Three-Toed Sloth

April Fool's Sloth

For April Fool's Day, Mark Liberman (a.k.a. Mr. LanguageLog) has arranged for me to give a colloquium talk to his colleagues at the University of Pennsylvania's Institute for Research in Cognitive Science. I'll be speaking this Friday at noon.

"Coarse-graining, symbolic dynamics and collective coordinates: How physicists deal with large, complex systems, and why cognitive scientists might care"

Abstract: Many systems in statistical physics admit multiple levels of description, from microscopic molecular detail up through very broad macroscopic features. The higher-level descriptions are "coarse-grainings" of the lower levels, and the higher-level variables are generally collective properties of many lower-level objects. Not every coarse-graining leads to a "good" set of macroscopic variables; those that do have certain statistical properties. These properties, in turn, have important information-theoretic implications, and, when the coarse-graining is discrete ("symbolic dynamics"), the system can be modeled by stochastic automata. After sketching these ideas, I suggest some ways they might help cognitive scientists relate symbolic or computational descriptions to neural, dynamical ones.

This is largely based on my paper with Cris Moore on the nature of macroscopic states in statistical mechanics, plus some irresponsible speculations about coarse-graining neural dynamics to yield symbolic cognitive states, which should on no account be held against him. Hopefully these speculations are not so irresponsible that I will have to deny knowing myself, but we'll see what people with actual knowledge of the relevant subjects think on Friday.

(I didn't post about my last three talks, but what would this blog be without my shameless, yet ineffectual, attempts at self-promotion? )

Self-Centered; Physics; Minds, Brains, and Neurons