Conscious Entities

The Observer has a discussion between Tallis and Eagleman, Eagleman representing neural reductionism and Tallis speaking for a more traditional view of mind and brain.

Although it’s worth reading, it turns out a slightly inconclusive encounter. Perhaps on this occasion you’d give Tallis a points victory because he does seem to be looking for a fight, whereas Eagleman is in rather cautious form. They circle each other but never quite identify a proposition which sums up their disagreement clearly enough to get things going.

What seems to emerge is a kind of agreement that mental activity needs to be addressed on more than one level of explanation, with the two antagonists merely giving a different balance of emphasis. This certainly understates the real disagreement between the two.

I think it probably is the case that nearly everyone grants the need for more than one level of explanation. There are those who would say the correct top level is the cosmos itself and that individual consciousness expresses a universal entity.  Not quite as high-level as that we surely need to address consciousness on the level of its explicit and social content; we could call this the ‘home’ level because it is sort of where we live, where we actually experience the world. Most would agree that there are levels of unconscious operation that are also a necessary part of the picture; not many people would say that the structure of the brain and its component neurons tell us nothing; and a majority nowadays would agree that there is ultimately a story at the classical molecular level which, though vastly complex, cannot  be ignored. Some say even this is not enough and that consciousness cannot be understood without giving quantum mechanics, or some as-yet-unknown lower level theory, a crucial role.

Only a very hard-line reductionist would say we only need one of these levels: it’s generally accepted that there are interesting things to be said on several of them which simply cannot be addressed at other levels. What mainly emerges here is Tallis’ defence of the ‘home’ level against Eagleman’s contention that we pay it too much attention and that for many purposes, including our treatment of crime and punishment, we should dethrone it. Intuitively, the motives for Tallis’ incredulity are pretty clear: wouldn’t it be weird if we had developed the apparatus of thought and consciousness and yet it had no important impact on our behaviour? Don’t we just know that discussion and conscious thought ultimately shape what we do, even if our behaviour is sometimes nudged in different directions by factors we’re not aware of?

Yet there is something deeply unsatisfactory about the whole idea of different levels of explanation, isn’t there? How can one reality require half-a-dozen different accounts? It seems a distressingly messy and arbitrary kind of way for the world to be set up, and certainly we greet any successful reduction of higher level entities to lower level ones as a valuable explanatory achievement. So it’s not hard to sympathise with Eagleman’s desire to emphasise the role of levels below consciousness either.

Generally speaking it seems that the lower the level of our explanation the better, as though ultimate reality resides at the lowest micro level we can get to. We always celebrate reductions, not elaborations. Yet there have been some rebellious attempts to push things the other way through ideas such as emergence and embodiment, which claim the whole can be more important than the parts. I notice myself that things seem to come most clearly into focus at or slightly below the home level: if we go far above or below that we start to get into regions where we have to deal in probabilities or slightly fuzzy concepts. Most notably there don’t seem to be identities at other levels in quite the sharp way there are on the home level. Even molecules are interchangeable: they tell us that it’s almost certain we’re breathing at least one atom from the oxygen previously breathed by Julius Caesar, but how could you possibly tell? You can’t label an atom. Another one of the same kind is distinguishable only by where it is. When we go further down even spatial positions start to get a bit smudged. Equally if we start going up the chain we can only draw slightly fuzzy conclusions about what my family, or the society I live in, thinks or does. This might be a reason to think that real reality is around the home level – or it might a reason to think that the whole business of levels simply flows from my restricted viewpoint and limited understanding.

Perhaps, if my brain were capable of holding it, there is a view on which all the levels could come together. After all, I go on thinking about temperature even though I know it is only molecular motion: perhaps in the end we’ll find a way of thinking about the different aspects of mental activity which brings them together without eliminating anything. Perhaps then it might become clear that Eagleman and Tallis don’t really disagree at all. I wouldn’t put any money on that, though.

Following on from preceding discussion, Doru kindly provided this very interesting link to information about a new chip designed at MIT which is designed to mimic the function of real neurons.

I hadn’t realised how much was going on, but it seems MIT is by no means alone in wanting to create such a chip. In the previous post I mentioned Dharmendra Modha’s somewhat controversial simulations of mammal brains: under his project leadership IBM, with DARPA participation, is now also working on a chip that simulates neuronal interaction. But while MIT and IBM slug it out those pesky Europeans had already produced a neural chip as part of the FACETS project back in 2009. Or had they? FACETS is now closed and its work continues within the BrainScaleS project working closely with Henry Markram’s Blue Brain project at EPFL, in which IBM, unless I’m getting confused by now, is also involved. Stanford, and no doubt others I’ve missed, are involved in the same kind of research.

So it seems that a lot of people think a neuron-simulating chip is a promising line to follow; if I were cynical I would also glean from the publicity that producing one that actually does useful stuff is not as easy as producing a design or a prototype; nevertheless it seems clear that this is an idea with legs.

What are these chips actually meant to do? There is a spectrum here from the pure simulation of what real brains really do to a loose importation of a functional idea which might be useful in computation regardless of biological realism. One obstacle for chip designers is that not all neurons are the same. If you are at the realist end of the spectrum, this is a serious issue but not necessarily an insoluble one. If we had to simulate the specific details of every single neuron in a brain the task would become insanely large: but it is probable that neurons are to some degree standardised. Categorising them is, so far as I know, a task which has not been completed for any complex brain: for Caenorhabditis elegans, the only organism whose connectome is fully known, it turned out that the number of categories was only slightly lower than the number of neurons, once allowance was made for bilateral symmetry; but that probably just reflects the very small number of neurons possessed by Caenorhabditis (about 300) and it is highly likely that in a human brain the ratio  would be much more favourable. We might not have to simulate more than a few hundred different kinds of standard neuron to get a pretty good working approximation of the real thing.

