Tag Archives: awareness

Ways to be less conscious

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multi-factor-awareness-cIs awareness an on/off thing? Or is it on a sort of dimmer switch? A degree of variation seems to be indicated by the peculiar vagueness of some metal content (or is that just me?). Fazekas and Overgaard argue that even a dimmer switch is far too simple; they suggest that there are at least four ways in which awareness can be graduated.

First, interestingly, we can be aware of things to different degrees on different levels. Our visual system identifies dark and light, then at a higher level identifies edges, at a higher level again sees three dimensional shapes, and higher again, particular objects. We don’t have to be equally clear at all levels, though. If we’re looking at the dog, for example, we may be aware that in the background is the cat, and a chair; but we are not distinctly aware of the cat’s whiskers or the pattern on the back of the chair. We have only a high-level awareness of cat and chair. It can work the other way, too; people who suffer from face-blindness, for example, may be well able to describe the nose and other features of someone presented to them without recognising that the face belongs to a friend.

That is certainly not the only way our awareness can vary, though; it can also be of higher or lower quality. That gives us a nice two-dimensional array of possible vagueness; job done? Well no, because Fazekas and Overgaard think quality varies in at least three ways.

  • Intensity
  • Precision
  • Temporal Stability

So in fact we have a matrix of vagueness which has four dimensions, or perhaps I should say three plus one.

The authors are scrupulous about explaining how intensity, precision, and temporal stability probably relate to neuronal activity, and they are quite convincing; if anything I should have liked a bit more discussion of the phenomenal aspects – what are some of these states of partially-degraded awareness actually like?

What they do discuss is what mechanism governs or produces their three quality factors. Intensity, they think, comes from the allocation of attention. When we really focus on something, more neuronal resources are pulled in and the result is in effect to turn up the volume of the experience a bit.

Precision is also connected with attention; paying attention to a feature produces sharpening and our awareness becomes less generic (so instead of merely seeing something is red, we can tell whether it is magenta or crimson, and so on). This is fair enough, but it does raise a small worry as to whether intensity and precision are really all that distinct. Mightn’t it just be that enhancing the intensity of a particular aspect of our awareness makes it more distinct and so increases precision? The authors acknowledge some linkage.

Temporal stability is another matter. Remember we’re not talking here about whether the stimulus itself is brief or sustained but whether our awareness is constant. This kind of stability, the authors say, is a feature of conscious experience rather than unconscious responses and depends on recurrence and feedback loops.

Is there a distinct mechanism underlying our different levels of awareness? The authors think not; they reckon that it is simply a matter of what quality of awareness we have on each level (I suppose we have to allow for the possibility if not the certainty that some levels will be not just poor quality but actually absent. I don’t think I’m typically aware of all possible levels of interpretation when considering something.

So there is the model in all its glory; but beware; there are folks around who argue that in fact awareness is actually not like this, but in at least some cases is an on/off matter. Some experiments by Asplund were based on the fact that if a subject is presented with two stimuli in quick succession, the second is missed. As the gap increases, we reach a point where the second stimulus can be reported; but subjects don’t see it gradually emerging as the interval grows; rather With one gap it’s not there, while With a slightly larger one, it is.

Fazekas and Overgaard argue that Asplund failed to appreciate the full complexity of the graduation that goes on; his case focuses too narrowly on precision alone. In that respect there may be a sharp change, but in terms of intensity or temporal stability, and hence in terms of awareness overall, they think there would be graduation.

A second rival theory which the authors call the ‘levels of processing view’ or LPV, suggests that while awareness of low-level items is graduated, at a high level you’re either aware or not. These experiments used colours to represent low-level features and numbers for high level ones, and found that while there was graduated awareness of the former, with the latter you either got the number or you didn’t.

