Archive for December, 2013

chiantiIt has always seemed remarkable to me that the ingestion of a single substance can have such complex effects on behaviour. Alcohol does it, in part, by promoting the effects of inhibitory neurotransmitters and suppressing the effects of excitatory ones, while also whacking up a nice surge of dopamine – or so I understand. This messes up co-ordination and can lead to loss of memory and indeed consciousness; but the most interesting effect, and the one for which alcohol is sometimes valued, is that it causes disinhibition. This allows us to relax and have a good time but may also encourage risky behaviour and lead to us saying things – in vino veritas – we wouldn’t normally let out.

Curiously, though, there’s no solid scientific support for the idea that alcohol causes disinhibition, and good evidence that alcohol is blamed for disinhibition it did not cause. One of the slippery things about the demon drink is that its effects are strongly conditioned by the drinkers expectations. It has been shown that people who merely thought they were consuming alcohol were disinhibited just as if they had been; while other studies have shown that risky sexual behaviour can actually be deterred in those who have had a few drinks, if the circumstances are right.

One piece of research suggests that meta-consciousness is impaired by alcohol; drink makes us less aware of our own mental state. But a popular and well-supported theory these days is that drinking causes ‘alcohol myopia’. On this theory, when we’re drunk we lose track of long-term and remote factors, while our immediate surroundings seem more salient. One useful aspect of the theory is that it explains the variability of the effects of alcohol. It may make remoter worries recede and so leave us feeling unjustifiably happy with ourselves; but if reminders of our problems are close while the long term looks more hopeful, the effect may be depressing. Apparently subjects who had the words ‘AIDS KILLS’ actually written on their arm were less likely to indulge in risky sex (I suspect it might kind of dent your chances of getting a casual partner, actually).

A merry and appropriately disinhibited Christmas to you!

(Bonus – some more recent papers on alcohol, providing more detail)

salienceI was interested to see reports here and there the other day that scientists had discovered the seat of the will in the anterior midcingulate cortex.

That’s not precisely the case, of course; there’s an article here which describes the research. The scientists in question had an unusual opportunity to use electrodes in the brains of two patients; although they did indeed operate in the anterior midcingulate cortex they believe they were stimulating the brain’s salience network, which is quite widely distributed. The effect was apparently to create feelings of needing to persist against challenging circumstances; the researchers themselves call it “the will to persevere”. The patients were fully conscious and able to describe their feelings, but alas no tests were carried out to see whether they were in fact more persistent when stimulated.

The correct interpretation of the results seems difficult to me. As I understand it, the theory of the salience network holds that brain activity is controlled by neural networks which stretch across several regions of the brain. The default mode network, or DMN, is the one that operates when we’re not focused on anything in particular, perhaps daydreaming. It has been suggested that loss of this function is what distinguishes people who have “locked-in” syndrome from those who are in a “persistent vegetative state” – if you lose your DMN you’re not really there any more, in other words.

When we concentrate on a task, another network takes over – the central executive network, or CEN. The role of the salience network, if I’ve got this right, is primarily to act as arbitrator between the two. It spots something that deserves attention – something salient, indeed – and switches control from DMN to CEN. That’s fine, but it doesn’t seem to have much to do with persistence; it’s actually about changing the object of attention, not sticking with it. But perhaps strong or continuing stimulation of the salience network has that kind of effect. The salience network says “you need to look at this”, so perhaps when it operates emphatically we think “yes, I’m going to look the hell out of that alright; I’m going to look at that intensively; when I’ve finished looking at that, by golly it’s going to stay looked at”.

More plausibly it might all be to do with physiological effects; besides directing attention the salience network has a role in gearing up our “fight or flight” state, and it might just be that in that state we feel ready for a challenge ( in which case a readiness to persist comes into it, but surely isn’t the whole point); that would be a William James style emotion, originally a matter of the gut more than the mind.

Anyway, this really has nothing to do with an organ of the will. That is an interesting notion, though, isn’t it? My own assumption is that the will emerges from the operation of general cognition and that there couldn’t be a separate will module. If such a module determined the actions to be willed, it would surely have to encompass almost the whole of cognition, and so be far more than just a module; if it merely willed the actions selected for it by the rest of the brain it wouldn’t amount to much at all.

