Posts tagged ‘consciousness’

waveAn article in the Chronicle of Higher Education (via the always-excellent Mind Hacks) argues cogently that as a new torrent of data about the brain looms, we need to ensure that it is balanced by a corresponding development in theory. That must surely be right: but I wonder whether the torrent of new information is going to bring about another change in paradigm, as the advent of computers in the twentieth century surely did?

We have mentioned before the two giant projects which aim to map and even simulate the neural structure of the brain, one in America, one in Europe. Other projects elsewhere and steady advances in technology seem to indicate that the progress of empirical neuroscience, already impressive, is likely to accelerate massively in coming years.

The paper points out that at present, in spite of enormous advances, we still know relatively little about the varied types of neurons and what they do; and much of what we think we do know is vague, tentative, and possibly misleading. Soon, however, ‘there will be exabytes (billions of gigabytes) of data, detailing what vast numbers of neurons do, in real time’.

The authors rightly suggest that data alone is no good without theoretical insights: they fear that at present there may be structural issues which lead to pure experimental work being funded while theory, in spite of being cheaper, is neglected or has to tag along as best it can. The study of the mind is an exceptionally interdisciplinary business, and they justifiably say research needs to welcome ‘mathematicians, engineers, computer scientists, cognitive psychologists, and anthropologists into the fold’. No philosophers in the list, I notice, although the authors quote Ned Block approvingly. (Certainly no novelists, although if we’re studying consciousness the greatest corpus of exploratory material is arguably in literature rather than science. Perhaps that’s asking a bit too much at this stage: grants are not going to be given to allow neurologists to read Henry as well as William James, amusing though that might be.)

I wonder if we’re about to see a big sea change; a Third Wave? There’s no doubt in my mind that the arrival of practical computers in the twentieth century had a vast intellectual impact. Until then philosophy of mind had not paid all that much attention to consciousness. Free Will, of course, had been debated for centuries, and personal identity was also a regular topic; but consciousness per se and qualia in particular did not seem to be that important until – I think – the seventies or eighties when a wide range of people began to have actual experience of computers. Locke was perhaps the first person to set out a version of the inverted spectrum argument, in which the blue in your mind is the same as the yellow in mine, and vice versa; but far from its being a key issue he mentions it only to dismiss it: we all call the same real world colours by the same names, so it’s a matter of no importance. Qualia? Of no philosophical interest.

I think the thing is that until computers actually appeared it was easy to assume, like Leibniz, that they could only be like mills: turning wheels, moving parts, nothing there that resembles a mind. When people could actually see a computer producing its results, they realised that there was actually the same kind of incomprehensible spookiness about it as there was in the case of human thought; maybe not exactly the same mystery, but a pseudo-magic quality far above the readily-comprehensible functioning of a mill. As a result, human thought no longer looked so unique and we needed something to stand in as the criterion which separated machines from people. Our concept of consciousness got reshaped and promoted to play that role, and a Second Wave of thought about the mind rolled in, making qualia and anything else that seemed uniquely human of special concern.

That wave included another change, though, more subtle but very important. In the past, the answer to questions about the mind had clearly been a matter of philosophy, or psychology; at any rate an academic issue. We were looking for a heavy tome containing a theory. Once computers came along, it turned out that we might be looking for a robot instead. The issues became a matter of technology, not pure theory. The unexpected result was that new issues revealed themselves and came to the fore. The descriptive theories of the past were all very well, but now we realised that if we wanted to make a conscious machine, they didn’t offer much help. A good example appears in Dan Dennett’s paper on cognitive wheels, which sets out a version of the Frame Problem. Dennett describes the problem, and then points out that although it is a problem for robots, it’s just as mysterious for human cognition; actually a deep problem about the human mind which had never been discussed; it’s just that until we tried to build robots we never noticed it. Most philosophical theories still have this quality, I’m afraid, even Dennett’s: OK, so I’m here with my soldering iron or my keyboard: how do I make a machine that adopts the intentional stance? No clue.

For the last sixty years or so I should say that the project of artificial intelligence has set the agenda and provided new illumination in this kind of way. Now it may be that neurology is at last about to inherit the throne.  If so, what new transformations can we expect? First I would think that the old-fashioned computational robots are likely to fall back further and that simulations, probably using neural network approaches, are likely to come to the fore. Grand Union theories, which provide coherent accounts from genetics through neurology to behaviour, are going to become more common, and build a bridgehead for evolutionary theories to make more of an impact on ideas about consciousness.  However, a lot of things we thought we knew about neurons are going to turn out to be wrong, and there will be new things we never spotted that will change the way we think about the brain. I would place a small bet that the idea of the connectome will look dusty and irrelevant within a few years, and that it will turn out that neurons don’t work quite the way we thought.

Above all though, the tide will surely turn for consciousness. Since about 1950 the game has been about showing what, if anything, was different about human beings; why they were not just machines (or why they were), and what was unique about human consciousness. In the coming decade I think it will all be about how consciousness is really the same as many other mental processes. Consciousness may begin to seem less important, or at any rate it may increasingly be seen as on a continuuum with the brain activity of other animals; really just a special case of the perfectly normal faculty of…  Well, I don’t actually know what, but I look forward to finding out.

gameScott has a nice discussion of our post-intentional future (or really our non-intentional present, if you like) here on Scientia Salon. He quotes Fodor saying that the loss of ‘common-sense intentional psychology’ would be the greatest intellectual catastrophe ever: hard to disagree, yet that seems to be just what faces us if we fully embrace materialism about the brain and its consequences. Scott, of course, has been exploring this territory for some time, both with his Blind Brain Theory  and his unforgettable novel Neuropath; a tough read, not because the writing is bad but  because it’s all too vividly good.

