Conscious Entities

Introspection, the direct examination of the contents of our own minds, seems itself to be in many minds at the moment.  The latest issue of the Journal of Consciousness Studies was devoted to papers on introspection, marking the tenth anniversary of the publication of The View from Within, by Francisco Varela and Jonathan Shear (which was itself a special edition of the JCS); and now Eric Schwitzgebel has produced a new entry for the Stanford Encyclopedia of Philosophy.

The two accounts are of course quite different in some respects. The encyclopaedia entry is a careful, scholarly account, neutral and comprehensive; the JCS issue is openly a rallying-cry in support of a programme flowing from Varela’s work.  This, it seems, called for an end to the ban on examination of lived experience;  the JCS gives the impression that it was something of a milestone, though Schwitzgebel’s piece does not mention it (he does cite an earlier paper by Varela, once again in the JCS).

What’s all this about a ban? Well, back in the nineteenth century, psychologists had no fears about using introspective evidence; it was thought that a proper scientific effort would lead to an objectively verifiable kind of phenomenology. We should be able to classify the elements of mental experience and clarify how they worked together, just by examining what went on in our own heads. A great deal of work was done on all this (It was a great disappointments for me to discover, on first opening Brentano’s Psychology from an Empirical Standpoint, that it consisted almost entirely of this kind of thing, and that the only passage about intentional inexistence, the interesting issue, was the couple of paragraphs which I had already read as quotes in several other books.).  There was a gradual refinement of the methods involved, leading on to the great heyday of introspectionism, with Wundt and Titchener in the lead. Unfortunately, it became clear that the rival schools of introspectionism had begun to come up with results which in some respects were radically different and incompatible, and since our own introspections are by their nature private and unverifiable, all they could really do by way of settling the issues was to shout at each other.

This embarrassing impasse led to a reaction away from introspection and to the rise of behaviourism, which not only denied the usefulness of examining our inner experience, but actually went to the extreme of denying that there was any such thing as inner experience.  Behaviourism in its turn fell out of favour, but according to Varela there remained an instinctive distrust of introspection which continued to put people off it as an avenue of research. This is the ‘ban’ he wanted to see overturned.

Was there, is there, really a ban? Not exactly.  Apart from the most dogmatic of the behaviourists, no-one has ever tried to exclude introspection altogether. In recent times, introspective evidence has been widely accepted – the problem of qualia, thought by some to be the problem of consciousness, depends entirely on introspection. I think the real problem arises when we adopt special methods. In order to obtain consistent results, the old introspectionists thought extensive training was necessary. It wasn’t enough to sit and think for a bit; you had to have mastered certain skills of discrimination and perception. The methodological dangers involved in teaching your researchers what kind of thing they could legitimately look for are clear.

Unfortunately, it seems to be very much this kind of programme which the JCS authors would like to resurrect – or rather, have resurrected, and wish to gain acceptance and support for.  Once again we are going to need to learn how to introspect properly before our observations will be acceptable. What makes it worse for me is that the proposal seems to be tied up with NLP – Neuro-linguistic Programming.  I don’t know a great deal about NLP: it seems to be a protean doctrine which shares with the Holy Roman Empire the property of not really being any of the three things in its name – but for me it does nothing to render another trip down this particular blind alley more attractive.

I don’t know about that, but aren’t they right to emphasise the potential value of introspection? Isn’t it the case that introspection is our only source of infallible information? Most of the things we perceive are subject to error and delusion, but we can’t, for example, be wrong about the fact that we are feeling pain, can we? That seems interesting to me. Our impressions of the outside world come to us through a chain of cause and effect, and at any stage errors or misinterpretations can creep in; but because introspection is direct, there’s no space for error to occur. You could well say it’s our only source of certain knowledge – isn’t that worth pursuing a little more systematically?

Infallible? That is the exact reverse of the truth: in fact all introspections are false. Think about it. Introspection can only address the contents of consciousness, right? You can’t introspect the unconscious mental processes that keep you balanced, or regulate your heartbeat. But all of the contents of consciousness have intentionality – they’re all about things, yes? So to have direct experience of mental content is to be thinking about something else – not about the mental state itself, but about the thing it’s about! Now when we attempt to think directly about our own mental states, it follows that we’re not experiencing them in themselves – we’re experiencing a different mental state which is about them. In short, we’re necessarily imagining our mental states. Far from having direct contact, we are inevitably thinking about something we’ve just made up.

I was wondering recently what we could do with all the new computing power which is becoming available.  One answer might be calculating phi, effectively a measure of consciousness, which was very kindly drawn to my attention by Christof Koch. Phi is actually a time- and state-dependent measure of integrated information developed by Giulio Tononi in support of the Integrated Information Theory (IIT) of consciousness which he and Koch have championed.  Some readable expositions of the theory are here and here with the manifesto here and a formal paper presenting phi here. Koch says the theory is the most exciting conceptual development he’s seen in “the inchoate science of consciousness”, and I can certainly see why.

The basic premise of the theory is simply that consciousness is constituted by integrated information. It stems from the phenomenological observations that there are vast numbers of possible conscious states, and that each of them appears to unify or integrate a very large number of items of information. What really lifts the theory above the level of most others in this area is the detailed mathematical under-pinning, which means phi is not a vague concept but a clear and possibly even a practically useful indicator.

