Conscious Entities

Jan-Markus Schwindt put up a complex and curious argument against physicalism in a recent JCS: one of those discussions whose course and conclusion seem wildly wrong-headed, but which provoke interesting reflections along the way.

His first point, if I followed him correctly, was that physics basically comes down to maths. In the early days, scientists thought of themselves as doing sums about some basic stuff which was out there in the world; as the sums and the theories behind them got more sophisticated and comprehensive, there was less and less need for the stuff-in-itself; the equations were really providing the whole show. In the end, the inescapable conclusion is that the world described by physics is a mathematical structure.

Schwindt quotes several scientists along these lines, such as Eddington saying ‘We have chased the solid substance from the continuous liquid to the atom, from the atom to the electron, and there we have lost it’. There’s no doubt, of course that maths is indeed the language, or perhaps the soul, of physics. Hooke claimed that Newton had stolen the idea of the inverse square law of gravity from him; but Christopher Wren gently remarked that he too had thought of the idea independently; so had many others he could name; the point was that only Newton could do the maths which turned it into a verifiable theory. Thes days, of course, it’s notoriously hard to describe the ’stuff’ that modern quantum physics is about in anything other than mathematical terms, and one respectable point of view is that there’s no point in trying.

But I don’t think physicalists are necessarily committed to the view that the world is mathematical to the core. In fact mathematicians have a noticeable tendency to be Platonists, believing that numbers and mathematical entities have a real existence in a world of their own. This is a form of dualism, and hence in opposition to physicalism, but very different to Schwindt’s point of view - instead of merging the physical into the mathematical, it keeps the precious formulae safe and unsullied in an eternal world of their own.

Moreover, at the risk of sounding like a bad philosopher, it all depends what you mean by mathematics. Numbers and formulae can be used in more than one way. n=1 is a testable statement in arithmetic; in many programming languages it’s true by fiat - it makes the variable n equal one. In Searlian terms, the direction of fit is different, or to put it less technically, in arithmetic it’s a statement, in programming an instruction. Now the kind of mathematical laws which hypothetically sustain the world would have to have the same direction of fit as the programming instruction: that is, it would be up to the world to resemble the law rather than up to the law to resemble the world. In fact they would require some more advanced metaphysical power than any mere high-level programming language; the sort of force which Adam’s words are supposed to have had in the garden of Eden, where his naming of a beast determined its very essence. If we could explain how apparently arbitrary laws of physics come to have this power over reality, it would be an unprecedented advance in metaphysics and the philosophy of science.

So when Schwindt tells us that the world is a mathematical structure, he may be right if he means mathematical in the sense of embodying a set of mysteriously potent ontological commands: but that’s just as complex and difficult as a world where the laws of physics are mere descriptions and the driving force of ontology is hidden away in ineffable stuff-in-itself. If, on the other hand, he means the world is reducible to a mathematical description, I think he’s mistaken - or at the least, he needs another argument to show how it could be.

For a second key point, Schwindt draws on an argument against functionalism proposed by Zuboff. This says that from a functionalist point of view, consciousness just consists of the firing of a certain pattern of neurons. But look, we could take out one neuron, put it in a dish somewhere, and then hand-feed the outputs and inputs between it and the rest of the brain in such a way that it functioned normally. Surely the relevant state of consciousness would be unaffected? If you’re happy with that, then you must accept that we could do the same with all the neurons in a brain. But if that’s so, we could put together a set of neurons which actually belong to different brains, but which together instantiate the right pattern for a particular experience, even though they don’t belong to any physically coherent individual? But surely this is absurd - so functionalism must be false.

Schwindt accepts this argument but gives it a different spin: for there to be patterns, he suggests, including patterns of neuron firing, there has to be an interpreter: someone who sees them as patterns. Since the world as described by physics is a mathematical structure, and since no mere mathematical structure can be an interpreter, consciousness requires something over and above the normal physical account. In fact, he proposes that consciousness is non-physical, and in effect the hardware which (if I’ve got this right) generates experience out of the mathematical structure of the physical world. This reasoning seems to lead naturally towards dualism, but Schwindt wants to stop just short of that: there seem to be two alternative reductions of the world on offer, he says, reasonably enough: the physicalist one and another which reduces everything to direct experience; but ultimately we can hope that there is some as yet unknown level on which monism is reasserted.

Alas, I think the Zuboffian argument (I haven’t read the original, so I rely on Schwindt’s account) fails because credible forms of functionalism don’t just require a pattern of neuron firing to exist: they require a relevant pattern of causal relations between neuron firing. As soon as hand-simulation enters the picture, all bets are off.

I think one reason Schwindt takes such an unlikely route is that he goes somewhat overboard in asserting the primacy of direct experience: he’s quite right that in one sense it’s all we’ve got; but like the idealists, he is in danger of mistaking an epistemological for an ontological primacy. It won’t come as any surprise, in any case, that I don’t really see how consciousness can be likened to hardware. Consciousness is content; arguably that’s all it is: whereas hardware is what gets left behind when you take the content out of a brain (or a computer). Isn’t it? Schwindt goes further and within consciousness has qualia playing a role analogous to a monitor, but I found that idea more confusing than illuminating.

Could consciousness be hardware? I can’t reject the idea: but that’s only because I don’t think I can properly grasp it to begin with.