Why do we suppose that human beings uniquely stand outside the basic account of physics, with real agency, free will, intentions and all the rest of it? Surely we just know that we do have intentions? We can be wrong about what’s in the world; that table may be an illusion; but our intentions are directly present to our minds in a way that means we can’t be wrong about them – aren’t they?

That kind of privileged access is what Scott questions. Cast your mind back, he says, to the days before philosophy of mind clouded your horizons, when we all lived the unexamined life. Back to Square One, as it were: did your ignorance of your own mental processes trouble you then? No: there was no obvious gaping hole in our mental lives;  we’re not bothered by things we’re not aware of. Alas,  we may think we’ve got a more sophisticated grasp of our cognitive life these days, but in fact the same problem remains. There’s still no good reason to think we enjoy an epistemic privilege in respect of our own version of our minds.

Of course, our understanding of intentions works in practice. All that really gets us, though, is that it seems to be a viable heuristic. We don’t actually have the underlying causal account we need to justify it; all we do is apply our intentional cognition to intentional cognition…

it can never tell us what cognition is simply because solving that problem requires the very information intentional cognition has evolved to do without.

Maybe then, we should turn aside from philosophy and hope that cognitive science will restore to us what physical science seems to take away? Alas, it turns out that according to cognitive science our idea of ourselves is badly out of kilter, the product of a mixed-up bunch of confabulation, misremembering, and chronically limited awareness. We don’t make decisions, we observe them, our reasons are not the ones we recognise, and our awareness of our own mental processes is narrow and error-filled.

That last part about the testimony of science is hard to disagree with; my experience has been that the more one reads about recent research the worse our self-knowledge seems to get.

If it’s really that bad, what would a post-intentional world look like? Well, probably like nothing really, because without our intentional thought we’d presumably have an outlook like that of dogs, and dogs don’t have any view of the mind. Thinking like dogs, of course, has a long and respectable philosophical pedigree going back to the original Cynics, whose name implies a d0g-level outlook. Diogenes himself did his best to lead a doggish, pre-intentional life,  living rough, splendidly telling Alexander the Great to fuck off and less splendidly, masturbating in public (‘Hey,  I wish I could cure hunger too just by rubbing my stomach’). Let’s hope that’s not where we’re heading.

However, that does sort of indicate the first point we might offer. Even Diogenes couldn’t really live like a dog: he couldn’t resist the chance to make Plato look a fool, or hold back when a good zinger came to mind. We don’t really cling to our intentional thoughts because we believe ourselves to have privileged access (though we may well believe that); we cling to them because believing we own those thoughts in some sense is just the precondition of addressing the issue at all, or perhaps even of having any articulate thoughts about anything. How could we stop? Some kind of spontaneous self-induced dissociative syndrome? Intensive meditation? There isn’t really any option but to go on thinking of our selves and our thoughts in more or less the way we do, even if we conclude that we have no real warrant for doing so.

Secondly, we might suggest that although our thoughts about our own cognition are not veridical, that doesn’t mean our thoughts or our cognition don’t exist. What they say about the contents of our mind is wrong perhaps, but what they imply about there being contents (inscrutable as they may be) can still be right. We don’t have to be able to think correctly about what we’re thinking in order to think. False ideas about our thoughts are still embodied in thoughts of some kind.

Is ‘Keep Calm and Carry On’ the best we can do?

 

 

meetingPetros Gelepithis has A Novel View of Consciousness in the International Journal of Machine Consciousness (alas, I can’t find a freely accessible version). Computers, as such, can’t be conscious, he thinks, but robots can; however, proper robot consciousness will necessarily be very unlike human consciousness in a way that implies some barriers to understanding.

Gelepithis draws on the theory of mind he developed in earlier papers, his theory of noèmona species. (I believe he uses the word noèmona mainly to avoid the varied and potentially confusing implications that attach to mind-related vocabulary in English.) It’s not really possible to do justice to the theory here, but it is briefly described in the following set of definitions, an edited version of the ones Gelepithis gives in the paper.

Definition 1. For a human H, a neural formation N is a structure of interacting sub-cellular components (synapses, glial structures, etc) across nerve cells able to influence the survival or reproduction of H.

Definition 2. For a human, H, a neural formation is meaningful (symbol Nm), if and only if it is an N that influences the attention of that H.

Definition 3. The meaning of a novel stimulus in context (Sc), for the human H at time t, is whatever Nm is created by the interaction of Sc and H.

Definition 4. The meaning of a previously encountered Sc, for H is the prevailed Np of Np

Definition 5. H is conscious of an external Sc if and only if, there are Nm structures that correspond to Sc and these structures are activated by H’s attention at that time.

Definition 6. H is conscious of an internal Sc if and only if the Nm structures identified with the internal Sc are activated by H’s attention at that time.

Definition 7. H is reflectively conscious of an internal Sc if and only if the Nm structures identified with the internal Sc are activated by H’s attention and they have already been modified by H’s thinking processes activated by primary consciousness at least once.

For Gelepithis consciousness is not an abstraction, of the kind that can be handled satisfactorily by formal and computational systems. Instead it is rooted in biology in a way that very broadly recalls Ruth Millikan’s views. It’s about attention and how it is directed, but meaning comes out of the experience and recollection of events related to evolutionary survival.

