of brain regions in simulation. These tools will continue to grow in detail and sophistication.

"We can have confidence of reverse-engineering the brain in twenty years or so. The reason that brain reverse engineering has not contributed much to artificial intelligence is that up until recently we didn’t have the right tools. If I gave you a computer and a few magnetic sensors and asked you to reverse-engineer it, you might figure out that there’s a magnetic device spinning when a file is saved, but you’d never get at the instruction set. Once you reverse-engineer the computer fully, however, you can express its principles of operation in just a few dozen pages.

"Now there are new tools that let us see the interneuronal connections and their signaling, in vivo, and in real-time. We’re just now getting these tools and there’s very rapid application of the tools to obtain the data.

"Twenty years from now we will have realistic simulations and models of all the regions of the brain and [we will] understand how they work. We won’t blindly or mindlessly copy those methods, we will understand them and use them to improve our AI toolkit. So we’ll learn how the brain works and then apply the sophisticated tools that we will obtain, as we discover how the brain works.
I''ll repeat one bit, one very important bit :
We can have confidence of reverse-engineering the brain in twenty years or so.
But wait, there's more :
But Kurzweil doesn’t think that the future will arrive in a rush. As William Gibson observed, "The future is here, it’s just not evenly distributed."

"Sure, it’d be interesting to take a human brain, scan it, reinstantiate the brain, and run it on another substrate. That will ultimately happen."

"But the most salient scenario is that we’ll gradually merge with our technology. We’ll use nanobots to kill pathogens, then to kill cancer cells, and then they’ll go into our brain and do benign things there like augment our memory, and very gradually they’ll get more and more sophisticated. There’s no single great leap, but there is ultimately a great leap comprised of many small steps.
The human brain's "wetware", the physical bits, turns out to be a lot less complex than we'd ever imagined, just as the arrangements and patterns within it are even more complex.
Think about the Mona Lisa. The hardware is just a few pigments, and a vegetable-based fibrous substrate. It's the arrangement of those that's important, not the raw materials.
But we now have a good handle on the raw materials, and are getting better and better at figuring out what the patterns are. Although at the ultimate level of quantum states of individual subatomic particles, to measure is to change what's being measured, that's not important, because our brains are changing in far more massive ways from moment to moment, yet we still retain the illusion(?) of continuity. Another quote:
(Ray Kurzweil speaks) If you follow that logic, then if you were to take me ten years ago, I could not pass for myself in a Ray Kurzweil Turing Test. But once the requisite uploading technology becomes available a few decades hence, you could make a perfect-enough copy of me, and it would pass the Ray Kurzweil Turing Test. The copy doesn’t have to match the quantum state of my every neuron, either: if you meet me the next day, I’d pass the Ray Kurzweil Turing Test. Nevertheless, none of the quantum states in my brain would be the same. There are quite a few changes that each of us undergo from day to day, we don’t examine the assumption that we are the same person closely.

"We gradually change our pattern of atoms and neurons but we very rapidly change the particles the pattern is made up of. We used to think that in the brain–the physical part of us most closely associated with our identity–cells change very slowly, but it turns out that the components of the neurons, the tubules and so forth, turn over in only days. I’m a completely different set of particles from what I was a week ago.

"Consciousness is a difficult subject, and I’m always surprised by how many people talk about consciousness routinely as if it could be easily and readily tested scientifically. But we can’t postulate a consciousness detector that does not have some assumptions about consciousness built into it.

"Science is about objective third party observations and logical deductions from them. Consciousness is about first-person, subjective experience, and there’s a fundamental gap there. We live in a world of assumptions about consciousness. We share the assumption that other human beings are conscious, for example. But that breaks down when we go outside of humans, when we consider, for example, animals. Some say only humans are conscious and animals are instinctive and machinelike. Others see humanlike behavior in an animal and consider the animal conscious, but even these observers don’t generally attribute consciousness to animals that aren’t humanlike.

"When machines are complex enough to have responses recognizable as emotions, those machines will be more humanlike than animals."
Take a look around you. The world in only 20 years time will be quite different, yet remain much the same in many ways. We already have the first prosthetic brain part replacements. In 20 years time, we may have some really good idea of how to go about implementing a human mind on non-biological hardware. Either "copying" an existing one, or making one out of whole cloth.

Science is full of disappointments: things we thought we'd be able to do "in 20 years time" that 20 yeasr later, we find we can't. Lunar bases. The Cure for Cancer. True AI, of the "HAL 9000" variety.

But compared with 20 years ago, many cancers are curable. And getting a lunar base going is not a matter of technology so much as economic priority. The latest programs for playing chess can now beat the best humans (while remaining dumb-as-a-post). In 1985, some of us were struggling with the problems of transferring data internationally via the ARPAnet/Internet. We really believed cerebrally that by 2005, most computers in the planet would be hooked up together, but not vicerally, it seemed too good to be true.

It's just possible that if you, the reader, can hang on for another 30 years without snuffing it, you may be able to get an upgrade to better hardware. Will it be "the same" as you? Not exactly. But it will be closer to the "you" of 2035 than that "you" is to the "you" of today. In fact, it will be closer than the "you" you were when you started treading this article, and the "you" you are now that you've finished reading it.

Close enough.

UPDATE : George Jr has some cogent thoughts on the subject, and writes :
It chimed with some of my recent reading - I've just finsihed Pinker's How the Mind Works and, yesterday, I received a copy of Julian Jaynes's work The Origin of Consciousness in the Breakdown of the Bicameral MInd.

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