[accessibleimage] Re: Probing Question: If a blind person gained sight, could they recognize objects previously touched?

Sight Unseen

 (By Michael Abrams.

Reprinted from Discover, June 2002.)

The Matilda Ziegler Magazine for the Blind, Vol.  97, No.  3
March 2003

The Matilda Ziegler Magazine for the Blind
80 Eighth Avenue, Room 1304,
New York, NY 10011
212-242-0263;
FAX:  212-633-1601
Website:
www.zieglermag.org E-mail:  blind@xxxxxxxxxxxxxxxx

 Mike May holds the world speed record for downhill skiing by a blind
person.  In his competitive days he would slalom down the steepest
black-diamond slopes at 65 miles an hour, with a guide 10 feet ahead to
shout "left" and "right."   The directions were just obvious cues.  The rest
came from the feel of the wind racing against his cheeks and the sound of
the guide's skis snicking over the snow.  But May's days as a world-class
blind athlete are behind him.  He's no longer blind.   May lost his vision
at the age of 3, when a jar of fuel for a miner's lantern exploded in his
face.  It destroyed his left eye and scarred the cornea of his right, but
over the next 43 years he never let those disabilities slow him down.  He
played flag football in elementary school, soccer in college, and nearly any
activity that didn't involve projectiles as an adult.  He earned a master's
degree in international affairs from Johns Hopkins, took a job with the CIA,
and became the president and CEO of the Sendero Group, a company that makes
talking Global Positioning Systems for the blind.  Along the way, he found
time to help develop the first laser turntable, marry, have two children,
and buy a house in Davis, CA.  "Someone once asked me if I could have vision
or fly to the moon, what would I choose?"  he once wrote.  "No question--I
would fly to the moon.  Lots of people have sight, few have gone to the
moon."    Then one November day in 1999, at St. Mary's Hospital in San
Francisco, surgeon Daniel Goodman dropped a doughnut of corneal stem cells
onto May's right eye (his left was too severely damaged to be repaired).
The cells replaced scar tissue and rebuilt the ocular surface, preparing the
eye for a corneal transplant.  On March 7, 2000, when the wraps were
removed, May got his first look at his wife, his children, and for the first
time since he was a toddler, himself.   Sight restoration is a periodic
miracle--both for its recipients and for the scientists who have the
privilege of studying them.  As early as the fifth century B.C., Egyptian
surgeons used a needle to push their patients' cataract- covered lenses away
from their pupils, affording them some degree of sight.  More recently, in
the late 1960's, surgeons learned to remove cataracts with ultrasound.  The
stem-cell surgery performed on May was developed in Japan and introduced in
1999.  Since then hundreds of people have benefited from it.  But of all
those who have had their sight restored throughout history, only about 20
recorded cases were blind since childhood, and of those, most had
less-than-perfect corneas after surgery.  When Goodman peered into May's eye
after the surgery, he saw a lens that ought to provide crystal-clear vision.
It doesn't.  May's brain has never been programmed to process the visual
information it receives.  May still travels with his dog, Josh, or taps the
sidewalk with a cane, and refers to himself as "a blind man with vision."
And that paradox fascinates Don MacLeod and Ione Fine, experimental
psychologists at the University of California at San Diego.  The speed with
which babies learn to understand the world suggests that they're born with
the ability to process some aspects of vision.  But which aspects, exactly?
What is learned and what is hardwired?  For a year and a half, Fine and
MacLeod put May through a battery of physical and psychological tests,
including functional magnetic resonance imaging, or fMRI, which tracks blood
flow in the brain.  The results are opening the first clear view into how we
learn to see.   MacLeod's laboratory at the university is a labyrinth of
filing cabinets, optical equipment, and oddly placed desks.  "It's well
booby-trapped," he says, steering May toward the first of many tests one
afternoon.  "But May has an uncanny ability to navigate complicated
arrangements."   Tall and athletic, with features that look boyishly
handsome despite his graying black hair, May would make a good James Bond if
not for a few side effects of his blindness.  Unlike the rest of his body,
his eyelids haven't had a lifelong workout.  Perpetually half closed, they
lend a stoic blankness to his face that's relieved only by the occasional