For him this implies a strong distinction between four different kinds of consciousness; animal consciousness, human consciousness, machine consciousness and robot consciousness. For machines, running a formal system, the primitives and the meanings are simply inserted by the human designer; with robots it may be different. Through, as I take it, living a simple robot life they may, if suitably endowed, gradually develop their own primitives and meanings and so attain their own form of consciousness. But there’s a snag…

Robots may be able to develop their own robot primitives and subsequently develop robot understanding. But no robot can ever understand human meanings; they can only interact successfully with humans on the basis of processing whatever human-based primitives and other notions were given…

Different robot experience gives rise to a different form of consciousness. They may also develop free will. Human beings act freely when their Acquired Belief and Knowledge (ABK) over-rides environmental and inherited influences in determining their behaviour; robots can do the same if they acquire an Own Robot Cognitive Architecture, the relevant counterpart. However, again…

A future possible conscious robotic species will not be able to communicate, except on exclusively formal bases, with the then Homo species.

‘then Homo’ because Gelepithis thinks it’s possible that human predecessors to Homo Sapiens would also have had distinct forms of consciousness (and presumably would have suffered similar communication issues).

Now we all have slightly different experiences and heritage, so Gelepithis’ views might imply that each of our consciousnesses is different. I suppose he believes that intra-species commonality is sufficient to make those differences relatively unimportant, but there should still be some small variation, which is an intriguing thought.

As an empirical matter, we actually manage to communicate rather well with some other species. Dogs don’t have our special language abilities and they don’t share our lineage or experiences to any great degree; yet very good practical understandings are often in place. Perhaps it would be worse with robots, who would not be products of evolution, would not eat or reproduce, and so on. Yet it seems strange to think that as a result their actual consciousness would be radically different?

Gelepithis’ system is based on attention, and robots would surely have a version of that; robot bodies would no doubt be very different from human ones, but surely the basics of proprioception, locomotion, manipulation and motivation would have to have some commonality?

I’m inclined to think we need to draw a further distinction here between the form and content of consciousness. It’s likely that robot consciousness would function differently from ours in certain ways: it might run faster, it might have access to superior memory, it might, who knows, be multi-threaded. Those would all be significant differences which might well impede communication. The robot’s basic drives might be very different from ours: uninterested in food, sex, and possibly even in survival, it might speak lyrically of the joys of electricity which must remain ever hidden from human beings. However, the basic contents of its mind would surely be of the same kind as the contents of our consciousness (hallo, yes, no, gimme, come here, go away) and expressible in the same languages?

TegmarkEarlier this year Tononi’s Integrated Information Theory (IIT) gained a prestigious supporter in Max Tegmark, professor of Physics at MIT. The boost for the theory came not just from Tegmark’s prestige, however; there was also a suggestion that the IIT dovetailed neatly with some deep problems of physics, providing a neat possible solution and the kind of bridge between neuroscience, physics and consciousness that we could hardly have dared to hope for.

Tegmark’s paper presents the idea rather strangely, suggesting that consciousness might be another state of matter like the states of being a gas, a liquid, or solid.  That surely can’t be true in any simple literal sense because those particular states are normally considered to be mutually exclusive: becoming a gas means ceasing to be a liquid. If consciousness were another member of that exclusive set it would mean that becoming conscious involved ceasing to be solid (or liquid, or gas), which is strange indeed. Moreover Tegmark goes on to name the new state ‘perceptronium’ as if it were a new element. He clearly means something slightly different, although the misleading claim perhaps garners him sensational headlines which wouldn’t be available if he were merely saying that consciousness arose from certain kinds of subtle informational organisation, which is closer to what he really means.

A better analogy might be the many different forms carbon can take according to the arrangement of its atoms: graphite, diamond, charcoal, graphene, and so on; it can have quite different physical properties without ceasing to be carbon. Tegmark is drawing on the idea of computronium proposed by Toffoli and Margolus. Computronium is a hypothetical substance whose atoms are arranged in such a way that it consists of many tiny modules capable of performing computations.  There is, I think, a bit of a hierarchy going on here: we start by thinking about the ability of substances to contain information; the ability of a particular atomic matrix to encode binary information is a relatively rigorous and unproblematic idea in information theory. Computronium is a big step up from that: we’re no longer thinking about a material’s ability to encode binary digits, but the far more complex functional property of adequately instantiating a universal Turing machine. There are an awful lot of problems packed into that ‘adequately’.

The leap from information to computation is as nothing, however, compared to the leap apparently required to go from computronium to perceptronium. Perceptronium embodies the property of consciousness, which may not be computational at all and of which there is no agreed definition. To say that raises a few problems is rather an understatement.

Aha! But this is surely where the IIT comes in. If Tononi is right, then there is in fact a hard-edged definition of consciousness available: it’s simply integrated information, and we can even say that the quantity required is Phi. We can detect it and measure it and if we do, perceptronium becomes mathematically tractable and clearly defined. I suppose if we were curmudgeons we might say that this is actually a hit against the IIT: if it makes something as absurd as perceptronium a possibility, there must be something pretty wrong with it. We’re surely not that curmudgeonly, but there is something oddly non-dynamic here. We think of consciousness, surely, as a process, a  function: but it seems we might integrate quite a lot of information and simply have it sit there as perceptronium in crystalline stillness; the theory says it would be conscious, but it wouldn’t do anything.  We could get round that by embracing the possibility of static conscious states, like one frame out of the movie film of experience; but Tegmark, if I understand him right, adds another requirement for consciousness: autonomy, which requires both dynamics and independence; so there has to be active information processing, and it has to be isolated from outside influence, much the way we typically think of computation.

