Susan Hurley Memorial Conference

As mentioned in my previous post, I was at the Susan Hurley Memorial Conference last weekend, so I thought I’d record a few thoughts and comments about it here for comments and discussion. In general, it was a very useful and enjoyable event, and left me with a strong impression of what a creative, energetic and intelligent individual Susan Hurley was. Her untimely death was a tragedy not just for those who knew her, but for the philosophical community as a whole, not least because her work seemed to be reaching new levels just before she died.

The brief to speakers was apparently to talk about something that Susan would have found interesting, rather responding to her work directly, although there was inevitably some crossover between the two. It was touching that many of the speakers chose to begin their talks with personal recollections or anecdotes about the time they spent with Susan, or the impression that she had made upon them. Indeed, the introductory session was given by Susan’s husband, Nick Rawlins, who, along with their son Merryn, was present throughout most of the conference. It was also a distinctly interdisciplinary gathering with many neuro- and cognitive scientists, as well as philosophers, in attendance—a mark of the nature and breadth of Susan’s work.

Rather than trying to give a comprehensive summary, I thought I’d just pick out a few talks that made a particular impression on me for one reason or another, although with so many high-profile philosophers in attendance, it is hard to be selective.

Mirror Neurons

The first and probably one of the best talks was given by Cecilia Hayes on ‘the meaning of mirror neurons’. Mirror neurons (MNs) are cells or structures in the brain that are (allegedly) activate both when the organism engages in a particular task and when it observes others doing the same. The discovery of MNs in monkeys and various other animals has provoked much speculation in the press, as well as amongst philosophers more generally, as to whether these might form the basis of phenomena as diverse as empathy, imitation, social interaction and—quite literally—mind-reading. Although the basis of these claims is somewhat dubious, what was interesting about the talk was the extent to which even the scientific evidence for the existence and role of MNs is open to question.

Firstly, there is no evidence that humans (as distinct from monkeys and apes) actually possess MNs, despite the fact that similar areas of the brain do appear to be implicated in the processing of both actions and observations of similar actions. Nevertheless, no direct evidence for the existence of MNs in humans has yet been found, partly due to the difficulties associated with conducting the relevant research.

Secondly, it seems that such neurons do not only ‘mirror’, i.e. fire when a similar action is being observed, but that some also fire when a corresponding or even the opposite action is performed; e.g. grasping and letting go, throwing and catching, etc. This suggests that mirror neurons do not ‘mirror’ at all, but are rather a form of adaptive learning mechanism that is activated in cases where the organism both observes and carries out actions at the same time. As such, there is nothing particularly special or unusual about MNs, undermining various extravagant claims as to their significance for human cognition and sociability in general.

Computational Theory of Mind

The keynote for the conference was given by none other than Daniel Dennett, and was also open to the general public in the form of a centenary lecture. Perhaps as a consequence of this, it was somewhat big on ideas and short on academic rigour, although Dennett delivered an excellent and enjoyable performance (which is, incidentally, now available online).

Dennett argued in favour of the computational theory of mind (CTM), likening words and language to a kind of ‘software’ that enables the physical ‘hardware’ of the brain to run various subroutines and processes in a way akin to how Java applets (sic) enable computers to execute programs downloaded from the web. The chief respect in which minds differ from conventional digital or analogue computers, Dennett claimed, is that they employ competitive (i.e. Darwinian) mechanisms, rather than co-operative ones. As such, those philosophers who oppose CTM are guilty of a colossal failure of imagination brought about by their prejudices as to what computation is or can achieve.

However, if consciousness is, as per Dennett’s hypothesis, a computational phenomena, then it should be possible to establish a principled distinction between the inputs and outputs to that computation—a distinction that Hurley vigorously opposed, and with good reason since it is not clear that the mind as a whole (as distinct from the individual elements from which it is comprised) can be partitioned in this way. For this reason, I did not find Dennett’s arguments persuasive, although no doubt many of the non-philosophers in the audience were impressed by his computational analogies.

