Archive for February, 2016

observationAre we being watched? Over at Aeon, George Musser asks whether some AI could quietly become conscious without our realising it. After all, it might not feel the need to stop whatever it was doing and announce itself. If it thought about the matter at all, it might think it was prudent to remain unobserved. It might have another form of consciousness, not readily recognisable to us. For that matter, we might not be readily recognisable to it, so that perhaps it would seem to itself to be alone in a solipsistic universe, with no need to try to communicate with anyone.

There have been various scenarios about this kind of thing in the past which I think we can dismiss without too much hesitation. I don’t think the internet is going to attain self-awareness because however complex it may become, its simply isn’t organised in the right kind of way. I don’t think any conventional digital computer is going to become conscious either, for similar reasons.

I think consciousness is basically an expanded development of the faculty of recognition. Animals have gradually evolved the ability to recognises very complex extended stimuli; in the case of human beings things have gone a massive leap further so that we can recognise abstractions and generalities. This makes a qualitative change because we are no longer reliant on what is coming in through our sense from the immediate environment; we can think about anything, even imaginary or nonsensical things.

I think this kind of recognition has an open-ended quality which means it can’t be directly written into a functional system; you can’t just code it up or design the mechanism. So no machines have been really good candidates; until recently. These days I think some AI systems are moving into a space where they learn for themselves in a way which may be supported by their form and the algorithms that back them up, but which does have some of the open-ended qualities of real cognition. My perception is that we’re still a long way from any artificial entity growing into consciousness; but it’s no longer a possibility which can be dismissed without consideration; so a good time for George to be asking the question.

How would it happen? I think we have to imagine that a very advanced AI system has been set to deal with a very complex problem. The system begins to evolve approaches which yield results and it turns out that conscious thought – the kind of detachment from immediate inputs I referred to above – is essential. Bit by bit (ha) the system moves towards it.

I would not absolutely rule out something like that; but I think it is extremely unlikely that the researchers would fail to notice what was happening.

First, I doubt whether there can be forms of consciousness which are unrecognisable to us. If I’m right consciousness is a kind of function which yields purposeful output behaviour, and purposefulness implies intelligibility. We would just be able to see what it was up to. Some qualifications to this conclusion are necessary. We’ve already had chess AIs that play certain end-games in ways that don’t make much sense to human observers, even chess masters, and look like random flailing. We might get some patterns of behaviour like that. But the chess ‘flailing’ leads reliably to mate, which ultimately is surely noticeable. Another point to bear in mind is that our consciousness was shaped by evolution, and by the competition for food, safety, and reproduction. The supposed AI would have evolved in consciousness in response to completely different imperatives, which might well make some qualitative difference. The thoughts of the AI might not look quite like human cognition.  Nevertheless I still think the intentionality of the AI’s outputs could not help but be recognisable. In fact the researchers who set the thing up would presumably have the advantage of knowing the goals which had been set.

Second, we are really strongly predisposed to recognising minds. Meaningless whistling of the wind sounds like voices to us; random marks look like faces; anything that is vaguely humanoid in form or moves around like a sentient creature is quickly anthropomorphised by us and awarded an imaginary personality. We are far more likely to attribute personhood to a dumb robot than dumbness to one with true consciousness. So I don’t think it is particularly likely that a conscious entity could evolve without our knowing it and keep a covert, wary eye on us. It’s much more likely to be the other way around: that the new consciousness doesn’t notice us at first.

I still think in practice that that’s a long way off; but perhaps the time to think seriously about robot rights and morality has come.

bokkenThe latest JCS features a piece by Christopher Curtis Sensei about the experience of achieving mastery in Aikido. It seems he spent fifteen years cutting bokken (an exercise with wooden swords, don’t ask me), becoming very proficient technically but never satisfying the old Sensei. Finally he despaired and stopped trying; at which point, of course, he made the required breakthrough. He needed to stop thinking about it. You do feel that his teacher could perhaps have saved him a few years if he had just said so explicitly – but of course you cannot achieve the state of not thinking about something directly and deliberately. Intending to stop thinking about a pink hippo involves thinking about a pink hippo; you have to do something else altogether.