Fazekas and Overgaard argue that this is because colours and numbers are not really suitable for this kind of comparison. Red and blue are on a continuous scale and one can morph gradually into the other; the numeral ‘7’ does not gradually change into ‘9’. This line of argument made sense to me, but on reflection caused me some problems. If it is true that numerals are just distinct in this way, that seems to me to concede a point that makes the LPV case seem intuitively appealing; in some circumstances things just are on/off. It seemed true at first sight that numerals are distinct in this way, but when I thought back to experiences in the optician’s chair, I could remember cases where the letter I was trying to read seemed genuinely indeterminate between two or even more alternatives. Now though, if My first thought was wrong and numerals are not in fact inherently distinct in this way, that seems to undercut Fazekas and Overgaard’s counter-argument.

On the whole the more complex model seems to provide better explanatory resources and I find it broadly convincing, but I wonder whether a reasonable compromise couldn’t be devised, allowing that for certain experiences there may be a relatively sharp change of awareness, with only marginal graduation? Probably I have come up with a vague and poorly graduated conclusion…

A Human Phenomenology Project

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introspection2We don’t know what we think, according to Alex Rosenberg in the NYT. It’s a piece of two halves, in my opinion; he starts with a pretty fair summary of the sceptical case. It has often been held that we have privileged knowledge of our own thoughts and feelings, and indeed of our own decisions; but the findings of Benjamin Libet about decisions being made before we are aware of them; the phenomenon of blindsight which shows we may go on having visual knowledge we’re not aware of; and many other cases where it can be shown that motives are confabulated and mental content is inaccessible to our conscious, reporting mind; these all go to show that things are much more complex than we might have thought, and that our thoughts are not, as it were, self-illuminating. Rosenberg plausibly suggests that we use on ourselves the kind of tools we use to work out what other people are thinking; but then he seems to make a radical leap to the conclusion that there is nothing else going on.

Our access to our own thoughts is just as indirect and fallible as our access to the thoughts of other people. We have no privileged access to our own minds. If our thoughts give the real meaning of our actions, our words, our lives, then we can’t ever be sure what we say or do, or for that matter, what we think or why we think it.

That seems to be going too far.  How could we ever play ‘I spy’ if we didn’t have any privileged access to private thoughts?

“I spy, with my little eye, something beginning with ‘c'”
“Is it ‘chair’?”
“I don’t know – is it?”

It’s more than possible that Rosenberg’s argument has suffered badly from editing (philosophical discussion, even in a newspaper piece, seems peculiarly information-dense; often you can’t lose much of it without damaging the content badly). But it looks as if he’s done what I think of as an ‘OMG bounce’; a kind of argumentative leap which crops up elsewhere. Sometimes we experience illusions:  OMG, our senses never tell us anything about the real world at all! There are problems with the justification of true belief: OMG there is no such thing as knowledge! Or in this case: sometimes we’re wrong about why we did things: OMG, we have no direct access to our own thoughts!

There are in fact several different reasons why we might claim that our thoughts about our thoughts are immune to error. In the game of ‘I spy’, my nominating ‘chair’ just makes it my choice; the content of my thought is established by a kind of fiat. In the case of a pain in my toe, I might argue I can’t be wrong because a pain can’t be false: it has no propositional content, it just is. Or I might argue that certain of my thoughts are unmediated; there’s no gap between them and me where error could creep in, the way it creeps in during the process of interpreting sensory impressions.

Still, it’s undeniable that in some cases we can be shown to adopt false rationales for our behaviour; sometimes we think we know why we said something, but we don’t. I think by contrast I have occasionally, when very tired, had the experience of hearing coherent and broadly relevant speech come out of my own mouth without it seeming to come from my conscious mind at all. Contemplating this kind of thing does undoubtedly promote scepticism, but what it ought to promote is a keener awareness of the complexity of human mental experience: many layered, explicit to greater or lesser degrees, partly attended to, partly in a sort of half-light of awareness… There seem to be unconscious impulses, conscious but inexplicit thought; definite thought (which may even be in recordable words); self-conscious thought of the kind where we are aware of thinking while we think… and that is at best the broadest outline of some of the larger architecture.

