Figure-Ground Reversal

‘Consciousness is irreducible,’ proclaimed John Searle in a recent TED talk. This was just after telling us that we need to learn to think of it as a wholly biological process.

So, let me get this straight – it’s an irreducible biological process. I like John Searle’s manner – the irritable, baggy-trousered old philosopher thing works well for him. He is best known for his Chinese room thought experiment: an argument against the possibility of true artificial intelligence (AI). He used an elaborate metaphor involving Chinese characters written on bits of paper being passed into a locked room where they are interpreted, using a set of logical rules, by a person who does not speak the language. The set of rules also enables the person in the room to respond in kind.

The argument, as you can see, is to do with ‘actual’ understanding. Searle was claiming that there would be no understanding of the language going on within the locked room; ergo, there would be no understanding going on inside even the most sophisticated AI subjected to the Turing test. I’ll admit that I’m a little biased against Searle’s argument, having seen it systematically disassembled by Daniel Dennett, in his book Consciousness Explained, but I don’t think it would be unfair to say that some of Searle’s claims about the nature of consciousness seem to be somewhat lacking in levels.

We know that the phenomenon of consciousness arises from the biological substrate of the brain. It’s a dualistic waste of time to argue otherwise. Searle is clearly frustrated by the endless philosophical debates over its real or illusory nature, and I’m with him on that, but not because I think we must unequivocally brand it as real; I’m frustrated by that debate because I think both words are wrong.

We often forget that there is a vast range of phenomena in the Universe for which we have no semantic classifications: What do you call that feeling of rocks changing shape by the process of erosion? What do you call that sense of thirsty tree root seeking water? You may argue that these examples have nothing to do with human consciousness. Nevertheless, there are all kinds of micro-processes going on inside you that you don’t ‘experience’ directly but which have some kind of teleonomic ‘direction’ to them.

Terrence Deacon’s Incomplete Nature has most recently influenced my thoughts on this. The book is hard going sometimes, but I’m excited by his formalisation of the idea of a kind of ‘figure-ground reversal’ – what may be important about phenomena like consciousness is not what is present but what is absent. It is a theory of constraints: a whirlpool is a phenomenon produced by the constraining of water molecules to follow a range of downward-spiralling trajectories; perhaps consciousness is an inevitable result of constraint of molecules into a very specific biological configuration. What is absent, in both these cases, is the near-infinite range of trajectories and configurations that those molecules might otherwise have followed or taken on.

Deacon’s ‘essential absences’ – ‘absentials’ – resonate with me. I think it is partly because they demonstrate just how inadequate our semantic modes in the consciousness debate have been. It’s also because I like the idea of being an absential rend in the fabric of the not-me Universe. For many, though, talk of essential absence induces a kind of existential trypophobia – an irrational fear of holes – rendering them confused, frightened, or even disgusted by the notion.

So what about the Chinese room? Well, you just fill it with a vast number of people who don’t understand the symbols, give them the correct rules, and set them to work. If it is correctly set up, the room will produce the correct answer. But, surely, the understanding is still missing. Exactly. There are many things missing from this setup – understanding is an essential one of them. It is a kind of phenomenon that is being generated despite its absence as a specific phenomenon. That is why it looks irreducible.

Strange? Yes, very. But cogito ergo sum! I suppose it’s a good enough shorthand for this: something is producing a phenomenon that other somethings producing this phenomenon and the something producing the phenomenon call ‘thinking’. Constraint steers that clumsy definition towards an essentially useful I.

As I am an inveterate reductionist, you might think I should be more concerned about the biological mechanisms that make this possible. Certainly, the mechanisms fascinate me. However, that does not mean that I expect to be able to tap my finger on a screen and say, ‘Look, that’s consciousness right there.’ I may be able to say, ‘Those are the structures from which the state of consciousness emerges’, but that’s not quite the same. Phenomenal states emerge, and they have many different characteristics. Try pinpointing the vorticity in a whirlpool.

Before I am dragged under, I’d better round this off. If this were a letter, I think it would be pleasing to sign it off with a warmly heartfelt...

...absentially, consciously yours,

Blue brain

The Blue Brain project is exciting. The idea of building a cortical simulation up from the molecular level is a massive challenge but, I think, an essential one if we are ever to fully understand the complex thinking machine that is the human brain.

The initial goals of the project were, in comparison to the current aims, fairly modest. In 2005 the goal was to simulate a rat cortical column (or hypercolumn). With that now achieved the scientists involved are heading in the direction of simulation of an entire human neocortex.

There are concerns that this project cannot tell us much new. It may come up with a working simulation that we can observe functioning and making neuronal connections but of which we have no understanding of what it is actually doing. Sounds a lot like a biological neocortex to me.

The current state of the art at the neuronal level of neuroscience is that we can begin to see such hitherto intangible processes as memories being formed. This appears to me to be roughly equivalent to watching our simulated brain making its virtual connections and forming its virtual memories. Of course the simulation allows us to gather comprehensive and accurate data about these events; something we can't do with a biological brain. When it comes to observing exactly what the world looks like to the entity (biological or virtual) as a result of those neuronal events we are still, largely, in the dark.

What I hope the Blue Brain project will do, and what some of its detractors may fear, is to put an end to any notion of duality. Consciousness will be proved, once and for all, to be an emergent property of the structure, connectional diversity and sheer quantity of neurons (supported by glia) forming the human neocortex. But there is no guarantee that the Blue Brain will ever reach human-level neuronal complexity. A huge investment would be required in this research, currently admirably supported by the Swiss government, to bring that possibility to fruition.

This is pure science and the investment is worth it. Understanding the construction and plasticity of our own brains will give us the tools we need to better shape ourselves and to recognise the negative neurobiological effects of bad interactions with other people and environments. Perhaps our future depends on that understanding.