AI (discrete) moodel and NN (continuous) model

[Terry Sejnowski]

Regarding my comments about ideologies vs concrete problems,
I was objecting to arguments about semantics (what is and what 
isn't AI) and the right problem to study (biology vs machines)
when it is clear that different people are interested in
different problems and you arn't going to solve any problems
by arguing about taste.  Ken Miller made this point much better 
than I did.

Regarding the issue of mathematics vs problems,
there are quite a lot of problems that can be attacked with
what is already known about nonlinear dynamical systems
(including the present generation of recurrent neural nets).  
If new mathematics is needed someday we can create it, 
but my own preference is to concentrate on interesting problems
and to let the problem, whether it is a computational, psychological,
or a biological one, guide you to the right assumptions.  The difficulty
with simply looking for new mathematics is that the number of 
models and mathematical formalisms is infinite and without some
guidance the chances are you will be studying vortices.
I agree here with Jim Bower and Ken Miller.

Therefore, debating ideologies is less productive than
discussing interesting research problems.

Regarding interesting research problems, has anyone made any
progress with the Lo problem posed by Feldman, Lakoff et al
last year?  This is a miniature language acquisition problem
that has elements of vision, planning and learning as well
as language.  As stated, the goal of the problem is to be
able to answer simple yes/no questions about pictures of
squares, triangles and circles ("Is the circle to the right
of the square?").  A variant on this problem would be to
include a motor component, that is, to have the system
perform simple manipulations of the picture ("Move the circle
to the right side of the square.")  I suspect that the motor
system is an important part of animal cognition that
wouldn't be captured by a system that simply 
answered questions. This problem would also provide interesting 
comparisons with Winograd's program.  It is at the systems level
and is the sort that Aaron Sloman was referring to in his long
contribution to this topic, started, you will all recall, by
Jerry Feldman's original posting asking for achievements
in connectionism.  I hope that we have contributed more than just
this ongoing debate.

Terry

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