Archive for April, 2007

Colourblind Synaesthesia. A team of researchers (Milán, Hochel, González, Tornay, McKenney, Díaz Caviedes, Mata Martín, Rodríguez Artacho, Domínguez García and Vila) have a paper in the JCS setting out their experiments with an unusually interesting subject. This person, referred to as ‘R’, is colour blind for certain colours: but he also experiences a spectrum of synaesthetic colours in which he can make the full range of clear distinctions. The team believes its research shows that qualia can be accesible and useful to science.

Synaesthesia, the occurence of sensations (often sensations of colour) in association with unrelated stimuli, is an interesting but treacherous subject. Many people feel that the days of the week, or the numbers from one to ten, seem to have their own appropriate colours, and sceptics may feel that the whole phenomenon of synaesthesia is largely a case of people allowing their poetic feelings to run away with them. But there is a good deal of evidence to show that vivid synaesthesia is a real phenomenon. One of the earliest and most striking of reported cases is the classic one recounted by Luria in The Mind of a Mnemonist. His subject (referred to as ‘S’) formed exceptionally strong associations, which had the beneift of giving him a ‘photographic’ memory, but was also a considerable handicap as unwanted associations intruded into his life, making it impossible, for example, to buy an ice cream when something in the vendor’s voice called up a vivid impression of red hot coals.

R’s synaesthesia is not on this troublesome scale: he experiences colour sensations in connection with pictures and people, but he experiences the colour as internal, rather than seeing it ‘out there’ as some synaesthetes do. For him, there is a kind of code, with each synaesthetic colour having certain emotional connotations: in the case of people, for example, red means attractive, green means ill or dirty, purple means upbeat, yellow means envious or aggressive, and brown means old or uninteresting (the reader may be able to guess at R’s own approximate age). A portion of the team’s research was devoted to exploring these emotional connotations, and they claim, unconvincingly I think, that their results show the possibility of an inverted spectrum of emotions (I think they merely show that R’s emotional reactions are in some respects atypical: the sky for him evokes red, which makes it exciting, whereas it is more commonly seen as restful: but that doesn’t amount to an inverted emotional spectrum).

The exploration of synaesthesia in colour blind subjects is not new – Ramachandran and Hubbard have produced many interesting findings, including a subject who referred to colours he could experience synaesthetically, but never with his eyes, as ‘Martian’ colours. This naturally raises the question of whether the Martian colours were ones which people with normal vision are used to, or something genuinely stranger. How would we know?

The exploration of qualia recounted in the JCS piece rests on an ingenious use of the Stroop effect. This effect occurs where, for example, the subject is shown a series of colour words, and asked to say, not what colour they name, but what the colour of the font is. If you’ve tried this, you’ll know that it is more difficult to do quickly and accurately than you might suppose: much harder, in any case, than when font and word indicate the same colour. Now if you were completely colour blind, you would of course be immune to Stroop interference. The team devised experiments which showed that R did indeed fail to show Stroop effects in certain cases where other subjects suffered them, very plausibly because of his limited colour vision. However, when he was shown pictures which evoked dissonant synaesthetic colours, Stroop interference did occur.

This seems to show that R’s inner colour experience – his qualia? – cover the normal range, distinct from the range of colours he can actually distinguish with his eyes. Moreover, in a separate series of experiments, the team got him to match his synaesthetic colours with real ones, confirming that in his case at least they were not Martian in character. Does all this show that qualia are ‘a useful scientific concept’?

Interestingly, the paper quotes (and slightly misdescribes) one of the ‘intuition pumps’ used by Daniel Dennett. Two coffee tasters (Chase and Sanborn) have ceased to enjoy Maxwell House, but seemingly for different reasons. To one, it tastes the same as ever, but he no longer likes that taste: the other still likes that taste, but the coffee, although it has not changed chemically or in any other objective respect, no longer tastes that way to him. Dennett’s case is that this distinction, between the qualia and the taster’s reaction, is not ultimately sustainable. One of the taster’s wives ultimately straightens him out on the point: so he’s still having the same taste experience, but now doesn’t like it? But doesn’t the fact that he doesn’t like it mean, in itself, that the experience is different? There’s just no point in talking about qualia as distinct from our reactive dispositions.

What would Dennett say about R? I think he would say the research is an interesting exploration of those reactive dispositions, but that nothing here requires us to talk of qualia at all. R’s brain reacts to certain stimuli in ways which other people’s brains react to certain inputs from their eyes, though R himself lacks those inputs. But just because synaesthetic colour doesn’t come from the eyes, we mustn’t conclude that it has the inner, subjective quality of qualia. Indeed, by ingeniously naturalising synaesthetic colour, and showing it to be accessible to science, the team has arguably shown that it can’t be identified with qualia.

The team concludes that their research shows the coffee taster thought experiment actually makes no sense: the quale and the reaction ‘seem to be rigidly connected and cannot change independently’. Dennett might not be unhappy with that conclusion: why not take one more step, he might say, and draw the conclusion that talk of qualia is really only talk of reactions…?

