Are we really conscious?

grazianoYes: I feel pretty sure that anyone reading this is indeed conscious. However, the NYT recently ran a short piece from Michael S. A. Graziano which apparently questioned it. A fuller account of his thinking is in this paper from 2011; the same ideas were developed at greater length in his book Consciousness and the Social Brain

I think the startling headline on the NYT piece misrepresents Graziano somewhat. The core of his theory is that awareness is in some sense a delusion, the reality of which is simple attention. We have ways of recognising the attention of other organisms, and what it is fixed on (the practical value of that skill in environments where human beings may be either hunters or hunted is obvious): awareness is just our garbled version of attention. he offers the analogy of colour. The reality out there is different wavelengths of light: colour, our version of that, is a slightly messed-up, neatened, artificial version which is nevertheless very vivid to us in spite of being artificial to a remarkably large extent.

I don’t think Graziano is even denying that awareness exists, in some sense: as a phenomenon of some kind it surely does: what he means is more that it isn’t veridical: what it tells us about itself, and what it tells us about attention, isn’t really true. As he acknowledges in the paper, there are labelling issues here, and I believe it would be possible to agree with the substance of what he says while recasting it in terms that look superficially much more conventional.

Another labelling issue may lurk around the concept of attention. On some accounts, it actually presupposes consciousness: to direct one’s attention towards something is precisely to bring it to the centre of your consciousness. That clearly isn’t what Graziano means: he has in mind a much more basic meaning. Attention for him is something simple like having your sensory organs locked on to a particular target. This needs to be clear and unambiguous, because otherwise we can immediately see potential problems over having to concede that cameras or other simple machines are capable of attention; but I’m happy to concede that we could probably put together some kind of criterion, perhaps neurological, that would fit the bill well enough and give Graziano the unproblematic materialist conception of attention that he needs.

All that looks reasonably OK as applied to other people, but Graziano wants the same system to supply our own mistaken impression of awareness. Just as we track the attention of others with the false surrogate of awareness, we pick up our own attentive states and make the same kind of mistake. This seems odd: when I sense my own awareness of something, it doesn’t feel like a deduction I’ve made from objective evidence about my own behaviour: I just sense it.  I think Graziano actually wants it to be like that for other people too. He isn’t talking about rational, Sherlock Holmes style reasoning about the awareness of other people, he has in mind something like a deep, old, lizard-brain kind of thing; like the sense of somebody there that makes the hairs rise on the back of the neck  and your eyes quickly saccade towards the presumed person.

That is quite a useful insight, because what Graziano is concerned to deny is the reality of subjective experience, of qualia, in a word. To do so he needs to be able to explain why awareness seems so special when the reality is nothing more than information processing. I think this remains a weak spot in the theory, but the idea that it comes from a very basic system whose whole function is to generate a feeling of ‘something there’ helps quite a bit, and is at least moderately compatible with my own intuitions and introspections.What Graziano really relies on is the suggestion that awareness is a second-order matter: it’s a cognitive state about other cognitive states, something we attribute to ourselves and not, as it seems to be, directly about the real world. It just happens to be a somewhat mistaken cognitive state.

That still leaves us in some difficulty over the difference between me and other people. If my sense of my own awareness is generated in exactly the same way as my sense of the awareness of others, it ought to seem equally distant  – but it doesn’t, it seems markedly more present and far less deniable.

More fundamentally, I still don’t really see why my attention should be misperceived. In the case of colours, the misrepresentation of reality comes from two sources, I think. One is the inadequacy of our eyes; our brain has to make do with very limited data on colour (and on distance and other factors) and so has to do things like hypothesising yellow light where it should be recognising both red and green, for example. Second, the brain wants to make it simple for us and so tries desperately to ensure that the same objects always look the same colour, although the wavelengths being received actually vary according to conditions. I find it hard to see what comparable difficulties affect our perception of attention. Why doesn’t it just seem like attention? Graziano’s view of it as a second-order matter explains how it can be wrong about attention, but not really why.

