Thursday, December 4, 2014

Susan Blackmore's Delusions

If you are going to tell people they are deluded then it is a good idea to have some fairly strong arguments to defend your claim. Dr Blackmore, speaking last night at the wonderfully collegiate atmosphere of the GV Art & Mind Symposium at the GV Art gallery, disappointingly failed to come up with much argument to defend her claim that we are deluded about free will and consciousness.

Susan Blackmore's manner of delivery is well known to those who have seen her perform: the plaintively confessional account of her failed adventures in parapsychology is followed by the verbal hammer blows with which she knocks down anyone who dares to frame a vague and unpractised question. This would all be good sport if only she would follow through with some hard logical arguments to support her own position.

She started with Ben Libet's famous experiment, which I shall summarise as follows. In a laboratory setting, a person is asked to watch a clock hand going round, and to exercise her free will to move her finger at some arbitrary point n time. She has to make a mental note of where the clock hand was at the instant when she first became aware of her decision to make the move. Meanwhile, the experimenter is monitoring electrical impulses in the subject's brain and hand. What the experiment establishes is that there is electrical activity in the motor cortex half a second before the point in time when the clock hand was in the position reported by the subject. A conclusion that people often derive from this experiment is that free will is a delusion. They say that, in fact, the brain decides what it is going to do, and then it generates the illusory feeling of the mind exercising free will. On this view, the mind is a spectator of the brain's activity. Dr Blackmore enthusiastically embraced that interpretation, and told us that we were deluded in thinking that we had any free will.

Susan Blackmore demonstrating Benjamin Libet's experiment in free will

There are several things wrong with Dr Libet's experiment and its interpretation. The central one is that it does not do what it says on the tin. There are four conceptually distinct episodes in the experiment: 1. First, there is the act of volition itself, the voluntary decision to move the hand. 2. Next there is the electrical activity in the motor cortex, which is caused by the act of volition, and which in turn causes the hand to move. 3. Then there is the conscious awareness of the act of volition, consisting in the occurrence of a 'volitional quale'. 4. Then the muscles contract and the hand moves. Libet's experiment shows that step 2 occurs about half a second before step 3, but it tells us nothing about when step 1 occurs. In fact, neither Libet's experiment nor any other laboratory test can tell us when the act of volition occurs, as it is not directly observable.

In the Q&A after Susan's presentation, I raised this question. Or, rather, I got half way through raising the question before Susan's usual manner of responding to questions kicked in. As soon as I mentioned that free will caused the electrical activity in the motor cortex, her response shot out like a greyhound from its trap. She demanded to know what this 'free will' is, and what 'consciousness' is, and how could something extraneous to matter interfere with the law-bound electrochemical operations of the brain. So, I started out by saying that the conscious mind affects a non-deterministic process inside the neural networks and ... Suddenly she's off again! "Well that's not going to help you. Random nerve activity isn't free will ...". I was prepared to let her talk over me a few times - after all, it was her evening - but talking over me in order to make such a howler was a bit too much. How could a famous author and speaker on the philosophy of mind make the elementary mistake of confusing randomness with non-determinism? So, I endeavoured to point this out. I said that non-determinism exists in a physical system (such as a brain) when an event occurs which was not determined by the antecedent physical state. This is a well-known quantum-mechanical process, and apparently occurs in various neural events such as neurotransmitters jumping across synapses. In contrast, a random process is one, like white noise, in which no discernible pattern exists and which exhibits a uniform probability distribution. At this, Susan changed the subject.

We then moved on to consciousness. Here, she showed another surprising failure to grasp a basic item of terminology of consciousness studies. "Hands up who is consciousness right now", and of course almost everyone raised a hand. "Were you conscious before I asked you?"  She maintained that we are conscious only when we pay attention to our being conscious. In other words, she was conflating consciousness with self-consciousness. I have met other people who make this mistake, which I find quite extraordinary. Look, if I am savouring the taste of wine (which we did quite a lot of, during the evening) then I am conscious of the taste. But I am not reflexively conscious of my being conscious. I am not usually self-conscious when drinking wine. If while I am drinking the wine, someone asks me whether I am tasting the wine rather that just gulping it down, then I would at that moment attend to my conscious taste experience, and become self-conscious. You see the difference? Well, Susan didn't.
Susan Blackmore pondering Thomas Nagel's question: What is it like to be a bat?
She then threw a fluffy penguin at me, but I am really slow at this sort of game so I didn't react. Luckily the artist who sat on my right was more alert, and snatched the fluffy penguin out of the air before it hit me on my head.  Susan's point n this demonstration is that the brain  reacts very quickly, and reaches out a hand even before there is conscious awareness of what is going on. But afterwards the mind makes up a story of how it was conscious of watching the penguin flying through the air and reaching out to catch it. Therefore, Susan told us, we are deluded about being conscious of flying fluffy penguins. Therefore we are deluded about being conscious at all. Therefore there is no such thing as consciousness.

Did you spot the non sequitur? Yes, well done. It wasn't hard, was it? The gentleman who was sitting next to Susan also spotted it and forced her to listen to his calm explanation that, just because someone can catch a fluffy penguin on auto-pilot, it simply does not follow that we are never conscious.

So, all in all, Susan offered a rather threadbare tapestry of argument that we are deluded about having free will and consciousness - things that, quite frankly, are so obvious it is as absurd to doubt them as it would be to doubt that two plus two make four.

Susan Blackmore asking whether the spoon is conscious. Thankfully, several of us assured her that it was ...
Photographs by Londowl

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