All of this really needs a systematic and authoritative investigation. Of course, since Plato there have been models of the structure of the mind which separate conscious and unconscious, id, ego and superego: philosophers of mind have run up various theories, usually to suit their own needs of the moment; and modern neurology increasingly provides good clues about how various mental functions are hosted and performed. But a proper mainstream conception of the structure and phenomenology of thought itself seems sadly lacking to me. Is this an area where we could get funding for a major research effort; a Human Phenomenology Project?

It can hardly be doubted that there are things to discover. Recently we were told, if not quite for the first time, that a substantial minority of people have no mental images (although at once we notice that there even seen to be different ways of having mental images). A systematic investigation might reveal that just as we have four blood groups, there are four (or seven) different ways the human mind can work. What if it turned out that consciousness is not a single consistent phenomenon, but a family of four different ones, and that the four tribes have been talking past each other all this time…?

Are we aware of concepts?

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jennifer2Are ideas conscious at all? Neuroscience of Consciousness is a promising new journal from OUP introduced by the editor Anil Seth here. It has an interesting opinion piece from David Kemmerer which asks – are we ever aware of concepts, or is conscious experience restricted to sensory, motor and affective states?

On the face of it a rather strange question? According to Kemmerer there are basically two positions. The ‘liberal’ one says yes, we can be aware of concepts in pretty much the same kind of way we’re aware of anything. Just as there is a subjective experience when we see a red rose, there is another kind of subjective experience when we simply think of the concept of roses. There are qualia that relate to concepts just as there are qualia that relate to colours or smells, and there is something it is like to think of an idea. Kemmerer identifies an august history for this kind of thinking stretching back to Descartes.

The conservative position denies that concepts enter our awareness. While our behaviour may be influenced by concepts, they actually operate below the level of conscious experience. While we may have the strong impression that we are aware of concepts, this is really a mistake based on awareness of the relevant words, symbols, or images. The intellectual tradition behind this line of thought is apparently a little less stellar – Kemmerer can only push it back as far as Wundt – but it is the view he leans towards himself.

So far so good – an interesting philosophical/psychological issue. What’s special here is that in line with the new journal’s orientation Kemmerer is concerned with the neurological implications of the debate and looks for empirical evidence. This is an unexpected but surely commendable project.

To do it he addresses three particular theories. Representing the liberal side he looks at Global Neural Workspace Theory (GNWT) as set out by Dehaene, and Tononi’s Integrated information Theory (IIT)’ on the conservative side he picks the Attended Intermediate-Level Representation Theory (AIRT) of Prinz. He finds that none of the three is fully in harmony with the neurological evidence, but contends that the conservative view has distinct advantages.

Dehaene points to research that identified specific neurons in a subject’s anterior temporal lobes that fire when the subject is shown a picture of, say, Jennifer Aniston (mentioned on CE – rather vaguely). The same neuron fires when shown photographs, drawing, or other images, and even when the subject is reporting seeing a picture of Aniston. Surely then, the neuron in some sense represents not an image but the concept of Jennifer Aniston?  against theconservative view Kemmerer argues that while a concept may be at work, imagery is always present in the conscious mind; indeed, he contends,  you cannot think of ‘Anistonicity’ in itself without a particular image of Aniston coming to mind. Secondly he quotes further research which shows that deterioration of this portion of the brain impairs our ability to recognise, but not to see, faces. This, he contends, is good evidence that while these neurons are indeed dealing with general concepts at some level, they are contributing nothing to conscious awareness, reinforcing the idea that concepts operate outside awareness. According to Tononi we can be conscious of the idea of a triangle, but how can we think of a triangle without supposing it to be equilateral, isosceles, or scalene?

Turning to the conservative view, Kemmerer notes that AIRT has awareness at a middle level, between the jumble of impressions delivered by raw sensory input on the one hand, and the invariant concepts which appear at the high level. Conscious information must be accessible but need not always be accessed.  It is implemented as gamma vector waves. This is apparently easier to square with the empirical data than the global workspace, which implies that conscious attention would involve a shift into the processing system in the lateral prefrontal cortex where there is access to working memory – something not actually observed in practice. Unfortunately although the AIRT has a good deal of data on its side the observed gamma responses don’t in fact line up with reported experience in the way you would expect if it’s correct.