One implication of the theory is that consciousness lies on a continuum: rather than being an on-or-off matter, it comes in degrees. The idea that lower levels of consciousness may occur when we are half-awake, or in dogs or other animals, is plausible and appealing. Perhaps a little less intuitive is the implication that there must be in theory be higher states of consciousness than any existing human being could ever have attained. I don’t think this means states of greater intelligence or enlightenment, necessarily; it’s more  a matter of being more awake than awake, an idea which (naturally enough, I suppose) is difficult to get one’s head around, but has a tantalising appeal.

Equally, the theory implies that some minimal level of consciousness goes a long way down to systems with only a small quantity of integrated information. As Koch points out, this looks like a variety of panpsychism or panexperientialism, though I think the most natural interpretation is that real consciousness probably does not extend all that far beyond observably animate entities.

One congenial aspect of the theory for me is that it puts causal relations at the centre of things: while a system with complex causal interactions may generate a high value of phi, a ‘replay’ of its surface dynamics would not. This seems to capture in a clearer form the hand-waving intuitive point I was making recently in discussion of Mark Muhlestein’s ideas.  Unfortunately calculation of Phi for the human brain remains beyond reach at the moment due to the unmanageable levels of complexity involved;  this is disappointing, but in a way it’s only what you would expect. Nevertheless, there is, unusually in this filed, some hope of empirical corroboration.

I think I’m convinced that phi measures something interesting and highly relevant to consciousness; perhaps it remains to be finally established that what it measures is consciousness itself, rather than some closely associated phenomenon, some necessary but not sufficient condition. Your view about this, pending further evidence, may be determined by how far you think phenomenal experience can be identified with information. Is consciousness in the end what information – integrated information – just feels like from the inside? Could this be the final answer to the insoluble question of qualia? The idea doesn’t strike me with the ‘aha!’ feeling of the blinding insight, but (and this is pretty good going in this field) it doesn’t seem obviously wrong either.  It seems the right kind of answer, the kind that could be correct.

Could it?

Kenneth Rogoff is putting his money on AI to be the new source of economic growth, and he seems to think the Turing Test is pretty much there for the taking.

His case is mainly based on an analogy with chess, where he observes that since the landmark victory of “Deep Blue” over Kasparov, things have continued to move on, so that computers now move in a sphere far above their human creators, making moves whose deep strategy is impenetrable to merely human brains. They can even imitate the typical play of particular Grandmasters in a way which reminds Rogoff of the Turing Test. If computers can play chess in a way indistinguishable from that of a human being, it seems they have already passed the ‘Chess Turing Test’. In fact he says that nowadays it takes a computer to spot another computer.

I wonder if that’s literally the case: I don’t know much about chess computing, but I’d be slightly surprised to hear that computer-detecting algorithms as such had been created. I think it’s more likely that where a chess player is accused of using illicit computer advice, his accusers are likely to point to a chess program which advises exactly the moves he made in the particular circumstances of the game. Aha, they presumably say, those moves of yours which turned out so well make no sense to us human beings, but look at what the well-known top-notch program Deep Gambule 5000 recommends…

There’s a kind of melancholy pleasure for old gits like me in the inversion which has occurred over chess; when we were young, chess used to singled out as a prime example of what computers couldn’t do, and the reason was usually given as being the combinatorial explosion which arises when you try to trace out every possible future move in a game of chess.  For a while people thought that more subtle programming would get round this, but the truth is that in the end the problem was mainly solved by sheer brute force; chess may be huge, but the computing power of contemporary computers has become even huger.

On the one hand, that suggests that Rogoff is wrong. We didn’t solve the chess problem by endowing computers with human-style chess reasoning; we did it by throwing ever bigger chunks of data around at ever greater speeds.  A computer playing grandmaster chess may be an awesome spectacle, but not even the most ardent computationalist thinks there’s someone in there. The Turing Test, on the other hand, is meant to test whether computers could think in broadly the human way; the task of holding a conversation is supposed to be something that couldn’t be done without human-style thought. So if it turns out we can crack the test by brute force (and mustn’t that be theoretically possible at some level?) it doesn’t mean we’ve achieved what passing the test was supposed to mean.

In another way, though, the success with chess suggests that Rogoff is right. Some of the major obstacles to human-style thought in computers belong to the family of issues related to the frame problem, in its broadest versions, and the handling of real-world relevance. These could plausibly be described as problems with combinatorial explosion, just like the original chess issue but on a grander scale. Perhaps, as with chess, it will finally turn out to be just a matter of capacity?

All of this is really a bit beside Rogoff’s main interest; he is primarily interested in new technology of a kind which might lead to an economic breakthrough; although he talks about Turing, the probable developments he has in mind don’t actually require us to solve the riddle of consciousness. His examples; “from managing the electronics and lighting in our homes to populating “smart grids” for water and electricity, helping monitor these and other systems to reduce waste” actually seem like fairly mild developments of existing techniques, hardly the sort of thing that requires deep AI innovation at all. The funny thing is, I’m not sure we really have all that many really big, really new ideas for what we might do with the awesome new computing power we are steadily acquiring. This must certainly be true of chess – where do we go from here, keep building even better programs to play games against each other, games of a depth and subtlety which we will never be able to appreciate?