But of course we don’t necessarily care that much about biological realism. Simulating all the different types of neurons might be a task like simulating real feathers, with the minute intricate barbicel latching structures – still unreplicated by human technology so far as I know – which make them such sophisticated air controllers, whereas to achieve flight it turns out we don’t need to consider any structure below the level of wing. It may well be that one kind of simulated neuron will be more than enough for many revolutionary projects, and perhaps even for some form of consciousness.

It’s very interesting to see that the MIT chip is described as working in a non-digital, analog way (Does anyone now remember the era when no-one knew whether digital or analog computers were going to be the wave of the future?). Stanford’s Neurogrid project is also said to use analog methods, while BrainScaleS speaks of non-Von Neumann approaches, which could refer to localised data storage or to parallelism but often just means ‘unconventional’. This all sounds like a tacit concession to those who have argued that the human mind was in some important respects non-computational: Penrose for mathematical insight, Searle for subjective experience, to name but two. My guess is that Penrose would be open-minded about the capacities of a non-computational neuron chip, but that Searle would probably say it was still the wrong kind of stuff to support consciousness.

In one respect the emergence of chips that mimic neurons is highly encouraging: it represents a nearly-complete bridge between neurology at one end and AI at the other. In both fields people have spoken of ‘connectionism’ in slightly different senses, but now there is a real prospect of the two converging. This is remarkable – I can’t think of another case where two different fields have tunnelled towards each other and met so neatly – and in its way seems to be a significant step towards the reunification of the physical and the mental. But let’s wait and see if the chips live up to the promise.

Are connectomes the future?  Although the derivation of the word “connectome” makes no sense – as I understand it the “-ome” bit is copied from “genome”, which in turn was copied from “chromosome”, losing a crucial ‘s’ in the process* – it was coined simultaneously but separately by Olaf Sporns and Patric Hagmann, so it is clearly a word whose time to emerge has come.

It means a functionally coherent set of neural connections, or a map of the same. This may be the entire set of connections in a brain or a nervous system, but it may also be a smaller set which link and work together.  There is quite a lot going on in this respect: the Human Connectome Project is preparing to move into its second, data-gathering phase; there’s also the (more modest or perhaps more realistic) Mouse Connectome Project.  One complete connectome, that for the worm Caenorhabditis elegans, already exists (in fact I think it existed before the word “connectome”) and is often mentioned. The Open Connectome Project has a great deal of information about this and much besides.

The idea of the connectome was given a new twist by Sebastian Seung in his TED talk “I Am My Connectome”, and he has now published a book called (guess what) Connectome. In that he gently and thoughtfully backs away a bit from the unqualified claim that personal identity is situated in the connectome of the whole brain. It’s a useful book which falls into three parts:  a lucid exposition of the neural structure of the brain, some discussion and proposals on connectomic investigation; and some more fanciful speculation, examined seriously but without losing touch with common sense. Seung touches briefly on the spat between Henry Markram and Dharmendra Modha: Markram’s Blue Brain project, you may recall, aims to simulate an entire brain, and he was infuriated by Modha’s claim to have simulated a cat brain on the basis of a far less detailed approach (Markram’s project seeks to model the complex behaviour of real neurons: Modha’s treated them as standard nodes). Seung is quite supportive of these simulations, but I thought his discussion of the very large difficulties involved and the simplifications inherent even in Markram’s scrupulous approach was implicitly devastating.

What should we make of all this connectome stuff? In practical terms the emergence of the term “connectome” adds nothing much to our conceptual armoury: we could and did talk about neural networks anyway. It’s more that it represents a new surge of confidence that neurological approaches can shoulder aside the psychologists, the programmers, and the philosophers and finally get the study of the human mind moving forward on a scientific basis. To a large extent this confidence springs from technical advances which mean it has finally begun to seem reasonable to talk about drawing up a detailed wiring diagram of sets of neurons.

Curiously though, the term also betrays an unexpected lack of confidence. The deliberate choice of a word which resembles one from genetics and recalls the Human Genome Project clearly indicates an envy of that successful field and a desire to emulate it. This is not the way thrusting, successful fields of study behave; the connectonauts seem to be embarking on their explorations without having shed that slightly resentful feeling of being the junior cousin. Perhaps it’s just that like most of us they are slightly frightened of Richard Dawkins. However, it could also be a well-founded sense that they are getting into something which is likely to turn out complicated in ways that no-one could have foreseen.

One potential source of difficulty lies in the fact that looking for connectomes tends to imply a commitment to modularity.  The modularity (or otherwise) of mind has been extensively discussed by philosophers and psychologists, and neurologists have come up with pretty strong evidence that localisation of many functions is a salient feature of the brain: but there is a risk that the modules devised by evolution don’t match the ones we expect to find, and hence are difficult to recognise or interpret; and worse, it’s quite possible that important functions are not modularised at all, but carried out by heterogeneous and variable sets of neurons distributed over a wide area. If so, looking for coherent connectomes might be a bad way of approaching the brain.

In this respect we may be prey to misconceiving the brain through thinking of it as though it were an artefact. Human-designed machines need to have an intelligible structure so that they can be constructed and repaired easily; and for complex systems modularisation is best practice. A complex machine is put together out of replaceable sub-systems that perform discrete tasks; good code is structured to maximise reusability and intelligibility.  But Nature doesn’t have to work like that: evolution might find tangled systems that work fine and actually generate lower overheads.

That might be so, but when we look at animal biology the modularisation is actually pretty striking: the internal organs of a human being, say, are structured in a way that bears a definite resemblance to the components of a machine. Evolution never had to take account of the possibility of replacement parts, but (immune system aside) in fact our internal organisation facilitates transplant surgery much more than it need have done.

