Dynamics


I was watching me some contact juggling, and I got to thinking about how they “represent” space.  I use the term “represent” in a rap fashion rather than a cog sci fashion, as they show off their conception of space, and it is Euclidian.  The beauty of the art form lies in the absence of body-based constraint: no top-heaviness or balance issues. Space is the metric space it seems to be in the performance.

Now look at time and the body.  What I object to most strenuously is the notion that anything could be timed independently of the body.  The oscillator modellers all seem to think that the time of behavior is a Euclidian time – a raw metric space, unformed by the proclivities, inertial drag, and symmetry properties of the body.  They treat movement as if it were contact juggling.

Let’s define an anti-embodied cognitive science.

We start, not by disagreeing with the enactivists, but by agreeing with them up to, but excluding agency.  Let’s discard the assumption that the lived body is the locus of experience.  That should get the party started.

Then we wait for someone to cry foul.  We take their argument, whatever it is, and we examine its agential commitments, and associated mentalese. There is no test one can do to distinguish between the tumblebot and the goldfish without presuming some locus of agency.  There will be many domains of relative autonomy though.

Take whatever ‘mind’ is offered, and call it the P-world.  The domain of present experience.  Identify the P-world in a variety of ways: Umwelt, milieu, consciousness.  The P-bomb is, of course, that the P-world does not exist.  It is a construct that allows the discussion of a world.

What’s the endgame?  Do we no longer draw the boundary at the species?  Is this the way to realize that we are the natural world?  We are the world we see.

The search for agency within the enactive movement is nothing more or less than an attempt to find a basis for “we”.  It is a search for that with which one identifies.  The mistake of trying to ground it in a “we” made up of individual human animals is a problem.  Agency lies wherever you shine the light.  The agency of a dyad is real.

Furthermore, once one has chosen to identify a given domain as agentive, one creates a blindspot.  Behind that, we must explain with non-observable constructs, like the shallow tinker toys of mechanistic psychology.

So I started working on a sketch today that links two ideas, and the combination is surprising.

On the one hand we have O’Regan and Noe’s take on sensorimotor correspondences.  This is actually not far from a lot of Gibsonian work within Ecological Psychology.  The basic idea is that in perceiving, we are skillfully engaging with the world, and that practiced and tuned action gives rise to a corresponding characteristic change in the sensory array.  Gibsonians would say this is the basis of direct perception.  Enaction-heads would say this is skillful coping, or some such.

On the other hand, we have the peculiar issue of sensorimotor synchronization, perhaps best illustrated by a group of people dancing or beating drums together.  In the scientific literature, this has withered to a laboratory situation in which people tap in time to a metronome. (The horror, the horror.)  This is a singularly human achievement, the very odd animal counterexample notwithstanding (yes, Snowball, I’m looking at you and the Gelada baboons).  A fuller account of the basis for sensorimotor synchronization would help us enormously.  It may underpin a burgeoning theory of memes; it speaks to Gibson’s intuition that the nervous system displays resonant properties; it fits with a range of specific situations, from air guitar to stuttering.  All can be described, in some fuzzy essence, with a conceptually simple model in which two processes enter into a coupled form of synergy which looks like resonance within and among coupled systems with many degrees of freedom.

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We can use linear time warping, via high speed cameras or time lapse, to perceive events at timescales that are at some remove from that established by our metabolism.  Watching drops into water, or watching plants fight and unfold, we recognize that events as salient as any we could see are going on all around us all the time.

But what if we explore non-linear time-warping.  We could look at the world through non-linear functions.  Start with periodic ones, and you are looking at loops. That’s cool and interesting. But once we break into non-periodic functions, the whole world becomes strange and different.  What do we see?  We will see more clearly that the simple things and events that we recognize are as much a function of the perceiver (the function) as they are of the world.  That should help us to develop a better sense of perspective for how we usually see things.

This post has some lovely things to say about the relation between cause and effect, derived from considerations of the frame of reference of a physical theory.  For a natural scientist from a past civilization to have the concept of conservation of momentum is astounding.  But his conception of weight is interesting.  We now differentiate between mass and weight.  He didn’t.  If you hold gravity constant, there is no difference.  His theory was completely consistent within its conventional frame of reference.  Science strives to expand that frame of reference, leaving old truths new in a new way, with more context.