There’s always the Blue Brain project, of course, and perhaps CYC and similar mega-projects; they can still absorb more capacity than we can yet provide. Perhaps in the end consciousness is the only worthy target for all that computing power after all.

One of the nice things about doing Conscious Entities is that from time to time people send me links to interesting things; new papers,  lectures, or ideas of their own.  I regret that I have generally kept this stuff to myself in the past, although it often deserves a mention, so I’ve been thinking about how best to deal with it. I would welcome suggestions, but as an experiment I’ve decided to try occasional round-up posts: so here goes.

Jesús Olmo, to whom many thanks, recently drew my attention to this review of  The Ego Tunnel; to PRISMs, Gom Jabbars, and Consciousness, and to the site Conscious Robots.

M.E. Tson has a Brief Explanation of Consciousness.

Mark Muhlestein has a thought experiment Consciousness and 2D Computation: a Curious Conundrum, and has been corresponding with David Chalmers. My own view is as follows.

I think causal relations are the crux of the matter. A computation essentially consists of a series of states of a Turing machine, doesn’t it? Normally each state is caused by the preceding state. Is that an essential feature? I think in the final analysis we’d say no, because the existence of a computation is really a matter of interpretation on the part of the observer. If the different states in the sequence are just written down on sheets of paper, we’d probably still be willing to call it a computation, or at least, we would in one sense. There’s another sense in which I personally wouldn’t: if we read ‘computation’ as meaning an actual run of a given algorithm, or an instantiation of the computation, I think the causal relationships have to be in place.

Now this would be even truer in the case of mental operations leading to consciousness. The causal relations in a Turing machine are to some degree artificial: the fact that we can program them in is really the point. In the human brain, by contrast, the causal relations are direct and arise from the physical constitution of the brain. To exhibit the relevant series of states (even if we assume consciousness in the brain is a matter of discrete states, which actually seems rather unlikely)would not be enough – they have to have caused each other directly in the right way for this to be an actual ‘run’ of the consciousness faculty.

It follows that your projected lights don’t give rise to a consciousness, or perhaps even to a computation. Does this mean I think zombies of some kind are possible? No, because the interesting kind of zombie is physically identical with a real person, and the projected lights are significantly different from the occurrence of the actual run of the computation. Real zombies remain impossible, and all we’re left with is a kind of puppet.

Readers of my post earlier this year about Sam Coleman’s views may be interested to see the nice comments he has provided.

You can send me links to interesting stuff at:

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Edge has an interesting talk by Stanislas Dehaene.  He and his team, using a range of tools, have identified ’signatures’ of awareness; marked changes in activity in certain brain regions which accompany awareness of a particular stimulus. They made a clever use of the phenomenon of ‘masking’, in which the perception of a word can be obliterated if it follows too rapidly after the presentation of an earlier one. By adjusting the relevant delay, the team could compare the effect of a stimulus which never reached consciousness with one that did. Using this and similar techniques they identified a number of clear indications of conscious awareness: increased activity in the early stages of processing and activity in new regions, including the prefrontal cortex and inferior parietal. It appears that this is accompanied by a ‘P3 wave’ which is quite easy to detect even with nothing more sophisticated than electrodes on the scalp. Interestingly it seems that the difference between a stimulus which does not make it into consciousness and one which does emerges quite late, after as much as a quarter of a second of processing.

No-one, I suspect, is going to be amazed by the news that conscious awareness is accompanied by distinctive patterns of brain activity; but identifying the actual ’signatures’ has direct clinical relevance in cases of coma and apparent persistent vegetative state. In principle Dehaene’s research should allow conscious reactions continuing in a paralysed patient to be identified; this possibility is being actively pursued.

More speculative and perhaps of deeper theoretical interest, Dehaene puts forward a theory of consciousness as a global neuronal workspace, another variation on the global workspace theory of Bernard Baars (an idea which keeps being picked up by others, which must suggest that it has something going for it). Dehaene offers the view that a particular function of the workspace is to allow inputs to hang around for an extended period instead of dissipating. Among other benefits, this allows the construction of chains of processing operations, something Dehaene likens to a Turing machine, though it sounds a little messier than that to me. Further ingenious experiments have lent support to this idea; the researchers were able to contrast subjects’ chaining ability when information was supplied subliminally or consciously (this may sound odd, but subjects can perform at better-than-chance levels even with subliminal stimuli).

Dehaene says that he is dealing only with one variety of consciousness – in the main it’s awareness, which in some respects is the basement level compared to the more high-flown self-reflective versions. But in passing the talk does clarify a question which has sometimes troubled me in the past about global workspace theories – why should they involve consciousness at all? It seems easy to understand that the brain might benefit from a kind of clearing house where information from different sources is shared – but couldn’t that happen, as it were, in the dark? What does the magic ingredient of consciousness add to the process?

Well, being in the global workspace means being accessible to several different systems (no intention here to commit to any particular view about modularity); and one of those systems is the vocal reporting system. So as a natural consequence of being in the workspace, inputs become things we can vocally report, things we can talk about. Things we can talk about are surely objects of consciousness in some quite high-level sense.

