Perceiving long distances in action scaled units

I have so many things I need to write up just now, but it's been a struggle finding the time. I hope to post on Chemero's last chapter, task-specific devices, calibration and some new coordination data soon. In the meantime, I thought I'd take advantage of the fact that I'm reading some new articles on an interesting topic, and I wanted to organise some thoughts and see if anyone had any comments!

Perception is action-scaled

Traditional theories of perception claim that we perceive the world in generic terms, and must transform that perception into a task relevant variable after picking the information up. The ecological suggestion is that the act of perception itself is directly scaled in action-relevant units, and that this perception will therefore be task-specific. In order to directly perceive action relevant properties (i.e. affordances) perception must be smart (think of the analogy of the polar planimeter).

We are capable of perceiving the distance of things in the world; but we don't perceive them as being '6m away'. Instead, the system is interested in how to reach for an object, so you need to calibrate your perception of distance in terms of, say, arm length units. Calibration is the process of placing a measurement on a scale, and the ecological approach has been interested in action relevant scales such as arm lengths (for reaching; Mon-Williams & Bingham, 2007) and leg lengths (for stair climbing; e.g. Warren, 1984). One of Chemero's points is relevant here; body scale is probably only a proxy measure for ability to perform the action and the real action scale the system is using (the effectivity) will be more complicated. But body scale is mostly where the field is at right now.

Chemero (2009) Chapter 8: Neurophilosophy Meets RECS

Chemero's book finishes with two chapters on some philosophical consequences of taking a radical, embodied approach to cognitive science. Chapter 8 is about the mind-body problem, and how various attempts to reduce cognitive science to, say, neuroscience, can be vigorously resisted via the RECS approach, without being dualist about the mind. There are many people who think cognitive science can be reduced to neuroscience (intertheoretic reduction), but one plank of any embodied approach is that this won't work. RECS is particularly committed to a more extended notion of cognition and so a strategy for resisting reduction is critical. Chemero's plan won't rely on the usual philosophical manoeuvres such as Martian pain mechanisms or zombies. Like me, Chemero is concerned that these create the impression that philosophers aren't tackling real problems; he wants the philosophical conclusions of RECS to be grounded in data, and I thoroughly endorse this approach.

Perception, Action & Dynamical Systems

Over Easter I visited the Center of Functionally Integrative Neuroscience at Aarhus University in Denmark, courtesy of the Interacting Minds group. I gave a talk, got the tour, and met some of the faculty and students - some interesting opportunities for future collaborations, I hope - thanks for the hospitality!

I wanted to lay out the basics of the talk I gave. I took the opportunity to present some ideas that have been developing as I work on this blog, reading Chemero and working on coordination experiments. There is a core of people in Aarhus interested in things ecological, as well as dynamical systems, so it was a good audience to try these ideas out and they seemed to go over well. This is also the sketch of a paper Sabrina and I are going to work on over the summer.

The take home message of the talk was simple - dynamical systems is the right kind of mindset for cognitive science, but it is not a theory of behaviour. Dynamics merely provides the right kind of modelling tools - the form of the model must be based on hypotheses about the specific kind of dynamical systems we are or else they are merely an exercise in data-fitting. Ecological psychology is the right theory, and the Bingham model of coordinated rhythmic movement is currently the only example of a genuinely perception-action dynamical systems model. My thoughts here are largely from my response to Chapter 4 of Chemero (on 'the dynamical stance') and Chapter 5, his initial attempt to use dynamics to serve as a guide to discovery which I think fails and which Chemero then replaces with ecological psychology. The description of Bingham's model comes from here.

Failing to Replicate Bem's Ability to Get Published in a Major Journal

I think Daryl Bem has done psychology an enormous favour. Possibly even two.

As you probably  know, Bem is the author of 'Feeling the future: Experimental evidence for anomalous retroactive influences on cognition and affect', a paper with claims to have found evidence for precognition by running standard psychological experiments in reverse and demonstrating small but statistically reliable effects on behaviour of stimuli which came after the response was made. I posted briefly about it here, and otherwise it's been all over all of the internet for months.