So I think the theory is less radical than it seems, and doesn’t quite nail the matter on some important points: but it does make certain kinds of sense and at the very least helps keep us roused from our dogmatic slumbers. Here’s a wild thought inspired (but certainly not endorsed) by Graziano. Suppose our sense of qualia really does come from a kind of primitive attention-detecting module. It detects our own attention and supplies that qualic feel, but since it also (in fact primarily) detects other people’s attention, should it not also provide a bit of a qualic feel for other people too? Normally when we think of our beliefs about other people, we remain in the explicit, higher realms of cognition: but what if we stay at a sort of visceral level, what if we stick with that hair-on-the back-of the-neck sensation? Could it be that now and then we get a whiff of other people’s qualia? Surely too heterodox an idea to contemplate…

Zoned-out rat consciousness

Zoned-out ratThe New Scientist suggests that zoned-out rats may give us a clue to consciousness.

It’s all to do with the Default Mode Network, or DMN. You might think that when we stop concentrating on a particular task and sit back for a few quiet minutes the level of activity in our brains would fall, but it turns out this isn’t really so: instead, more or less the same level of activity appears to continue, but it switches to a different set of areas – in particular, a linked set of areas in the cortex and elsewhere. This is the DMN, but what is it doing?

A completely honest answer, I think, would be that we don’t exactly know except that it’s something other than concentrating on a task.  In human subjects the DMN seems to be associated with daydreaming, but also with other detached modes of thought.  Why would this help explain consciousness? It seems that in patients with locked-in syndrome, where consciousness is fully retained but the patient is unable to move, the DMN is functioning normally, whereas in persistent vegetative syndrome, where consciousness is absent, it is disrupted.

I can think of a further reason to think that this might shed light on consciousness. It’s not much of a stretch to see DMN activity as being the kind of thinking that isn’t directly related to inputs and outputs. When we’re working on a task those are crucial, but one plausible account of the role of consciousness is exactly that it lets us escape from giving instant responses to our surroundings and lets us develop longer-term plans, deeper understanding, and more complex behaviour. If the DMN represents useful mental activity detached from inputs and outputs it is exactly the thing whose existence the behaviourists denied, which is pretty much the same as one conception of consciousness.

The New Scientist and others speak of the DMN as associated with introspection, but I can’t see the evidence for that. To be daydreaming or thinking in general terms about stuff that is or might be going on is not introspection. I think there’s some confusion going on here between thinking internally and thinking about what’s going on internally: and perhaps a further suggestion that introspection= self-awareness = consciousness: those are tenable but debatable equations which don’t seem to be vindicated or disproved by the mere existence of the DMN. So perhaps the excitement is premature.

The rats are not that reassuring either. The New Scientist reports that analogues of the human DMN have been found in monkeys, and now even in rats. That’s interesting, but unless we rate the consciousness of rats unusually highly it seems to show that the DMN  cannot explain any uniquely human level of consciousness. Fair enough: I don’t disdain rat consciousness altogether: but it’s worse than that because, as I understand it, the evidence currently suggests that younger human children don’t have an identifiable DMN. It would be somewhat weird to attribute to rats a level of reflective consciousness which is absent in human infants – wouldn’t it?  If more were needed to put us off, it is not quite 100% agreed that the DMN is in fact a functional entity in itself; it could yet turn out to be more like the mere absence of the TPN, the Task Positive Network which is its opposite (or complement) – the similar set of areas which appear to work together when we’re engaged in a specific task. Perhaps the level of neuronal activity in the brain stays high, not because the DMN is really processing anything, but because the brain just uses a lot of energy to tick over?

Still, if the DMN doesn’t explain what consciousness is, it’s hard to resist the view that it’s telling us something about how it works. Problems with the DMN have been put forward as possible causes of Alzheimer’s, autism, and schizophrenia (I think everything has been put forward as a possible cause of schizophrenia). The range of problems is perhaps an indication of the vagueness of the theories. There is some good evidence of a correlation between Alzheimer’s and disrupted DMN: but then the DMN includes quite a siginficant sampling of some important areas of the brain, so that may not mean all that much. It could be that when consciousness is disrupted the DMN tends naturally to get disrupted too, without that implying that the DMN actually runs or constitutes even the less-focused forms of consciousness.

At the end of the day what we’re left with is that our brains – and even rat brains – don’t use the same circuits for task-related and non-task related activity, but go through a fairly large-scale switch of resources.  Even if we’re idly daydreaming about driving into town already, it seems we bring in a different set of neurons to do it with. There has to be some good reason for this, but what…?