Benjamin Libet’s experimental finding that decisions had in effect already been made before the conscious mind became aware of making them is both famous and controversial; now new research (published in a ‘Brief Communication’ in Nature Neuroscience by Chun Siong Soon, Marcel Brass, Hans-Jochen Heinze and John-Dylan Haynes) goes beyond it. Whereas the delay between decision and awareness detected by Libet lasted 500 milliseconds, the new research seems to show that decisions can be predicted up to ten seconds before the deciders are aware of having made up their minds.

The breakthrough here, like so many recent advances, comes from the use of fMRI scanning. Libet could only measure electrical activity, and had to use the Readiness Potential (RP) as an indicator that a decision had been made: the new research can go much further, mapping activity in a number of brain regions and applying statistical pattern recognition techniques to see whether any of it could be used to predict the subject’s decision.

The design of the experiments varied slightly from Libet’s original ingenious set-up. This time a series of letters was displayed on a screen. The subject were asked to press either a right or a left button at a moment chosen by them; they then identified the letter which had been displayed at the moment they felt themselves deciding to press either right or left. In the main series of experiments, no time constraints were imposed.

Two regions proved to show activity which predicted the subject’s choice: primary motor cortex and the Supplementary Motor Area (SMA) - the SMA is the source of the RP which Libet used in his research. In the SMA the researchers found activity which predicted the decision some five seconds before the moment of conscious awareness, but it was elsewhere that the earliest signs appeared - in the frontopolar cortex and the precuneus. Here the subject’s decision could be seen as much as seven seconds ahead of time: allowing for the delay in the fMRI response, this tots up to a real figure of ten seconds. One contrast with earlier findings is that there was no activation of the dorsolateral prefrontal cortex: the researchers hypothesise that this was because the design of their experiment did not require subjects to remember previous button presses. Another difference, of course, is the huge delay of five seconds in the SMA, which one would have expected to be comparable with the findings of earlier, RP-based research. Here the suggested explanation is that in the new experiments the timing of button presses was wholly unconstrained so that there was more time for activity to build up. The time delay in the fMRI study apparently means that the possibility that there was additional activity within the last few hundred milliseconds cannot be excluded: I conjecture that this offers another possible explanation if the RP studies actually detected a late spike which the fMRI couldn’t detect.

The experimenters also ran a series of experiments where the subject chose left or right at a pre-determined time: this does not seem to have shortened the delays, but it showed up a difference between the activation in the frontopolar cortex and the precuneus: briefly, it looks as if the former peaks at the earliest stage, with the precuneus ’storing’ the decision through more continuous activation.

What is the significance of these new findings? The researchers suggest the results do three things: they show that the delay is not confined to areas which are closely associated with motor activity, but begins in ‘higher’ areas; they demonstrate clearly that the activity relates to identifiable decisions, not just general preparation; and they rule out one of the main lines of attack on Libet’s findings, namely that the small delay observed is a result of mistiming, error, or misunderstanding of the chronology. That seems correct - a variety of arguments of differing degrees of subtlety have been launched against the timings of Libet’s original work. Although Libet himself was scrupulous about demonstrating solid reasons for his conclusions, it always seemed that a delay of a few hundred milliseconds might perhaps be attributable to some sort of error in the book-keeping, especially since timing a decision is obviously a tricky business. A delay of ten seconds is altogether harder to explain away.

However, it seems to me that while the new results close off one line of attack, they reinforce another - the claim that these experiments do not represent normal decision making. We do not typically make random decisions at a random moment of our choosing, and it can therefore fairly be argued that the research has narrower implications than might appear, or even that they are merely a strange by-product of the peculiar mental processes the subjects were asked to undertake. While the delay was restricted to half a second, it was intuitively believable that all our normal decisions were subject to a similar time-lag - surprising, but believable. A delay of ten seconds in normal conscious thought is not credible at all; it’s easy to think of cases where an unexpected contingency arises and we act on it thoughtfully and consciously within much shorter periods than that.

The researchers might well bite the bullet so far as that goes, accepting that their results show only that the delay can be as long as ten seconds, not that it invariably is. Libet himself, had he lived to see these results might perhaps have been tempted to elaborate his idea of ‘free won’t’ - that while decisions build up in our brains for a period before we are aware of them, the conscious mind retains a kind of veto at the last moment.

What would be best of all, of course, is further research into decisions made in more real-life circumstances, though devising a way in which decisions can be identified and timed accurately in such circumstances is something of a challenge.

In the meantime, is this another blow to the idea of free will generally? The research will certainly hearten hard determinists, but personally I remain a compatibilist. I think making a decision and becoming aware of having made that decision are two different things, and I have no deep problem with the idea that they may occur at different times. The delay between decision and awareness does not mean the decision wasn’t ours, any more than the short delay before we hear our own voice means we didn’t intend what we said. Others, I know, will feel that this relegates consciousness to the status of an epiphenomenon.

Chris Chatham has gamely picked up on my remarks about his interesting earlier piece, which set out a number of significant differences between brains and computers. We are, I think, somewhere between 90 and 100 percent in agreement about most of this, but Chris has come back with a defence of some of the things I questioned. So it seems only right that I should respond in turn and acknowledge some overstatement on my part.

