[From Gary Cziko 930124.0500 GMT]
Avery Andrews 930123.1350 says:
There is perhaps an avenue of empirical investigation into Muscle Selection
as well. People appear to have a fixed handwriting
style that is invariant over a substantial size range, from blackboard
writing done with arm muscles, to ordinary writing done with fingers.
I read somewhere (maybe in Bill Powers's writings?) that this range is
considerably larger, all the way up to "writing" on the ground with a
"lime" cart (i.e., dropping white powder on the ground with carts as used
to mark playing fields) and sky writing from an airplane.
This suggests that a size-scalable perceptual target is involved,
perhaps involving kinesthetic effort perceptions, etc. If so, then
*deafferented* people would not be expected to have a size-scalable
handwriting style, at least when their eyes were closed. Writing
on the blackboard with your eyes closed and rubber bands attached to
your arms might reveal things as well.
There are some neat demos that can be done with writing. I described some
a while back again, but let me mention some of them again since I ran out
of time and didn't get a chance to demonstrate them at the Durango CSG
meeting last year. A blackboard with chalk works best for these. And your
subject should be a right-handed writer if you don't want her to get all
tangled up. No rubber bands or deafferentated people needed.
1. First, have your subject write a sentence like "The dog chased the cat"
with her right hand (RH). Easy. Now have her write the same sentence
under the first using her left hand (LH). Much harder for most.
Obviously, she knows what the words should LOOK like, but she doesn't know
what her LHed writing actions should FEEL like to make her writing look
normal. So the result is pretty sloppy writing.
2. Now have her write the same sentence mirror-reversed from right to left
with her left hand. This should be very hard if not impossible, since she
probably doesn't know what it should feel like OR look like (unless, of
course, she has studied Da Vinci's original manuscripts or facsimiles
thereof).
3. Now have your subject take a piece of chalk in each hand and while she
writes the sentence from right to left with her RH, have her write the
same words mirror-reversed with her LH from right to left. MUCH easier,
n'est-pas? Since she knows what it should feel like with her RH, she know
only needs to control a relationship of symmetrical movement between her
hands to write well with her LH.
4. After she's done this double writing for a while, she can stop writing
with her RH and continue with her left by IMAGINING that she is still
writing with her RH and controlling the symmetrical relationship between
them.
I've used this demo to show how effective it is to teach new skills by
basing them on what is already known. I will have one right-handed student
try to write mirror-reversed from right to left with her left hand without
instruction. For the other, I have her do the two-handed writing and then
imagine the right hand is still writing. The instructed student is always
much better much quicker on this task when given this shortcut to learning.
--Gary
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Gary Cziko Telephone: 217-333-8527
Educational Psychology FAX: 217-244-7620
University of Illinois E-mail: g-cziko@uiuc.edu
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210 Education Building
Champaign, Illinois 61820-6990
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