smile.  He has yet to learn facial expressions.   Sitting in front of a
computer monitor, May watches as thick black-and-orange bars appear on the
screen.  MacLeod and Fine are testing his ability to see detail.  His job is
to adjust the contrast with a trackball until he can just see the bars.  A
click on a mouse brings up another set of bars, thinner than the last, and
he plays around with those until he can see them too.  Although his right
eye ought to provide 20/20 vision, in reality it's closer to 20/500.
Instead of discerning the letter E on an eye chart from 25 feet, May can see
it only from two.  In the past the blurred vision of people with restored
sight was blamed on scar tissue from surgery.  But stem-cell surgery leaves
no scars.  The signals are reaching May's brain, but they are not being
interpreted very well.   More than 300 years ago, in a famous letter to the
philosopher John Locke, the Irish thinker William Molyneux anticipated what
May sees.  A blind man who is suddenly given vision, Molyneux suggested,
wouldn't be able to tell the difference between a cube and a sphere.  Sight
is one kind of perception and touch another; they can be linked only through
experience.   In the past half century, studies of sight restoration, most
notably by Oliver Sacks and Richard Gregory, have verified that some things
can't be understood without experience.  Objects, faces, depth--just about
everything that helps us function in the world--are meaningless when a
person who has never seen before gets sight.  "Babies are born in a bright,
buzzing confusion, but we can't ask them what it's like," Fine says.  "In
some ways talking to Mike May is like getting to talk to a 7-month-old."
In the first months after his surgery, May couldn't distinguish a sphere
from a cube.  Since then his sight has improved only slightly.  He has a
better grasp of spheres and squares ("We've shown him an awful lot of them,"
Fine says), and with practice he can understand things he's seen again and
again.  But this is only a work-around:  He's past the critical period for
learning to recognize objects instantly.   "Two of the major clues I have
are color and context," May says.  "When I see an orange thing on a
basketball court, I assume it's round.  But I may not be really seeing the
roundness of it."   Faces give him even more trouble.  Although he has seen
faces everywhere since the first day his vision was restored, they simply
don't coalesce into recognizable people.  Their expressions--their moods and
personalities--elude him entirely.  Even his wife is familiar to him only by
the quality of her gait, the length of her hair, and the clothes she wears.
"If a face has no hair and a fake moustache, [sighted people] can still tell
the gender," Fine says.  "But he can't....  The bit of the brain that does
that isn't working."    The best proof of this can be seen in the basement,
where MacLeod's interferometer sits.  Designed to test the brain's ability
to process visual information, the machine shines a split laser beam into a
subject's eye.  The beams bypass the optics of the cornea and project a
pattern onto the retina.  Most sighted subjects who sit in front of the
interferometer will see light and dark stripes, regardless of the quality of
their optics.  But when May opens his eyes to receive the beams, he sees
nothing at all.   The interferometer results are backed by fMRI scans, which
track May's brain activity as it's occurring.  The scans show that when May
sees faces and objects, the part of his brain that should be used to
recognize them is inactive.  But there's a catch.  When he sees an object in
motion, the motion-detection part of his brain lights up like a disco ball.
He can interpret movement on a computer screen as well as any normal-sighted
adult and seems to have the same skill in real life.  "We were driving
along, and a minivan came up to us pretty fast on his side," Fine remembers.
"It whizzed by him, and he mentioned that it was going fast.  That's a
complicated calculation.  The motion on the retina depends on how big the
car is, how close, and how fast it's going."    It's hard to escape the
conclusion that motion detection, unlike every other visual experience aside
from color, is largely hardwired.  It may explain why May, who can barely
recognize a stationary ball, is pretty good at catching a moving one.
Blind people spend their entire lives understanding the world through their
hands.  Their memories, their mental maps of the places they know, their
understanding of Labradors, doorknobs and the moguls on a ski slope are all
tactile.  The sudden introduction of a new sense can't alter that