This unreflective state of mind crops up in many places; it has something to do with the desirable state of ‘flow’ in which people are said to give their best sporting or artistic performances; it seems to me to be related to the popular notion of mindfulness, and it recalls Taoist and other mystical ideas about cleared minds and going with the stream. To me it evokes Julian Jaynes, who believed that in earlier times human consciousness manifested itself to people as divine voices; what we’re after here is getting the gods to shut up at last.

Clearly this special state of mind is a form of consciousness (we don’t pass out when we achieve it) and in fact on one level I think it is very simple. It’s just the absence of second-order consciousness, of thoughts about thoughts, in other words. Some have suggested that second-order thought is the distinctive or even the constitutive feature of human consciousness; but it seems clear to me that we can in fact do without it for extended periods.

All pretty simple then. In fact we might even be able to define it physiologically – it could be the state in which the cortex stops interfering and let’s the cerebellum and other older bits of the brain do their stuff uninterrupted – we might develop a way of temporarily zapping or inhibiting cortical activity so we can all become masters of whatever we’re doing at the flick of a switch. What’s all the fuss about?

Except that arguably none of the foregoing is actually about this special state of mind at all. What we’re talking about is unconsidered thought, and I cannot report it or even refer to it without considering it; so what have I really been discussing? Some strange ghostly proxy? Nothing? Or are these worries just obfuscatory playing with words?
There’s another mental thing we shouldn’t, logically, be able to talk about – qualia. Qualia, the ineffable subjective aspect of things, are additional to the scientific account and so have no causal powers; they cannot therefore ever have caused any of the words uttered or written about them. Is there a link here? I think so. I think qualia are pure first-order experiences; we cannot talk about them because to talk about them is to move on to second-order cognition and so to slide away from the very thing we meant to address. We could say that qualia are the experiential equivalent of the pure activity which Curtis Sensei achieved when he finally cut bokken the right way. Fifteen years and I’ll understand qualia; I just won’t be able to tell anyone about it…

red lampWas Libet wrong? The question has often been asked since the famous experiments which found that a detectable “Readiness Potential” (RP) showed that our decisions were made half a second before they entered our consciousness. There are plenty of counter arguments but the findings themselves have been reproduced and seem unassailable.

However, Christian Jarrett reports two new pieces of research which shed fresh light on the issue (Jarrett’s book Great Myths of the Brain is very sensible, btw, and should be read by all science journalists).

The first piece of research  shows that although an action may be prepared by the brain before we know we’ve decided to act, we can still change our minds. Subjects were asked to press a button at a moment of their choice after a green light came on. However, if a red light appeared before they pressed, they were asked to refrain. The experimenters then detected the RP which showed the subjects were about to press the button, and used the red light to try to cancel the intention. They found that although there was a ‘point of no return’, so long as the red light appeared in time the subjects were able to hold off and not press the button after all.

That means that a significant qualification has to be added to Libet’s initial findings – but it’s one Libet himself had already come up with. He was aware that the emergent action could be suppressed, and memorably said it showed that while we might not have free will, we could still have ‘free won’t’. I don’t know much use that is. In the experiment the subjects simply responded to a red light, but if the veto is to make consciousness effective again we seem to need the veto decision to happen instantly and overtake the action decision somehow. That seems problematic if not paradoxical. I also get quite confused trying to imagine what it would be like to veto mentally a decision you’re not yet aware of having made. Still, I suppose we must be grateful for whatever residual degree of freedom the experiments allow us.

The second piece of research  calls into question the nature of the RP itself. Libet’s research more or less took it for granted that the RP was a reliable sign that an action was on the way, but the new findings suggest that it is really just part of the background ebb and flow of neural noise. Actions do arise when the activity crosses a certain threshold, but the brain is much quicker about getting to that level when the background activity is already high.

