Path: utzoo!attcan!uunet!husc6!bloom-beacon!bu-cs!purdue!decwrl!labrea!agate!helios.ee.lbl.gov!lll-tis!oodis01!uplherc!sp7040!obie!wsccs!dharvey
From: dharvey@wsccs.UUCP (David Harvey)
Newsgroups: comp.ai
Subject: Re: Lightbulbs and Related Thoughts
Summary: Extend your scope
Keywords: problem solving,thought linkage
Message-ID: <778@wsccs.UUCP>
Date: 10 Nov 88 12:23:41 GMT
References: <1020@rlgvax.UUCP>
Lines: 128

In article <1020@rlgvax.UUCP>, tony@rlgvax.UUCP (Tony Stuart) writes:
> 
> 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.
>

Usually, advances by humans comes on top of what has gone before,
not inside a vacuumn.  I realize that this is not exactly what you
intended to present here, but it comes out that way regardless.
As to the better solution, that usually is the way it happens.
For examples, consider Keppler seeing inconsistencies between the
model proposed by Aristotle and the calculations (just think how
much faster his work would have been with a computer!) he made.
This of course prompted him to devise a new model.  Galileo and
Newton also saw inconsistencies between what was commonly believed
and the effects of gravity, ie, that accelaration was a constant
not affected by the mass of the object.  Einstein saw inconsistencies
even in this model and developed the theory of relativity.  In other
words, these people KNEW the textbook solutions.  What characterized
them as being different from the masses is that they had the tenacity
to reject the 'textbook' solution when a better model came to mind.
Just how this can be emulated in a computer is not that easy.  The
only thing that can be said is that inconsistencies of data with the
rule base must allow for a retraction of the rule and assertion for
new ones.

> 
> I've often wondered about the differences between short term
> and long term memory.
>

Don't forget to include the iconic memory.  This is the buffers
so to speak of our sensory processes.  I am sure that you have
saw many aspects of this phenomenon by now.  Examples are staring
at a flag of the United States for 30 seconds, then observing the
complementary colors of the flag if you then look at a blank wall
(usually works best if the wall is dark).  There are other ways
of observing that there really is such a thing as iconic memory,
but these must be performed in a lab setting with blind studies.
I helped perform one of these at the University of Utah.  How do
you implement this into your model?  I don't know, and I doubt
anyone else does either since much research must yet be done to
see the relationship between iconic, short term, and long term
memory.  Also, the differences between conscious and subconscious
memory processes must be considered.  Much of this iconic information
makes its way into memory via the subconscious track,  which I
would cite as evidence the studies being performed by various
researchers in Psychology.

You have observed the linking process that takes place in our
long term memories.  This is of course a dandy model until you
begin to look at some of our links.  They have some of the
following characteristics:

	[1]	Some of them seem to link together totally randomly.
		I am sure you have observed the phenomenon that some
		of your own links are rather mysterious, where the
		items are not logically related at all.  Nevertheless
		most of them ARE logically related.  Maybe we can
		randomly throw in a time frame for the other links.
		This of course supposes that we can prove that time
		is indeed the model that determines them.  By time
		I mean close time proximity for the linked structures.
	[2]	There are a massive amount of them that we search,
		sometimes in vain.  As witness to this consider the
		tip-of-the-tongue phenomenon that we are cursed with.
		I am sure that we all have experienced it.  Perhaps
		those with photographic memory are not cursed with it,
		but not being so blessed I would not know.  Also, some
		of these sturctures unlink with time and fall away.
		This last tidbit of course goes against the conventional
		textbook wisdom that they stay there forever.
	[3]	Since there are so many, we MUST use parallel processing
		to search them all.  Also realize that they are massive
		in nature, perhaps to the point of exceeding most mass
		storage devices (disks) in use today.

The short term memory does not necessarily have to have a different
data representation.  It still has a linking type nature.  The main
difference I see between the two is that short term memory has far
fewer links than long term.  What needs to be done is to study why and
how this short term memory links up with the long term memory.  Perhaps
frequency of use could be researched as the causal factor.  Initially,
we must establish a linking base for these short term facts to attach
themselves to.  As I see it there are several ways it will link into
the established long term memory.  First of course is the logical link.
Another would be a time frame link where what was considered immediately
before or after would be what we attach it to.  Also, since it is a well
established fact that we can chain things much better via poetry than
prose, rhythm and actual morphemes must be considered for chaining.

> 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.
> 

The problem is that there are more than enough holes for something
to be fit in.  Inconsistency seems to thrive in human beings.  It
is only when new information conflicts enough with old that we attempt
to rationalize the two conflicting 'facts'.  Unless the new information
outweighs the old in some way it never replaces it.  It can and does
coexist with the old in tension in many cases.  It is only when we reach
the discomfort level that we attempt to resolve the disparity of the
two in our fact base.

Well, now that I have given enough for Psychologists and AI researchers
to work on for the next 50 years (:-) I can go back to such mundane
chores as homework and sleeping.  Hmm, are we going to model the
activity of sleeping in our machine?

dharvey@wscss

The only thing you can know for sure,
is that you can't know anything for sure.