Why is that? I’d suggest that there is a secondary principle of evolution at work. When evolution is (so to speak) devising a creature for a new ecological niche, it doesn’t actually start from scratch: it modifies one of the organisms already to hand. Just as a designer finds it easier to build a new machine out of existing parts, a well-modularised creature is more likely to give rise to variant descendants that work in new roles. So besides fitness to survive, we have fitness to give rise to new descendant species; and modularisation enhances that second-order kind of fitness.  Lots of weird creatures that worked well back in the Cambrian did not lend themselves easily to redesign, and hence have no living descendant species, whereas some creature with a backbone, four limbs with five digits each and a tail, proved to be a fertile source of useable variation: leave out some digits, a pair of limbs or the tail; put big legs on the back and small ones on the front, and straightaway you’ve got a viable new modus operandi. In the same way a creature that bolted on an appendix to its gut might be more ready to produce descendants without the appendix function than one which had reconditioned the function of its whole system (I’m getting well out of my depth here). In short, maybe there is an evolutionary tendency to modularisation after all, so it is reasonable to look for connectomes.  As a further argument, we may note that it would seem to make sense in general for neurons that interact a lot to be close together, forming natural connectomes, though given the promiscuous connectivity of the brain some caution about that may be appropriate.

Anyway, what we care about here is consciousness, so the question for us must be: is there a consciousness connectome? In one sense, of course, there must be (and here we stub our toe on another potential danger of the connectome approach): if we just go on listing all the neurons that play a part in consciousness we will at some point have a full set.  But that might end up being the entire brain: what we want to know is whether there is a coherent self-contained module or set of modules supporting consciousness. Things we might be looking out for would surely include a Global Workspace connectome, and I think perhaps a Higher Order Thought Connectome: either might be relatively clearly identifiable on the basis of their pattern of connections.

I don’t think we’re in any position to say yet, but as a speculation I would guess that in fact there is a set of connectomes that have to act together to support a set  of interlocking functions making up consciousness:  sub-conscious thought,  awareness/input, conscious reflection, emotional tone, and so on. I’m not suggesting by any means that that is the actual list; rather I think it is likely that connectome research might cause us to rethink our categories just as research is already causing us to stop thinking that memory (as we had always supposed)  is a single function.

There is already some sign that connectomes might carve up the brain in ways that don’t match our existing ways of thinking about it:  Martijn van den Heuvel and Olaf Sporns have published a paper which seems to show that there are twelve sites of special interest where interconnections are especially dense: they call this a “rich club”, but I think the functional implications of these twelve special zones remain tantalisingly obscure for the moment.

In the end my guess is that by about 2040 we shall look back on the connectome as a paradigm that turned out to be inadequate to the full complexity of the brain, but one which inspired research essential to a much improved understanding.

*I do realise BTW that words are under no obligation to mean what the Latin or Greek they were derived from suggests – “chromosome” would mean “colour body” which is a trifle opaque to say the least.

Homo Artificialis had a post at the beginning of the month about Dmitry Itskov and his three-part project:

• the development of a functional humanoid synthetic body manipulated through an effective brain-machine interface
• the development of such a body, but including a life-support system for a human brain, so that the synthetic body can replace an existing organic one, and
• the mapping of human consciousness such that it, rather than the physical brain, can be housed in the synthetic body

The daunting gradient in this progression is all too obvious. The first step is something that hasn’t been done but looks to be pretty much within the reach of current technology. The second step is something we have a broad idea of how to do – but it goes well beyond current capacity and may therefore turn out to be impossible even in the long run. The third step is one where we don’t even understand the goal properly or know whether the ambitious words “mapping of human consciousness” even denote something intelligible.

The idea of transferring your consciousness, to another person or to a machine, is often raised, but there isn’t always much discussion of the exact nature of the thing to be transferred. Generally, I suppose, the transferists reckon that consciousness arises from a physical substrate and that if we transfer the relevant properties of that substrate the consciousness will necessarily go with it. That may very well be true, but the devil is in that ‘relevant’.  If early inventors had tried to develop a flying machine by building in the relevant properties of birds, they would probably have gone long on feathers and flapping.

At least we could deal with feathers and flapping, but with consciousness it’s hard even to go wrong creatively because two of the leading features of the phenomenon as we now generally see it are simply not understood at all.  Qualia have no physical causality and are undetectable; and there is no generally accepted theory of intentionality, meaningfulness.

But let’s not despair too easily.  Perhaps we shouldn’t get too hooked up on the problems of consciousness here because the thing we’re looking to transfer is not consciousness per se but a consciousness. What we’re really talking about is personal identity. There’s a large philosophical literature about that subject, which was well established centuries before the issues relating to consciousness came into focus, and I think what we’re dealing with is essentially a modern view that personal identity equates to identity of consciousness. Who knows, maybe approaching from this angle will provide us with a new way in?

In any case, I think a popular view in this context might be that consciousness is built out of information, and that’s what we would be transferring. Unfortunately identity of information doesn’t seem to be what we need for personal identity. When we talk about the same information, we have no problem with it being in several places at once, for example: we don’t say that two copies of the same book have the same content but that the identity of the information is different; we say they contain the same information.  Speaking of books points to another problem: we can put any information we like down on paper but it doesn’t seem to me that I could exist in print form (I may be lacking in energy at times, but I’m more dynamic than that).

So perhaps it’s not that the information constitutes the identity; perhaps it simply allows us to reconstruct the identity? I can’t be a text, but perhaps my identity could persist in frozen recorded form in a truly gigantic text?

There’s a science fiction story in there somewhere about slow transfer; once dematerialised, instead of being beamed to his destination, the prophet is recorded in a huge set of books, carried by donkey across the deserts of innumerable planets, painstakingly transcribed in scriptoria, and finally reconstituted by the faithful far away in time for the end of the world. As a side observation, most transfer proposals these days speak of uploading your consciousness to a computer; that implies that whatever the essential properties of you are, they survive digitisation. Without being a Luddite, I think that if my survival depended on there being no difference between a digitised version of me and the messy analogue blob typing these words, I would get pretty damn picky about lossy codecs and the like.