I think the discussion is slightly hampered by the way Kemmerer uses ‘awareness’ and ‘consciousness’ as synonyms. I’d be tempted to reserve awareness for what he is talking about, and allow that concepts could enter consciousness without our being (subjectively) aware of them. I do think there’s a third possibility being overlooked in his discussion – that concepts are indeed in our easy-problem consciousness while lacking the hard-problem qualia that go with phenomenal experience. Kemmerer alludes to this possibility at one point when he raises Ned Block’s distinction between access and phenomenal  (a- and p-consciousness), but doesn’t make much of it.

Whatever you think of Kemmerer’s ambivalent;y conservative conclusion, I think the way the paper seeks to create a bridge between the philosophical and the neurological is really welcome and, to a degree, surprisingly successful. If the new journal is going to give us more like that it will definitely be a publication to look forward to.

 

That’s you all over…

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all overAn interesting study at Vanderbilt University (something not quite right about the brain picture on that page) suggests that consciousness is not narrowly localised within small regions of the cortex, but occurs when lots of connections to all regions are active. This is potentially of considerable significance, but some caution is appropriate.

The experiment asked subjects to report whether they could see a disc that flashed up only briefly, and how certain they were about it. Then it compared scans from occasions when awareness of the disc was clearly present or absent. The initial results provided the same kind of pattern we’ve become used to, in which small regions became active when awareness was present. Hypothetically these might be regions particularly devoted to disc detection; other studies in the past have found patterns and regions that appeared to be specific for individual objects, or even the faces of particular people.

Then, however, the team went on to assess connectedness, and found that awareness was associated with many connections to all parts of the cortex. This might be taken to mean that while particular small bits of brain may have to do with particular things in the world, awareness itself is something the whole cortex does. This would be a very interesting result, congenial to some, and it would certainly affect the way we think about consciousness and its relation to the brain.

However, we shouldn’t get too carried away too quickly.  To begin with, the study was about awareness of a flashing disc; a legitimate example of a conscious state, but not a particularly complex one and not necessarily typical of distinctively human types of higher-level conscious activity. Second, I’m not remotely competent to make any technical judgement about the methods used to assess what connections were in place, but I’d guess there’s a chance other teams in the field might have some criticisms.

Third, there seems to be scope for other interpretations of the results. At best we know that moments of disc awareness were correlated with moments of high connectedness. That might mean the connectedness caused or constituted the awareness, but it might also mean that it was just something that happens at the same time. Perhaps those narrow regions are still doing the real work: after all, when there’s a key political debate the rest of the country connects up with it; but the debate still happens in a single chamber and would happen just the same if the wider connectivity failed. It might be that awareness gives a wide selection of other regions a chance to chip in, or to be activated in turn, but that that is not an essential feature of the experience of the disc.

For some people, the idea of consciousness bring radically decentralised will be unpalatable. To them, it’s a functional matter which more or less has to happen in a defined area. OK, that area could be stretched out, but the idea that merely linking up disparate parts of the cortex could in itself bring about a conscious state will seem too unlikely to be taken seriously. For others, who think the brain itself is too narrow an area to fully contain consciousness, the results will hardly seem to go far enough.

For myself, I feel some sympathy with the view expressed by Margaret Boden in this interview, where she speaks disparagingly of current neuroscience being mere ‘natural history’ – we just don’t have enough of a theory yet to know what we’re looking at. We’re still in the stage where we’re merely collecting facts, findings that will one day fit neatly into a proper theoretical framework, but at the moment don’t really prove or disprove any general hypotheses. To put it another way, we’re still collecting pieces of the jigsaw puzzle but we don’t have any idea what the picture is. When we spot that, then perhaps the pieces will all… connect.

Are we really conscious?

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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…

Strange Smells of the Mind

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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?).

