Tuesday, 21 June 2011

Chemero (2009) Chapter 9 - The Metaphysics of Radical Embodiment

The final chapter of RECS tackles the metaphysical implications of the radical stance. Gibson was a staunch realist, but there are some odd elements to entities like affordances that, to certain minds, sound like idealism or antirealism of some kind. Realism is, essentially, the claim that there is a world independent of our experience of it, and that we can have basically accurate knowledge of that external world. In modern times this reality has been equated with the description given by physics. Affordances don't belong to physics, however; whether relations or dispositions, they are, at heart, facts which span the organism and the environment. This sounds wrong to a lot of ears (as Ken's comments on that post readily show!). Chemero therefore devotes the final chapter to defending the claim that RECS can be realist; this matters, because people tend not to like idealism in their science these days, and it's going to be a standard philosophical objection to the RECS programme if not addressed.

The problem is this: embodied cognition stories describe organisms who only perceive certain things which are very personal to themselves (e.g. affordances) and who essentially operate within a world defined by their own sensori-motor abilities. This sounds like idealism, the idea that we all simply inhabit our own little worlds and these aren't connected to anything external to the organism. This is clearly an issue.

Many non-representational stories simply reject the realism/idealism dichotomy - Varela et al (1991), for example, claim that replacing representation with embodied action simply changes the game so that they can dodge the problem. Andy Clark thinks this move doesn't work, and part of his plan for a non-radical embodied cognitive science involves action-oriented representations, who's content is firmly grounded in an objective world. Chemero, however, thinks Clark runs into the same basic problem, because even an action-oriented representation must be tied to specific sensori-motor capacities and runs the risk of locking an individual up inside their own abilities. This just makes Clark's representations walk into essentially the same idealist trap as he thinks non-representational accounts suffer from. 

One potential way out of this mess, Chemero suggests, is plasticity. The above story, that organisms are locked into an understanding of the world dictated by their sensori-motor capacities and are therefore idealists, falls apart once you allow for neural (or other) plasticity. Plasticity enables a system to adapt and change in response to changes in it's environment; allowing this requires allowing a path from the world to what the organism knows about the world. Problem solved.

Entity Realism
So if plasticity allows RECS to embrace realism, what flavour of realism should it embrace? Philosophy has spent a long time delineating an ever increasing list of realisms; Chemero advocates entity realism (Hacking, 1982, 1983). According to this flavour, you are entitled to claim something is real (i.e. exists independent of you) and that you can have accurate knowledge of that thing when you are able to use the thing to achieve some scientific goal. Hacking's example is the electron; scientists are justified in believing electrons to be real because they can use them to do things (e.g. investigate other particles). This makes the electron part of the lab just like a glass beaker is part of the lab, and so it is at least as real as that beaker is.

So entity realism says something is real if it can be used as part of your scientific practice. Chemero simply extends this idea to embrace other practices, such as action. Affordances can therefore be real because they can be used as part of the successful practice of acting in the world. Chemero suggests this maps on nicely to the whole RECS approach to things. And while there are, of course, philosophers who don't think entity realism is tenable, the basic approach is robust enough to at least serve as a sensible first draft. Actually this is mostly just a stance, still, and as such is a bit weak, but Chemero acknowledges the limitations here.

Chemero then describes three strands of scientific research which assume affordances and use these to investigate other aspects of perception and action; this is another way to demonstrate how entity realism lets affordances being perfectly real.
  1. Affordances and events: Chemero and colleagues have been able to manipulate the presence and absence of gap-crossing affordances and systematically vary the behaviour of participants (Chemero et al, 2003).
  2. Affordances and distance perception: Chemero cites the work of Dennis Proffit and colleagues (which I have mention here and will come back to in the next few weeks). Proffitt et al vary the affordance and task structure to investigate the perception of distance, i.e. how it is scaled.
  3. Affordances and perception of tools:  Casler & Keleman (2005, 2007) have manipulated the affordances of tools to investigate how children attribute functions to objects.
Two Non-Problems: Qualia & Mental Causation
Chemero then explains how two classic problems in philosophy of mind have no traction in a radical embodied cognitive science.

The first problem is mental causation: how can something like cognition cause physical things to happen? How does causation cross levels of explanation, e.g. from the action of neurotransmitters to the movement of my laptop keys? Chemero claims that a RECS based in dynamical systems doesn't have the levels problem. Take the HKB model (or at least, take the model as described by Chemero earlier; I don't think this specific example quite does the work Chemero needs, although I buy the broader point). Relative phase is an order parameter which is composed of lower level elements and yet also controls their behaviour. The kind of level-ignoring causation in dynamical systems seems to be the right kind of causation for RECS.