fundamental way of experiencing the universe.  Instead, any new information
gleaned from light is simply graphed onto the original, tactile map.  "The
old idea that there is one picture of the world on the surface of the cortex
is way too simple," MacLeod says.  "In fact, we have a couple dozen complete
maps."   For someone just learning how to merge all that information, this
can make for a great deal of confusion.  But it might also offer a richer,
truer sense of the world than the one perceived by those who have never been
blind.   May's tactile experience with hallways and highways tells him that
their sides are parallel.  He can't perceive converging lines of
perspective.  "A hallway doesn't look like it closes in at all," he says.
"I see the lines on either side of the path, but I don't really think of
them as coming closer in the distance."   He pauses to mull this over.  "Or
maybe my mind doesn't believe what my mind is perceiving.  When I see an
object, it doesn't look different to me as I circle around it.  I know
orange cones around vehicles are cones because of context, not because I'm
seeing the shape.  If I picture looking down on a cone, it still looks like
a cone."    Learning to see, for May, is really about learning to fall for
the same illusions that sighted people do, to call a certain mass of colors
and lines his son, to call another group of them a ball.   One April
morning, only weeks after his eye surgery, May took his skis and his family
up to the Kirkwood Mountain Resort in the Sierra Nevadas--a place he knew
like the texture on the back of his hand.  This was where he had first
learned to ski and where he had later met his wife.  The sun was out, the
trees were green and the slopes were surrounded by gorgeous cliffs (Were
they miles away or just a few hundred yards?).  As the lift churned above,
skiers in puffy parkas flitted by, popping into his field of vision.  His
wife, acting as a guide, had to remind him to stop gawking and ski.   With
only one working eye, May already lacked depth perception.  But he also had
little experience reading the shades and contours of a landscape.  Heading
down the mountain, he could hardly distinguish shadows from people, poles or
rocks.  At first, he tried to compute the lay of the land consciously.  But
once he hit his first bump, he was tempted to close his eyes and ski the way
he knew and loved.   Only a handful of adults have ever seen the world
through the eyes of a newborn, and many who did came away wishing they were
still blind.  Their family and friends had convinced them that vision would
offer a miraculous new appreciation and understanding of the world.
Instead, even the simplest actions--walking down stairs, crossing the
street--became terrifyingly difficult.  Dispirited and depressed, about a
third of them reverted back to the world of the blind, preferring dark rooms
and walking with their eyes shut.   If May feels differently, it may be
because his expectations were so low.  For a man who used to enjoy
windsurfing blind and alone, able more often than not to return to the pier
from which he'd started, sight is just another adventure in a life of
invigorating obstacles.  Two years after his return to Kirkwood Mountain,
May has learned to match what he sees on a ski slope with his repeated
physical experience of it.  "He has jury-rigged himself quite a functional
little system," Fine says.  "He knows that this kind of shadow makes this
bump, this kind makes another."   Instead of closing his eyes on even the
easiest slopes, he can now negotiate moguls without a guide.   "People have
this idea that it's so overwhelmingly practical to have sight," May says.
"I say it's great from an entertainment point of view.  I'm constantly
looking for things that are unique to vision.  Running and catching a ball
is one of them--I've been chasing balls my whole life.  Seeing the
difference between the blue of my two sons' eyes is another.  Or if you drop
something, you can find it."

----- Original Message ----- 
From: "Peter Meijer" <blindfold@xxxxxxxxxx>
To: <accessibleimage@xxxxxxxxxxxxx>
Sent: Friday, April 21, 2006 12:30 AM
Subject: [accessibleimage] Probing Question: If a blind person gained sight,
could they recognize objects previously touched?


Hi All,

For your information, the subject line is the title of
an article that appeared yesterday on PhysOrg, addressing
a modern incarnation of the 17th century Molyneux question.
The article is at the URL

    http://www.physorg.com/news64769651.html

Best regards,

Peter Meijer


Seeing with Sound - The vOICe
http://www.seeingwithsound.com

Other related posts: