In some respects this post is a continuation of the last one. The following week’s issue of New Scientist (3 April 2010) had a cover story on ‘Frontiers of the Mind’ covering what it called Nine Big Brain Questions. One of these addressed the question of free will, which happened to be where my last post ended. In the commentary on question 8: How Powerful is the Subconscious? New Scientist refers to well-known studies demonstrating that neuron activity precedes conscious decision-making by 50 milliseconds. In fact, John-Dylan Haynes of the Bernstein Centre for Computational Neuroscience, Berlin, has ‘found brain activity up to 10 seconds before a conscious decision to move [a finger].’ To quote Haynes: “The conscious mind is not free. What we think of as ‘free will’ is actually found in the subconscious.”New Scientist actually reported Haynes' work in this field back in their 19 April 2008 issue. Curiously, in the same issue, they carried an interview with Jill Bolte Taylor, who was recovering from a stroke, and claimed that she "was consciously choosing and rebuilding my brain to be what I wanted it to be". I wrote to New Scientist at the time, and the letter can still be found on the Net: You report John-Dylan Haynes finding it possible to detect a decision to press a button up to 7 seconds before subjects are aware of deciding to do so (19 April, p 14). Haynes then concludes: "I think it says there is no free will." In the same issue Michael Reilly interviews Jill Bolte Taylor, who says she "was consciously choosing and rebuilding my brain to be what I wanted it to be" while recovering from a stroke affecting her cerebral cortex (p 42) . Taylor obviously believes she was executing free will. If free will is an illusion, Taylor's experience suggests that the brain can subconsciously rewire itself while giving us the illusion that it was our decision to make it do so. There comes a point where the illusion makes less sense than the reality.To add more confusion, during the last week, I heard an interview with Norman Doidge MD, Research psychiatrist at the Columbia University Psychoanalytic Centre and the University of Toronto, who wrote the book, The Brain That Changes Itself. I haven’t read the book, but the interview was all about brain plasticity, and Doidge specifically asserts that we can physically change our brains, just through thought. What Haynes' experimentation demonstrates is that consciousness is dependent on brain neuronal activity, and that’s exactly the point I made in my last post. Our subconscious becomes conscious when it goes ‘global’, so one would expect a time-lapse between a ‘local’ brain activity (that is subconscious) and the more global brain activity (that is conscious). But the weird part is that Taylor’s experience, and Doidge’s assertions, is that our conscious thoughts can also affect our brain at the neuron level. This reminds me of Douglas Hofstadter’s thesis that we all are a ‘strange loop’, that he introduced in his book, Godel, Escher, Bach, and then elaborated on in a book called I am a Strange Loop. I’ve read the former tome but not the latter one (refer my post on AI & Consciousness, Feb.2009). We will learn more and more about consciousness, I’m sure, but I’m not at all sure that we will ever truly understand it. As John Searle points out in his book, Mind, at the end of the day, it is an experience, and a totally subjective experience at that. In regard to studying it and analysing it, we can only ever treat it as an objective phenomenon. The Dalai Lama makes the same point in his book, The Universe in a Single Atom.People tend to think about this from a purely reductionist viewpoint: once we understand the correlation between neuron activity and conscious experience, the mystery stops being a mystery. But I disagree: I expect the more we understand, the bigger the mystery will become. If consciousness is no less weird than quantum mechanics, I’ll be very surprised. And we are already seeing quite a lot of weirdness, when consciousness is clearly dependent on neuronal activity, and yet the brain’s plasticity can be affected by conscious thought. So where does this leave free will? Well, I don’t think that we are automatons, and I admit I would find it very depressing if that was the case. The last of the Nine Questions in last week’s New Scientist, asks: will AI ever become sentient? In its response, New Scientist reports on some of the latest developments in AI, where they talk about ‘subconscious’ and ‘conscious’ layers of activity (read software). Raul Arrables of the Carlos III University of Madrid, has developed ‘software agents’ called IDA (Intelligent Distribution Agent) and is currently working on LIDA (Learning IDA). By ‘subconcious’ and ‘conscious’ levels, the scientists are really talking about tiers of ‘decision-making’, or a hierarchic learning structure, which is an idea I’ve explored in my own fiction. At the top level, the AI has goals, which are effectively criteria of success or failure. At the lower level it explores various avenues until something is ‘found’ that can be passed onto the higher level. In effect, the higher level chooses the best option from the lower level. The scientists working on this 2 level arrangement, have even given their AI ‘emotions’, which are built-in biases that direct them in certain directions. I also explored this in my fiction, with the notion of artificial attachment to a human subject that would simulate loyalty. But, even in my fiction, I tend to agree with Searle, that these are all simulations, which might conceivably convince a human that an AI entity really thinks like us. But I don’t believe the brain is a computer, so I think it will only ever be an analogy or a very good simulation. Both this development in AI and the conscious/subconscious loop we seem to have in our own brains reminds me of the ‘Bayesian’ model of the brain developed by Karl Friston and also reported in New Scientist (31 May 2008). They mention it again in an unrelated article in last week’s issue – one of the little unremarkable reports they do – this time on how the brain predicts the future. Friston effectively argues that the brain, and therefore the mind, makes predictions and then modifies the predictions based on feedback. It’s effectively how the scientific method works as well, but we do it all the time in everyday encounters, without even thinking about it. But Friston argues that it works at the neuron level as well as the cognitive level. Neuron pathways are reinforced through use, which is a point that Norman Doidge makes in his interview. We now know that the brain literally rewires itself, based on repeated neuron firings. Because we think in a language, which has become a default ‘software’ for ourselves, we tend to think that we really are just ‘wetware’ computers, yet we don’t share this ability with other species. We are the only species that ‘downloads’ a language to our progeny, independently of our genetic material. And our genetic material (DNA) really is software, as it is for every life form on the planet. We have a 4-letter code that provides the instructions to create an entire organism, materially and functionally – nature’s greatest magical trick. One of the most important aspects of consciousness, not only in humans, but for most of the animal kingdom (one suspects) is that we all ‘feel’. I don’t expect an AI ever to feel anything, even if we programme it to have emotions.
But it is because we can all ‘feel’, that our lives mean so much to us. So, whether we have free will or not, what really matters is what we feel. And without feeling, I would argue that we would not only be not human, but not sentient.
Footnote: If you're interested in neuroscience at all, the interview linked above is well worth listening to, even though it's 40 mins long.