Getting back to the point, then perhaps the required identity is like the identity of a game? We could record the positions half-way through a chess game and reproduce them on any chessboard.  Although in a sense that does allow us to reconstitute the same game in another place or time, there’s an important sense in which it wouldn’t really be the same game unless it was the same players resuming after an interval. In the same way we might be able to record my data and produce any number of identical twins, but I’d be inclined to say none of them would in fact be me unless the same… what?

There’s a clear danger here of circularity if we say that the chess game is the same only if the same people are involved. That works for chess, but it will hardly help us to say that my identity is preserved if the same person is making the decisions before and after. But we might scrape past the difficulty if we say that the key thing is that the same plans and intentions are resumed. It’s the same game if the same strategies and inclinations are resumed, and in a similar way it’s the same person if the same attitudes and intentions are reconstituted.

That sounds alright at first, though it raises further questions, but it takes us back towards the quagmire of intentionality, and moreover it faces the same problem we had earlier with information. It’s even clearer in the case of a game of chess that someone else could have the same plans and intentions without being me; why should someone built to the same design as me, no matter how exquisitely faithful in the minutest detail, be me?

I confess that to me the whole idea of a transfer seems to hark back to old-fashioned dualism.  I think most transferists would consider themselves materialists, but it does look as if what we’re transferring is an ill-defined but important entity distinct from the simple material substance of our brain. But I’m not an abstraction or a set of information, I’m a brute physical entity. It is, I think, a failure to recognise that the world does not consist of theory, and that a theory of redness does not contain any actual red, which gives rise to puzzlement over qualia; and a similar failure leads us to think that I myself, in all my inexplicably specific physical haecceity, can be reduced to an ethereal set of data.

The Nuffield Council on bioethics is running a consultation on the ethics of new brain technologies: specifically they mention neurostimulation and neural stem cell therapy. Neurostimulation includes transcranial magnetic stimulation (TMS) which typically requires nothing more than putting on a special cap or set of electrodes; and  deep brain stimulation (DBS) where the electrodes are surgically inserted into the brain.

All of these are existing technologies which are already in use to varying degrees, and the consultation is prudently geared towards gathering real experience. But of course we can range a bit more freely than that, and it raises an interesting general question: what new crimes can we now commit?

Disappointingly it actually seems that there aren’t many really new neurocrimes; most of the candidates turn out to be variations or extensions of the old ones. Even where there is an element of novelty there’s often a strong analogy which allows us to transpose an existing moral framework to the new conditions (not that that necessarily means that there are easy or uncontroversial answers to the questions, of course).

I think I’ve said before, for example, that TMS seems to hold out the prospect of something analogous to the trade in illicit drugs. An unscrupulous neurologist could surely sell wonderful experiences produced by neural stimulation and might well be able to create a dependency which could be exploited for money and general blackmail. The main difference here is that the crucial lever is control of the technology rather than control of the substance, but that is  a relatively small matter which has some blurry edges anyway.

It’s possible the new technologies might also be able to enhance your brain – if they allow better concentration or recall of information, for example. There is apparently some evidence that TMS might be capable of improving your exam scores. That clearly opens up a question as to whether enhanced performance in an exam, produced by neural stimulation, is cheating; and the wider question of whether easier access to TMS by wealthier citizens would build in a politically unacceptable advantage for those who are already privileged. So far as I know there’s no current drug or regime which automatically and reliably boosts academic performance; nevertheless, the issues are essentially the same as those which arise in the case of various other forms of exam cheating, or over access to superior educational facilities. There may be a new aspect to the problem here in that traditional approaches generally rest on the idea that each person has a genuine inherent level of ability; this may become less clear. If a quick shot of TMS through the skull boosts your performance for the next hour only, we might see things one way; whereas if wearing a set of electrodes helps you study and acquire permanently better understanding, we might be more inclined to think it is legitimate in at least some respects. Moreover a boost which can be represented as therapeutic, correcting a deficit rather than providing an enhancement, is far more likely to be deemed acceptable. All in all, we haven’t got anything much more than new twists on existing questions.

There is likely to be some scope for improperly influencing the behaviour of others through neural techniques, but this has clear parallels in hypnotism, confidence trickery, and other persuasive techniques; again there’s nothing completely novel here. Indeed, it could be argued that many con tricks and feats of conjuring rest on exploiting neurological quirks as it is.

To steal information from someone’s brain is morally not fundamentally different from stealing it out of their diary; and to injure someone by destroying a mental faculty broadly resembles physical injury – the two may indeed go together in many cases.

So what is new? I think if there is fresh scope for evil-doing it is probably to be found in the manipulation of personality and identity. Even here the path is not untrodden, with a substantial history of attempts to modify the personality through drugs or leucotomy; but there is now at least a prospect, albeit still some way off, of far better and more precise tools. As with cosmetic surgery, we might expect the modification of personality to be limited to cases where it has a therapeutic value, together with a range of elective cases over which there might be some argument. The novel thing here is that many cases would require consent; but unlike a nose job, personality modification attacks the basis of consent.

Consider an absurd example in which subject A seeks modification to achieve greater courage and maturity; having achieved both, the improved A now disapproves of the idea of personality modification and insists the changes constitute an injury which must be reversed; once they are reversed, A, with the old personality, wants them done again.

It could be worse; since personality and identity are linked, the new A might take a different line and insist that the changes made in the brain he inhabits were effectively the murder of an older self. This would be as bad a crime as old-fashioned killing, but now it’s no good reversing the changes because that amounts to a further murder, and it could be argued that the restored A is in fact not the original come back, but a third person who merely resembles the original; a kind of belated twin. A’s brother might sue all the new personalities on the basis that none of them has any more rights to the property and body of the original than a squatter in someone’s house.