Picture of Robert Lanza. Robert Lanza, well-known in the area of cloning and stem cells, has fired off a broadside in another direction. Never mind the physicists, he says, with their long-awaited Theories of Everything and their bizarre multi-dimensional intangible substrates: in fact the fundamental science is biology. Space and time are not even real except inasmuch as we perceive them; and perception is a product of consciousness, a biological mystery the physicists can never hope to penetrate.

It’s easy to sympathise with Lanza’s irritation over the triumphalism indulged in by some physicists – while physics itself seems in some ways to be getting ever more deeply into difficulty. In terms of clear progress and perhaps even methodological purity, biology seems to have a far better story to tell in recent years. But can biology really be more fundamental than physics?

Lanza’s key theme is that reality depends on perception; perception on consciousness; and consciousness on biology. With the first step, we’re back with Bishop Berkeley, whose controversial view that ‘to be is to be perceived’ Lanza almost seems to take for granted. A substantial, centuries-long debate has already taken place over this, which I cannot hope to do justice to here; but to take just one contrary argument: if all reality depends on perception, there’s an unsolved problem about how things get started at all. There I am, for the sake of argument, hanging in the metaphysical void. Nothing exists until I perceive it; but how do I start perceiving something which doesn’t exist? Even my own thoughts must be there before I can become aware of them; yet they can’t exist until I have perceived them. So I can’t even think? Lanza acknowledges that some have seen his philosophy as leading inevitably to solipsism: but it seems it might lead to utter nullity. Lanza says that the illusions suffered by schizophrenic patients are as real to them as the ordinary world is to us: but the possibility of error is not sufficient to demonstrate the impossibility of truth (though Lanza is not the first person to have given up too easily on objective reality). In places Lanza actually seems rather equivocal about his Berkeleyanism: he offers the analogy of a CD player: until it works on the relevant tracks, the music doesn’t exist: and in the same way, there’s no reality until our minds have operated on… what? It ought to be the underlying realities of physics, but they are what Lanza seems to want to deny.

Though no doubt it is true that consciousness is biological, that cannot altogether be taken for granted either. Among others Lanza cites Descartes, Kant, and Leibniz as well as Berkeley in support of the primacy of consciousness: but none of them would have accepted that it was a matter of biology. When Hume daringly had one of his characters declare that the processes of consciousness in the brain were not fundamentally different from the processes of decay in a cauliflower, he took care to distance himself from a view he knew would be regarded as an insult to the human spirit, far beyond the pale of civilised discourse. Moreover, Lanza’s own views, curiously enough, place a barrier between him and the biology he wishes to celebrate. Our knowledge of biology, after all, comes to us in much the same kind of way as our knowledge of physics; through our senses – our perceptions. If time and space, and other concepts of physics, are really illusions, then surely so are cells and organisms and brains. Lanza says experience is something generated ‘inside your head’, but what head? The only knowledge we have of heads comes to us through, guess what, experience. The truth here seems to be that biology simply cannot take the role Lanza wants to assign to it, and in seeking to ‘get below’ physics, he ends up resorting to metaphysics, the only subject (with the possible exception of maths) which really does operate at an even more fundamental level.

Lanza puts forward a couple of other arguments to support his case. He appeals (curiously enough) to physics itself in the shape of quantum theory, which he suggests has eliminated the idea of a reality independent of perception. Like Berkeleyanism, the correct interpretation of quantum physics is a large subject, but my impression is that it would be at the radical end of the spectrum to suppose that it did away with the idea of an objective, independent reality altogether.

He also mentions the argument that many features of the universe seem to have been set up with great precision to allow the eventual possibility of life. If gravity or the strong nuclear force were slightly different from what they are, the world would never have been a habitable place. I’m not exactly certain about how Lanza means this to fit withhis overall view, but it seems he must be suggesting that the world actually began, in some non-chronological sense, with human perception, which then extrapolated backwards the necessary conditions for its arising in a presumed physical world. If so, I’d like more explanation about how that would work and why it would necessarily give rise to these exquisitely precise physical constants: but the underlying anthropic argument seems weak to me.

First of all, the reasoning smacks of Warty Bliggens, the toad:

he explained that when the cosmos
was created
that toadstool was especially
planned for his personal
shelter from sun and rain
thought out and prepared
for him

It’s not surprising that the set-up of the Universe favours the existence of human beings because if it didn’t, we shouldn’t be here to worry about it (but perhaps something else would).

It may be, in fact I suspect it must be, that there are, as yet unknown to us, deep metaphysical reasons why the cosmos is the way it is and could not have been otherwise: in which case there’s no real scope for surprise about the way it turned out. But if the basic laws and constants are in some way arbitrary, as Lanza’s argument supposes, we can’t really claim to know what the range of possible universes, or the range of possible conscious entities, really is. It may be that tinkering slightly with a few of the current constants produces a world in which human beings cannot occur; but why stop there? If we vary the basic rules more fundamentally, it might well be that there are countless possible universes utterly unlike ours, containing innumerable multitudes of unimaginable thinking beings. In that case, it is again unsurprising that we should chance to occur in a possible world which happens to suit us.

So although it’s interesting to entertain the idea, I don’t think biology, for all its merits, can be enthroned as the most fundamental of sciences.

Thanks to Karen for telling me about Lanza’s theory and providing the link.

I am very grateful to Riccardo Manzotti, who has provided a commentary on my piece about his Radical Externalist theory of onphenes.