Today, we learn to see. The University of Houston's
College of Engineering presents this series about
the machines that make our civilization run, and
the people whose ingenuity created them.
Michael May is news at
summer's end, in 2003. May is the president of his
own company, and he's an excellent skier as well.
The surprising thing about May is that he'd
forgotten what it was to see, for a chemical
explosion blinded him when he was only three.
In 2000, a doctor did a radical operation that
restored sight in one of May's eyes. May is not the
first lifelong-blind person to have sight restored,
but such cases are very rare. Now May, articulate
and analytical, is helping us to understand how
vision works.
And so I turn to an old essay by neurophysiologist
Richard Gregory. Gregory tells how seventeenth
century philosophers asked what a person's reaction
to the sudden acquisition of sight might be. They
got their answer after Isaac Newton died. Newton's
physician, William Cheselden, went on to restore
sight to a boy born blind. He did so by operating
on congenital cataracts.
It turns out that the philosophers had predicted
the boy's response quite accurately. At first,
vision made no sense. Then the boy expected to be
able to touch everything his eyes showed him. He
was amazed by portraits. They had the same
general content as real faces; but, when he touched
them, they were flat and formless.
Being suddenly able to see for the first time is
the stuff of movie plots; but those plots are
not based on experience. The learning
curve is long and slow. Like that
eighteenth-century boy, Michael May still struggles
with nearness and distance. How to sort out a
landscape — why can't one touch trees in the
distance? May also echoes old cases histories with
his dislike of sights that're not smooth, clean,
and hard edged. Others have expressed repugnance at
any imperfection. And, at the heart of all cases,
is a need to use one's fingers to make sense of
visual images.
May also reports being stunned by what he called
the faucet of color that'd been turned on.
He'd heard that his wife was blonde. But, when he
finally saw her hair, he was bewildered by the
array of colors it presented. He couldn't separate
the hues in her hair from the shadows that hair
cast upon her face.
After three years, May still struggles with that
mountain cliff of a learning curve. He can catch a
ball, but he can't recognize faces. To identify
his own wife, he needs to add sound, touch,
and context to the sight of her. When he skis, he
has to close his eyes, now and then, to keep his
bearings.
May is providing physiologists with the chance to
learn all kinds of things about how the mind learns
to see. They now have a much clearer idea how the
mind loses the ability to accommodate certain new
sense data, after a certain age.
Still, this all leaves one key question hanging:
What would it be like for you or me to gain another
sense? I try to conceive a sixth sense, and I
cannot. Try as I may I find myself couching any new
sense in terms that I already know —
reading minds or seeing the
future, feeling a presence,
smelling fear — or tasting joy.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
R. L. Gregory, At First Sight. Even Odder
Perceptions, New York: Routledge, 1994, Chapter
8.
For material on Michael May, see:
http://www.sciencedaily.com/releases/2003/08/030826065256.htm
http://ucsdnews.ucsd.edu/newsrel/soc/sightregained.htm
http://www.guardian.co.uk/science/2003/aug/26/genetics.g2
The Engines of Our Ingenuity is
Copyright © 1988-2003 by John H.
Lienhard.