Dehaene does not go down this path, but I wondered how far we could take it; is there a plausible explanation of phenomenal consciousness in terms of a global workspace? If we followed the same pattern of argument we used above, we would be looking to say that conscious experiences acquired qualia because being in the workspace made them available to the qualic system, whatever that might be. I think some people, those who tend to want to reduce qualia to flags or badges that give inputs a special weight, might find this kind of perspective congenial, but it doesn’t appeal all that much to me. I would prefer an argument that related the appearance of qualia to a sensory input’s being available to a global collection of sensory and other systems; something to do with resonances across modalities; but I happily confess I have no clear idea of how or exactly why that would work either.

Among a number of interesting features, The Ego Tunnel includes a substantial account of out-of-body experiences (OBEs) and similar phenomena. Experiments where the subjects are tricked into mistaking a plastic dummy for their real hand (all done with mirrors), or into feeling themselves to be situated somewhere behind their own head (you need a camera for this) show that our perception of our own body and our own location are generated within our brain and are susceptible to error and distortion; and according to Metzinger this shows that they are really no more than illusions (Is that right, by the way – or are they only illusions when they’re wrong or misleading? The fact that a camera can be made to generate false or misleading pictures doesn’t mean that all photographs are delusions, does it?).

There are many interesting details in this account, quite apart from its value as part of the overall argument.  Metzinger briefly touches on four varieties of autoscopic (self-seeing) phenomena, all of which can be related to distinct areas of the brain:  autoscopic hallucination, where the subject sees an image of themselves; the feeling of a presence, where the subject has the strong sense of someone there without seeing anyone; the particularly disturbing heautoscopy, where the subject sees another self and switches back and forth into and out of it, unsure which is ‘the real me’; and the better-known OBE. OBEs arise in various ways: often detachment from the body is sudden, but in other cases the second self may lift out gradually from the feet, or may exit the corporeal body via the top of the head.  Metzinger tells us that he himself has experienced OBEs and made many efforts to have more (going so far as to persuade his anaesthetist to use ketamine on him in advance of an operation, with no result – I wonder whether the anaesthetist actually kept his word) ; speaking of lucid dreams, another personal interest, he tells the story of having one in which he dreamed an OBE. That seems an interesting bit of evidence: if you can dream a credible OBE, mightn’t they all be dreams? This seems to undercut the apparently strong sense of reality which typically accompanies them.

Interestingly, Metzinger reports that a conversation with Susan Blackmore helped him understand his own experiences.  Blackmore is of course another emphatic denier of the reality of the self. I don’t in any way mean to offer an ad hominem argument here, but it is striking that these two people both seem to have had a particular interest in ’spooky’ dualistic phenomena which their rational scientific minds ultimately rejected, leading on to an especially robust rejection of the self. Perhaps people who lean towards dualism in their early years develop a particularly strong conception of the self, so that when they adopt monist materialism they reject the self altogether instead of seeking to redefine and accommodate it, as many of us would be inclined to do?

On that basis, you would expect Metzinger to be the hardest of hard determinists; his ideas seem to lean in that direction, but not decisively. He suggests that certain brain processes involved in preparing actions are brought up into the Ego Tunnel and hence seem to belong to us. They seem to be our own thoughts, our own goals and because the earlier stages remain outside the Tunnel, they seem to have come from nowhere, to be our own spontaneous creations. There are really no such things as goals in the world, any more than colours, but the delusion that they do exist is useful to us; the idea of being responsible for our own actions enables a kind of moral competition which is ultimately to our advantage (I’m not quite sure exactly how this  works). But in this case Metzinger pulls his punch: perhaps this is not the full story, he says, and describes compatibilism as the most beautiful position.

Metzinger pours scorn on the idea that we must have freedom of the will because we feel our actions to be free, yet he does give an important place to the phenomenology of the issue, pointing out that it is more complex than might appear. The more you look at them, he suggests, the more evasive conscious intentions become.  How curious it is then, that Metzinger, whose attention to phenomenology is outstandingly meticulous, should seem so sure that we have at all times a robust (albeit delusional) sense of our selves. I don’t find it so at all, and of course on this no less a person than David Hume is with me; with characteristically gentle but devastating scepticism, he famously remarked “For my part, when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never can observe any thing but the perception.”

Metzinger concludes by considering a range of moral and social issues which he thinks we need to address as our understanding of the mind improves. In his view, for example, we ought not to try to generate artificial consciousness. As a conscious entity, the AI would be capable of suffering, and in Metzinger’s view the chances are its existence would be more painful than pleasant. One reason for thinking so is the constrained and curtailed existence it could expect; another is that we only have our own minds to go on and would be likely to produce inferior, messed-up versions of it. But more alarming, Metzinger argues that human life itself involves an overall preponderance of pain over pleasure; he invokes Schopenhauer and Buddha. With characteristic thoroughness, he concedes that pleasure and pain may not be all that life is about; otherr achievements can justify a life of discomfort. But even so, the chances for an artificial consciousness, he feels are poor.

This is surely too bleak. I see no convincing reason to think that pain outweighs pleasure in general (certainly the Buddhist case, based on the perverse assumption that change is always painful, seems a weak point in that otherwise logical religion), and I see some reasons to think that a conscious robot would be less vulnerable to bad experiences than we are. It’s millions of years of evolution which have ingrained in us a fear of death and the motivating experience of pain:  the artificial consciousness need have none of that, but would surely be most likely to face its experiences with superhuman equanimity.

