Tag Archives: Phi

Doorknobs and Intuition

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doorknob‘…stupid as a doorknob…’ Just part of Luboš Motl’s vigorous attack on Scott Aaronson’s critique of IIT, the Integrated Information Theory of Giulio Tononi.

To begin at the beginning. IIT says that consciousness arises from integrated information, and proposes a mathematical approach to quantifying the level of integrated information in a system, a quantity it names Phi (actually there are several variant ways to define Phi that differ in various details, which is perhaps unfortunate). Aaronson and Motl both describe this idea as a worthy effort but both have various reservations about it – though Aaronson thinks the problems are fatal while Motl thinks IIT offers a promising direction for further work.

Both pieces contain a lot of interesting side discussion, including Aaronson’s speculation that approximating phi for a real brain might be an NP-hard problem. This is the digression that prompted the doorknob comment: so what if it were NP-hard, demands Motl; you think nature is barred from containing NP-hard problems?

The real crux as I understand it is Aaronson’s argument that we can give examples of systems with high scores for Phi that we know intuitively could not be conscious. Eric Schwitzgebel has given a somewhat similar argument but cast in more approachable terms; Aaronson uses a Vandermonde matrix for his example of a high-phi but intuitively non-conscious entity, whereas Schwitzgebel uses the United States.

Motl takes exception to Aaronson’s use of intuition here. How does he know that his matrix lacks consciousness? If Aaronson’s intuition is the test, what’s the point of having a theory? The whole point of a theory is to improve on and correct our intuitive judgements, isn’t it? If we’re going to fall back on our intuitions argument is pointless.

I think appeals to intuition are rare in physics, where it is probably natural to regard them as illegitimate, but they’re not that unusual in philosophy, especially in ethics. You could argue that G.E. Moore’s approach was essentially to give up on ethical theory and rely on intuition instead. Often intuition limits what we regard as acceptable theorising, but our theories can also ‘tutor’ and change our intuitions. My impression is that real world beliefs about death, for example, have changed substantially in recent decades under the influence of utilitarian reasoning; we’re now much less likely to think that death is simply forbidden and more likely to accept calculations about the value of lives. We still, however, rule out as unintuitive (‘just obviously wrong’) such utilitarian conclusions as the propriety of sometimes punishing the innocent.

There’s an interesting question as to whether there actually is, in itself, such a thing as intuition. Myself I’d suggest the word covers any appealing pre-rational thought; we use it in several ways. One is indeed to test our conclusions where no other means is available; it’s interesting that Motl actually remarks that the absence of a reliable objective test of consciousness is one of IIT’s problems; he obviously does not accept that intuition could be a fall-back, so he is presumably left with the gap (which must surely affect all theories of consciousness). Philosophers also use an appeal to intuition to help cut to the chase, by implicitly invoking shared axioms and assumptions; and often enough ‘thought experiments’ which are not really experiments at all but in the Dennettian phrase ‘intuition pumps’ are used for persuasive effect; they’re not proofs but they may help to get people to agree.

Now as a matter of fact I think in Aaronson’s case we can actually supply a partial argument to replace pure intuition. In this discussion we are mainly talking about subjective consciousness, the ‘something it is like’ to experience things. But I think many people would argue that that Hard Problem consciousness requires the Easy Problem kind to be in place first as a basis. Subjective experience, we might argue, requires the less mysterious apparatus of normal sensory or cognitive experience; and Aaronson (or Schwitzgebel) could argue that their example structures definitely don’t have the sort of structure needed for that, a conclusion we can reach through functional argument without the need for intuition,

Not everybody would agree, though; some, especially those who lean towards panpsychism and related theories of ‘consciousness everywhere’ might see nothing wrong with the idea of subjective consciousness without the ‘mechanical’ kind. The standard philosophical zombie has Easy Problem consciousness without qualia; these people would accept an inverted zombie who has qualia with no brain function. It seems a bit odd to me to pair such a view with IIT (if you don’t think functional properties are required I’d have thought you would think that integrating information was also dispensable) but there’s nothing strictly illogical about it. Perhaps the dispute over intuition really masks a different disagreement, over the plausibility of such inverted zombies, obviously impossible in  Aaronson’s eyes, but potentially viable in Motl’s?

