the symbol grounding problem

[Phillipe Schyns]

Here is the abstract of a paper that will appear in Cognitive Science.
Although its main topic is conceptual development and lexical acquisition, 
it presents a solution to the symbol grounding problem which is compatible
with Harnard's proposal.

Schyns, P. G.  (in press).  A neural network model of conceptual development,
   Cognitive Science.

                                 Abstract

Previous neural network models of concept learning were mainly implemented
with supervised learning schemes.  However, studies of human conceptual
memory have shown that concepts may be learned without a teacher who
provides the category name to associate with exemplars.  A modular neural
network architecture that realizes concept acquisition through two 
functionally distinct operations, categorizing and naming, is proposed as
an alternative.  An unsupervised algorithm realizes the categorizing module
by constructing representations of categories compatible with Prototype
Theory.  The naming module associates category names to the output of the
categorizing module in a supervised mode.  In such modular architecture,
the interface between the modules can be conceived of as an "informational
relay" that encodes, constrains and propagates important information.
Five experiments were conducted to analyze the relationships between 
internal conceptual codes and simple conceptual and lexical development.
The first wo experiments show a prototype effect and illustrate some
basic characteristics of the system.  The third experiment presents a
bottom-up model of the narrowing down of children's early lexical categories
that honors Mutual Exclusivity.  The fourth experiment introduces top-down
constraints on conceptual coding.  The fifth experiment exhibits how
hierarchical relationships between concepts are learned by the architecture
while it also demonstrates how a spectrum of conceptual expertise may
gradually emerge as a consequence of experiencing more with certain categories
than with others.

Part of this work appeared in the Proceedings of the 1990 Connectionist
Models Summer School.

Schyns, P. G. (1990). A modular neural network model of the acquisition of
  category names in children. Proceedings of the 1990 Connectionist Models 
  Summer School, 228-235, Morgan Kaufmann, CA.

Philippe


===========================================================================
Philippe G. Schyns
Dpt. of Cognitive and Linguistic Sciences
Box 1978
Brown University
Providence, RI, 02912