Of course caution is justified, but Metzinger in effect wants us to wait until we’ve sorted out the meaning of life before we get on with living it.

His attempt to raise this and other issues is commendable though; he’s right that the implications of recent progress have not received enough intelligent attention. Unfortunately I think the chances of some of these issues being addressed with philosophic rationality are slim. Another topic Metzinger raises, for example, is the question of what kinds of altered or enhanced mental states, from among the greatly expanded repertoire we are likely to have available in the near future, we ought to allow or facilitate; not much chance that his mild suggestions on that will have much impact.

There’s a vein of pessimism in his views on another topic. Metzinger fears that the progress of science, before the deeper issues have been sorted out, could inspire an unduly cynical, stripped-down view of human nature; a ‘vulgar materialism’, he calls it. Uninformed members of the public falling prey to this crude point of view might be tempted to think:

“The cat is out of the bag. We are gene-copying bio-robots, living out here on a lonely planet in a cold and empty physical universe. We have brains but no immortal souls and after seventy years or so the curtain drops. There will never be an afterlife, or any kind of reward or punishment for anyone… I get the message.”

Gosh: do we know anyone vulgar and unsophisticated enough to think like that?

The denial of one’s own existence might seem a desperate philosophical strategy, but denying the reality of the self is a line which a number of people have taken, and Thomas Metzinger is prominent among them. The thesis of his massive 2003 work is summed up in the title: Being No One: The Self-Model Theory of Subjectivity. In that book, Metzinger made a commendable effort to balance philosophy and science; but the sheer size of the resulting text may have deterred some readers – I confess to being somewhat daunted myself. Now he has come back with a slimmer volume The Ego Tunnel which is aimed at a wider public and raises wider issues which Metzinger suggests need public attention.

Metzinger’s theory – the Self-model Theory of Subjectivity or SMT – suggests that subjective experience is really a kind of trick the brain plays on itself. Our brain sets up a model of the world (actually based on fairly limited data) to which it then adds a model of us, ourselves. The coherence of the model and the fact that the processes supporting it are transparent – ie invisible to us – yield the vivid impression of a self in direct contact with reality, and that’s where subjectivity arises; although in fact the whole thing is simply an illusion.

Metzinger’s view of qualia is characteristically complex. He has a good argument against the existence of what he calls canonical qualia, qualia conceived as subjective universals. He points out that our ability to discriminate is far greater than our ability to recognise. So, if we are presented with examples of green 64 and green 66, we can readily tell the difference: but if at a later stage we are presented with one of the examples, we have no hope of telling which it is. So there is no single thing that consistently goes along with the experience of green 64.
Concluding that at any rate we need to distinguish between ‘qualia’ available to memory and qualia available to the faculty of recognition, Metzinger goes on to distinguish a series of possible conceptions of qualia, ending with ‘Metzinger qualia’ which are available attentionally but not cognitively. These are slippery customers for obvious reasons, impossible to report and broadly ineffable – but then that’s how qualia are generally assumed to be.

Even as a summary, the foregoing is a bare and radically, probably over- simplified view of the theory, however. Metzinger actually presents ten constraints which need to be satisfied for the occurrence of subjective experience: they are:

• Globality; as in ‘global workspace’; conscious items are always integrated into an overall world-model,
• Presentationality; present in the now , temporal immediacy,
• Convolved holism; objects of experience are made up of collections of other objects in a nested hierarchy,
• Dynamicity; the perceived world flows through constant changes,
• Perspectivalness; we experience the world from a point of view,
• Transparency; we cannot see the works – the neural processing which gives rise to our experience is excluded from conscious experience,
• Offline activation; subjective experience is not confined to the live inputs from our senses, a notable exception being dreams, where a whole non-existent world appears.
• Representation of intensities; besides distinguishing between qualia (whichever version we’re dealing with) we can distinguish their levels of intensity,
• Homogeneity; areas of pink, for example, are made up of smaller areas of pink, not red and white at once, and
• Adaptivity; the features of subjective experience have to be things that could reasonably have appeared in the course of evolution.

You may feel that there’s something a bit odd about this list, especially the appearance of ‘adaptivity’. One does not have to be a creationist to feel uneasy about the idea that that is really an essential feature of conscious experience in any deep sense. In a précis which he prepared for a discussion on the Psyche site – sadly this no longer appears to be available – Metzinger discussed only the first six constraints, which suggests that the last four are at least somewhat dispensable. This is a bit confusing – is homogeneity essential to conscious experience, or was that just a kind of bonus, a description of a property of phenomenal experience which is important but not a defining requirement? I think one issue here may be that Metzinger seems to want to do two jobs at once; he wants to explain subjectivity in a philosophical sense, but he also wants to describe and categorise phenomenal experience in a way which can be related to scientific observation, clarifying the puzzling phenomenology of blindsight and other unusual conditions. These are not incompatible aims, exactly, and there’s no absolute reason why one account couldn’t do both, but there is a tension. A robust philosophical explanation would pare down the account to its essentials, while the description of subjectivity seems to be something we would want to do as fully as possible.