The really exciting part, however,  is the potential linkage with deep cosmological problems – in particular the quantum factorisation problem. This is way beyond my understanding, and the pages of equations Tegmark offers are no help, but the gist appears to be that  quantum mechanics offers us a range of possible universes.  If we want to get ‘physics from scratch’, all we have to work with is, in Tegmark’s words,

two Hermitian matrices, the density matrix p encoding the state of our world and the Hamiltonian H determining its time-evolution…

Please don’t ask me to explain; the point is that the three things don’t pin down a single universe; there are an infinite number of acceptable solutions to the equations. If we want to know why we’ve got the universe we have – and in particular why we’ve got classical physics, more or less, and a world with an object hierarchy – we need something more. Very briefly, I take Tegmark’s suggestion to be that consciousness, with its property of autonomy, tends naturally to pick out versions of the universe in which there are similarly integrated and independent entities – in other words the kind of object-hierarchical world we do in fact see around us. To put it another way and rather baldly, the universe looks like this because it’s the only kind of universe which is compatible with the existence of conscious entities capable of perceiving it.

That’s some pretty neat footwork, although frankly I have to let Tegmark take the steering wheel through the physics and in at least one place I felt a little nervous about his driving. It’s not a key point, but consider this passage:

Indeed, Penrose and others have speculated that gravity is crucial for a proper understanding of quantum mechanics even on small scales relevant to brains and laboratory experiments, and that it causes non-unitary wavefunction collapse. Yet the Occam’s razor approach is clearly the commonly held view that neither relativistic, gravitational nor non-unitary effects are central to understanding consciousness or how conscious observers perceive their immediate surroundings: astronauts appear to still perceive themselves in a semi-classical 3D space even when they are effectively in a zero-gravity environment, seemingly independently of relativistic effects, Planck-scale spacetime fluctuations, black hole evaporation, cosmic expansion of astronomically distant regions, etc

Yeah… no. It’s not really possible that a professor of physics at MIT thinks that astronauts float around their capsules because the force of gravity is literally absent, is it? That kind of  ‘zero g’ is just an effect of being in orbit. Penrose definitely wasn’t talking about the gravitational effects of the Earth, by the way; he explicitly suggests an imaginary location at the centre of the Earth so that they can be ruled out. But I must surely be misunderstanding.

So far as consciousness is concerned, the appeal of Tegmark’s views will naturally be tied to whether one finds the IIT attractive, though they surely add a bit of weight to that idea. So far as quantum factorisation is concerned, I think he could have his result without the IIT if he wanted: although the IIT makes it particularly neat, it’s more the concept of autonomy he relies on, and that would very likely still be available even if our view of consciousness were ultimately somewhat different. The linkage with cosmological metaphysics is certainly appealing, essentially a sensible version of the Anthropic Principle which Stephen Hawking for one has been prepared to invoke in a much less attractive form

grazianoYes: I feel pretty sure that anyone reading this is indeed conscious. However, the NYT recently ran a short piece from Michael S. A. Graziano which apparently questioned it. A fuller account of his thinking is in this paper from 2011; the same ideas were developed at greater length in his book Consciousness and the Social Brain

I think the startling headline on the NYT piece misrepresents Graziano somewhat. The core of his theory is that awareness is in some sense a delusion, the reality of which is simple attention. We have ways of recognising the attention of other organisms, and what it is fixed on (the practical value of that skill in environments where human beings may be either hunters or hunted is obvious): awareness is just our garbled version of attention. he offers the analogy of colour. The reality out there is different wavelengths of light: colour, our version of that, is a slightly messed-up, neatened, artificial version which is nevertheless very vivid to us in spite of being artificial to a remarkably large extent.

I don’t think Graziano is even denying that awareness exists, in some sense: as a phenomenon of some kind it surely does: what he means is more that it isn’t veridical: what it tells us about itself, and what it tells us about attention, isn’t really true. As he acknowledges in the paper, there are labelling issues here, and I believe it would be possible to agree with the substance of what he says while recasting it in terms that look superficially much more conventional.

Another labelling issue may lurk around the concept of attention. On some accounts, it actually presupposes consciousness: to direct one’s attention towards something is precisely to bring it to the centre of your consciousness. That clearly isn’t what Graziano means: he has in mind a much more basic meaning. Attention for him is something simple like having your sensory organs locked on to a particular target. This needs to be clear and unambiguous, because otherwise we can immediately see potential problems over having to concede that cameras or other simple machines are capable of attention; but I’m happy to concede that we could probably put together some kind of criterion, perhaps neurological, that would fit the bill well enough and give Graziano the unproblematic materialist conception of attention that he needs.

All that looks reasonably OK as applied to other people, but Graziano wants the same system to supply our own mistaken impression of awareness. Just as we track the attention of others with the false surrogate of awareness, we pick up our own attentive states and make the same kind of mistake. This seems odd: when I sense my own awareness of something, it doesn’t feel like a deduction I’ve made from objective evidence about my own behaviour: I just sense it.  I think Graziano actually wants it to be like that for other people too. He isn’t talking about rational, Sherlock Holmes style reasoning about the awareness of other people, he has in mind something like a deep, old, lizard-brain kind of thing; like the sense of somebody there that makes the hairs rise on the back of the neck  and your eyes quickly saccade towards the presumed person.

