Archive for March, 2013

NagelThomas Nagel is one of the panjandrums of consciousness, author of the classic paper ‘What Is It Like To Be A Bat’ and so a champion of qualia; but also an important figure in inspiring the Mysterian school of pessimism.

Now he has inspired new controversy with his book ‘Mind and Cosmos: Why The Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False.’ Probably the part of the book which has elicited the most negative reaction is the doubts Nagel expresses about evolution itself, or rather about the currently accepted view of it. It’s not that Nagel disbelieves in evolution per se, but he thinks there are important gaps in its account; in particular he doesn’t think it accounts satisfactorily for the origin of life, or for the availability of the large range of living forms on which natural selection has worked. He is not endorsing Intelligent Design but he thinks some of its proponents have arguments which deserve a wider and more sympathetic readership.

That does seem a bit alarming. It’s true, I think, that we don’t yet have a full and convincing story of how life came out of inert chemistry. I’d also agree that some of the theories put forward in the past – like the naked replicators championed by Richard Dawkins in the Selfish Gene – look a bit sketchy and optimistic. But none of that would stop me putting my money on the true story being a fully materialist one in which Darwinian evolution plays an early and crucial role. Nagel’s second problem, with the way nature seems to have provided a remarkable fund of variation in organisms, of a kind which lent itself to the emergence of sophisticated organisms, just seems misconceived. He offers no statistical analysis or other reasoning as to why the standard account is unlikely, just mere incredulity. It seems amazing that that could have happened; well yes, it does, but then it also seems amazing that we’re sitting on a huge oblate spheroid which is rotating and orbiting round an even vaster sphere of terrifying thermonuclear activity; but there it is.

The real problem is that Nagel wants these doubts (together with some more specific objections to standard materialism) to justify a large metaphysical change in our conception of the whole cosmos. His book professes only to offer tentative and inadequately imaginative speculations, and the discussion is largely at a meta-theoretical level – he isn’t telling us what he thinks is the case, he’s discussing the kinds of theory that could in principle be advocated – but it’s clear enough what kind of theory he would prefer to reductive materialism. What he leans towards is a teleological theory; one in which some underlying principle drives the world towards a particular goal. He does not want this to be an intentional goal; he does not want God in the picture or any other Designer; rather he wants there to be a natural push towards value; value being conceived as a sort of goodness or moral utility, although this part of the speculative potential theory clearly needs development.

Nagel’s critique of evolution may seem alarmingly misplaced, but the idea of introducing teleology to fill the gaps seems really astonishing. What, we’re going to abandon the idea that DNA came together through natural selection and say instead that it came together because it sort of wanted to or was sort of meant to? The history of science has been a history of driving out teleological explanations – and the reason that represents progress is that teleological explanations are just not very good; they are usually vacuous and provide no real insight or predictive power.

In some ways what Nagel is after seems like an inverted law of entropy. Instead of things running down and tending to disorder, he wants there to be something built into the cosmos that shoves things towards elaboration, complexity, and indeed self-awareness (he positions the evolution of human consciousness as a peak of the process, and likens it to the Universe waking up). In itself that vision is quite appealling, but Nagel wants it to be driven by the worst kind of teleology.

I’m not sure what the official ontological status of the law of entropy is – it could be a meta-law which says the laws of nature must be such that entropy always increases, or it could be something that emerges from those laws (perhaps from any viable set of laws) – but it is definitely fully compatible with the rest of physics. If Nagel’s new teleology worked like this, it might be viable, but he actually supposes it is going to have to discreetly intervene at some point and turn events in a direction other than the one mere physics would have dictated. This seems a disastrous requirement. If there’s one thing the whole weight of science goes to prove, it’s that the laws of physics are not intermittent or interruptable; every experiment ever conducted has contributed evidence that they are consistent and complete. Yes, there are some places in quantum physics or wherever where some might hope to smuggle in a bit of jiggery-pokery, but I think on examination even these recondite areas offer no real hope of a loophole.

This is a general issue with Nagel’s case. We can sympathise with the view that evolution is not a Theory of Everything, but the other theories we need should be compatible with the broadly materialist world view which, despite some problems, is really the only fully-worked out one we’ve got: but Nagel hankers after something stranger and thinner.

What about those other theories? Nagel isn’t basing his argument simply on his doubts about evolution; he has three places in which he thinks the standard materialist view is just not adequate. Consciousness, unsurprisingly, is one; cognitive thought, more unexpectedly, is another; and the third is his concept of value. In the next post let’s consider what he has to say about each.

correspondentA quick mention for an interesting piece in the NYT reviewing reader’s opinions on two of the most famous arguments about qualia, all in the sensible hands of Gary Gutting, professor of philosophy at the University of Notre Dame.

Also worth a look is this essay considering the history of ideas about animal consciousness, leading up to a favourable mention for Thomas Nagel and his seminal paper on What Is It Like To Be A Bat – more on Nagel and his recent book very soon.