Motl goes on to offer what I think is a rather good objection to IIT as it stands; ie that it seems to award consciousness to ‘frozen’ or static structures if they have a high enough Phi score. He thinks it’s necessary to reformulate the idea to capture the point that consciousness is a process. I agree – but how does Motl know consciousness requires a process? Could it be that it’s just…  intuitively obvious?

Oh, Phi!

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Giulio Tononi’s Phi is an extraordinary book.  It’s heavy, and I mean that literally: presumably because of the high quality glossy paper, it is noticeably weighty in the hand; not one I’d want to hold up before my eyes for long without support, though perhaps my wrists have been weakened by habitual Kindle use.

That glossy paper is there for the vast number of sumptuous pictures with which the book is crammed; mainly great works of art, but also scientific scans and diagrams (towards the end a Pollock-style painting and a Golgi-Cox image of real neurons are amusingly juxtaposed: you really can barely tell which is which). What is going on with all this stuff?

My theory is that the book reflects a taste conditioned by internet use. The culture of the World Wide Web is quotational and referential: it favours links to good stuff and instant impact. In putting together a blog authors tend to gather striking bits and pieces rather the way a bower bird picks up brightly coloured objects to enhance its display ground, without worrying too much about coherence or context. (If we were pessimistic we might take this as a sign that our culture, like classical Greek culture before it, is moving away from the era of original thought into an age of encyclopedists; myself I’m not that gloomy –  I think that however frothy the Internet may get in places it’s all extra and mostly beneficial.) Anyway, that’s a bit what this book is like; a site decorated with tons of ‘good stuff’ trawled up from all over, and in that slightly uncomplimentary sense it’s very modern.

You may have guessed that I’m not sure I like this magpie approach.  The pictures are forced into a new context unrelated to what the original artist had in mind, one in which they jostle for space, and many are edited or changed, sometimes rather crudely (I know: I should talk, when it comes to crude editing of borrowed images – but there we are). The choice of image skews towards serious art (no cartoons here) and towards the erotic, scary, or grotesque. Poor Maddalena Svenuta gets tipped on her back, perhaps to emphasise the sexual overtones of the painting – although they are unignorable enough in the original orientation. This may seem to suggest a certain lack of respect for sources and certainly produces a rather indigestible result; but perhaps we ought to cut Tononi a bit of slack. The overflowing cornucopia of images seems to reflect his honest excitement and enthusiasm: he may, who knows, be pioneering a new form which we need time to get used to; and like an over-stuffed blog, the overwhelming gallimaufry is likely here and there to introduce any reader to new things worth knowing about. Besides the images the text itself is crammed with disguised quotes and allusions.  Prepare to be shocked: there is no index.

I’m late to the party here. Gary Williams has made some sharp-eyed observations on the implicit panpsychism of Tononi’s views;  Scott Bakker rather liked the book and the way some parts of Tononi’s theory chimed with his own Blind Brain theory (more on that another time, btw). Scott, however, raised a ‘quibble’ about sexism: I think he must have in mind this hair-raising sentence in the notes to Chapter 29:

At the end, Emily Dickinson saves the day with one of those pronouncements that show how poets (or women) have deeper intuition of what is real than scientists (or men) ever might: internal difference, where all the meanings are.

Ouch, indeed: but I don’t think this is meant to be Tononi speaking.

The book is arranged to resemble Dante’s Divine Comedy in a loose way: Galileo is presented as the main character, being led through dreamlike but enlightening encounters in three main Parts, which in this case present in turn, more or less, the facts about brain and mind – the evidence, the theory of Phi, and the implications. Galileo has a different guide in each Part: first someone who is more or less Francis Crick, then someone who is more or less Alan Turing, and finally for reasons I couldn’t really fathom, someone who is more or less Charles Darwin (a bit of an English selection, as the notes point out); typically each chapter involves an encounter with some notable personality in the midst of an illuminating experience or experiment; quite often, as Tononi frankly explains, one that probably did not feature in their real lives. Each chapter ends with notes that set out the source of images and quotations and give warnings about any alterations: the notes also criticise the chapter, its presentation, and the attitudes of the personalities involved, often accusing them of arrogance and taking a very negative view of the presumed author’s choices. I presume the note writer is, as it were, a sock puppet, and I suppose this provides an entertaining way for Tononi to voice the reservations he feels about the main text, backing up the dialogues within that text with a kind of one-sided meta-textual critique.

