## Dynamics in Cognitive Science

*17 Dec 2004 09:10*

Since the early 1990s, some people have gotten very excited about the idea
that dynamical systems theory can be used to model cognitive processes. As somebody trained
in nonlinear dynamics, I applaud this development,
since, if successful, it will enhance my material and academic prospects.
Sadly, when they do things like purporting to explain decision-making with a low (8) dimensional model with
no noise, I grow deeply suspicious. Worse, many of these same people believe
that dynamics gives them an account of cognition which is *incompatible*
with traditional models, whether of the (Newell-Simon)
symbol-processing or connectionist sort, and in
fact one which is fundamentally non-computational. As somebody trained in the symbolic aspects of nonlinear dynamics, and
who uses that math to study the intrinsic computation carried out by
dynamical systems, I have to wonder what they're talking about.

*To do*: Find something interesting to say about this by December,
when abstracts are due for the Potsdam workshop
on Dynamical
Systems Approaches to Language and Symbol
Grounding. **Update**, December 2005: Well, I don't
know if what I found to say *was* interesting, but you can read the
abstract here.

*See also*:
Artificial Intelligence;
Notes on a Lecture on "Origins of
an Embodied Cognition: Moving, Perceiving, and Thinking in Infancy";
Philosophy of Mind

- Recommended:
- James P. Crutchfield,
"Dynamical Embodiments of Computation in Cognitive Processes", Behavioral
and Brain Sciences
**21**(1998): 635--637 [Online] - Chris Eliasmith, "Attractive and In-discrete: A Critique of Two
Putative Virtues of the Dynamicist Theory of Mind", Minds and
Machines
**11**(2001): 417--426 [Journal link, HTML preprint] - Clark
Glymour, "Goethe to van Gelder: Comments on 'Dynamical Systems' Models of
Cognition" [
*Abstract*: "The 'dynamical systems' model of cognitive processing is not an alternative computational model. The proposals about 'computation' that accompany it are either vacuous or do not distinguish it from a variety of standard computational models. I conclude that the real motivation for van Gelder's version of the account is not technical or computational, but is rather in the spirit of*natur-philosophie*." Available as a (boo, his) RTF document, PHIL-SCI 139] - Melanie Mitchell
- "A complex-systems perspective on the 'computation vs. dynamics' debate in cognitive science", in M. A. Gernsbacher and S. J. Derry (eds.), Proceedings of the 20th Annual Conference of the Cognitive Science Society (Cogsci98), pp. 710--715 [PDF]
- "Theories of structure vs. theories of change",
Behavioral and Brain Sciences
**21**(1998): 645--646 [PDF]

- Dis-recommended:
- Marco Giunti, Computation, Dynamics and Cognition
[Actually, there's a lot of good stuff in this book, but I think it's quite
unhelpful
*on this topic*. For instance, while he correctly points out that all computational systems*are*dynamical systems, he takes a ridiculously restrictive view of computation, especially of analog computation. By his definition, y=sin(x) is an uncomputable function, and I think even y=x, the identity function, is uncomputable.] - T. van Gelder, "The dynamical hypothesis in cognitive
science", Behavioral and Brain Sciences
**21**(1998): 615--665 [On which the papers by Crutchfield and Mitchell in the same volume of BBS are commentary. Frankly the rest of van Gelder's work, e.g. the book he edited with R. Port called Mind as Motion, is no more impressive to me.]

- To read:
- Peter beim Graben, "Incompatible implementations of physical symbol
systems", Mind and Matter
**2**(2004): 29--51 [PDF via Dr. beim Graben] - Istavan S. N. Berkeley, "What the #$*%! is a
Subsymbol?", Minds and Machines
**10**(2000): 1--13 - Rick Dale and Michael J. Spivey, "From apples and oranges to
symbolic dynamics: a framework for conciliating notions of cognitive
representation",
Journal of
Experimental and Theoretical Artificial Intelligence
**17**(2005): 317--342 - Herbert Jaeger, "From Continuous Dynamics to Symbols", in W. Tschacher and J.-P. Dauwalder (eds.), Dynamics, Synergetics, Autonomous Agents (Singapore: World Scientific, 1999) pp. 29--48 [PDF]
- Teed Rockwell, "Attractor Spaces as Modules: A Semi-Eliminative
Reduction of Symbolic AI to Dynamic Systems Theory", Minds and
Machines
**15**(2005): 23--55 - Whit Schonbein, "Cognition and the Power of Continuous Dynamical
Systems", Minds and
Machines
**15**(2005): 57--71