So Metzinger, for example, notes that convolution is one property of phenomenal experience and homogeneity is another. If we’re looking for one kind of explanation, to be told that subjective experience breaks down into things which are different, and also that subjective experience sometimes breaks down into things that are the same, is not very helpful; but as a description of different ways phenomenology can work it’s a legitimate clarification.

In the new book, Metzinger boils the requirement down in terms which make it easier for us to get to grips with the theory in ways that relate to our usual concerns here, by asking what it would take to build an Ego Machine, an artificial conscious subject.

The recipe requires us to begin with an integrated and dynamical world-model . We must then ensure that the information flow is organised so as to assign events to a present moment, a Now; and that the images presented by the model are transparent: again, we must not be able to see the works. If these constraints are satisfied, a world appears. The last step is to add to the model an equally transparent representation of an experiencing self; then the artificial entity will finally appear to itself to be someone, and to be there. There will seem to be someone in the Ego Tunnel, Metzinger’s equivalent of Plato’s cave.

This seems to me to make quite a lot of sense, but the reader’s verdict is likely to be determined by whether it ‘feels right’ – does it finally dispel that sense of mystery? It must be taken into account that Metzinger’s theory itself provides strong reasons why his conclusions are going to seem intuitively unacceptable, so a kind of mental ‘aiming off’ may be required. I think we have to ask ourselves two questions. The first is: can we imagine that all of Metzinger’s requirements could be met in the absence of ‘inner experience’: does it seem that we could have his kind of world-model running with a representation of a self in it and yet still be, as it were, only a Metzinger zombie?

If we’re happy that this is not a possibility, there still remains the question of whether Metzinger has smuggled his consciousness into the tunnel. Do any of his constraints covertly imply that consciousness is already present?

I think some of them could – presentationality? Perspectivalness? – but carefully read, I don’t think they need do. Whether some of their intuitive appeal derives from the reader having unconsciously done some illicit importation is, I suppose, a matter for the reader. Some of the constraints do look a bit strange in other ways. Let’s consider that requirement of transparency, for example. In the ego tunnel, data about the outside world must be globally available, but there must be no information about how this data got to the tunnel, since that would dispel the illusion that what we are dealing with is the real world itself. But why would there be? A TV screen does not automatically contain an account of how the TV itself or the local transmitter works. Metzinger has an odd perspective here which seems to start with the idea that the mind naturally knows everything and has to be carefully shielded. In The Ego Tunnel he talks about our sensory apparatus filtering out most of the potential information about the world, limiting us to a meagre trickle, as though our natural state was a kind of omniscience which is only reined in by the limitations of our eyes. Isn’t it the other way round?

Look at it the other way: suppose we were consciously aware of the fact that light rays were being processed by our retinas, would that destroy our sense of ourselves as existing in the world? Actually, I doubt it. The fact that we can see the edges of the screen does not inhibit us much from getting immersed in a film: for that matter the very visible appearance of the book does not prevent our getting immersed in a novel. Similarly, the fact that I can see a ‘floater’ in my right eye at the moment doesn’t cause reality to recede from me although it is a tell-tale sign of the visual processes that intervene between my brain and the world.

But there’s more in the Ego Tunnel…

(My apologies if things have been a bit slow here – I rashly committed to Nanowrimo this year so a lot of my energy is going to turning out a 50,000 word novel text this month. You can read the results here.  – Peter)

I see via MLU that Robert Sloan at the University of Illinois at Chicago has been given half a million dollars for a three year project on common sense. Alas, the press release gives few details, but Sloan describes the goal of common sense as “the Holy Grail of artificial intelligence research”.

I think he’s right. There is a fundamental problem here that shows itself in several different forms. One is understanding: computers don’t really understand anything, and since translation, for example, requires understanding, they’ve never been very good at it. They can swap a French word for an English word, but without some understanding of what the original sentence was conveying, this mechanical substitution doesn’t work very well. Another outcrop of the same issue is the frame problem: computer programs need explicit data about their surroundings, but updating this data proves to be an unmanageably large problem, because the implications of every new piece of data are potentially infinite. Every time something changes, the program has to check the implications for every other piece of data it is holding; it needs to check the ones that are the same just as much as those that have changed, and the task rapidly mushrooms out of control. Somehow, humans get round this: they seem to be able to pick out the relevant items from a huge background of facts immediately, without having to run through everything.

In formulating the frame problem originally back in the 1960s,  John McCarthy speculated that the solution might lie in non-monotonic logics; that is, systems that don’t require everything to be simply true or false, as old-fashioned logical calculus does.  Systems based on rigid propositional/predicate calculus needed to check everything in their database every time something changed in order to ensure there were no contradictions, since a contradiction is fatal in these formalisations. On the whole, McCarthy’s prediction has been borne out in that research since then has tended towards the use of Bayesian methods, which can tolerate contradictions and which can give propositions degrees of belief rather than simply holding them true or false. As well as providing practical solutions to frame problem  issues, this seems intuitively much more like the way a human mind works.