That is quite a useful insight, because what Graziano is concerned to deny is the reality of subjective experience, of qualia, in a word. To do so he needs to be able to explain why awareness seems so special when the reality is nothing more than information processing. I think this remains a weak spot in the theory, but the idea that it comes from a very basic system whose whole function is to generate a feeling of ‘something there’ helps quite a bit, and is at least moderately compatible with my own intuitions and introspections.What Graziano really relies on is the suggestion that awareness is a second-order matter: it’s a cognitive state about other cognitive states, something we attribute to ourselves and not, as it seems to be, directly about the real world. It just happens to be a somewhat mistaken cognitive state.

That still leaves us in some difficulty over the difference between me and other people. If my sense of my own awareness is generated in exactly the same way as my sense of the awareness of others, it ought to seem equally distant  – but it doesn’t, it seems markedly more present and far less deniable.

More fundamentally, I still don’t really see why my attention should be misperceived. In the case of colours, the misrepresentation of reality comes from two sources, I think. One is the inadequacy of our eyes; our brain has to make do with very limited data on colour (and on distance and other factors) and so has to do things like hypothesising yellow light where it should be recognising both red and green, for example. Second, the brain wants to make it simple for us and so tries desperately to ensure that the same objects always look the same colour, although the wavelengths being received actually vary according to conditions. I find it hard to see what comparable difficulties affect our perception of attention. Why doesn’t it just seem like attention? Graziano’s view of it as a second-order matter explains how it can be wrong about attention, but not really why.

So I think the theory is less radical than it seems, and doesn’t quite nail the matter on some important points: but it does make certain kinds of sense and at the very least helps keep us roused from our dogmatic slumbers. Here’s a wild thought inspired (but certainly not endorsed) by Graziano. Suppose our sense of qualia really does come from a kind of primitive attention-detecting module. It detects our own attention and supplies that qualic feel, but since it also (in fact primarily) detects other people’s attention, should it not also provide a bit of a qualic feel for other people too? Normally when we think of our beliefs about other people, we remain in the explicit, higher realms of cognition: but what if we stay at a sort of visceral level, what if we stick with that hair-on-the back-of the-neck sensation? Could it be that now and then we get a whiff of other people’s qualia? Surely too heterodox an idea to contemplate…

gapWe’re often told that when facing philosophical problems, we should try to ‘carve them at the joints’. The biggest joint on offer in the case of consciousness has seemed to be the ‘explanatory gap’ between the physical activity of neurons and the subjective experience of consciousness. Now, in the latest JCS, Reggia, Monner, and Sylvester suggest that there is another gap, and one where our attention should rightly be focussed.

They suggest that while the simulation of certain cognitive processes has proceeded quite well, the project of actually instantiating consciousness computationally has essentially got nowhere.  That project, as they say, is affected by a variety of problems about defining and recognising success. But the real problem lies in an unrecognised issue: the computational explanatory gap. Whereas the explanatory gap we’re used to is between mind and brain, the computational gap is between high-level computational algorithms and low-level neuronal activity. At the high level, working top-down, we’ve done relatively well in elucidating how certain kinds of problem-solving, goal-directed kinds of computation work, and been able to simulate them relatively effectively.  At the neuronal, bottom-up level we’ve been able to explain certain kinds of pattern-recognition and routine learning systems. The two different kinds of processing have complementary strengths and weaknesses, but at the moment we have no clear idea of how one is built out of the other. This is the computational explanatory gap.

In philosophy, the authors plausibly claim, this important gap has been overlooked because in philosophical terms these are all ‘easy problem’ matters, and so tend to be dismissed as essentially similar matters of detail. In psychology, by contrast, the gap is salient but not clearly recognised as such: the lower-level processes correspond well to those identified as sub-conscious, while the higher-level ones match up with the reportable processes generally identified as conscious.

If Reggia, Monner and Sylvester are right, the well-established quest for the neural correlates of consciousness has been all very well, but what we really need is to bridge the gap by finding the computational correlates of consciousness. As a project, bridging this gap looks relatively promising, because it is all computational. We do not need to address any spooky phenomenology, we do not need to wonder how to express ‘what it is like’, or deal with anything ineffable; we just need to find the read-across between neural networking and the high-level algorithms which we can sort of see in operation. That may not be easy, but compared to the Hard Problem it sounds quite tractable. If solved, it will deliver a coherent account right from neural activity through to high-level decision making.

Of course, that leaves us with the Hard Problem unsolved, but the authors are optimistic that success might still banish the problem. They draw an analogy with artificial life: once it seemed obvious that there was a mysterious quality of being alive, and it was unclear how simple chemistry and physics could ever account for it. That problem of life has never been solved in terms, but as our understanding of the immensely subtle chemistry of living things has improved, it has gradually come to seem les and less obvious that it is really a problem. In a similar way the authors hope that if the computational explanatory gap can be bridged, so that we gradually develop a full account of cognitive processes from the ground-level firing of neurons up to high-level conscious problem-solving, the Hard Problem will gradually cease to seem like something we need to worry about.

That is optimistic, but not unreasonably so, and I think the new perspective offered is a very interesting and plausible one. I’m convinced that the gap exists and that it needs to be bridged: but I’m less sure that it can easily be done.  It might be that Reggia, Monner, and Sylvester are affected in a different way by the same kind of outlook they criticise in philosophers: these are all computational problems, so they’re all tractable. I’m not sure how we can best address the gap, and I suspect it’s there not just because people have failed to recognise it, but because it is also genuinely difficult to deal with.

