Path: utzoo!attcan!uunet!ogicse!milton!wcalvin
From: wcalvin@milton.u.washington.edu (William Calvin)
Newsgroups: comp.ai.philosophy
Subject: Re: emergence
Message-ID: <8712@milton.u.washington.edu>
Date: 7 Oct 90 01:25:51 GMT
References: <1990Oct4.152527.28413@watdragon.waterloo.edu> <1990Oct4.173933.7319@ux1.cso.uiuc.edu> <6@tdatirv.UUCP>
Organization: University of Washington, Seattle
Lines: 22

The emergent properties of the pattern generation circuits of the
lobster stomatogastric ganglion may be found in:
	Daniel K. Hartline, "Pattern generation in the lobster
(Panulirus) stomatogastric ganglion. II.  Pyloric network
simulation."  Biological Cybernetics 33:223-236 (1979).
	Daniel K. Hartline, "Simulation of restricted neurla networks
with reprogrammable neurons."  IEEE Trans. Circuits SSystems
36:653-660 (1989).

Briefly, the stomatogastric ganglion has only 30 neurons (all known
as identifiable individuals) and generates two independent rhythms, a
gastric mill rhythm (lobsters and crabs have teeth in their stomachs)
and a pyloric rhythm (for squeezing stomach contents into the gut). 
About 15 cells generate the gastric mill rhythm, the other 15 the
pyloric rhythm (which is a complicated three-phase rhythm, not your
usual rhythmic alternation).  Furthermore, the circuits are
functionally "rewired" by neuromodulators.

  William H. Calvin, University of Washington NJ-15, Seattle WA 98195 USA
  wcalvin@u.washington.edu         Favorite books on brains and evolution
  (probably because I wrote them myself):  _The Cerebral Symphony_
  (Bantam 1989); _The River that Flows Uphill_ (Sierra Club Books 1987).