Dialogue is a long-established format for philosophy and has certain definite advantages: in particular it allows an author to set out different cases with full vigour without a lot of circumlocution and potential confusion. I think on the whole it works here, though I must admit some reservation about having Galileo put into the role of the naive explorer. I sort of revere Galileo as a man whose powers of observation and analysis were truly extraordinary, and personally I wouldn’t dare put words into his mouth, let alone thoughts into his head: I’d have preferred someone else: perhaps a fictional Lemuel Gulliver figure. It makes it worse that while other characters have their names lightly disguised (which I take to be in part a graceful acknowledgement that they are really figments of Tononi) Galileo is plain Galileo.

Why has Tononi produced such an unusual book? Isn’t there a danger that this will actually cause his Integrated Information Theory to be taken less seriously in some quarters? I think to Tononi the theory is both exciting and illuminating, with the widest of implications, and that’s what he wants to share with us. At times I’m afraid that enthusiasm and the torrent of one damn thing after another became wearing for me and made the book harder to read: but in general it cannot help but be engaging.

The theory, moreover, has a lot of good qualities. We’ve discussed it before: in essence Tononi suggests that consciousness arises where sufficient information is integrated. Even a small amount may yield a spark of awareness, but the more we integrate, the greater the level of consciousness. Integrated potential is as important as integrated activity: the fact that darkness is not blue and not loud and not sweet-tasting makes it, for us, a far more complex thing that it could ever be to an entity that lacked the capacity for those perceptions.  It’s this role of absent or subliminal qualities that make qualia seem so ineffable.

This makes more sense than some theories I’ve read but for me it’s still somewhat problematic. I’m unclear about the status of the ‘information’ we’re integrating and I don’t really understand what the integration amounts to, either. Tononi starts out with information in the unobjectionable sense defined by Shannon, but he seems to want it to do things that Shannon was clear it couldn’t. He talks about information having meaning when seen from the inside, but what’s this inside and how did it get there? He says that when a lot of information is aggregated it generates new information – hard to resist the idea that in the guise of ‘new information’ he is smuggling in a meaningfulness that Shannonian information simply doesn’t have.  The suggestion that inactive bits of the system may be making important contributions just seems to make it worse. It’s one thing for some neural activity to be subliminal or outside the zone of consciousness: it’s quite different for neurons that don’t fire to be contributing to experience. What’s the functional difference between neurons that don’t fire and those that don’t exist? Is it about the possibility that the existing ones could have fired? I don’t even want to think about the problems that raises.

I don’t like the idea of qualia space, another of Tononi’s concepts, either. As Dennett nearly said, what qualia space? To have an orderly space of this kind you must be able to reduce the phenomenon in question to a set of numerical variables which can be plotted along axes. Nobody can do this with qualia; nobody knows if it is even possible in principle. When Wundt and his successors set out to map the basic units of subjective experience, they failed to reach agreement, as Tononi mentions. As an aspiration qualia space might be reasonable, but you cannot just assume it’s OK, and doing so raises a fear that Tononi has unconsciously slipped from thinking about real qualia to thinking about sense-data or some other tractable proxy. People do that a lot, I’m afraid.

One implication of the theory which I don’t much like is the sliding scale of consciousness it provides. If the level of consciousness relates to the quantity of information integrated, then it is infinitely variable, from the extremely dim awareness of a photodiode up through flatworms to birds, humans and – why not – to hypothetical beings whose consciousness far exceeds our own. Without denying that consciousness can be clear or dim, I prefer to think that in certain important respects there are plateaux: that for moral purposes, in particular, enough is enough. A certain level of consciousness is necessary for the awareness of pain, but being twice as bright doesn’t make my feelings twice as great. I need a certain level of consciousness to be responsible for my own actions, but having a more massive brain doesn’t thereafter make me more responsible. Not, of course, that Tononi is saying that, exactly: but if super-brained aliens land one day and tell us that their massive information capacity means their interests take precedence over ours, I hope Tononi isn’t World President.

All that said, I ought to concede that in broad terms I think it’s quite likely Tononi is right: it probably is the integration of information that gives rise to consciousness. We just need more clarity about how – and about what that actually means.

The Consciousness Meter

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Picture: meter. It has been reported in various places recently that Giulio Tononi is developing a consciousness meter.  I think this all stems from a New York Times article by the excellent Carl Zimmer where, to be tediously accurate, Tononi said “The theory has to be developed a bit more before I worry about what’s the best consciousness meter you could develop.”   Wired discussed the ethical implications of such a meter, suggesting it could be problematic for those who espouse euthanasia but reject abortion.