Chris points out that “processing speed” is a well-established psychometric construct. I must concede that this is true: the term is used to cover various sound and useful measures of speed of recognition and the like: so I was too sweeping when I said that ‘processing speed’ had no useful application to the brain. That said, this kind of measurement of humans is really a measurement of performance rather than directly of the speed of internal working, as it would be when applied to computers. Chris also mentions some other speed constraints in the brain - things like rate of firing of neurons, speed of transmission along nerves - which are closer to what ‘processing speed’ means in computers (though not that close, as he was saying in the first place). In passing, I wonder how much connection there is between the two kinds of speed constraint in humans? The speed of performance of a PC is strongly affected by its clock speed; but do variations in rates of neuron firing have a big influence on human performance? It seems intuitively plausible that in older people neurons might take slightly longer to get ready to fire again, and that this might make some contribution to longer reaction times and the like (I don’t know of any research on the subject), but otherwise I suspect differences in performance speed between individual humans arise from other factors.

In a nutshell, Chris is right when he says that Peter is probably uncomfortable with equating “sparse distributed representation” with “analog,”. To me it looks like a whole nother thing from what used to go on in analog computers, where a particular value might be represented by a particular level of current. The whole topic of mental representation is a scary one for me in any case: if Chris wanted a twelfth difference to add to his list, I think he could add Computers don’t really do representation. That may seem an odd thing to say about machines that are all about manipulating symbols; but nothing in a computer represents anything except in so far as a human or humans have deemed or designed it to represent something. Whereas the human brain somehow succeeds in representing things to itself, and then to other humans, and manages to confer representational qualities on noises, marks on paper - and computers. This surely remains one of the bogglingly strange abilities of the mind, and it’s unlikely the computer analogy is going to help much in understanding it.

I do accept that in some intuitive sense the brain can be described as ‘massively parallel’ - people who so describe it are trying to put their finger on a characteristic of the brain which is real and important . But the phrase is surely drawn from massively parallel computing, which really isn’t very brain-like. ‘Parallel’ is a good way of describing how different bits of a process can be shepherded in an orderly manner through different CPUs or computers and then reintegrated; in the brain, it looks more as if the processes are going off in all directions, constantly interfering with each other, and reaching no definite conclusion. How all this results in an ordered and integrated progression of conscious experience is of course another notorious boggler, which we may solve if we can get a better grasp of how this ‘massively parallel’ - I’d rather say ‘luxuriantly non-linear’ way of operating works. My fear is that use of the phrase ‘massively parallel’ risks deluding us into thinking we’ve got the gist already.

Whatever the answer there, Chris’s insightful remarks and the links he provided have certainly improved my grasp of the gist of things in a number of areas, however, for which I’m very grateful.

Chris Chatham has a nice summary of ten key differences between brains and computers which is well worth a read. Briefly, the list is:

• Brains are analogue; computers are digital
• The brain uses content-addressable memory
• The brain is a massively parallel machine; computers are modular and serial
• Processing speed is not fixed in the brain; there is no system clock
• Short-term memory is not like RAM
• No hardware/software distinction can be made with respect to the brain or mind
• Synapses are far more complex than electrical logic gates
• Unlike computers, processing and memory are performed by the same components in the brain
• The brain is a self-organizing system
• Brains have bodies
• The brain is much, much bigger than any [current] computer

Actually eleven differences - there’s a bonus one in there.

Hard to argue with most of these, and there are some points among them which are well worth making. There is always a danger, when comparing the capacities of brains and computers, of assuming a similarity even when trying to point up the contrast. There have, for example, been many attempts to estimate the storage capacity of the brain, or the memory, over the years for example, always concluding that it is huge; but a figure in megabytes doesn’t really make much sense. Asking how many bytes there are in the memory is like asking how many pixels Leonardo needed to do the Mona Lisa: it’s not like that. Chris generally steers just clear of this danger, although I’d be more inclined to say, for example, that the concept of processing speed has no useful application in the brain rather than that it isn’t fixed.

I wonder a bit about some of the positive assertions he makes. Are brains analogue? Granted they’re not digital, at least not in the straightforward way that a digital computer is, but unless we take ‘analogue’ as a synonym for ‘non-digital’ it’s not really clear to me. I take digital and analogue to be two different ways of representing real-world quantities; I don’t think we really know exactly how the brain represents things at the moment. It’s possible that when we do know, the digital/analogue distinction may seem to be beside the point.
And are brains ‘massively parallel’? It’s a popular phrase, but one of the older bits of this site long ago looked at a few reasons why the resemblance to massively parallel computing seems slight. In fairness, when people make this assertion they aren’t really saying that the brain is like a parallel processing set-up; they’re trying to describe a quality of the brain for which there is no good word; ie that things seem to be going on all over it at the same time. Chris is really warning against an excessively modular view. Once again we can agree that the brain is unlike computers - this time in the way they funnel data and instructions together in one or more processors; but the positive comparison is more problematic.