Dynamic Entanglement

On the second day of the conference, Andy Clark spoke about Hurley and Alva Noë’s notion of extended consciousness (TXCM) due to the ‘dynamic entanglement’ between the brain, the body and its environment. TXCM goes beyond Clark and Chalmers thesis that objects outside of the body can be constitutive of cognition in at least some cases (e.g. Otto’s diary) to claim that the mechanisms underlying consciousness itself similarly extend into the world. Although it would take too much space to go into detail here, the general gist of his talk was that none of the arguments in favour of this view are successful, and that consciousness, unlike cognition, is all ‘in the head’.

Clark did, however, identify the move that Hurley made from discussing the causal/constitutive basis of consciousness to the explanatory role of external objects as being the most promising line of argument in favour of TXCM, even though it is, by itself, ultimately inconclusive. He finished by presenting his own admittedly sketchy account of what differentiates conscious processes from merely cognitive ones in terms of the ‘bandwidth’ and/or frequency of neural activity, which is far higher than that of the brain’s connection with the surrounding environment, resulting in a kind of ‘low-pass filter’ separating consciousness from its contents.

Although this last point was by far the least convincing aspect of his talk, I was impressed by the clarity, detail and subtlety of the arguments given, which have certainly given me plenty of food for thought for my own research into the role of external objects in perceptual experience. The whole issue as to how to differentiate causal and constitutive relations is also very interesting, although Hurley herself thought that there was no solution to this problem.

The Classical Sandwich

Jesse Prinz’s talk, despite ostensibly being about moral psychology, dealt mainly with Hurley’s rejection of what she called the ‘Classical Sandwich’ model (CSM) of the mind in favour of the dynamic-entanglement model (which Prinz gave the somewhat tongue-in-cheek title of the ‘Hurleyan Bun’).

Despite some excellent exposition, I couldn’t help feeling that Prinz gave Susan’s critique of the input–output model, not to mention her many detailed examples and thought experiments, fairly short shrift, and I would have liked to see a more in-depth discussion of these issues from within the context of theories of action and perception, rather than moral theory. Nevertheless, Prinz concluded, perhaps surprisingly, that these ideas have a natural home in the context of moral thinking, where emotion and judgement are closely intertwined—a result that would no doubt have interested Hume—much as Susan predicted in the case of perception of action.

Language without a Theory of Mind

Perhaps the most surprising talks of the conference was Ruth Millikan’s account of speech comprehension, which she characterised as a kind of direct perception. This was surprising not only in terms of its thesis, to which I am somewhat sympathetic, but because Millikan seemed to have no particular interest in either the philosophy of perception or in the way that people talk about or describe their perceptual and/or testimonial experiences (she actually said exactly that in response to a question from John Campbell, who took her to task over the idea that, in understanding another’s speech, we can literally ‘hear’ the world).

Furthermore, Millikan’s talk was entirely lacking in references to philosophers who have taken this or similar positions in the past—e.g. Thomas Reid, to name just one—which seemed a little odd, almost as if she thought herself to be the first philosopher ever to have taken this position! Millikan’s delivery was, however, quite captivating, and there was a palpable respect and affection for her amongst the audience who were in no doubt as to the value of her contributions to philosophy, most notably, although not exclusively, in the field of teleosemantics.

Honourable Mentions

Other talks that are worthy of mention include Nicholas Shea’s discussion of Hurley’s ‘shared circuits model’ of human cognition, John Campbell’s account of mental causation (more entertaining than it was enlightening—it turns out that he is something of a character, although perhaps that is only to be expected from a fellow Scot!), Thomas Metzinger’s work on the physiological basis of out of body experiences and how this can inform an account of the minimal phenomenal self, Sarah-Jayne Blakemore’s research into the development of the ‘social brain’ during childhood and adolescence (more neuroscientific than philosophical), and Mike Wheeler’s functionalist account of the (allegedly) external vehicles of consciousness.

All in all, it was an excellent conference, although it was a pity that not more speakers were arguing for something closer to Susan’s own point of view (Alva Noë unfortunately cancelled a few weeks before the event). For this reason, at times the dialectic sometimes felt a little skewed, although perhaps this inevitable at an event in which philosophers are responding, albeit indirectly, to a set of views that are not their own. In any case, it was apparent that Susan Hurley’s contribution to philosophy was substantial and that she continues to influence the discussion, although I suspect it will be some years before the extent of her philosophical talents are fully recognised.

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