Signatures of Consciousness

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Picture: Stanislas Dehaene. 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.

Forget AI…

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Picture: heraldic whale. … it’s AGI now. I was interested to hear via Robots.net that Artificial General Intelligence had enjoyed a successful second conference recently.

In recent years there seems to have been a general trend in AI research towards more narrow and perhaps more realistic sets of goals; towards achieving particular skills and designing particular modules tied to specific tasks rather than confronting the grand problem of consciousness itself. The proponents of AGI feel that this has gone so far that the terms ‘artificial intelligence’ and AI no longer really designate the topic they’re interested in, the topic of real thinking machines.  ‘An AI’ these days is more likely to refer to the bits of code which direct the hostile goons in a first-person shooter game than to anything with aspirations to real awareness, or even real intelligence.

The mention of  ‘real intelligence’ of course, reminds us that plenty of other terms have been knocked out of shape over the years in this field. It is an old complaint from AI sceptics that roboteers keep grabbing items of psychological vocabulary and redefining them as something simpler and more computable. The claim that machines can learn, for example, remains controversial to some, who would insist that real learning involves understanding, while others don’t see how else you would describe the behaviour of a machine that gathers data and modifies its own behaviour as a result.

I think there is a kind of continuum here, from claims it seems hard to reject to those it seems bonkers to accept, rather like this…

Claim: machines… Objection
add numbers. Really the ‘numbers’ are a human interpretation of meaningless switching operations.
control factory machines. Control implies foresight and intentions whereas machines just follow a set of instructions.
play chess. Playing a game involves expectations and social interaction, which machines don’t really have.
hold conversations Chat-bots merely reshuffle set phrases to give the impression of understanding.
react emotionally There may be machines that display smiley faces or even operate in different ’emotional’ modes, but none of that touches the real business of emotions.

Readers will probably find it easy to improve on this list, but you get the gist. Although there’s something in even the first objection, it seems pointless to me to deny that machines can do addition – and equally pointless to claim that any existing machine experiences emotions – although I don’t rule even that idea out of consideration forever.

I think the most natural reaction is to conclude that in all such cases, but especially in the middling ones, there are two different senses – there’s playing chess and really playing chess. What annoys the sceptics is their perception that AIers have often stolen terms for the easy computable sense when the normal reading is the difficult one laden with understanding, intentionality and affect.

But is this phenomenon not simply an example of the redefinition of terms which science has always introduced? We no longer call whales fish, because biologists decided it made sense to make fish and mammals exclusive categories – although people had been calling whales fish on and off for a long time before that. Aren’t the sceptics on this like diehard whalefishers? Hey, they say, you claimed to be elucidating the nature of fish, but all you’ve done is make it easy for yourself by making the word apply just to piscine fish, the easy ones to deal with. The difficult problem of elucidating the deeper fishiness remains untouched!

The analogy is debatable, but it could be claimed that redefinitions of  ‘intelligence’ and ‘learning’ have actually helped to clarify important distinctions in broadly the way that excluding the whales helped with biological taxonomy. However, I think it’s hard to deny that there has also at times been a certain dilution going on. This kind of thing is not unique to consciousness – look what happened to ‘virtual reality’, which started out as quite a demanding concept, and was soon being used as a marketing term for any program with slight pretensions to 3D graphics.

Anyway, given all that background it would be understandable if the sceptical camp took some pleasure in the idea that the AI people have finally been hoist with their own petard, and that just as the sceptics, over the years, have been forced to talk about ‘real intelligence’ and ‘human-level awareness’, the robot builders now have to talk about ‘artificial general intelligence’.

But you can’t help warming to people who want to take on the big challenge. It was the bold advent of the original AI project which really brought consciousness back on to the agenda of all the other disciplines, and the challenge of computer thought which injected a new burst of creative energy into the philosophy of mind, to take just one example. I think even the sceptics might tacitly feel that things would be a little quiet without the ‘rude mechanicals’: if AGI means they’re back and spoiling for a fight, who could forbear to cheer?