In circumstances like these there might be a lobby for the view that personality modification should be subject to a blanket ban, in rather the same way that society generally bans us from editing out undesirable personalities with a gun – even our own.

Of course there is in principle another novel crime we might be able to commit: the removal of someone’s qualia, their inward subjective experience. This has often been contemplated in the philosophical literature (it is remarkable how many of the most popular thought-experiments in philosophy of mind – whose devotees generally seem the mildest and most enlightened of people – involve atrocious crimes); perhaps now it can become real. The crime would be undetectable since the ineffable qualities it removes could never be mentioned by the victim; the snag is that since there could be no way of measuring our success it’s probably impossible to devise or test the required diabolical apparatus…

I was brought up short by this bold assertion recently:

 … since last two decades, research towards making machines conscious has gained great momentum

 Surely not? My perception of the state of play is quite different, at any rate; it seems to me that the optimism and energy which was evident in the quest for machine consciousness twenty or perhaps thirty years ago has gradually ebbed. Not that anyone has really changed their minds on the ultimate feasibility of a conscious artefact, but expectations about when it might be achieved have generally been slipped back further into the future. Effort has been redirected towards related but more tractable problems, ones that typically move us on in useful ways but do not attempt to crack the big challenge in a single bite. You could say that the grand project was in a state of decline, though I think it would be kinder and perhaps more accurate to say it has moved into a period of greater maturity.

That optimistic aside was from Starzyk and Prasad, at the start of their paper A Computational Model of Machine Consciousness in the International Journal of Machine Consciousness. It’s not really fair to describe what they’re offering as GOFAI (Good Old-Fashioned Artificial Intelligence) in the original derogatory sense of the term, but I thought their paper had a definite whiff of the heady optimism of those earlier days.

Notwithstanding that optimism their view is that there are still some bits of foundational work to be done…

there is a lack of a physical description of consciousness that could become a foundation for such models.

…and of course they propose to fill the gap.

They start off with a tip of the hat to five axioms proposed by Aleksander and Dunmall back in 2003 which suggest essential functional properties of a conscious system:  embodiment and situatedness, episodic memory, attention, goals and motivation, and emotions. These are said to be necessary but not sufficient conditions for consciousness. If we were in an argumentative mood, I think we could put together a case that some of these are not necessarily essential but we can take it as a useful list for all practical purposes, which is very much where Starzyk and Prasad are coming from.

They give a quick review to some scientific theories (oddly John Searle gets a mention here) and then some philosophical ones. This is avowedly not a comprehensive survey, nor a very lengthy one and the selection is idiosyncratic. Prominent mentions go to Rosenthal’s HOT (Higher Order Theory – roughly the view that a thought is conscious if there is another thought about it) and Baars’ Global Workspace (which must be the most-cited theoretical model by some distance).

In an unexpected and refreshing leap away from the Anglo-Saxon tradition they also cite Nisargadatta, a leading exponent of the Advaita tradition on the distinction between awareness and consciousness. The two words have been recruited to deal with a lot of different distinctions over the years: generally I think ‘awareness’ tends to get used for mere sensory operation or something of that kind which ‘consciousness’ is reserved for something more ruminative. Nisargadatta seems to be on a different tack:

When he uses the term “consciousness”, he seems to equate that term with the knowledge of “I Am”. On the other hand, when he talks about “awareness”, he points to the absolute, something altogether beyond consciousness, which exists non-dualistically irrespective of the presence or absence of consciousness. Thus, according to him, awareness comes first and it exists always. Consciousness can appear and disappear, but awareness always remains.

But then we’re also told:

 A plant may be aware of a damage done to it [!], but it cannot be conscious about it, since it is not intelligent. In a similar way a worm cut in half is aware and may even feel the pain but it is not conscious about its own body being destroyed.

To allow awareness to a plant seems like the last extreme of generosity in this area – right at the final point before we tip over into outright panpsychism- but in general these remarks makes it sound more as if we’re dealing with something like the kind of distinction we’re most used to.

Then we have a section on evolution and the development of consciousness, including a table. While I understand that Starzyk and Prasad are keen to situate their account securely in an evolutionary context, it does seem premature to me to discuss the evolution of consciousness before you’ve defined it. In the case of giraffe’s necks, say, there may not be too much of a difficulty, but consciousness is a slippery concept and there is always a danger that you end up discussing something different from, and simpler than, what you first had in mind.

So on to the definition.

…our aim was not to remove ambiguity from philosophers’ discussion about intelligence or various types of intelligence, but to describe mechanisms and the minimum requirements for the machine to be considered intelligent. In a similar effort, we will try to define machine consciousness in functional terms, such that once a machine satisfies this definition, it is conscious, disregarding the level or form of consciousness it may possess.

 I felt a slight sense of foreboding at this, but here at last is the definition itself.

A machine is conscious if besides the required mechanisms for perception, action, learning and associative memory, it has a central executive that controls all the processes (conscious or subconscious) of the machine…

…[the] central executive, by relating cognitive experience to internal motivations and plans, creates self-awareness and conscious states of mind.

 I’m afraid this too reminds me of the old days when we were routinely presented with accounts that described a possible architecture without ever giving us any explanation of how this particular arrangement of functions gave rise to the magic inner experience of consciousness itself. We ask ourselves: could we put together a machine with a central executive of this kind that wasn’t conscious at all? It’s hard to see why not.

I suppose the central executive idea is why Starzyk and Prasad feel keen on the Global Workspace, though I think it would be wrong to take that as genuinely similar; rather than a central control module, it’s a space where miscellaneous functions can co-operate in an anarchic but productive manner.

Starzyk and Prasad go on to flesh out the  model, which consists of three main functional blocks –  Sensory-motor, Episodic Memory and Learning, and Central Executive; but none of this helped me with the basic question. There’s also an interesting suggestion that attention switching is analogous to the saccades performed by our eyes. These are instant ballistic movements of the eye’s direction towards things of potential interest (like a flash of light in a dark place); I’m not precisely sure how the analogy works but it seems thought-provoking at least.

