[accessibleimage] Senses special: The art of seeing without sight

Hi, 
Forwarded from the AEB list.

New Scientist
Thursday, January 27, 2005

Senses special: The art of seeing without sight

By Alison Motluk

IT IS an odd sight. A middle-aged man, fully reclined,
drawing pictures of 
hammers and mugs and animal figurines on a special
clipboard, which is 
balanced precariously on a pillow atop his ample stomach.

A half-dozen people buzz around him. One adjusts a towel
under his neck to 
make him more comfortable, another wields a stopwatch and
chants 
instructions to start doing this or stop doing that, and yet
another 
translates everything into Turkish. A small group convenes
in a corner to 
assess the proceedings. A few of us just stand around
watching, and trying 
not to get in the way. The elaborate ritual is a practice
run for an 
upcoming brain scan and the researchers want to get
everything just right. 
Meanwhile, the man at the centre of all this attention, a
blind painter, 
cracks jokes that keep everyone tittering.

The painter is Esref Armagan. And he is here in Boston to
see if a peek 
inside his brain can explain how a man who has never seen
can paint pictures 
that the sighted easily recognise - and even admire. He
paints houses and 
mountains and lakes and faces and butterflies, but he's
never seen any of 
these things. He depicts colour, shadow and perspective, but
it is not clear 
how he could have witnessed these things either. How does he
do it?

Because if Armagan can represent images in the same way a
sighted person 
can, it raises big questions not only about how our brains
construct mental 
images, but also about the role those images play in seeing.
Do we build up 
mental images using just our eyes or do other senses
contribute too? How 
much can congenitally blind people really understand about
space and the 
layout of objects within it? How much "seeing" does a blind
person actually 
do?

Armagan was born 51 years ago in one of Istanbul's poorer
neighbourhoods. 
One of his eyes failed to develop beyond a rudimentary bud,
the other is 
stunted and scarred. It is impossible to know if he had some
vision as an 
infant, but he certainly never saw normally and his brain
detects no light 
now. Few of the children in his neighbourhood were formally
educated, and 
like them, he spent his early years playing in the streets.
But Armagan's 
blindness isolated him, and to pass the time, he turned to
drawing. At first 
he just scratched in the dirt. But by age 6 he was using
pencil and paper. 
At 18 he started painting with his fingers, first on paper,
then on canvas 
with oils. At age 42 he discovered fast-drying acrylics.

"He paints houses and mountains and lakes and faces and
butterflies, but 
he's never seen any of these things"His paintings are
disarmingly realistic. 
And his skills are formidable. "I have tested blind people
for decades," 
says John Kennedy, a psychologist at the University of
Toronto, "and I have 
never seen a performance like his." Kennedy's first
opportunity to meet and 
test Armagan in person was during a visit to New York last
May, for a forum 
organised by a group called Art Education for the Blind.
Armagan, who is 
something of a celebrity in Turkey, has become used to
touring with his 
canvases to the Czech Republic, China, Italy and the
Netherlands. What made 
this visit different was the interest shown by scientists -
both Kennedy and 
a team from Boston.

Kennedy put Armagan through a battery of tests. For
instance, he presented 
him with solid objects that he could feel - a cube, a cone
and a ball all in 
a row (dubbed the "three mountains task") - and asked him to
draw them. He 
then asked him to draw them as though he was perched
elsewhere at the table, 
across from himself, then to his right and left and hovering
overhead. 
Kennedy asked him to draw two rows of glasses, stretching
off into the 
distance. Representing this kind of perspective is tough
even for a sighted 
person. And when he asked him to draw a cube, and then to
rotate it to the 
left, and then further to the left, Armagan drew a scene
with all three 
cubes. Astonishingly, he drew it in three-point perspective
- showing a 
perfect grasp of how horizontal and vertical lines converge
at imaginary 
points in the distance. "My breath was taken away," Kennedy
says.

