Paul P. Mealing

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Sunday, 11 April 2010

To have or not to have free will

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.

Saturday, 3 April 2010

Consciousness explained (well, almost, sort of)

As anyone knows, who has followed this blog for any length of time, I’ve touched on this subject a number of times. It deals with so many issues, including the possibilities inherent in AI and the subject of free will (the latter being one of my earliest posts).

Just to clarify one point: I haven’t read Daniel C. Dennett’s book of the same name. Paul Davies once gave him the very generous accolade by referencing it as 1 of the 4 most influential books he’s read (in company with Douglas Hofstadter’s Godel, Escher, Bach). He said: “[It] may not live up to its claim… it definitely set the agenda for how we should think about thinking.” Then, in parenthesis, he quipped: “Some people say Dennett explained consciousness away.”

In an interview in Philosophy Now (early last year) Dennett echoed David Chalmers’ famous quote that “a thermostat thinks: it thinks it’s too hot, or it thinks it’s too cold, or it thinks the temperature is just right.” And I don’t think Dennett was talking metaphorically. This, by itself, doesn’t imbue a thermostat with consciousness, if one argues that most of our ‘thinking’ happens subconsciously.

I recently had a discussion with Larry Niven on his blog, on this very topic, where we to-and-fro’d over the merits of John Searle’s book, Mind. Needless to say, Larry and I have different, though mutually respectful, views on this subject.

In reference to Mind, Searle addresses that very quote by Chalmers by saying: “Consciousness is not spread out like jam on a piece of bread…” However, if one believes that consciousness is an ‘emergent’ property, it may very well be ‘spread out like jam on a piece of bread’, and evidence suggests, in fact, that this may well be the case.

This brings me to the reason for writing this post:New Scientist, 20 March 2010, pp.39-41; an article entitled Brain Chat by Anil Ananthaswarmy (consulting editor). The article refers to a theory proposed originally by Bernard Baars of The Neuroscience Institute in San Diego, California. In essence, Baars differentiated between ‘local’ brain activity and ‘global’ brain activity, since dubbed the ‘global workspace’ theory of consciousness.

According to the article, this has now been demonstrated by experiment, the details of which, I won’t go into. Essentially, it has been demonstrated that when a person thinks of something subconsciously, it is local in the brain, but when it becomes conscious it becomes more global: ‘…signals are broadcast to an assembly of neurons distributed across many different regions of the brain.’

One of the benefits, of this mechanism, is that if effectively filters out anything that’s irrelevant. What becomes conscious is what the brain considers important. What criterion the brain uses to determine this is not discussed. So this is not the explanation that people really want – it’s merely postulating a neuronal mechanism that correlates with consciousness as we experience it. Another benefit of this theory is that it explains why we can’t consider 2 conflicting images at once. Everyone has seen the duck/rabbit combination and there are numerous other examples. Try listening to a Bach contrapuntal fugue so that you listen to both melodies at once – you can’t. The brain mechanism (as proposed above) says that only one of these can go global, not both. It doesn’t explain, of course, how we manage to consciously ‘switch’ from one to the other.

However, both the experimental evidence and the theory, are consistent with something that we’ve known for a long time: a lot of our thinking happens subconsciously. Everyone has come across a puzzle that they can’t solve, then they walk away from it, or sleep on it overnight, and the next time they look at it, the solution just jumps out at them. Professor Robert Winston, demonstrated this once on TV, with himself as the guinea pig. He was trying to solve a visual puzzle (find an animal in a camouflaged background) and when he had that ‘Ah-ha’ experience, it showed up as a spike on his brain waves. Possibly the very signal of it going global, although I’m only speculating based on my new-found knowledge.

Mathematicians have this experience a lot, but so do artists. No artist knows where their art comes from. Writing a story, for me, is a lot like trying to solve a puzzle. Quite often, I have no better idea what’s going to happen than the reader does. As Woody Allen once said, it’s like you get to read it first. (Actually, he said it’s like you hear the joke first.) But his point is that all artists feel the creative act is like receiving something rather than creating it. So we all know that something is happening in the subconscious – a lot of our thinking happens where we’re unaware of it.

As I alluded to in my introduction, there are 2 issues that are closely related to consciousness, which are AI and free will. I’ve said enough about AI in previous posts, so I won’t digress, except to restate my position that I think AI will never exhibit consciousness. I also concede that one day someone may prove me wrong. It’s one aspect of consciousness that I believe will be resolved one day, one way or the other.

One rarely sees a discussion on consciousness that includes free will (Searle’s aforementioned book, Mind, is an exception, and he devotes an entire chapter to it). Science seems to have an aversion to free will (refer my post, Sep.07) which is perfectly understandable. Behaviours can only be explained by genes or environment or the interaction of the two – free will is a loose cannon and explains nothing. So for many scientists, and philosophers, free will is seen as a nice-to-have illusion.

Conciousness evolved, but if most of our thinking is subconscious, it begs the question: why? As I expounded on Larry’s blog, I believe that one day we will have AI that will ‘learn’; what Penrose calls ‘bottom-up’ AI. Some people might argue that we require consciousness for learning but insects demonstrate learning capabilities, albeit rudimentary compared to what we achieve. Insects may have consciousness, by the way, but learning can be achieved by reinforcement and punishment – we’ve seen it demonstrated in animals at all levels – they don’t have to be conscious of what they’re doing in order to learn.

So the only evolutionary reason I can see for consciousness is free will, and I’m not confining this to the human species. If, as science likes to claim, we don’t need, or indeed don’t have, free will, then arguably, we don’t need consciousness either.

To demonstrate what I mean, I will relate 2 stories of people reacting in an aggressive manner in a hostile situation, even though they were unconscious.

One case, was in the last 10 years, in Sydney, Australia (from memory) when a female security guard was knocked unconscious and her bag (of money) was taken from her. In front of witnesses, she got up, walked over to the guy (who was now in his car), pulled out her gun and shot him dead. She had no recollection of doing it. Now, you may say that’s a good defence, but I know of at least one other similar incident.

My father was a boxer, and when he first told me this story, I didn’t believe him, until I heard of other cases. He was knocked out, and when he came to, he was standing and the other guy was on the deck. He had to ask his second what happened. He gave up boxing after that, by the way.

The point is that both of those cases illustrate that humans can perform complicated acts of self-defence without being consciously cognisant of it. The question is: why is this the exception and not the norm?

Addendum: Nicholas Humphrey, whom I have possibly incorrectly criticised in the past, has an interesting evolutionary explanation: consciousness allows us to read other’s minds. Previously, I thought he authored an article in SEED magazine (2008) that argued that consciousness is an illusion, but I can only conclude that it must be someone else. Humphrey discovered ‘blindsight’ in a monkey (called Helen) with a surgically-removed visual cortex, which is an example of a subconscious phenomenon (sight) with no conscious correlation. (This specific phenomenon has since been found in humans as well, with damaged visual cortex.)

Addendum 2: I have since written a post called Consciousness unexplained in Dec. 2011 for those interested.