People do, of course, often hypothesise that there might be a special function for assigning value, or flagging up those things we ought to pursue as desirable. To me, though, that seems a bit different; the will, properly understood, is not a matter of basic motivation, but a faculty which might over-ride that motivation, either by operating at a meta level or simply by acting as a restraining and countervailing force.

Would that even be a distinct faculty of its own? Some would probably question whether talking about the will is a useful approach at all, rather than a relic from outmoded ideas about the soul controlling the body through acts of will. I must admit I find it hard to think of any subject that can’t be adequately discussed without mentioning  the will. Even free will doesn’t really lose anything if we talk about free action.  So is the will even worth persisting with? I can feel my DMN kicking in…

SocratesWhy is it that we can’t solve the mind/body problem? Well, if we define that problem as being about the capacity of mental events to cause physical events, there is a project in progress at Durham University that says it’s about the lack of good philosophy, or more specifically, that our problem stems from inadequate ontology (ontology being the branch of metaphysics that deals with what there is).  The project has been running for a few years, and now a substantial volume of corrective metaphysics has been published, with a thoughtful and full review here.  (Hat-tip to Micha for drawing this to my attention).

 The book is not a manifesto, because the authors do not share a single view: it’s more like an exhibition. What’s on offer here is a variety of philosophical views of mental causation, all more sophisticated than the ones we typically encounter in discussions of  artificial intelligence. The review gives a good sense of what’s on offer, and depending on your inclinations you may see it as a collection of esoteric and unhelpful complications, or as a magic sweetshop whose every jar holds the way to a new world of possibility and enlightenment. I think the average view will see it as a bookshop with many volumes of dull sermons and outdated almanacs which might nevertheless just be holding somewhere in the dusty back room that one book that makes sense of everything.

Is it likely that better philosophy will deliver the answer? There is  a horrid vision in my mind in which the neurologists and/or the AI people produce a model which seems to work; we’re able to build machines which talk to us in the same way as human beings, and we can explain exactly how the brain does its stuff and how it is analogous to these machines: but the philosophers go on doubting whether this machine consciousness is real consciousness. No-one else cares.

Moreover, there are some identifiable weaknesses in philosophy which are clearly on display in the current volume. First is the fissiparous nature of philosophical discussion. I said this was an exhibition rather than a manifesto; but wouldn’t a manifesto have been better? It’s not achievable because every philosopher has his or her own view and the longer discussion goes on the more possible views there are. In one way it’s a pleasing, exploratory quality, but if you want a solution it’s a grave handicap. Second, and related, there’s no objective test beyond logical consistency. Experiments will never prove any of these views wrong.

Third, although philosophy is too difficult, it’s also too easy. Someone somewhere once said that Aristotle’s problem was that he was too clever. For him, it was always possible to come up with a theory which justified the outlook of a complacent middle-aged Ancient Greek: theories which have turned out, so far as we can test them, to be almost invariably false or incomplete. Less clever pre-Socratic philosophers like Heraclitus or Parmenides were forced to adopt weirder points of view which in the long run might actually tell us more.

The current volume, I think, might contain many cases of clever people making cases that broadly  justify common sense while the real truth may be out there in the wild regions beyond. E.J.Lowe, one of the editors of the book and champions of the project, has a view about the powers of the will. He characterises powers as active or passive on the one hand and causal or non-causal. This leaves open the possibility of a power which is both active and non-causal. He wants the human will to have these properties, so that it is  spontaneous and not causally inefficacious without the agent per se thereby bringing about any sort of effect (if I’ve got that right). The spontaneity is supposed to resemble the spontaneity of the decay of a specific radium atom, and hence be consistent with physics, while the causal  efficacy is of a kind that does  not require an interruption of normal physics while still being an important corollary of our status as rational beings.

This is clever stuff, no doubt, but it looks like an attempt – you may consider it a doomed attempt – to explain away the problems with our common sense views rather than correcting them. We’re being offered loopholes which may – debatably – let us carry on thinking what we’ve always thought, rather than offering us a new perspective. It leaves me feeling the way I might feel after a clever lawyer has explained why his client should not be convicted; yeah, but did he do it? There’s no ‘aha!’ moment on offer. In her review Sara Bernstein suggests that sceptics may be inclined to turn back to reductionism, and I must confess that is indeed my inclination.

Still, I can’t shake my hope that somewhere in that dusty old bookshop the truth is to be found, and so I can’t help wishing the project well.