If you missed it I also recommend a look at Scott Bakker’s post on Reengineering Dennett: Intentionality and the Curse of Dimensionality.

frogSo it turns out consciousness really is an electric buzz around the brain.

JohnJoe McFadden claims his conscious electromagnetic field information (CEMI) theory – which says that consciousness lies in the brain’s electromagnetic field – has now been borne out by a number of recent research findings. His paper is in the JCS, but a pdf can be accessed at Machines Like Us. We first discussed the CEMI theory eight years ago (can it really be that long?).

The case for CEMI is based in turn on the idea that synchronous neural firing can be shown to correlate with conscious awareness. Others have thought that lots of neurons firing in harmony at the right frequencies might be important of course; but the CEMI theory explains why it should be important by suggesting that synchronous firing produces effects in the endogenous magnetic field, which unsynchronised activity does not. If registering in that field is taken to be the same as presentation to consciousness we have a neat account of the phenomenon.

The first of the new studies quoted by McFadden, by Fujisawa et al, showed that fields of the kind generated by gamma oscillations in a slice of rat hippocampus affected the neuronal firing pattern. This demonstrates that neurons can influence each other significantly by electromagnetic means quite separate from ‘normal’ synaptic activity. The second, by Frohlich and McCormick, showed broadly similar influences of electromagnetic fields in the visual cortex of ferrets, supporting the claim that the endogenous fields provide a positive feedback loop that helps set up oscillatory networks. The third is research by Anastassiou et al which showed that neurons could influence each other through electric field effects: we discussed this ‘ephaptic coupling’ and pointed out its relevance to McFadden a couple of years ago (you read it here first, folks!).

So there’s the evidence; what does it actually mean? I think McFadden is right to claim that the evidence for electromagnetic field effects on neuron firing is now too strong to ignore. At a minimum, it’s something brain simulations will need to take into account. It’s likely, moreover, that rather than simply being a nuisance factor, it actually plays some functional role in how networks of neurons are recruited and operate together. Anything more?  McFadden suggests it may solve the binding problem; I’m not so sure. The binding problem is essentially the question of how information flows from different senses, processed at different speeds, with lags and gaps, somehow manage to end up in a smoothly coherent perception of reality with no jumps or lip-synch problems. Solving that problem may well involve bringing the activity of different neural assemblies together, but to me it’s not clear how field effects could do anything other than smoosh all the inputs together, which is almost the opposite of what we want.

Speculatively McFadden suggests the EM field might be doing field computing, whatever that may be. He quotes a bizarre finding from the School of Cognitive & Computing Sciences (COGS) group at the University of Sussex. They used an evolutionary approach to develop a network which could perform  a certain task, and then deleted the nodes which weren’t playing any part in the the final network.  Weirdly, they found that one of the essential nodes was not actually connected to anything; yet removing it made the network stop working; put it back and the network worked again. They concluded that electromagnetic coupling must be playing a part. Of course electromagnetic effects in a field-programmable gate array (the equipment used by COGS) are not particularly likely to be anything like electromagnetic effects in the radically different physical substrate of neuronal tissue, but it does illustrate the general principle.

I still don’t see that there are particularly good reasons to say that the EM field is the home of consciousness. For one thing consciousness is full of very complex content: while I can easily see how that complexity could be encoded in the fantastically complex patterns of neuron firing which go on in the cortex, it’s harder to think that the EM field has a sufficiently elaborate structure. My consciousness is (in places) quite sharply defined and multi-layered, whereas a EM field seems more likely to provide a misty general glow. Perhaps the neurons provide the content and the EM field the subjectivity?

But one thing McFadden’s theory cannot be is a solution to the ‘Hard Problem’ of subjective experience; his electromagnetic consciousness is playing a vital functional role in the operation of the brain, whereas qualia, strictly defined, have no causal effects. So much the worse for the theory of qualia, you might think; that just helps show that Dennett was right and the whole business of qualia is nonsensical. However, Sue Pockett, whose electromagnetic theory of consciousness is a kind of cousin of McFadden’s, has jumped the other way on this, accepting that her own electromagnetic consciousness is epiphenomenal: it is produced by the brain but doesn’t in turn produce any effects of its own; consciousness is a mere observer. This enables her to stay in the game so far as the Hard Problem is concerned, but of course it lands her with a different set of problems.

Perhaps in another eight years things will look very different – I rather hope so.

 

correspondentRichard J R Miles has kindly provided the text of a short speech he prepared for a CFA: AISB workshop on the emergence of consciousness

Emergence of consciousness and the Soul.             

My Hypothesis.                                           

Trees and flowers do not need to evolve a brain, everything they require is taken care of by their environment. The sea squirt digests its brain when no longer required, which shows the economics of nature. Bodies evolve without brains, not vice-versa.

Often when the mind is discussed, the body is taken as such a banal subject that it does not get considered much, if at all. For me this is completely wrong, as I hope to explain with my hypothesis. Looking at the brain without considering the body is like trying to understand an electronic control unit without knowing what it is connected to.