They also provide a very handy comparison with a number of other models – a useful section, but it sort of undermines the earlier assertion that there is a gap in this area waiting for attention.

Overall, it turns out that the sense of older times we got at the beginning of the paper is sort of borne out by the conclusion. Many technically inclined people have always been impatient with the philosophical whiffling and keen to get on with building the machine instead, confident that the theoretical insights would bloom from a soil fertilised with practical achievements. But by now we can surely say we’ve tried that, and it didn’t work. Researchers forging ahead without a clear philosophy ran into the frame problem, or simple under-performance, or the inability of their machines to deal with intentionality and meaning. They either abandoned the attempt, adopted more modest goals, or got sidetracked into vast enabling projects such as the compilation of a total encyclopedia to embody background knowledge or the neuronal modelling of an entire brain. In a few cases brute force approaches actually ended up yielding some practical results, but never touched the core issue of consciousness.

I don’t quite know whether it’s sort of depressing that effort is still being devoted to essentially doomed avenues, or sort of heartening that optimism never quite dies.

We have become accustomed over the years to exaggerated claims about brain research.  I think my favourite will always be the unexpected claim from British Telecom in 1996 that they were to develop a chip, by 2025, which would fit behind the human eye.  I suspect the original idea was to record all retinal activity and hence have, in a sense, a record of the person’s whole visual experience – an extremely ambitious but not inherently impossible goal; but somewhere along the way they convinced themselves they would be able to record, not just optical input, but people’s thoughts, too.  Realising there was no point in under-selling this amazing future achievement, they announced they were going to call it the ‘Soul Catcher’. Dr Chris Winter was prepared to go still further and went on record as saying that this was actually “the end of death”.  I wonder how the project is getting along now?

 Not many researchers can match the scope of Dr Winter’s imagination or the sheer insolence of his chutzpah, but we have often seen claims to have decoded the mind which are essentially based on identifying simple correspondences between scan results and an item of mental activity. The subject is shown a picture of, say, John Malkovich and scan results obtained: then from scan results the researchers succeed in telling with statistically significant rates of success the occasions when the subject is looking at the same picture of John Malkovich and not one of John Cusack. Voila! The secret language of the brain is cracked!  It is not shown that similar scan patterns can be obtained from other subjects looking at the picture of John Malkovich, or from the same subject looking at other pictures of John Malkovich, or thinking about John Malkovich, or even from the same subject looking at the same picture the next day. No general encoding of mental activity is revealed, no general encoding of visual activity, in fact we don’t even get for sure a general encoding of that particular picture of John Malkovich in that particular subject on that particular day. The only truth securely revealed is that if you have an experience and then soon afterwards another one just like it, you probably use quite a few of the same neurons in responding to it.

So it was with a certain sinking feeling that I heard the BBC announce that researchers had decoded the language of the brain. The radio report was quite definite about it; they could now reconstruct with their receiving equipment words that subjects were merely thinking: they played back the sound of a suitably robotic-sounding word apparently picked up from someone’s inner thoughts. They suggested this could be brought into use in identifying and communicating with ‘locked-in’ patients, those who though immobilised remain mentally alert. Similar reports appear elsewhere in the press today.

The paper behind all this is here: as often happens, the paper is far more circumspect than the publicity. It makes generally modest and well-supported claims; only in one place does it venture a little speculation, and doesn’t pretend then that it’s anything else.

What actually happened is that the experimenters took advantage of an unusual therapeutic situation which allowed them to record directly from electrodes on the brain – a technique which yields far better resolution than any form of scanning. They read their subjects a list of words and noted patterns of activity; they were then able to produce a programme which automatically reconstructed the characteristics of the sound being heard, sufficiently well for the right word from the list to be identified with a high level of success.

This is not without interest – it sheds some light on the brain’s processing of heard information. It shows that quite a lot of information about the actual sound survives at least some distance into the processing – a result we can perhaps compare with visual processing. The kind of worries I alluded to above about generalisability are not absent here, but we do seem, if I’ve understood correctly, to have got results that should be transferrable and reproducible between subjects.

But reading thoughts?  Let’s not worry about that for a moment and ask ourselves whether a much improved version of this technology could tell us what someone was saying as well as what someone was hearing. It seems to me that that would be a whole new game.  When the brain interprets sounds as words it necessarily concerns itself with the properties of sound, because that’s what it has to deal with; when it delivers an utterance it has no direct interest in the matter, only in tongue, palate, breathing and so on (that may be over-simplifying a touch, admittedly – it would be surprising, for example if feedback didn’t play a significant role). It’s not likely that the neural patterns for recognising a spoken word are the same as those for speaking it, any more than the neural activity required for reading a word is generally the same as writing it, except inasmuch as both probably involve thinking about the word. For once Heraclitus is wrong: the path up is not the same as the path down.

So what about thinking? Is it like hearing, or like speaking? Well, I doubt very much whether thinking of John Malkovich, or even thinking of the words ‘John Malkovich’ necessarily resembles decoding a sound or preparing to manipulate the lips – unless we are deliberately going through the act of mentally entertaining the idea of hearing or speaking. In the latter case it might plausibly be the case that there are at least some mirror neurons involved in both activities which would bridge the gap between thought and act sufficiently to produce some recognisable activity.

So, if these results can be generalised to a system capable of recognising words in general, and if it’s one that demonstrably works for different subjects, and if a way can be found of running it without taking the top of the skull off, and if it turns out that thinking about the sound of a word is sufficiently connected to actually hearing it to stimulate neural patterns which are sufficiently similar that the system can still pick them up  in an identifiable form, and if we’re talking about someone who is deliberately thinking about the sound of a word, then yes there is some hope here that in that sense we might be able in practice to identify the word being thought.