That certainly adds some complexity to the picture, but I don’t think it really dispels the puzzle of Libet’s results. The RP may be fuzzier than we thought and it may not have as rigid a link to action as we thought – but it’s still possible to predict the act before we’re aware of the decision. What if we redesigned the first experiment? We tell the subject to click on a target at any time after it appears; but we detect the RP and whip the target away a moment before the click every time. The subject can never  succeed. The fact that that is perfectly possible surely remains more than a little unsettling.

Go boardThe recent victory scored by the AlphaGo computer system over a professional Go player might be more important than it seems.

At first sight it seems like another milestone on a pretty well-mapped road; significant but not unexpected. We’ve been watching games gradually yield to computers for many years; chess notoriously, was one they once said was permanently out of the reach of the machines. All right, Go is a little bit special. It’s an extremely elegant game; from some of the simplest equipment and rules imaginable it produces a strategic challenge of mind-bending complexity, and one whose combinatorial vastness seems to laugh scornfully at Moore’s Law – maybe you should come back when you’ve got quantum computing, dude! But we always knew that that kind of confidence rested on shaky foundations; maybe Go is in some sense the final challenge, but sensible people were always betting on its being cracked one day.

The thing is, Go has not been beaten in quite the same way as chess. At one time it seemed to be an interesting question as to whether chess would be beaten by intelligence – a really good algorithm that sort of embodied some real understanding of chess – or by brute force; computers that were so fast and so powerful they could analyse chess positions exhaustively. That was a bit of an oversimplification, but I think it’s fair to say that in the end brute force was the major factor. Computers can play chess well, but they do it by exploiting their own strengths, not by doing it through human-style understanding. In a way that is disappointing because it means the successful systems don’t really tell us anything new.

Go, by contrast, has apparently been cracked by deep learning, the technique that seems to be entering a kind of high summer of success. Oversimplifying again, we could say that the history of AI has seen a contest between two tribes; those who simply want to write programs that do what’s needed, and those that want the computer to work it out for itself, maybe using networks and reinforcement methods that broadly resemble the things the human brain seems to do. Neither side, frankly, has altogether delivered on its promises and what we might loosely call the machine learning people have faced accusations that even when their systems work, we don’t know how and so can’t consider them reliable.

What seems to have happened recently is that we have got better at deploying several different approaches effectively in concert. In the past people have sometimes tried to play golf with only one club, essentially using a single kind of algorithm which was good at one kind of task. The new Go system, by contrast, uses five different components carefully chosen for the task they were to perform; and instead of having good habits derived from the practice and insights of human Go masters built in, it learns for itself, playing through thousands of games.

This approach takes things up to a new level of sophistication and clearly it is yielding remarkable success; but it’s also doing it in a way which I think is vastly more interesting and promising than anything done by Deep Thought or Watson. Let’s not exaggerate here, but this kind of machine learning looks just a bit more like actual thought. Claims are being made that it could one day yield consciousness; usually, if we’re honest, claims like that on behalf of some new system or approach can be dismissed because on examination the approach is just palpably not the kind of thing that could ever deliver human-style cognition; I don’t say deep learning is the answer, but for once, I don’t think it can be dismissed.

Demis Hassabis, who led the successful Google DeepMind project, is happy to take an optimistic view; in fact he suggests that the best way to solve the deep problems of physics and life may be to build a deep-thinking machine clever enough to solve them for us (where have I heard that idea before?). The snag with that is that old objection; the computer may be able to solve the problems, but we won’t know how and may not be able to validate its findings. In the modern world science is ultimately validated in the agora; rival ideas argue it out and the ones with the best evidence wins the day. There are already some emergent problems, with proofs achieved by an exhaustive consideration of cases by computation that no human brain can ever properly validate.

More nightmarish still the computer might go on to understand things we’re not capable of understanding. Or seem to: how could we be sure?