There’s some underlying scope for confusion, too, about what we mean when we assert that brains are not computers. We could just intend the trivial point that there isn’t actually a physical PC in our heads. More plausibly, we could mean that the brain doesn’t have the same general architecture and functional features as a computer (which I think is about what Chris means to do). We could mean that the brain doesn’t do stuff that we could easily recognise as computation, although it might be functionally similar in the sense of producing the same output to input relationships as a computed process. We might mean it doesn’t do stuff that we could easily recognise as computation, and that there appears to be no non-trivial way of deriving algorithms which would do the same thing. We might go one further and assert, as Roger Penrose does, that some of what the brain is doing is non-computable in the same sort of way as the tiling problem (though here again we have to ask is it really like that since the question of computability seems to assume the brain is typically solving problems and seeking proofs). Finally, we could be saying that the brain has altogether mysterious properties of free will and phenomenal experience which go beyond anything in our current understanding of the physical world, and ergo far beyond anything a mere computer might possess.

A good thought-provoking discussion, in any case.

I’ve suggested previously that one of the important features of qualia (the redness of red, the smelliness of Gorgonzola, etc) is haecceity, thisness. When we experience redness, it’s not any Platonic kind of redness, it’s not an idea of redness, it’s that. When people say there is something it is like to smell that smell, we might reply, yes: that. That’s what it’s like. The difficulty of even talking about qualia is notorious, I’m afraid.

But it occurred to me that there was another problem, not so often addressed, which has the same characteristic: the problem of one’s own haecceity.

Both problems are ones that often occur to people of a philosophical turn of mind, even if they have no academic knowledge of the subject. People sometimes remark ‘For all we know, when I see the colour blue, you might be seeing what I see when I see red’, and similarly, thoughtful people are sometimes struck by puzzlement as to why they are themselves and not someone else. That particular problem has a trivial interpretation - if you weren’t you, it would be someone else’s problem - but there is a real and difficult issue related to the grand ultimate question of why there is anything at all, and why specifically this.

One of the standard arguments for qualia, of course, is the possibility of philosophical zombies, people who resemble us in every way except that they have no qualia. They talk and behave just like us, but there is nothing happening inside, no phenomenal experience. Qualophiles contend that the possibility of such zombies establishes qualia as real and additional to the normal physical story. Can we have personhood zombies, too? These would be people who, again, are to all appearances like us, but they don’t have any experience of being anyone, no sense of being a particular self. It seems at least a prima facie possibility.

That means that if we consider both qualia and selfhood, we have a range of four possible zomboid variants. Number one, not in fact a zombie at all, would have both qualia and the experience of selfhood - probably what the majority would consider the normal state of affairs. His opposite would have neither qualia nor a special sense of self, and that would be what a Dennettian sceptic takes to be the normal position. Number three has a phenomenal awareness of his own existence, but no qualia. This is what I would take to be the standard philosophical zombie. This is not really clear, of course: I assume the absence of discussion of the self in normal qualia discussion implies that zombies are normal in this respect, but others might not agree and some might even be inclined to regard the sense of self as just a specific example of a quale (there are, presumably, proprioceptive qualia, though I don’t think that’s what I’m talking about here), not really worthy of independent discussion.

It’s number four that really is a bit strange; he has qualia going on inside, but no him in him: phenomenal experience, but no apparent experiencer. Is this conceivable? I certainly have no knock-down argument, but my inclination is to say it isn’t: I’m inclined to say that all experiences have an experiencer just as surely as causes have effects. If that’s true, then it suggests the two cases of haecceity might be reducible to one: the thisness of your qualia is really just your own thisness as the experiencer (I hope you’re still with me here, reader). That in turn might mean we haven’t been looking in quite the right place for a proper account of qualia.

What if number four were conceivable? If qualia can exist in the absence of any subjective self-awareness, that suggests they’re not as tightly tied to people as we might have thought. That would surely give comfort to the panpsychists, who might be happy to think of qualia blossoming everywhere, in inanimate matter as well as in brains. I don’t find this an especially congenial perspective myself, but if it were true, we’d still want to look at personal thisness and how it makes the qualia of human beings different from the qualia of stones.

At this point I ought to have a blindingly original new idea of the metaphysics of the sense of self which would illuminate the whole question as never before. I’m afraid I’ll have to come back to you on that one.

A bit of an update in Seed magazine on the Blue Brain project. This is the project that set out to simulate the brain by actually reproducing it in full biological detail down to the behaviour of individual neurons and beyond: with some success, it seems.

The idea of actually simulating a real brain in full has always seemed fantastically ambitious, of course, and in fact the immediate aim was more modest: to simulate one of the columnar structures in the cortex. This is still an undertaking of mind-boggling complexity: 10,000 neurons, 30 million synaptic connections, using 30 different kinds of ion channel. In fact it seems the ion channels were one of the problem areas; in order to get good enough information about them, the project apparently had to set up its own robotic research. I hope the findings of this particular bit of the project are being published in a peer-reviewed journal somewhere.

However, the remarkable thing is that it worked: eventually the simulated column was created and proved to behave in the same way as a real one. So is the way open for a full brain simulation? Not quite. Even setting aside the many structural challenges which surely remain to be unravelled (don’t they - the brain isn’t simply an agglomeration of neocortical columns?) Henry Markram, the project Director, estimates that an entire brain would require the processing of 500 petabytes of data, way beyond current feasibility. Markram believes that within ten years, the inexorable increase in computing power will make this a serious possibility. Maybe: it doesn’t pay to bet against Moore’s Law - but I can’t help noticing that there has been a big historical inflation in the estimated need, too. Markram now wants 500 petabytes: a single petabyte is 10¹⁵ bytes; but in 1950 Turing thought that 10¹⁵ bits represented the highest likely capacity of the brain, with about 10⁹ enough for a machine which could pass the Turing Test. OK, perhaps not really a fair comparison, since Turing had nothing like Blue Brain in mind.