Sloan, as I understand it, is very much in this tradition; his earlier published work deals with sophisticated techniques for the manipulation of Horn knowledge bases. I’m afraid I frankly have only a vague idea of what that means, but I imagine it is a pretty good clue to the direction of the new project. Interestingly, the press release suggests the team will be looking at CYC and other long-established projects. These older projects tended to focus on the accumulation of a gigantic database of background knowledge about the world, in the possibly naive belief that once you had enough background information, the thing would start to work. I suppose the combination of unbelievably large databases of common sense knowledge with sophisticated techniques for manipulating and updating knowledge might just be exciting. If you were a cyberpunk fan and  unreasonably optimistic, you might think that something like the meeting of Neuromancer and Wintermute was quietly happening.

Let’s not get over-excited, though, because of course the whole thing is completely wrong. We may be getting really good at manipulating knowledge bases, but that isn’t what the human brain does at all. Or does it? Well,  on the one hand, manipulating knowledge bases is all we’ve got: it may not work all that well, but for the time being it’s pretty much the only game in town – and it’s getting better. On the other hand, intuitively it just doesn’t seem likely that that’s what brains do: it’s more as if they used some entirely unknown technique of inference which we just haven’t grasped yet. Horn knowledge bases may be good, but really are they any more like natural brain functions than Aristotelian syllogisms?

Maybe, maybe not: perhaps it doesn’t matter. I mentioned the comparable issue of translation. Nobody supposes we are anywhere near doing translation by computation in the way the human brain does it, yet the available programs are getting noticeably better. There will always be some level of error in computer translation, but there is no theoretical limit to how far it can be reduced, and at some point it ceases to matter: after all, even human translators get things wrong.

What if the same were true for knowledge management? We could have AI that worked to all intents and purposes as well as the human brain, yet worked in a completely different way. There has long been a school of thought that says this doesn’t matter: we never learnt to fly the way birds do, but we learnt how to fly. Maybe the only way to artificial consciousness in the end will be the cognitive equivalent of a plane. Is that so bad?

If the half-million dollars is well spent, we could be a little closer to finding out…

One of the most frequently visited pages on Conscious Entities is this account of Benjamin Libet’s remarkable experiments, which seemed to show that decisions to move were really made half a second before we were aware of having decided. To some this seemed like a practical disproof of the freedom of the will – if the decision was already made before we were consciously aware of it, how could our conscious thoughts have determined what the decision was?  Libet’s findings have remained controversial ever since they were published; they have been attacked from several different angles, but his results were confirmed and repeated by other researchers and seemed solid.

However, Libet’s conclusions rested on the use of Readiness Potentials (RPs). Earlier research had shown that the occurence of an RP in the brain reliably indicated that a movement was coming along just afterwards, and they were therefore seen as a neurological sign that the decision to move had been taken (Libet himself found that the movement could sometimes be suppressed after the RP had appeared, but this possibility, which he referred to as ‘free won’t ‘, seemed only to provide an interesting footnote). The new research, by Trevena and Miller at Otago, undermines the idea that RPs indicate a decision.

Two separate sets of similar experiments were carried out. They resembled Libet’s original ones in most respects, although computer screens and keyboards replaced Libet’s more primitive equipment, and the hand movement took the form of a key-press. A clock face similar to that in Libet’s experiments was shown, and they even provided a circling dot. In the earlier experiments this had provided an ingenious way of timing the subject’s awareness that a decision had been made – the subject would report the position of the dot at the moment of decision – but in Trevena and Miller’s research the clock and dot were provided only to make conditions resemble Libet’s as much as possible. Subjects were told to ignore them (which you might think rendered their inclusion pointless). This was because instead of allowing the subject to choose their own time for action, as in Libet’s original experiments, the subjects in the new research were prompted by a randomly-timed tone. This is obviously a significant change from the original experiment; the reason for doing it this way was that Trevena and Miller wanted to be able to measure occasions when the subject decided not to move as well as those when there was movement. Some of the subjects were told to strike a key whenever the tone sounded,  while the rest were asked to do so only about half the time (it was left up to them to select which tones to respond to, though if they seemed to be falling well below a 50-50 split they got a reminder in the latter part of the experiment).  Another significant difference from Libet’s tests is that left and right hands were used: in one set of experiments the subjects were told by a letter in the centre of the screen whether they should use the right or left hand on each occasion, in the other it was left up to them.

There were two interesting results. One was that the same kind of RP appeared whether the subject pressed a key or not. Trevena and Miller say this shows that the RP was not, after all, an indication of a decision to move, and was presumably instead associated with some more general kind of sustained attention or preparing for a decision. Second, they found that a different kind of RP, the Lateralised Readiness Potential or LRP, which provides an indication of readiness to move a particular hand, did provide an indication of a decision, appearing only where a movement followed; but the LRP did not appear until just after the tone. This suggests, in contradiction to Libet, that the early stages of action followed the conscious experience of deciding, rather than preceding it.

The differences between these new experiments and Libet’s originals provide a weak spot which Libetians will certainly attack.  Marcel Brass, whose own work with fMRI scanning confirmed and even extended Libet’s delay, seeming to show that decisions could be predicted anything up to ten seconds before conscious awareness, has apparently already said that in his view the changes undermine the conclusions Trevena and Miller would like to draw. Given the complex arguments over the exact significance of timings in Libet’s results, I’m sure the new results will prove contentious. However, it does seem as if a significant blow has been struck for the first time against the foundations of Libet’s remarkable results.

Over at Robots.net, they’ve noticed a bit of a resurgence of dualism recently, and it seems that Avshalom C. Elitzur is in the vanguard, with this paper presenting an argument from bafflement.