For one thing, the authors tend to assume the problem is computational. It’s not clear that computation is of the essence here. The low-level processes at a neuronal level don’t look to be based on running any algorithm – that’s part of the nature of the gap. High-level processes may be capable of simulation algorithmically, but that doesn’t mean that’s the way the brain actually does it. Take the example of catching a ball – how do we get to the right place to intercept a ball flying through the air?  One way to do this would be some complex calculations about perspective and vectors: the brain could abstract the data, do the sums, and send back the instructions that result. We could simulate that process in a computer quite well. But we know – I think – that that isn’t the way it’s actually done: the brain uses a simpler and quicker process which never involves abstract calculation, but is based on straight matching of two inputs; a process which incidentally corresponds to a sub-optimal algorithm, but one that is good enough in practice. We just run forward if the elevation of the ball is reducing and back if it’s increasing. Fielders are incapable of predicting where a ball is going, but they can run towards the spot in such a way as to be there when the ball arrives.  It might be that all the ‘higher-level’ processes are like this, and that an attempt to match up with ideally-modelled algorithms is therefore categorically off-track.

Even if those doubts are right, however, it doesn’t mean that the proposed re-framing of the investigation is wrong or unhelpful, and in fact I’m inclined to think it’s a very useful new perspective.

 

pixelated eyeYou’ve heard of splitting the atom: W. Alex Escobar wants to split the quale. His recent paper (short article here) proposes that in order to understand subjective experience we may need to break it down into millions of tiny units of experience.  He proposes a neurological model which to my naive eyes seems reasonable: the extraordinary part is really the phenomenology.

Like a lot of qualia theorists Escobar seems to have based his view squarely on visual experience, and the idea of micro-qualia is perhaps inspired by the idea of pixels in digitised images, or other analytical image-handling techniques.  Why would the idea help explain qualia?

I don’t think Escobar explains this very directly, at least from a philosophical point of view, but you can see why the idea might appeal to some people. Panexperientialists, for example, take the view that there are tiny bits of experience everywhere, so the idea that our minds assemble complex experiences out of micro-qualia might be quite congenial to them.  As we know, Christof Koch says that consciousness arises from the integration of information, so perhaps he would see Escobar’s theory as offering a potentially reasonable phenomenal view of the same process.

Unfortunately Escobar has taken a wrong turning, as others have done before, and isn’t really talking about ineffable qualia at all: instead, we might say he is merely effing the effable.

Ineffability, the quality of being inexpressible, is a defining characteristic of qualia as canonically understood in the philosophical literature. I cannot express to you what redness is like to me; if I could, you would be able to tell whether it was the same as your experience. If qualia could be expressed, my zombie twin  (who has none) would presumably become aware of their absence; when asked what it was like to see red, he would look puzzled and admit he didn’t really know, whereas ex hypothesi he gives the same fluent and lucidly illuminating answers that I do – in spite of not having the things we’re both talking about.

Qualia, in fact, have no causal effects and cannot be part of the scientific story. That doesn’t mean Escobar’s science is wrong or uninteresting, just that what he’s calling qualia aren’t really the philosophically slippery items of experience we keep chasing in vain in our quest for consciousness.

Alright, but setting that aside, is it possible that real qualia could be made up of many micro-qualia? No, it absolutely isn’t! In physics, a table can seem to be a single thing but actually be millions of molecules.  Similarly, what looks like a flat expanse of uniform colour on a screen may actually be thousands of pixels. But qualia are units of experience; what they seem like is what they are. They don’t seem like a cloud of micro-qualia, and so they aren’t. Now there could be some neuronal or psychological story going on at a lower level which did involve micro units; but that wouldn’t make qualia themselves splittable. What they are like is all there is to them; they can’t have a hidden nature.

Alas, Escobar could not have noticed that, because he was too busy effing the Effable.

intuitronMark O’Brien gives a good statement of the computationalist case here; clear, brief, and commendably mild and dispassionate. My impression is that enthusiasm for computationalism – approximately, the belief that human thought is essentially computational in nature – is not what it was. It’s not that computationalists lost the argument, it’s more that the robots failed to come through. What AI research delivered has so far been, in this respect, much less than the optimists had hoped.

Anyway O’Brien’s case rests on two assumptions:

  • Naturalism is true.
  • The laws of physics are computable, that is, any physical process can be simulated to any desired degree of precision by a computer.

It’s immediately clear where he’s going. T0 represent it crudely, the intuition here is that naturalism means the world ultimately consists of  physical processes, any physical process can run on a computer, ergo anything in the world can run on a computer, ergo it must be possible to run consciousness on a computer.

There’s an awful lot packed into those two assumptions. O’Brien tackles one issue with the idea of simulation: namely that simulating something isn’t doing it for real. A simulated rainstorm doesn’t make us wet. His answer is that simulation doesn’t produce physical realities, but it does seem to work for abstract things. I think this is basically right. If we simulate a flight to Paris, we don’t end up there; but the route calculated by the program is the actual route; it makes no sense to say it’s only a simulated route, because it’s actually identical with the one we should use if we really went to Paris. So the power of simulation is greater for informational entities than for physical ones, and it’s not unreasonable to suggest that consciousness seems more like a matter of information than of material stuff.

There’s a deeper point, though. To simulate is not to reproduce: a simulation is the reproduction of the relevant aspects of the thing simulated. It’s implied that some features of the thing simulated are left out, ones that don’t matter. That’s why we get the different results for our Parisian exercise: the simulation necessarily leaves our actual physical locations untouched; those are irrelevant when it comes to describing the route, but essential when it comes to actually visiting Paris.