One criticism of the project asks how it judges its own success - or rather, suggests that the fact that it does judge its own success is a problem. If we had a full brain which could operate a humanoid robot and talk to us, there would be no doubt about the success of the project; but how do we judge whether a simulated neuronal column is actually working? The project team say that their conclusions are based on scrupulous comparisons with real biological brains, and no doubt that’s right; but there’s still a danger that the simulation merely confirms the expectations fed into it. They came up with an idea of how a column works; they built something that worked like that: and behold, it works how they think a column works.

There is also undeniably something a bit strange about the project. Before Blue Brain was ever thought of, proponents of AI would sometimes use the idea of a total simulation as a kind of thought-experiment to establish the merely neurological nature of the mind. OK, there might be all these mechanisms we didn’t understand, and emergent phenomena, and all the rest, but at the end of the day, what if we just simulated everything? Surely then you’d have to admit, we would have made an artificial mind - and what was to stop us, except practicality? It was an unexpected development back in 2005 when someone actually set about making this last-ditch argument a reality. It is unique; I can’t think of another case where someone set out to reproduce a biological process by building a fully detailed simulation, without having any theory of how the thing worked in principle.

This raises some peculiar possibilities. We might put together the full Blue Brain; it might be demonstrably performing like a human brain, controlling a robot which walked around and discussed philosophy with us, yet we still wouldn’t know how it did it. Or, worse perhaps, we might put it all together, see everything working perfectly at a neuronal level, and yet have our attached robot standing slack-jawed or rolling around in a fit, without our being able to tell why.

It may seem unfair to describe Markram and his colleagues as having no theory, but some of his remarks in the article suggest he may be one of those scientists who doesn’t really get the Hard Problem at all.

…It’s the transformation of those cells into experience that’s so hard. Still, Markram insists that it’s not impossible. The first step, he says, will be to decipher the connection between the sensations entering the robotic rat and the flickering voltages of its brain cells. Once that problem is solved—and that’s just a matter of massive correlation—the supercomputer should be able to reverse the process. It should be able to take its map of the cortex and generate a movie of experience, a first person view of reality rooted in the details of the brain…

It could be that Markram merely denies the existence of qualia, a perfectly respectable point of view; but it looks as if he hasn’t really grasped what they are, and that they can’t be captured on any kind of movie. Perhaps this outlook is a natural or even a necessary quality of someone running this kind of project. I suppose we’ll have to wait and see what happens when he gets his 500 petabyte capacity.

More about babies - of a sort. You may have seen reports that Plymouth University, with support from many other institutions, has won the opportunity to teach a baby robot to speak. The robot in question is the iCub, and the project is part of Italk, funded by the EU under its Seventh Framework Programme, to the tune of £4.7 million (you can’t help wondering whether it wouldn’t have been value for money to have slipped Steve Grand half a million while they were at it…).

The gist of it seems to be that next year the people at Plymouth will get the iCub to engage in various dull activities like block-stacking (a perennial with both babies and AI) and try to introduce speech communication about the tasks. It is meant to be learning in a way far closer to the typical human experience than anything attempted before. Unfortunately, I haven’t been able to find any clear statement of how they expect the language skills to work, though there is quite a lot of technical detail available about the iCub. This is evidently a pretty splendid piece of kit, although the current model has a mask for a face, which means none of the potent interactive procedures which depend on facial expression, as explored by Cynthia Brezeal and others, will be available. This is a shame, since real babies do use face recognition and smiles to get more feedback out of adults.

In one respect the project has an impeccable background, since Alan Turing, in the famous paper which arguably gave rise to modern Artificial Intelligence, speculated that a thinking robot might have to begin as a baby and be educated. But it seems a tremendously ambitious undertaking. If we are to believe Chomsky, the human language acquisition device is built in - it has to be, since human babies get such poor input, with few corrections and limited samples, yet learn at a fantastic speed. They just don’t get enough information about the language around them to be able to reverse-engineer its rules; so they must in fact simply be customising the setting of their language machine and filling up its vocabulary stores. The structures of real-world languages arguably support this point of view, since the variations in grammar seem to fall within certain limited options, rather than exploiting the full range of logical possibilities. If this is all true, then a robot which doesn’t have a built-in language facility is not going to get very far with talking just by playing with some toys.Of course Chomsky is not, as it were, the only game in town: a more recent school of thought says that by treating language as a formal code, and assuming that babies have to learn the rules before they can work out what people mean, Chomsky puts the cart before the horse; actually, it’s because babies can see what people mean that they can crack the code of grammar so efficiently.

That’s a more congenial point of view for the current project, I imagine, but it raises another question. On this view, babies are not using an innate language module, but they are using an innate ability to understand, to get people’s drift. I don’t think the Plymouth team have worked out a way of building understanding in beforehand (that would be a feat well worth trumpeting in its own right), so is it their expectation that the iCub will acquire understanding through training? Or are their aims somewhat lower?