Some creatures do not need much of a brain to survive in their environment, as they are moved around by the tide, wind, light or dark. The environment aids their survival. Their brain being operated by their body senses send the required action.

Some creatures needed to evolve a more complex brain for the 3 F’s, but this came at a cost. A large brain needs more fuel to run and maintain. A way to conserve energy was evolved, so part of the brain and body could be used when necessary, and relaxed when not. This proved to be more advantageous for their environmental survival. More beneficial than a less capable brain running 24/7. This improvement was achieved by a natural division of the nervous system in the body and brain. These are the autonomic and somatic nervous systems. It is the interaction between these two nervous systems which form the basis of my hypothesis, which combined with our dexterity has allowed us to evolve as we are.

Obviously I did not discover these two nervous systems, but I hope to show how their two feedback loops cause physical duality interaction of the body and brain, essentially the mind.

The autonomic nervous system is unconscious, to and from both the body and brain, which functions 24/7 and is the main control of our internal existence, a large part of our body and brain keeping us alive, as it has done since before we were born.

The somatic nervous system is the conscious to and from both the body and brain, and is the means of controlling and managing actions in the outside world to keep us alive.

The unconscious autonomic nervous system is indirectly connected, interacts, affects and effects the conscious somatic nervous system and vice-versa. Our conscious manages the somatic action in the environment and decides to act or not, assisted by, and sometimes urged by, the unconscious autonomic nervous system.  It is this dual interaction of essentially different parts of the nervous spectrum that complement each other making a formidable partnership that is the basis of my hypothesis and is how we are.

Our soul is simply our conscious inability to understand our unconscious activity.

 

 

ratsThis paper  by Pais-Vieira, Lebedev, Kunicki, Wang, and Nicolelis has attracted a great deal of media attention. The BBC described it as ‘literally mind-boggling’. It describes a series of experiments in which the minds of two rats were apparently melded to act as one.

Or does it? One rat, the ‘encoder’ was given a choice of levers to push – left or right (in some cases a more rat-friendly nose-activated switch was used instead of a lever). If it selected the correct one when cued, it got a reward in form of a few drops of water (it seems even lab rats are not getting the rewards they used to these days). Some of the rats learned to pick the right lever in 95% of cases and these went on to the next stage where the patterns of activation from their sensorimotor cortex as they pushed the right lever were picked up and transmitted.

Meanwhile ‘decoder’ rats had been fitted with similar brain implants and trained to respond to a series of impulses delvered in the same sensorimotor area by pressing the right lever. In this training stage they were not receiving impulses from another rat, just an artificially produced stream of blips. This phase of training apparently took about 45 days.

Finally, the two rats were joined up and lo: the impulses recorded from the ‘encoder’ rat, once delivered to the brain of the ‘decoder’ rat, enabled it to hit the right lever with up to 70% accuracy (you could get 50% from random pressing, of course, but it’s still a significant improvement in performance). In one pointless variation, the encoder and decoder rats were in different labs thousands of miles apart; so what? Are we still amazed that electrical signals can be transmitted over long distances?

A couple of other aspects of the experiments seem odd to me. They did not have a control experiment where the signals went to a different part of the decoder rat’s cortex, so we can’t tell whether the use of the particular areas they settled on was significant. Second, they provided the encoder rat with incentives: it got water only when the decoder rat got it right. What was that meant to achieve, apart from making the encoder rat’s life slightly worse than it already was? In essence, it encourages the encoder rat to develop effective signals: to step up the clarity and strength of the neural signals it was sending out. That may have helped to make the experiment a success, but it also detracts from any claim that what was being sent was normal neural activity.

So, what have we got, overall? Really, nothing to speak of. We’re encouraged to think that the decoder rat was hearing the encoder’s thoughts, or feeling its inclinations, or something of the kind, but there’s clearly a much simpler explanation baked into the experiment: it was simply responding to electric impulses of a kind that it had already been trained to respond to (for 45 days, which must be the rat equivalent of post-doctorate levels of lever-pushing knowledge).

Given the lengthy training and selection of the rats, I don’t think a 70% success rate is that amazing: it seems clear that they could have got a better rate if, instead of inserting precise neural connections, they had simply clipped an electrode to the decoder rat’s left ear.

There’s no evidence here of direct transmission of cognitive content: the simple information transferred is delivered via the association already trained into the ‘decoder’. There’s no decoding, and no communication in rat mentalese.

The discussion in the paper ends with the following remarkable proposition.

 …in theory, channel accuracy can be increased if instead of a dyad a whole grid of multiple reciprocally interconnected brains are employed. Such a computing structure could define the first example of an organic computer capable of solving heuristic problems that would be deemed non-computable by a general Turing-machine. Future works will elucidate in detail the characteristics of this multi-brain system, its computational capabilities, and how it compares to other non-Turing computational architectures…

Well, I’m boggling now.