paper available: "Connectionism, Novel Skill Combinations, Cognitive Architecture"

[Bob Hadley]

FTP-host: ftp.fas.sfu.ca
FTP-filename: pub/cs/hadley/skills.ps
Total pages: 32 at 1.2 spacing.



          Connectionism and Novel Combinations of Skills: 
              Implications for Cognitive Architecture
 
			   by

                     Robert F. Hadley

                Technical Report  SFU CMPT TR 1998-01
  
                        ABSTRACT

In the late 1980s, there were many who heralded the
emergence of connectionism as a new paradigm -- one which would
eventually displace the classically symbolic methods then
dominant in AI and Cognitive Science.   At present, there remain
influential connectionists who 
continue to defend connectionism as a more realistic paradigm
for modelling cognition, at all levels of abstraction, than
the classical algorithmic methods of AI.  Not infrequently, one
encounters arguments along these lines:  given what we know about
neurophysiology, it is just not plausible to suppose that our
brains possess an architecture anything like classical von
Neumann machines.   Our brains are not digital computers, and so,
cannot support a classical architecture.  

In this paper, I  advocate a middle ground.  I assume, for
argument's sake, that some form(s) of connectionism  can  provide
reasonably approximate models --  at least for lower-level
cognitive processes.   Given this assumption, I argue on
theoretical and empirical grounds that MOST  human  mental skills
must reside in *separate* connectionist modules or
``sub-networks''.     Ultimately, it is argued  that the basic
tenets of connectionism, in conjunction with the fact that humans
often employ  novel combinations of skill modules in rule
following and problem solving, lead to the  plausible
conclusion that, in  certain domains, high level cognition
requires some form of classical architecture.    During the
course of argument, it emerges that only an architecture with
classical structure could support the novel patterns of 
*information flow* and interaction that would exist among the
relevant set of modules.  Such  a classical architecture  might
very well reside in the abstract levels of a hybrid system whose
lower-level modules are purely connectionist.      

N.B.  "Classical architecture" here derives from models found in
computer science.  My arguments are not the same as those given
by Fodor and Pylyshyn, 1988.

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The paper,  ``Connectionism and Novel Combinations ...''
can be obtained  via ftp by doing the following:

    ftp   ftp.fas.sfu.ca

    When asked for your name, type the word:  anonymous  

    When asked for a password, use your e-mail address.

    Then, you should change directories as follows:


	 cd  pub
	 cd  cs
	 cd hadley

	 
	 and then do a get, as in:

	 get skills.ps
	 
  To exit from ftp, type : quit