Re: [Phys-l] "Unlearning"

[Richard Grandy <rgrandy@rice.edu>]

It seems to me that this is not evidence of unlearning, here is an alternative:

On Monday students have stored the memory that the instructors shirt 
was blue.   On  Tuesday they store the image/memory of the shirt 
being red.  On Wed both are in storage and what they "recall" 
depends on which memory they access.

I think that there is a lot of experimental evidence that students 
(and faculty) who have learned Newtonian physics will access their 
still existing knowledge of Aristotelian/medieval physics if the 
situation is presented in  a way to elicit that.   (For faculty it 
requires some time pressure.)

It seems to me very important whether we model learning a new 
alternative as involving erasing the old beliers/concepts or instead 
as creating a new one which exists alongside the old one.

Richard Grandy
Philosophy & Cognitive Sciences
Rice University
Houston TX USA

> There is an example of unlearning from cognitive science.  It is now known
> that when you recall something you store it back before it leaves short term
> memory.  This is called reconsolidation.  It is possible to use this to
> unlearn something.
>
> The classic experiment is where the professor comes into a class on Monday
> with a blue shirt.  He calls attention to it.  Then the next day he asks the
> class what color shirt he had on, and many will remember it was blue.  Then
> he asks the class to just mentally picture him as coming in a red shirt.
> The following day he give a small quiz asking what color shirt he had on
> Monday.  A significant number will respond red.  They will even argue that
> they saw it as red, and that he couldn't have had a blue shirt.
>
> This is one of the reasons for prediction before demos.  The original memory
> can be effectively erased by subsequent cognition.  After all we do not have
> infinite memory, so we have to erase some things.  But you don't necessarily
> erase everything, so you modify some mental structures, but some others can
> be erased.
>
> Unlearning in the case of physics often involves much more difficult
> changes.  The students have to modify long standing conceptual paradigms
> that they formed through observation and through social communication.  The
> social interaction part of the message is often very hard to break.  So the
> idea of there being no gravity in space is often very hard to overcome.  You
> can ask them why the astronauts stayed on the Moon and you will get the
> reply they wore heavy boots.  The problem here is that their ability to
> realize when things are contradictory is low.  They need both an increase in
> thinking ability and experience in physics, or at least science.
>
> So unlearning or reconsolidation does exist as experiments have shown.  Look
> it up!
>
> John M. Clement
> Houston, TX
>
> >  -----Original Message-----
> >
> >  >
> >  >> - whether anything can be "unlearned" at all
> >  >
> >  > Habits can be changed.  For example, when people travel
> >  > from Britain to the US, we expect them to learn to drive
> >  > on the right side of the road.  Some of them struggle
> >  > with it more than others.
> >  >
> >  Sure, but you're not convincing me that "unlearning" exists.  Mental
> >  structures aren't overwhelmingly being erased --  but modified, extended
> >  and some aspects are suppressed -- the original stuff is ALL PRETTY MUCH
> >  STILL THERE.  When the people return to Britain they won't need to re-
> >  learn to drive from scratch, though they may have some inappropriate
> >  reactions at times.  They will not restart from zero.
>
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