I suppose that must be worth half a cheer.

Eric Schwitzgebel has done a TEDx talk setting out his doctrine of crazyism. The audio is not top quality, but if you prefer there is a full exposition and a”a short, folksy version” available here.

The claim, briefly is that any successful theory of consciousness – in fact, any metaphysical theory – will have to include some core elements that are clearly crazy. “Crazy” is taken to describe any thesis which conflicts with common sense, and which we have no strong epistemic reason for accepting.

Schwitzgebel defends this thesis mainly by surveying the range of options available in philosophy of mind and pointing out that all of them – even those which set out to be pragmatic or commonsensical – imply propositions which are demonstrably crazy. I think he’s right about this; I’ve observed myself in the past that for any given theory of consciousness the strongest arguments are always the ones against: unnervingly this somehow remains true even when one theory is essentially just the negation of another theory. Schwitzgebel suggests we should never think that our own preferred view is, on balance, more likely than the combination of the alternatives – we should always give less than 50% credence to our preferred view or, if you like, never quite believe anything.

I won’t recapitulate Schwitzgebel’s case here, but it did provoke me to wonder about the issue of what we would find acceptable as an answer to the problem of consciousness. It’s certainly true that some theories would not, as it were, be crazy enough to appeal. Suppose the Blue Brain project triumphed, and delivered a brain simulated down to neuronal level. We could run the simulation and predict the brain’s behaviour; for anything the simulated person said or thought, we could give a complete neuronal specification, and in that sense a complete explanation. But it wouldn’t seem that that really answered any of the deeper questions.

Equally, for all those theories that tell us there’s really nothing to explain, our consciousness and our selfhood are just delusions generated by aspects of the mental mechanism, one problem is that the answer seems too easy (though in another sense these views are surely crazy enough). We don’t want to be told to move along, nothing to see here, folks; what we want is an “Aha!” moment, a theory that makes things suddenly fall into places where they make dramatic new sense. How do we get such moments?

I think they come from a translation or bridge that lets us see how one understood realm transfers across into another realm which is also understood but not connected. Maybe we find out that Hesperus is Phosphorus and that both are in fact the planet Venus; then the strange behaviour of the evening star and the morning star suddenly make more sense. Another related way of generating the Aha! is to discover that we have been conceptualising things wrongly: that two things we thought were separate are really aspects of the same thing, or that a thing we took to be a single phenomenon is actually two different things we have conflated together: temperature and heat, for example.

It certainly looks as if consciousness is right for an Aha! of those kinds – we have the two separate realms, the mental and the physical, all ready to go.  But Colin McGinn has argues that the very distinctness of the realms means that no explanation can ever be forthcoming, and many people since Brentano have shared the sense that no bridging or reshuffling of concepts is even conceivable. The thing is, we don’t get the kind of paradigm shift we need by labouring away within the existing framework: we need something to jolt us out of it and there’s no telling what. We know now that in order to come up with the theory that speciation occurs through differential survival of the fittest, you needed to visit the tropics and collect a lot of examples of local fauna, read Malthus and then fall ill. Darwin and Wallace both had their dogmatic slumbers shaken up in this way; but it was not evident in advance that that was what it took. Perhaps even now a young doctor who has treated schizophrenics, has had the required motorbike accident and is just about to read the text on encryption which is an essential precursors to the Theory.

I sort of hope and believe that something like that is the case and that when the Theory is available we shall see that one of those theses that look crazy now are not quite what we thought: so crazyism will turn out to be false, or at any rate only provisional. But Schwitzgebel’s essential pessimism could turn out to be justified. We could end up with a theory like quantum mechanics, which seems to do the job so far as anyone can see, but which just refuses to click with our brains positively enough for the Aha! moment.

Schwitzgebel doesn’t spend much time on the wider claim that metaphysics as a whole is crazy, but it’s an interesting possibility that the problem doesn’t really lie with philosophy of mind but something altogether deeper. Maybe we need to look away from the mind as such and spend some time on… what? Causality? Basic ontology? Once again, I have no idea.

If you haven’t already seen it, it’s well worth watching this charmingly animated talk by Iain McGilchrist on the two hemispheres of the brain. At a brisk pace he explains how people in the past went overboard with a false and over- simplified version of what the two hemispheres do and provides a fascinating corrective. You may feel that towards the end he goes a teensy bit overboard himself in a new direction.

Also from TED is this talk in which Antonio Damasio goes in pursuit of the self – in his view an essential component of consciousness – and unexpectedly tracks it down to the brain stem.

Finally, Sergey Bulanov has kindly drawn my attention to his new website devoted to his work on developing a non-computational artificial intelligence. Sergey was originally inspired by a book of logic problems: he invented a network system for solving them and in a second phase is seeking to generalise his approach.

Thanks to Sergey and to Jesús Olmo and Ivan Savov respectively for the other links.

Researchers from the Max Planck Institute and St Andrew’s University have come up with some fresh evidence that chimps have a theory of mind (ToM) – that is to say that they are aware that other individuals possess knowledge and that what they know doesn’t always match what we know.

The researchers placed dummy snakes in the path of wild chimps: the chimps gave warning calls more frequently in the presence of others who, so far as they could tell, had no prior knowledge of the presumed hazard.

This kind of research is fraught with difficulty. Morgan’s Canon tells us that we should only use consciousness as an explanation for some item of behaviour where no simpler explanation is available, and similarly we should be reluctant to grant chimps ToM unless there is no alternative.  Couldn’t the explanation be, for example, that chimps who are alone are more likely to give warning calls, either because that response is just hard-wired, or because they are more fearful when alone? Alternatively, perhaps the observed behaviour could be largely explained if chimps are programmed to give a warning call, but only one, for each member of the troupe they spot or hear approaching?