It's back on my radar because several psychologists, including Richard Wiseman, recently submitted a failure to replicate the studies to the Journal of Personality & Social Psychology (JPSP), which is where Bem published his work. As reported here, Eliot Smith, the editor, refused to even send this (and another, successful replication as well) out for review. The reason Smith gives is that JPSP is not in the business of publishing mere replications - it prioritises novel results, and he suggests the authors take their work to other (presumably lesser) journals. This is nothing new - flagship journals like JPSP all have policies in place like this. But it's not a good look, and it got me thinking.

Reading Group - Gibson (1979) Chapter 6 Part 2

So, it's been four months, but here's part 2 of Gibson '79 chapter six:

Gibson believes that events are specified in the optic array, just as stationary objects are. In this part of the chapter he describes three classes of events (changes of surface layout, changes of surface colour or texture, and changes in the existence of a surface). He goes on to discuss the types of optical disturbances that can specify these events.

Chemero (2009) - A Brief Pause to See Where I'm At

There are still a couple of chapters left for me to go over in Chemero, but the last two were the crux of the book for me, and I want to try and summarise where my analysis has left me before I go on holiday for Easter.

First, I'd like to separate out a couple of themes. First, there's the overall 'radical embodied cognitive science' programme, and second is the specific form of the 'shored up ecological psychology' that Chemero advocates as a basis for this programme. I am entirely on board with the basic idea of RECS; specifically, I think that cognition, whatever that is, is non-representational and that we can make great progress by making our science non-representational. I think Chemero has written a clear exposition of what such a radical science might look like, and why we might want to bother, and I think this makes RECS a must read for the field. 

Second, I think that Chemero is right to go to ecological psychology for a theoretical basis. The more I look, the more I have come to believe that James Gibson is about the only psychologist to have actually proposed a genuine scientific theory in psychology. A true theory provides you with tools to empirically attack novel problems in your domain, and provides you with a clear basis to interpret the results of your tests and to begin to tell a coherent story. Psychology has been chasing phenomena for most of it's scientific life, with no clear framework emerging to tell us a story about why things are the way they are. Ecological psychology is a genuine theory, and it's about a critical feature of our psychological lives: how we maintain contact with our world and move through it successfully. Regardless of what topic you're specifically interested in, you need to understand how we come to have knowledge about our environments.

Finally, though, I have problems with the proposals Chemero makes about the two pillars of an ecological psychology, affordances and information. It's these problems I want to try and sum up here, to focus the conversation a little.

Chemero (2009) Chapter 7: Affordances, etc (Pt 2)

Last time I went over affordances-as-dispositions, and Chemero's first swing at affordances-as-relations. Affordances can't be dispositions, claims Chemero, because

1. Dispositions manifest when the conditions are met; this is compulsory. But I am not currently trying to effect all the affordances in my vicinity, so they can't be dispositions. Relations are functions, and thus support malfunctions.
2. Dispositions require complements - for perception-action, the complement of an affordance is an effectivity. But what exactly is this? Body scale (e.g. leg length)? Actually, it's more likely in terms of ability (per some unpublished experiments Chemero has run); people's judgements of stair climbability are a relation between the riser height and the person's ability to step that high.
3. If affordances are properties that are directly perceived, then when two people perceive the same affordance their minds will overlap: the problem of two minds. Relations solve this problem by making the overall relation which the directly perceived affordance is part of unique to each observer.

This would be all well and good, except that 

1. Affordances and effectivities are complex dispositions, and the conditions for being realised can be a long list. In addition, I can only be one kind of effecting device at a time, so when seated I am literally not capable of complementing the climbing affordances of my stairs at that moment in time.
2. Noting that 'body scale' is an imperfect proxy for an effectivity, and then claiming that this means nothing is an effectivity makes no sense. In addition, 'abilities' are equally approximate. The issue (being careful what you claim is the actual complement of the affordance) is valid but applies equally to dispositions or relations.
3. The solution to the problem of two minds that Heft outlined and Chemero thinks supports his case lies in making the act of perception relational, not the thing perceived. The affordance does not, itself, need to be a relation.

So far, nothing has convinced me that affordances need to be relational. But to round the story out, I want to finish the chapter and address the final tweak Chemero adds: Affordances 2.0.