It seems a key question to me: if they want the robot to understand what it’s saying, they’re aiming high and it would be good to know what the basis for their optimism is (and how they’re going to demonstrate the achievement). If not, if they’re merely aiming for a basic level of performance without worrying about understanding (and the selection of experiments does rather point in that direction), the project seems a bit underwhelming. Would this be any different, fundamentally, from what Terry Winograd was doing, getting on for forty years ago (albeit with SHRDLU, a less charismatic robot)?

If ever you suspected that the ‘hard problem’ of consciousness was a recondite philosophical matter, of no significance in the real world, a recent piece in the NYT (discussed briefly by our old friend Steve Esser) should convince you otherwise.

It explains how Kanwaljeet Anand discovered that new-born babies were receiving surgery without anaesthetics, and goes on to discuss the evidence that fetal surgery, increasingly common, also causes pain responses in the unborn child.

Why would doctors be so callous? They don’t believe new-born children, let alone fetuses, feel any pain. When they operate on a new-born baby, there may be some reflexes, but there are no pain qualia - no pain is really being felt. So all they need to give in the way of drugs is a paralytic - something that makes the subject keep still during the operation, but has no effect on how it feels.

It seems to me that, although they may not be clearly aware of it, the doctors here are making important real world decisions on the basis of their philosophical beliefs about qualia. Quite bold beliefs too: they don’t believe the fetuses can be feeling pain because the brain, and in particular the cortex, is not yet wired up sufficiently for consciousness, and if you’re not conscious, you can’t have qualia.

It’s quite possible they are right, I suppose, but I think most people who have been through some of the philosophical arguments would doubt whether we can speak of these matters with such certainty, and would be inclined to err on the side of safety. To be honest, it’s a bit hard to shake the suspicion that the real reason fetuses don’t get anaesthetics is because fetuses don’t complain…

I think the real issue here is slightly different. Why was Anand concerned about the babies who were coming back to him after surgery, before he even knew they weren’t being anaesthetised? Because they were traumatised. Their systems had been flooded with hormones usually associated with pain, their breathing was poor, their blood sugar was out of order. When they were given anaesthetics, instead of just paralytics, they survived the operations in better health. There were medical reasons for avoiding the pain, not just subjective ones. The problem arose out of the fact that the surgeons and anaesthetists had got used to the idea that relief of subjective pain was all that mattered. So when they were dealing with patients who they judged incapable of subjective pain, they saw no reason to anaesthetise. They were, in fact, paying too much attention to the idea of qualia, and not enough to the physical, medical events which actually constitute pain even if your cortex isn’t working. (The passage in the NYT piece about people with hydranencephaly is a dreadful red herring, by the way: it just isn’t true that they have no cortex.)

True, there were other reasons for using anaesthetics in that particular case. But where do the doctors get their certainty that no pain is being felt? You can’t talk about your qualia if your cortex isn’t working, but since qualia are an utter mystery and separable in principle from the physical operation of the brain altogether, there’s no strong reason to think you’re not feeling them. We take winces and grimaces as good indicators of pain in normal people: how can we be sure it’s any different in fetuses? Is it just the talking that matters? Is an unreportable pain no pain at all? Surely not.

You say qualia are separable from the physical operation of the brain, but you don’t really believe that in any important way. You know quite well that brain events like the firing of certain neurons are what cause these sensations you misdescribe as ineffable qualia. If I hit you with a physical spade, you’ll feel pain qualia alright, however ’separable’ you think they are.

Let’s get a bit more philosophical here. Why is pain bad? Why is it to be avoided and minimised? There are several traditional answers — I’d say the following just about cover it.

• It just is. Pain is just bad in its essential nature.
• The moral rules agreed by our society enjoin us not to cause pain.
• Ethics requires us to seek the greatest possible balance of pleasure over pain.
• You wouldn’t want pain inflicted on you, so don’t inflict it on other people.
• Witnessing or hearing about pain makes me feel bad.
• Carelessness about pain is the beginning of a general callousness which might undermine our concern for others, without which we’re doomed.

The first doesn’t mean anything, if you ask me. The second might be right, but the established rules, judging by medical practice, seem to say fetal pain is something we don’t have to worry about. Social rules are negotiable, anyway, so there’s no final answer there. The third one, like the first one, just assumes pain is bad. The fourth is OK, but begs the question so far as fetuses are concerned, because we don’t know what I’d want done to me if I were a fetus. I might just want them to get on with the operation, unbothered by the apparent ‘pain’ I wasn’t actually feeling. Numbers five and six, if you ask me, get close to the real motivation here.

Got that? OK, now let’s revert to your question — why do the doctors behave like this, why do they torture babies? It’s not just, I suggest, that they don’t believe in fetal pain. The more crucial point is that they know fetuses don’t remember pain. There was a time, in the not-too-distant past, when some children, not just babies, were merely given curare before being operated on. Just like the new-born babies here, it paralysed them so the surgeon could get on with the job, but did nothing whatever to relieve the pain. Did the doctors think the children didn’t feel the pain? Well, there’s some talk about them thinking curare was aneasthetic, but that’s balderdash — they didn’t use it for adults. No, I believe they knew quite well the children were in pain, they just thought it didn’t matter because children don’t remember these things. Give ‘em an ice cream, they thought, and we’ll hear no more about it. (I’m not saying that’s necessarily correct, by the way).

