Path: utzoo!attcan!uunet!rlgvax!tony
From: tony@rlgvax.UUCP (Tony Stuart)
Newsgroups: comp.ai
Subject: Lightbulbs and Related Thoughts
Keywords: problem solving,thought linkage
Message-ID: <1020@rlgvax.UUCP>
Date: 2 Nov 88 13:55:48 GMT
Organization: Computer Consoles Inc, Reston VA
Lines: 77

On the way into work this morning I was stopped at a light
near an office building. They were washing the windows using
a large crane. This lead me to think about the time that a
light was out in CCI's sign and they used a crane to replace
it. I began to wonder whether they replace all the lights while
they have the crane up or just the one that is out. Maybe it
depends on how close the lights are to the end of their rated
life. This got me thinking about the lights in the vanity at
home. Two of the four have blown in the last couple of weeks.
I remarked to Anne how it was interesting that lightbulbs do
start to blow out at around the same time. This lead me to
suggest that we remember to replace the blown out lightbulbs.

The point is that an external stimulus, seeing the men wash
the windows of the building, lead to a problem to solve, replacing
the lights in the vanity. I have no doubt that if I had replaced
those lights already then the train of thought would have
continued until I encountered a problem that needed attention.
The mind seems optimized for problem solving and perhaps one
reason for miscellaneous ramblings is that they uncover problems.

On a similar track, I have often thought that once we find a
solution to a problem it is much more difficult to search for
another solution. Over evolutionary history it is likely that
life was sufficiently primitive that a single good solution was
sufficient. The brain might be optimized such that the first
good solution satisifies the problem seeking mode and to go
beyond that solution requires concious effort. This is an
argument for not resorting to a textbook as the first line of
problem solving. The textbook is sure to give a good solution
but perhaps not the best. With the textbook solution in mind
it may be much more difficult to come up with an original
solution that is better than the textbook one. For this reason
it is best to try to solve the problem internally before going
to some external device.

There may also be some insite into how to make computers
think. Lets say I designed my computer to follow trains of
thought and at each thought it looked for unresolved questions.
If there were no unresolved questions it would continue onto
the next linked thought. Otherwise it would look for the
solution to the problem. If the search did not turn up the
information in memory it would result in the formation of
a question. Anne suggests that these trains of thought are
often triggered by external stimulae that a computer would
not have. She says that we live in a sea of stimulae.

I've often wondered about the differences between short term
and long term memory. Here's a computer model for it. Assume
that short term memory is information stored as sentences and
long term memory is information stored in data structures with
organized field name/field value/relationship links. Information
is initially stored in the sentence based short term memory.
In a background process, or when our minds are otherwise idle,
a task searches through the short term memory for data that
might resolve questions (holes) in the long term memory. (Which
is searched I don't really know.) This information in the short
term memory is then appropriately cataloged in the long term
memory. Another task is responsible for purging sentences
from the short term memory. It could use a first in-first out
or more likely a least frequently used algorithm.

A side effect of this model is that information in short
term memory cannot be used unless there is a hole in the long
term memory. This leads to problems in bootstrapping the
process, but assuming there is a solution to that problem, it
also models behavior that is present in humans. This is the
case of feeling that one hears a word or phrase a lot after
he knows what it means. Another part of the side effect is
that one cannot use information that he has unless it fits.
This means that it must be discarded until the long term
memory is sufficiently developed to accept it.

-- 

        Anthony F. Stuart, {uunet|sundc}!rlgvax!tony
        CCI, 11490 Commerce Park Drive, Reston, VA 22091