The problem is we don’t know which properties are relevant to consciousness, and to assume they are the kind of thing handled by computation simply begs the question. It can’t be assumed without an argument that physical properties are irrelevant here: John Searle and Roger Penrose in different ways both assert that they are of the essence. Even if consciousness doesn’t rely quite so brutally as that on the physical nature of the brain, we need to start with a knowledge of how consciousness works. Otherwise, we can’t tell whether we’ve got the right properties in our simulation –  even if they are in principle computational.

I don’t myself think Searle or Penrose are right: but I think it’s quite likely that the causal relationships in cognitive processes are the kind of essential thing a simulation would have to incorporate. This is a serious problem because there are reasons to think computer simulations never reproduce the causal relationships intact. In my brain event A causes event B and that’s all there is to it: in a computer, there’s always a script involved. At its worst what we get is a program that holds up flag A to represent event A and then flag B to represent event B: but the causality is mediated through the program. It seems to me this might well be a real issue.

O’Brien tackles another of Searle’s arguments: that you can’t get semantics from syntax: ie, you can’t deal with meanings just by manipulating digits. O’Brien’s strategy here is to assume a robot that behaves pretty much the way I do: does it have beliefs? It says it does, and it behaves as if it did. Perhaps we’re not willing to concede that those are real beliefs: OK, let’s call them beliefs*. On examination it turns out that the differences between beliefs and beliefs* are nugatory: so on gorunds of parsimony if nothing else we should assume they are the same.

The snag here is that there are no robots that behave the way I do.  We’ve had sixty years of failure since Turing: you can’t just have it as an assumption that our robot pals are self-evidently achievable (alas).  We know that human beings, when they do translation for example, extract meanings and then put the meanings into other words, whereas the most successful translation programs avoid meanings altogether and simply swap text strings for text strings according to a kind of mighty look-up table.

That kind of strategy won’t work when dealing with the formless complexity of the real world: you run into the analogues of the Frame Problem or you just don’t get really started. It doesn’t even work that well for language: we know now that human understanding of language relies on pragmatic Gricean implicatures, and no-one can formalise those.

Finally O’Brien turns to qualia, and here I agree with him on the broad picture. He describes some of the severe difficulties around qualia and says, rightly I think, that in the end it comes down to competing intuitions.  All the arguments for qualia are essentially thought experiments: if we want, we can just say ‘no’ to all of them (as Dennett and the Churchlands, for example, do). O’Brien makes a kind of zombie argument: my zombie twin, who lacks qualia but resembles me in all other respects, would claim to have qualia and would talk about them just the way we do.  So the explanation for talk about qualia is not qualia themselves: given that, there’s no reason to think we ourselves have them.

Up to a point: but we get the conclusion that my zombie twin talks about qualia purely ex hypothesi: it’s just specified. It’s not an explanation, and I think that’s what we really need to be in a position to dismiss the strong introspective sense most people have that qualia exist. If we could actually explain what makes the Twin talk about qualia, we’d be in a much better position.

So I mostly disagree, but I salute O’Brien’s exposition, which is really helpful.

smellingAn intriguing paper from Benjamin D. Young claims that we can have phenomenal experiences of which we are unaware – although experiences of which we are aware always have phenomenal content. The paper is about smell, though I don’t really see why similar considerations shouldn’t apply to other senses.

At first sight the idea of phenomenal experience of which we are unaware seems like a contradiction in terms. Phenomenal experience is the subjective aspect of consciousness, isn’t it? How could an aspect of consciousness exist without consciousness itself? Young rightly says that it is well established that things we only register subconsciously can affect our behaviour – but that can’t include the sort of experience which for some people is the real essence of consciousness, can it?

The only way I can imagine subjectivity going on in my head without me experiencing it is if someone else were experiencing it – not a matter of me experiencing things subconsciously, but of my subconscious being a real separate entity, or perhaps of it all going on in the mind of alternate personality of the kind that seems to occur is Dissociative Identity Disorder (Multiple Personality, as it used to be called).

On further reflection, I don’t think that’s the kind of thing Young meant at all: I think instead he is drawing a distinction between explicit and inexplicit awareness. So his point is that I can experience qualia without having any accompanying conscious thought about those qualia or the experience.

That’s true and an important point. One reason qualia seem so slippery, I think, is that discussion is always in second order terms: we exchange reports of qualia. But because the things themselves are irredeemably first order they have a way of disappearing from the discussion, leaving us talking about their effable accompaniments.

Ironically, something like that may have happened in Young’s paper, as he goes on to discuss experiments which allegedly shed light on subjective experience. Smell is a complex phenomenon of course; compared with the neat structure of colours the rambling and apparently inexhaustible structure of smell space is daunting;y hard to grasp. However, smell conveniently has valence in a way that colours don’t: some smells are nice and some are nasty. Humans apparently vary their sniff rate partly in response to a smell’s valence and Young thinks that this provides an objective, measurable way into the subjectivity of the experience.

Beyond that he goes on to consider mating choice: it seems human beings, like other mammals, choose their mates partly on the basis of smell. I imagine this might be controversial to some, and some of the research Young quotes sounds amusingly naive. In answer to a questionnaire, female subjects rated body odour as an important factor in selecting a sexual partner; well yes, if a guy smells you’re maybe not going to date him, huh?

I haven’t read the study which was doubtless on a much more sophisticated level, and Young cites a whole wealth of other interesting papers. The problem is that while this is all fascinating psychologically, none of it can properly bear on the philosophical issue because qualia, the ultimate bearers of subjectivity, are acausal and cannot affect our behaviour. This is shown clearly by the zombie twin argument: my zombie twin has no qualia but his behaviour is ex hypothesi the same as mine.