With P-world theory, my goal is to provide a little more context.  A framework within what we know has its place, but it is a larger place, admitting of more kinds of truth.

Dehaene has an interesting article in Edge.org on his work in studying brain activity related to consciousness experience, or rather brain activity associated with the ability to report on the nature of brief stimuli presented visually. He uses language in an infuriating way typical of neuroscience:

We can see a lot of cortical activation created by a subliminal word. It enters the visual parts of the cortex, and travels through the visual areas of the ventral face of the brain.

Now, If I have a basin of water, and I tap the side, waves propagate through the basin, but my tap is not propagating, and there is an important distinction between the wave pattern and the tap. Yet neuroscientists talk as if stimuli were being passed around in the brain. An important insight of the enactive tradition is to clearly separate between the tap and the waves, or between a perturbation to the dynamics of the organism and the effect of that perturbation.

Causal explanation is tricky. I have in mind what I think is the Aristotelian distinction between Formal Cause and Efficient Cause. Of course I interpret these from the standpoint of a soggy philosopher/scientist in 2009, so Aristotle would probably not concur. Efficient Cause is closest to folk usage of the word. A causes B iff A precedes B, A necessarily gives rise to B, etc. Let us not get into necessary and sufficeint conditions, but suffice it to acknowledge that often, this kind of causation is what we mean by ’cause’. Formal Cause is completely different. A full dynamical description of, say, a pendulum, that captures essential properties of the system (typically position of the bob over time) is a formal causative account, but it does not contain any notion of efficient cause. With a full dynamical description, we have determinism, but, critically, you can run time backwards or forwards, and the lawfulness remains the same.

Now fans of efficient cause like to distinguish between explanation and mere description. Formal cause, as I interpret it here, is description. But I claim that it is as full a causal story as one can have. The notion of mere description sugests that description is theory neutral. It is not. In providing a description of the movement of the pendulum over time, I have selected some properties of the world as relevant (idealized bob position) and some as irrelevant (pendulum colour). Description is never theory neutral. Efficient cause fans seem to suggest that a causative account takes a theory neutral description and improves on it by adding causal relations within a theory. I would argue that one can do no better than describe, and that description is the building of a theory.

Most of the time, the desiderata of a full formal dynamical description are not available to us. System boundaries are unclear, knowledge is incomplete, the objects of our attention are subject to too many uncontrolled influences, etc. That is just the everyday messy world of observational science. Efficient causal stories try and limit this complexity by positing hypothetical idealized entities A and B, which stand in causal relation.

By preferring formal causal accounts, we are acknowledging that any selection of A and B is the imposition of a theory, and full description is the best we can do. Efficient causal stories are just that: stories. They need langauge for expression (which formal causal accounts do not: they are captured by equations). Language gives us causal stories. They are important in coming to grips with the world in a common sense way. But they are not privileged. Nor do they trump formal causal accounts.

In this article, the consequences of transparency in public life are considered. It appears that money revels the collective nature of the system. Lawfulness appears in behavior, but that lawfulness requires us to posit a limited sort of an individual. Essentially selfish, but with a limited notion of self. Revealing our collective side, once again. Brains drive those smaller units, as they generate P-worlds. Consensus will be of our common nature, and not of that which is first person.

I have been re-engaging with a bit of theory.

When we find any unmistakably periodic behavior from an organism, one sensible theory is that something is oscillating to control that behavior. (Bob Port)

I need to consider why this is important. What is it that is oscillating? The undamped oscillator of task dynamics is a hack. That’s not a good enough description. But the maths gets hairy when you get more complex.

First, since the theory specifies attractors in terms of phase angle,
we expect that at least for moderate changes in rate (that is, changes
in the duration of the repetition cycle), the attractors should be
unaffected in terms of phase but vary in direct proportion with cycle
duration.

My stance here would be to shun the notion of control, and recognize that periodic system behavior is simply a  common form of viable, stable self-organized behavior.  It needs no controller, and indeed, it makes no sense if there is a controller.  It only makes sense because this is how simple systems, each with some autonomy, will couple.

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