In essence, the doctors implicitly agreed with me. There were no deep metaphysical or ethical reasons to avoid pain, and reciprocity never really worked, because there were always relevant differences between you and the person suffering the pain (unless you were fighting your twin brother, perhaps). You could always say; yeah, do as you would be done by, but if I were in the state that person’s in, I would want it done to me. So, the doctors rightly concluded, there were only two fundamental reasons to avoid causing pain; first, it upset people. As a result, our social rules were generally set to minimise it, and so second, the unnecessary infliction of pain would tend to have bad social effects, undermining the rules and generally risking a withdrawal of social consent. Pain which will never be remembered cannot upset us or have bad social consequences — so it doesn’t matter.

There’s more evidence that this is the established medical view. Besides paralysing and anaesthetising patients, doctors use drugs which specifically remove the memory. In some cases, drugs which remove the memory have been used instead of anaesthetics, just because in medical eyes, pain you don’t remember is the same as pain that never happened. It’s perfectly normal contemporary practice to use a mixture of true anaesthestics and amnestics.

So, to sum up, pain has three aspects: medical (the hormonal reaction, the changes in the body), psychological (we don’t like thinking about it), and social (we’ve agreed to outlaw pain, and erosion of that rule undermines society generally). And that’s all there is. The medical, psychological, and social aspects add up to what pain is: there’s no mystical component, no qualia.

That just seems mad to me - bonkers and almost diabolical. Surely you can see that the reason pain is bad is because it hurts? That’s all pain is - hurting.

You and your supposed doctor friends are a bit over-confident about your amnesia anyway, aren’t you? The NYT article reports evidence that pain experienced early on affects a child’s responses later. Do you really feel confident that agonising episodes early on — even in the womb — are not lurking in some damaging form in the subconscious of the child, or even the adult?

Asim Roy insists (Connectionism, controllers and a brain theory) that there are controllers in the brain. This is not as sinister as it might sound.

Roy presents his views as an attack on connectionist orthodoxy. Connectionists, he says, believe that the brain does not have in it groups of cells that control other parts of the brain. He cites many sources, and quotes explicitly from Rumelhart, Hinton, and McClelland, who say

“There is one final aspect of our models which is vaguely derived from our understanding of brain functioning. This is the notion that there is no central executive overseeing the general flow of processing…”

Roy begins by addressing a startlingly radical argument against the notion of controllers in any system. He takes up the analogy of a human being driving a car. The steering and other systems, according to a normal understanding, are controlled by the driver; but, he says, there is an argument that this is the wrong way of looking at it. It’s true that the steering is guided by input from the driver, but there is also feedback to the driver from the various systems of the car, which also determine what the driver does. The current position of the wheel and the response of the car determine how much force the driver applies to the wheel. So really the car is controlling the driver as well as vice versa, and the very idea of a controller within a system is a misapprehension.

This is obviously a slightly silly argument, but it serves to show that we need to define the notion of a controller properly. Roy suggests that the essence of a controller is that it is not dependent on inputs. The steering moves only in response to my inputs, whereas if I choose (and am tired of life, presumably) I can ignore any feedback from the car and turn the wheel any arbitrary number of degrees I settle on. Similarly, although my channel-hopping is normally guided by what appears on the TV screen, if I wish I can choose to change channels arbitrarily, or tap out a rhythm on the remote control which has nothing to do with the TV. A controller, in short can operate in different modes while a subservient system cannot.Armed with this definition, Roy argues that a connectionist network which learns by back-propagation requires an external agent to set the parameters, whether it be a human operator or another module within the overall system. I suppose it could be retorted that this controller is indeed external, and exercises its influence only during learning, but Roy would probably say that if we’re modelling the human brain, these controllers would have to be taken to be part of the neural set-up. In any case, he goes on to give examples from neuroscience to show that some parts of the brain do indeed seem to operate as controllers of some other parts. I must say that this claim seems so evidently true to me that argument in its favour seems almost redundant.

Roy’s conclusion is that his reasoning opens the way to a better approach, where instead of being left to local learning, the methods and weightings to be used can be dictated by a central system, at least on some occasions.

I think Roy’s conclusion that there must be controllers within the brain is hard to disagree with: the question is more whether he’s demolishing a straw man. What did Rumelhart, Hinton, and McClelland actually mean? I suspect they meant to deny the existence of a central ‘homunculus’. a little man in the brain who does all the real work; and also to deny that the brain has a CPU, a place where all the data and instructions get matched together and processed. I don’t really think they meant to deny that any part of the brain ever controls any other part. I’m not sure that connectionists have ever reached the point of proposing an overall architecture for the brain, or even that that would be within the scope of the theory; rather, they just want to investigate a way of working which may be characteristic of parts of the brain.