I think a casual reader could be forgiven for dismissing this talk of a consciousness meter. Over the last few years there have been regular reports of scientific mind-reading: usually what it amounts to is that the subject has been asked to think of x while undergoing a scan; then having recorded the characteristic pattern of activity the researchers have been able to spot from scans with passable accuracy the cases where the subject is thinking of x rather than y or z.  In all cases the ability to spot thoughts about x are confined to a single individual on a single occasion, with no suggestion that the researchers could identify thoughts of x in anyone else, or even in the same individual a day later. This is still a notable achievement; it resembles (can’t remember who originally said this) working out what’s going on in town by observing the pattern of lights from an orbiting spaceship; but it falls a long way short of mind-reading.

But in Tononi’s case we’re dealing with something far more sophisticated.  We discussed a few months ago Tononi’s Integrated Information Theory (IIT), which holds that consciousness is a graduated phenomenon which corresponds to Phi: the quantity of information integrated. If true, the theory would provide a reasonable basis for assessing levels of consciousness, and might indeed conceivably lead to something that could be called a consciousness meter; although it seems likely that measuring the level of integration of information would provide a good rule-of-thumb measure of consciousness even if in fact that wasn’t what constituted consciousness. There are some reasons to be doubtful about Tononi’s theory: wouldn’t contemplating a very complex object lead to a lot of integration of information? Would that mean you were more conscious? Is someone gazing at the ceiling of the Sistine Chapel necessarily more conscious than someone in a whitewashed cell?

Tononi has in fact gone much further than this: in a paper with David Balduzzi he suggested the notion of qualia space. The idea here is that unique patterns of neuronal activation define unique subjective experiences.  There is some sophisticated maths going on here to define qualia space, far beyond my clear comprehension; yet I feel confident that it’s all misguided.  In the first place, qualia are not patterns of neuronal activation; the word was defined precisely to identify those aspects of experience which are over and above simple physics;  the defining text of Mary the colour scientist is meant to tell us that whatever qualia are, they are not information. You may want to reject that view; you may want to say that in the end qualia are just aspects of neuron firing; but you can’t have that conclusion as an assumption. To take it as such is like writing an alchemical text which begins: “OK, so this lead is gold; now here are some really neat ways to shape it up into ingots”.

And alas, that’s not all. The idea of qualia space, if I’ve understood it correctly, rests on the idea that subjective experience can be reduced to combinations of activation along a number of different axes.  We know that colour can be reduced to the combination of three independent values (though experienced colour is of course a large can of worms which I will not open here) ; maybe experience as a whole just needs more scales of value.  Well, probably not.  Many people have tried to reduce the scope of human thought to an orderly categorisation: encyclopediae;  Dewey’s decimal index; and the international customs tariff to name but three; and it never works without capacious ‘other’ categories.  I mean, read Borges, dude:

I have registered the arbitrarities of Wilkins, of the unknown (or false) Chinese encyclopaedia writer and of the Bibliographic Institute of Brussels; it is clear that there is no classification of the Universe not being arbitrary and full of conjectures. The reason for this is very simple: we do not know what thing the universe is. “The world – David Hume writes – is perhaps the rudimentary sketch of a childish god, who left it half done, ashamed by his deficient work; it is created by a subordinate god, at whom the superior gods laugh; it is the confused production of a decrepit and retiring divinity, who has already died” (‘Dialogues Concerning Natural Religion’, V. 1779). We are allowed to go further; we can suspect that there is no universe in the organic, unifying sense of this ambitious term. If there is a universe, its aim is not conjectured yet; we have not yet conjectured the words, the definitions, the etymologies, the synonyms, from the secret dictionary of God.

The metaphor of ‘x-space’ is only useful where you can guarantee that the interesting features of x are exhausted and exemplified by linear relationships; and that’s not the case with experience.  Think of a large digital TV screen: we can easily define a space of all possible pictures by simply mapping out all possible values of each pixel. Does that exhaust television? Does it even tell us anything useful about the relationship of one picture to another? Does the set of frames from Coronation Street describe an intelligible trajectory through screen space? I may be missing the point, but it seems to me it’s not that simple.