Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!pterodactyl.cis.ohio-state.edu!zwicky
From: zwicky@pterodactyl.cis.ohio-state.edu (Elizabeth D Zwicky)
Newsgroups: comp.cog-eng
Subject: Re: Handedness
Message-ID: <45540@tut.cis.ohio-state.edu>
Date: 26 Apr 89 21:23:08 GMT
References: <0ejKI2d3Uw1010VXzqU@amdahl.uts.amdahl.com> <1256@mmm.UUCP> <784@adobe.UUCP>
Sender: news@tut.cis.ohio-state.edu
Reply-To: Elizabeth D Zwicky <zwicky@cis.ohio-state.edu>
Distribution: na
Organization: Ohio State University Computer and Information Science
Lines: 36

In article <1256@mmm.UUCP> cipher@mmm.UUCP (Andre Guirard) writes:
>This suggests an interesting experiment... using various animals,
>test to see which ones can be trained to distinguish between left
>and right.  If a dog can understand the concept, it's probably not too
>abstract.

I don't know about dogs, but if you generalize about the abstractness
of right/left from horses, you'll be in trouble. Horses know right
from left very well; it is built into them. If you are training a
horse, and it decides that some inanimate object on the track is
a terrifying thing, you will have to train it out of this decision
twice; once with the object on the left, once with the object on the
right. In fact, everything you do on a horse must be done either
both ways, or always the same way. (For instance, you train movements
to both sides, but you don't train the horse to be mounted from either
side; you just always mount it from its left, and who care what it knows
about mounting from the right.)

However, this shouldn't tell us anything about how abstract right/left
is for humans, because this is primarily due to an important
*neurological* difference between people and horses. Horses do
not have a corpus callosum (the bundle of nerve fibers that in
most mammals connect the two hemispheres of the brain). Although
there is still communication between the hemispheres, it is small
enough that for many purposes a horse effectively has two brains.
There's no way for it not to make a right/left distinction; it *is*
a right/left distinction.

Since humans do have a corpus callosum, I can't see that data from
horses are applicable. In fact, I'm not certain that I'm willing to
take evidence from animals at all. Almost anything you can train at
all can be trained to distinguish squares from triangles, but that
doesn't make me think that "square", "triangle" and "shape" are not
abstract concepts. 

	Elizabeth