Still, the use of valence as a way in is interesting. The normal philosophical argument is that we have no way of telling whether my subjective red is your subjective green: but it’s hard to argue that m subjective nasty is your subjective nice (unless we also hypothesise that you seek out nasty experiences and avoid nice ones?).

sorates and branestawmQuentin Ruyant has written a thoughtful piece about quantum mechanics and philosophy of mind: in a nutshell he argues both that quantum theory may be relevant to the explanation of consciousness and that consciousness may be relevant to the interpretation of quantum theory.

Is quantum theory relevant to consciousness? Well. of course some people have said so, notably Sir Roger Penrose and Stuart Hameroff.  I think Ruyant is right, though, that the majority of philosophers and probably the majority of physicists dismiss the idea that quantum theory might be needed to explain consciousness. People often suggest that the combination of the two only appeals because both are hard to explain: ‘here’s one mystery and here’s another: maybe one explains the other’. Besides, people say, the brain is far too big and hot and messy for anything other than classical physics to be required

In making the case for the relevance of quantum theory, Ruyant relies on the Hard Problem.  His position is that the Hard Problem is not biological but a matter of physics, whereas the Easy Problem, to do with all the scientifically tractable aspects of consciousness, can be dealt with by biology or psychology.

Actually, turning aside from the main thread of Ruyant’s argument, there are some reasons to suggest that quantum physics is relevant to the Easy Problem. Penrose’s case, in fact, seems to suggest just that: in his view consciousness is demonstrably non-computable and some kind of novel quantum mechanics is his favoured candidate to fill the gap. Penrose’s examples, things like solving mathematical problems, look like ‘Easy’ Problem matters to me.

Although I don’t think anyone (including me) advocates the idea, it also seems possible to argue that the ‘spooky action at a distance’ associated with quantum entanglement might conceivably have something to tell us about intentionality and its remarkable power to address things that are remote and not directly connected with us.

Anyway, Ruyant is mainly concerned with the Hard Problem, and his argument is that metaphysics and physics are closely related. Topics like the essential nature of physical things straddle the borderline between the two subjects, and it is not at all implausible therefore that the deep physics of quantum mechanics might shed light on the deep metaphysics of phenomenal experience. It seems to me a weakish line of argument, possibly tinged with a bit of prejudice: some physicists are inclined to feel that while their subject deals with the great fundamentals, biology deals only with the chance details of life; sort of a more intellectual kind of butterfly collecting.  That kind of thinking is not really well founded, and it seems particularly odd to think that biology is irrelevant when considering a phenomenon that, so far as we know, appears only in animals and is definitely linked very strongly with the operation of the brain. John Searle for one argues that ‘Hard Problem’ consciousness arises from natural biological properties of brain tissue. We don’t yet know what those properties are, but in his view it’s absurd to think that the job of nerves could equally well be performed by beer cans and string. Ruth Millikan, somewhat differently, has argued that consciousness is purely biological in nature, arising from and defined by evolutionary needs.

I think the truth is that it’s difficult to get anywhere at this meta-theoretical level:  we don’t really decide what kind of theory is most likely to be right and then concentrate on that area; we decide what the true theory most likely is and then root for the kind of theory it happens to be. That, to a great extent, is why quantum theories are not very popular: no-one has come up with a particular one that is cogent and appealing.  It seems to me that Ruyant likes the idea of physics-based theories because he favours panpsychism, or panphenomenalism, and so is inclined to think that the essential nature of matter is likely to be the right place to look for a theory.

To be honest, though, I doubt whether any kind of science can touch the Hard Problem.  It’s about entities that have no causal properties and are ineffable: how could empirical science ever deal with that? It might well be that a scientist will eventually give us the answer, but if so it won’t be by doing science, because neither classical nor quantum physics can really touch the inexpressible.

Actually, though there is a long shot.  If Colin McGinn is partly on the right track, it may be that consciousness seems mysterious to us simply because we’re not looking at it the right way: our minds won’t conceptualise it correctly. Now the same could be true of quantum theory. We struggle with the interpretation of quantum mechanics, but what if we could reorient our brains so that it simply seemed natural, and we groped instead for an acceptable ‘interpretation’ of spooky classical physics? If we could make such a transformation in our mental orientation, then perhaps consciousness would make sense too? It’s possible, but we’re back to banging two mysteries together in the hope that some spark will be generated.

Ruyant’s general case, that metaphysicians should be informed by our best physics is hard to argue with. At the moment few philosophers really engage with the physics and few physicists really grasp the philosophy. Why do philosophers avoid quantum physics? Partly, no doubt, just because it’s difficult, and relies on mathematics which few philosophers can handle. Partly also, I think there’s an unspoken fear that in learning about quantum physics your intuitions will be trained into accepting a particular weltanschauung that might not be helpful. Connected with that is the fear that quantum physics isn’t really finished or definitive. Where would I be if I came up with a metaphysical system that perfectly supported quantum theory and then a few years later it turns out that I should have been thinking in terms of string theory? Metaphysicians cross their fingers and hope they can deal with the key issues at a level of generality that means they won’t be rudely contradicted by an unexpected advance in physics a few years later.

I suppose what we really need is someone who can come up with a really good specific theory that shows the value of metaphysics informed by physics, but few people are qualified to produce one. I must say that Ruyant seems to be an exception, with an excellent grasp of the theories on both sides of the divide. Perhaps he has a theory of consciousness in his back pocket…?