I can imagine two ways connectionists might respond to Roy’s claims without directly contesting them. One would be to accept that the control function he describes exists, but claim that it doesn’t reside in one fixed place. Different parts of the overall network might be in control at different times; it’s not that bits of the brain don’t control other parts, merely that control is sort of smeared around. But equally I can imagine a connectionist simply saying; of course we never meant to deny that that sort of control relation exists, so thanks for the clarification…

I think Roy’s attempt to define what a controller does is interesting, however. A controller, on his view, can follow the inputs, or operate without them. But surely other systems can operate without inputs, too? If I black out and cease to provide the car with control inputs, it doesn’t cease to function. It may function disastrously, but that’s also true if I exercise my controller’s right to ignore inputs and take a kind of existentialist approach to steering. You could say that in cases like the black-out one the controlled system is continuing to receive inputs - they’re just consistently zero. The point really is not operating without inputs, but being able to ignore the ones you’re getting. I think what we’re grasping for here is that the inputs to a controller don’t determine the outputs. That’s interesting because it sounds like one version of free will. When I act freely, my actions were not determined by the environmental inputs. But it’s notoriously hard to explain how that could be so in a deterministic world.

If you’re a softy compatibilist about free will, you may be inclined to argue that it is to some extent a matter of degree. Where input A always gets output B, no question of freedom or controllerhood arises. But if there is a complex internal algorithm working away, such that input A may get any letter of the alphabet on different occasions, things start to look different. And if the outputs begin to show a certain kind of coherence or meaningful salience - if they begin to spell intelligible words - we might be inclined to say that the system is in some sense in control. If when we turn the wheel, the car does not respond, we might gasp metaphorically “The damn thing’s got a will of it’s own!”; further, if it actually directs itself down a side road and into the filling station we might seriously and literally begin to credit the car with intelligence. So far so Dennettian.

If that line of reasoning is right, controllerhood is indeed a tricky business: it might be that the only way to know whether some group of cells is a controller would be to watch it and see whether it did controllery things. And if that’s the case, maybe smeary connectionism has something in it after all…

It often happens that when someone has had a limb amputated, they experience feelings in the limb they haven’t got any more - the ‘phantom limb’ phenomenon. The phantoms may be just temporary, a curious by-product of the operation. Sometimes the feelings are partial - where an arm has been removed, for example, patients may feel as though they still had their hand, but attached to the shoulder without any intervening arm. Sometimes the experience is more of a problem, with feelings of intense pain in the amputated part which won’t go away and can’t be treated by normal means.

I therefore winced slightly on learning that as well as phantom limbs, there are phantom penises, experienced by those who have undergone a penectomy (a word which is well worthy of a wince in itself). V.S.Ramachandran, who devised an ingenious way of using mirrors to help people with phantom limb pain, by fooling the brain into briefly believing that the missing limb was back, has now turned his attention to penises, together with P.D. McGeoch. This time the research is not about pain relief, however, but gender identity, where the possession or lack of a penis is clearly highly relevant.
Penectomies, it seems, are performed for two main reasons; to eliminate a malignant cancer, or as part of gender reassignment treatment. Since male-to-female transsexuals typically feel themselves to be ‘a woman in a man’s body’, Ramachandran and McGeoch reasoned that their response to penectomy might well be different from that of other patients. And so it proved: while 58% of men who have undergone penectomy for other reasons reported sensation in a phantom penis afterwards, only 30% of those who had done so as part of gender reassignment had a similar experience. So people who felt that a penis was not part of their true body image were much less likely to experience a phantom penis after removal.

Stranger still, perhaps, 62% of a group of female-to-male transsexuals reported having had phantom penis sensations before any surgery. In many cases the sensations dated back for years: in others, they did not occur until hormone treatment had begun. No non-transsexual women, unsurprisingly, reported the sensation of having a phantom penis (’even when prompted’ as the researchers say).
Ramachandran and McGeoch conclude that the study backs the view that gender identity feelings are hard-wired into the brain, and in transsexuals may be at odds with actual physical shape. They recognise, however, that there are some potential criticisms of the way the research was done.

One weak point is the risk of confabulation. By asking female-to-male transsexuals whether they had ever had phantom penis sensations, were the researchers discovering a phenomenon, or creating one? Transsexuals often have to struggle for the acceptance of their view of themselves; they have a natural reason to want to assert anything that might strengthen their case. The experience of a phantom penis would clearly be a useful piece of evidence in this context. Since female-to-male transsexuals by definition feel that they ought to have a penis, it may not be much of a leap to say they feel as though they have one, once the possibility is suggested.

To some extent, moreover, male-to-female transsexuals might have been inclined to feel that any report of phantom sensations was letting the side down in some subtle way; suggesting that they or their bodies somehow couldn’t give up the idea of having a penis very readily. Indeed, an old Freudian theory which the researchers pour scorn on, had it that the symptoms of phantom limbs expressed an unconscious desire that the limb was still there, so reasoning along those lines is by no means impossible.

However, the researchers have a number of counterarguments. Perhaps the most striking is that female-to-male transsexuals were often able to report details of the phantom penis and its behaviour, saying that it fell short of their ideal penis, for example. Surely an imagined penis, a wish-fulfilment penis, would be fully satisfactory? Less convincingly, I think, the researchers quote cases where the subjects reported the phantom penis behaving in ways - morning or unprompted erections, for example - which a female subject allegedly would have been unlikely to add to a confabulated account. I suspect the female subjects are likely to have been more aware of this kind of detail than the researchers suppose.

At the end of the day, we seem to have some suggestive evidence, but not a fully convincing case. Ramachandran and McGeoch rightly say that evidence from brain imaging studies would be very useful - notably in establishing whether a pre-operative female-to-male transsexual having a phantom penis experience has similar brain activity to a male having normal penis sensations.