Although I think Morgan’s Canon is absolutely the right kind of principle to apply, it is difficult to satisfy, and if read too literally perhaps impossible. We know from all the discussions of philosophical zombies that there are plenty of thoughtful people who find it conceivable that all of human behaviour could be produced without consciousness (at any rate, without the kind of consciousness that requires actual phenomenal subjective experience). If that’s really true then there are surely no cases in which behaviour can strictly be explained only by consciousness. It’s equally hard, going on impossible, to rule out every conceivable alternative explanation for the chimps’ behaviour – but the researchers were well aware of the problem and the key point of the research is the observation of circumstances where, for example, chimp A could be presumed to have heard an earlier warning, but chimp B could not. So we can take the claims they make as well grounded. It seems that with some inevitable margin of doubt we can reasonably take it as established that chimps do have ToM.

So what? We might have been willing to assume that that was probably the case anyway. We already know chimps are extremely bright and there are many who believe they can develop language skills which approach human levels. Language is what makes it so much easier to know for sure that human beings have ToM – they can tell us about it – so if chimps are anywhere near that level it’s really no surprise that they also have ToM. (Interesting, by the way that the current research uses the chimps’ proto-linguistic warning calls.) One further conclusion offered by the researchers themselves is that ToM must have emerged in the primate lineage at a point before the divergence of chimp and human ancestors: but that ain’t necessarily so. It could equally be that each lineage has developed a functionally comparable capacity in parallel, one which the latest shared ancestor need never have had.

Do we and our pongid cousins have the same ToM? In some respects obviously not. For one thing, we humans really do have actual academic theories of mind; and we write novels filled with the putative contents of minds that never existed. We have ToM on levels which completely transcend the mental lives of chimps. Are these, though, just fancy overlays on an underlying ability which remains essentially the same?  Alas, there’s no easy way of telling without knowing what’s going on in the chimp’s mind – what it is like to be a chimp – and Nagel long ago told us that that was impossible.

Attempting to know the unknowable is nothing new for us, though, so let’s at least briefly try to achieve the impossible. There are lots of possibilities for what might be passing through the chimp’s mind: by way of illustration it could be any of the following.

1. A cloudy sense of something indefinable but importantly snake-related which is missing in Chimp B.
2. A mental picture of Chimp B continuing to advance and stumbling on the snake.
3. A brief empathetic sense of being Chimp B, and a recollection that seeing the snake or hearing a warning has not occurred.
4. Routine enumeration of the troupe and its whereabouts leading to a realisation that Chimp B hasn’t been around for a while.
5. Occurence of proto-verbal content equivalent to uttering the sentence “Look there’s B, who doesn’t know about the snake yet!”

There are plenty of other possibilities: cataloguing them would in itself be a challenging task. Moreover, humans are clearly capable of operating on two or more of these levels at once, and it would be mere speciesism to assume that chimps are not. Still, can we pare it down a bit: given that chimps lack full-blown human linguistic abilities and are relatively limited in their foresight, can we plausibly hypothesise that cases like 5 and other involving relatively complex levels of abstraction are probably absent from the chimp experience? I’m not sure, and even if we can it doesn’t help all that much.

So instead I ask myself what state obtained in my own mind last time I warned someone about a potential hazard. Luckily I do remember a couple of occasions, but interestingly introspection leaves me quite uncertain about the answer. This could be a result of hazy memory, but I think it’s worse than that: I think the main problem is that so far as conscious thought goes I could have been thinking anything.  It feels as if there is no distinct single state of mind which corresponds to noticing that somebody needs to be warned about something; curiously I feel tempted to examine my own behaviour and conclude that if I did go on to warn someone, I must have been thinking that they needed warning.

That kind of approach is another option, I suppose: we can take a behaviourist tack and say that if chimps behave in a way that displays ToM, then they have it, and that’s all there is to be said about it. If we can’t formulate clearly what kind of behaviour that would be, that just means ToM itself turns out to be mentalistic nonsense.  The snag with that is that ToM is pretty certainly mentalistic nonsense to behaviourists anyway; so if we think the question is worth answering we have to look elsewhere.

We could get neuronal on this: we might, for example, be able to scan human and chimp brains and detect some distinctive patterns of activity which occur just when the relevant primate appears to be getting ready to issue a warning. If these patterns of activity occurred in the corresponding sections of the chimp and human brain (perhaps involving some of those special mirror neurons) we should be inclined to conclude that our ToMs were basically the same: if they occurred in different places we should be very tempted to conclude that evolution had recruited different sections of the two species’ brains to carry out the same function. This latter case is quite plausible – in human brains, for example, the areas used for speech don’t match the bits of the chimp brain used for vocalisations (which apparently correspond to areas used by humans only for involuntary gasps and cries and, strangely enough, for swearing).

Results like that might settle the evolutionary question; but not the deeper philosophical one. Even if we did use a different set of neurons, it wouldn’t prove we weren’t running the same ToM. Different human beings certainly use somewhat different arrays of neurons – no two brains are wired identically. If we came across the yeti and found he was fully up to human levels of consciousness, able to hold an impeccably normal human-style conversation with us and discuss ToM just as we do, and then we made the astonishing discovery that he had no prefrontal cortex and was using what in humans would have been his cerebellum to do his conscious thinking with, we would not on that account alone say he had a different kind of consciousness (at least, I don’t think we would).

So it looks to me as if we have a radical pattern of variation at both ends. All sorts of neuronal wiring (or maybe silicon or beer cans and string – why not?) will do at the bottom level; all sorts of cogitative content will do at the top levels. Somewhere in the middle is there a level of description where deciding that someone needs to be warned is just that and nothing else, and where we can meaningfully compare and contrast human and chimp?  I suspect there is, but I also suspect that it resides in something analogous to a high-level mental metacode of a kind we should need a proper theory of mind even to begin imagining.