The first part of the paper provides a nice, gentle introduction to the issue of qualia in dialogue form. Elitzur explains the bind that we’re in in this respect: we seem to have an undeniable first-hand experience of qualia, yet they don’t fit into the normal physical account of the world. We seem to be faced with a dilemma: either reject qualia – perhaps we just misperceive our percepts as qualia – or accept some violation of normal physics. The position is baffling: but Elitzur wants to suggest that that very bafflement provides a clue.  His strategy is to try to drag the issue into the realm of science, and the argument goes like this:

1. By physicalism, consciousness and brain processes are identical.
2. Whence, then, the dualistic bafflement about their apparent nonidentity?
3. By physicalism, this nonidentity, and hence the resultant bafflement, must be due to error.
4. But then, again by physicalism, an error must have a causal explanation.
5. Logic, cognitive science and AI are advanced enough nowadays to provide such an explanation for the alleged error underlying dualism, and future neurophysiology must be able to point out its neural correlate.

That last point seems optimistic. Cognitive science may be advanced enough to provide explanations for a number of cognitive deficits and illusions, but sometimes only partial ones; and not all errors are the result of a structural problem. It’s particularly optimistic to think that all errors must have an identifiable neural correlate. But this seems to be what Elitzur believes. He actually says

“When future neurophysiology becomes advanced enough to point out the neural correlates of false beliefs, a specific correlate of this kind would be found to underlie the bafflement about qualia.”

The neural correlates of false beliefs? Crikey! It’s perfectly reasonable to assume that all false beliefs have neural correlates – because one assumes that all beliefs do – but the idea that false ones can be distinguished by their neural properties is surely evidently wrong. An argument hardly seems required, but it’s easy, for example, to picture a man who believes a coin has come down heads. If it has, his belief is true, but if it’s actually tails, exactly the same belief, with identical neural patterns would be false. I think Elitzur must mean something less startling than what he seems to be saying; he must, I think, take it as read that if qualia are a delusion, they would be a product of some twist or quirk in our mental set-up. That’s not an unreasonable position, one that would be shared by Metzinger, for example (discussion coming soon).

As it happens, Elitzur doesn’t think qualia are delusions; instead he has an argument which he thinks shows that interactionist dualism – a position he doesn’t otherwise find very attractive – must be true. The argument is to do with  zombies.  Zombies in this context, as regular readers will know, are people who have all the qualities normal people posess, except qualia. Because qualia have no physical causal effects,  the behaviour of zombies, caused by normal physical factors, is exactly like that of normal people. Elitzur quotes Chalmers explaining that zombie-Chalmers even talks about qualia and writes philosophical papers about them, though in fact he has none. The core of Elitzur’s position is his incredulity over this conclusion. How could zombies who don’t have qualia come to be worried about them?

It is an uncomfortable position, but if we accept that zombies are possible and qualia exist, Chalmers’ logic seems irrefutable.  Ex hypothesi, zombies follow the same physical laws as us:  it’s ultimately physics that causes the movements of our hands and mouths involved in writing or speaking about qualia: so our zombie counterparts must go through the same motions, writing the same books and emitting the same sounds. Since this seems totally illogical to Elitzur, he offers the rationalisation that when zombies talk about qualia, they must in fact merely be talking about their percepts. But this asymmetry provides a chink which can be used to prose zombies and qualiate people apart. If we ask Chalmers whether his zombie equivalent is possible, he replies that it is; but, suggests Elitzur, if we ask zombie Chalmers (whom he call ‘Charmless’) the same question, he replies in the negative.  Chalmers can imagine himself functioning without qualia, because qualia have no functional role: but Charmless cannot imagine himself functioning without percepts, because percepts are part of the essence of his sensory system. (It is possible to take the analogous view about qualia of course – namely that zombies are impossible, because a physically identical person just would necessarily have the same qualia). So zombies differ from us, oddly enough, in not being able to conceive of their own zombies.

For Elitzur, the conclusion is inescapable; qualia do have an effect on our brains. He chooses therefore to bite the bullet of accepting that the laws of physics must be messed up in some way – that where qualia intervene, conservation laws are breached, unpalatable as this conclusion is. One consoling feature is that if qualia do have physical effects, they can be included in the evolutionary story; perhaps they serve to hasten or intensify our responses: but overall it’s regrettable that dualism turns out to be the answer.

I don’t think this is a convincing conclusion; it seems as if Elitzur’s incredulity has led him into not taking the premises of the zombie question seriously enough. It just is the case ex hypothesi that all of our zombies’ behaviour is caused by the same physical factors as our own behaviour; it follows that if their talk about qualia is not caused by qualia, neither is ours (note that this doesn’t have to mean that either we or the zombies fail to talk about qualia). There are other ways out of this uncomfortable position, discussed by Chalmers (perhaps, for example, our words about qualia are over-determined, caused both by physical factors and by our actual experiences). My own preferred view is that whatever qualia might be, they certainly go along with certain physical brain functions, and that therefore any physical duplicate of ourselves would have the same qualia; that zombies, in other words, are not possible. It’s just a coincidence, I’m sure, that in Elitzur’s theory this is the kind of thing a zombie would say…