The second is the problem of conscious experience. Computational systems can have content, and so, for computational cognitive science, my mind and my laptop can both have states which represent some state of affairs. But only I can have the conscious experience of having this knowledge; my laptop lacks qualia.This problem is a side effect of a computational solution to the problem of how we get up to things, and thus RECS doesn't have this problem. RECS is, in fact, all about accounting for our experience of the world as meaningful - meaning is not a separate element which must be somehow included in the mix, it's part of the act of perception.

To many, this claim simply attempts to dodge a bullet with an extensive pedigree - the problem of qualia and how to get conscious experience into our lives has been around for a long time. But it's actually a positive hypothesis, a claim which RECS makes on the basis of everything that's come before in this book.

And that's it! Let me end this extended trawl through this book with a brief summary of what I think this book is good for.

As you may recall, I have a few detailed problems with the specific flavour of ecological psychology Chemero lays out:
  1. I think affordances need to be dispositions, and not relations, and I think all the reasons Chemero cites for the relational story are entirely accounted for by the fact that the act of perception is relational. Chemero & Turvey have banged this around some in a technical paper I frankly didn't understand, but the practical upshot is that the two accounts, relational and dispositional, essentially amount to the same thing. OK, fine - I'll treat affordances as dispositions and not stay too worried about this fight. 
  2. I think that the situation semantics expansion of the idea of information is interesting, but worrying. I think it loses too many important features (the symmetry principle, for instance) and again, I wasn't entirely convinced by the motivations. That said, Sabrina and I have been going round and round on this question, and there are times when I can see how relaxing the law based requirement might help. I'll keep thinking about this.
I also think Chemero's use of the HKB model is a swing and a miss. This isn't his fault - his read is indeed the way the model gets talked about in the literature. But it's an incorrect analysis, and Sabrina and I are working on a paper this summer laying out the case for a better style of modelling based on Bingham's model of coordination. Any suggestions for good journals to send this to gratefully received :)

So I have some quibbles with some details. But Chemero achieves his primary goal - laying out a positive, productive approach to cognitive science that doesn't rely on the crutch of mental representation. This is very, very important: most cognitive scientists assume that such a thing is entirely impossible even in principle, and it is without a doubt the single most important reason the work of James J Gibson has been sidelined for so long. Given that the ecological approach is a highly successful theory and the root of a strong empirical programme responsible for introducing dynamical systems to psychology, this side lining by many scientists is a real problem. It's also a problem with consequences: the notion of affordances has been readily embraced by cognitive science, but untethered by the complementary notion of information it has lost all it's meaning and has been reduced to one of those terms people throw in as if they know what it means.

So my quibbles aside, I like this book and it does an important job. Now it's time to spend a little time doing radical embodied cognitive science, and trying to draw the literature into the broader conversation about the way we study the mind and behaviour.

Casler, K., and D. Kelemen (2005). Young children’s rapid learning about artifacts. Developmental Science, 8, 472-480.  Download

Casler, K., and D. Kelemen (2007). Reasoning about artifacts at 24 months: The developing teleo functional stance. Cognition, 103, 120-130.  Download

Chemero, A., C. Klein, and W. Cordeiro (2003). Events as changes in the layout of affordances. Ecological Psychology, 15, 19-28. DOI

Hacking, I. (1982). Experimentation and scientific realism. Philosophical Topics, 13, 71-87.

Hacking, I. (1983). Representing and Intervening. Cambridge: Cambridge University Press. 

1 comment:

  1. Nice review! Thanks for having it up here.


    As for the "realism", I suspect this will take some time to sort out. I am increasingly appreciating the amazing difference in style between what used to be called "American Philosophy" vs. "Continental Philosophy". Of course, the terms are inaccurate to describe the current location of people doing those things.

    Gibson's work (as Heft and others have developed) fits within the American tradition, from Peirce to James/Dewey to Holt. The philosophical baggage of European traditions interferes with understanding what is going on. As "cognitive psychology", at least in it's initial form, entailed the continental tradition taking the field back, it makes it very hard for the two sides to communicate. Everything interesting about Gibson's system, and hence Tony's, makes much more sense in the context of American philosophers: There is no clean line between "higher" and "lower" mental processes, "mind" is something a body does, outcomes are what matters - acting sensibly in the world, "truth" (i.e., reality) is to be sought not by avoiding error at all cost-but by having a perceptual system that can correct when you are wrong, etc., etc.

    The American approach has been so marginalized (e.g., it's founders discouraged their students from going into philosophy) and abused (e.g. by people like Quine and Fish), that it remains very poorly understood.

    Tony's argument that something is "real" if you can manipulate does a good job as a place holder, but I'm not sure it will do in the long run. That is, it definitely buys us realism in some recognizable and established sense, which is A Very Good Thing, but I'm not sure if it buys us the realism that we want. I suspect someone will ultimately have to go all the way back to Peirce, and put things together from there.