TR announcement: W. Levelt, Multilayer FF Nets & Turing machines

[Jeff Elman]

I am forwarding the following Tech Report announcement on behalf of 
Pim Levelt, Max-Planck-Institute for Psycholinguistics.  Note that 
requests for reprints should go to 'pim at hnympi51.bitnet' -- not to me!

Jeff

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Jeff Elman suggested I announce the existence of the following
new paper:
 
Willem J.M. Levelt, ARE MULTILAYER FEEDFORWARD NETWORKS EFFECTIVELY
TURING MACHINES?
 
(Paper for conference on "Domains of Mental Functioning: Attempts
at a synthesis". Center for Interdisciplinary Research, Bielefeld,
December 4-8, 1989. Proceedings to be published in Psychological
Research, 1990).
 
Abstract:
Can connectionist networks implement any symbolic computation? That
would be the case if networks have effective Turing machine power. It
has been claimed that a recent mathematical result by Hornik,
Stinchcombe and White on the generative power of multilayer
feedforward networks has that implication. The present paper
considers whether that claim is correct. It is shown that finite
approximation measures, as used in Hornik et al.'s proof, are not adequate
for capturing the infinite recursiveness of recursive functions.
Therefore, the result is irrelevant to the issue at hand.
 
Willem Levelt, Max Plank Institute for Psycholinguistics, Nijmegen,
The Netherlands, e-mail: PIM at HNYMPI51 (on BITNET).
 
(PS. Jeff Elman and Don Norman own copies of the paper)