Kennedy has spent much of his career exploring art from the
perspective of 
blind people. He has shown that people who are congenitally
blind understand 
outline drawings when they feel them just as seeing people
do. They 
understand and can draw in three dimensions. In fact, blind
children develop 
the ability to draw, he has found, much as sighted children
do - but all too 
few blind children ever get the opportunity to explore this
ability. Even 
knowledge about perspective, he has come to believe, is
acquired in similar 
ways for both. "Where a sighted person looks out, a blind
person reaches 
out, and they will discover the same things," says Kennedy.
"The geometry of 
direction is common to vision and touch."

Lines and one-liners

It is the night before the Boston team's first brain scan.
Armagan is 
sitting at a long table at an inn, entertaining everyone
with one-liners, 
trying to explain how he does his artwork. Alvaro
Pascual-Leone, the Harvard 
neurologist who invited him here, and Amir Amedi, his
colleague, are 
challenging him with more and more complex tasks. Draw a
road leading away, 
says Pascual-Leone, with poles on either side and with a
source of light 
underneath. Armagan smiles confidently.

He uses a special rubberised tablet, called a "Sewell raised
line drawing 
kit". This device allows him to draw lines that rise off his
paper as tiny 
puckers, so that he can detect them with his fingertips. And
so he draws the 
road and the poles: one hand holding the pencil, the other
tracing along 
behind, like surrogate eyes, "observing" the image as it is
being laid down. 
A minute or so later, the picture is done. Pascual-Leone and
Amedi shake 
their heads in wonder.

So, we ask, how do you know how long these poles should be
as they recede? I 
was taught, he says. Not by any formal teacher, but by
casual comments by 
friends and acquaintances. How do you know about shadows? He
learned that 
too. He confides that for a long time he figured that if an
object was red, 
its shadow would be red too. "But I was told it wasn't," he
says. But how do 
you know about red? He knows that there's an important
visual quality to 
seen objects called "colour" and that it varies from object
to object. He's 
memorised what has what colour and even which ones clash.

Scanning the mind's eye

Next day, and the time has come for Armagan to get into the
scanner. The 
Harvard scientists are collaborating with scanning experts
at Boston 
University. In addition to taking a structural snapshot of
Armagan's brain 
and establishing if it can perceive any light (they
confirmed it cannot), 
this morning's experiment will have him doing some odd
sequences of tasks. 
He'll have a set number of seconds to feel an object,
imagine it and draw 
it. But he has also been asked to scribble, pretend to feel
an object and 
recall a list of objects that he learned days earlier.

Pascual-Leone and Amedi want to see what Armagan's brain can
tell them about 
neural plasticity. Both scientists have evidence that in the
absence of 
vision, the "visual" cortex - the part of the brain that
makes sense of the 
information coming from our eyes - does not lie idle.
Pascual-Leone has 
found that proficient Braille readers recruit this area for
touch. Amedi, 
along with Ehud Zohary at the Hebrew University in
Jerusalem, found that the 
area is also activated in verbal memory tasks.

When Amedi analysed the results, however, he found that
Armagan's visual 
cortex lit up during the drawing task, but hardly at all for
the verbal 
recall. Amedi was startled by this. "To get such
extraordinary plasticity 
for [drawing] and zero for verbal memory and language - it
was such a strong 
result," he says. He suspects that, to a certain extent, how
the unused 
visual areas are deployed depends on who you are and what
you need from your 
brain.

Even more intriguing was the way in which drawing activated
Armagan's visual 
cortex. It is now well established that when sighted people
try to imagine 
things - faces, scenes, colours, items they've just looked
at - they engage 
the same parts of their visual cortex that they use to see,
only to a much 
lesser degree. Creating these mental images is a lot like
seeing, only less 
powerful. When Armagan imagined items he had touched, parts
of his visual 
cortex, too, were mildly activated. But when he drew, his
visual cortex lit 
up as though he was seeing. In fact, says Pascual-Leone, a
naive viewer of 
his scan might assume Armagan really could see.

That result cracks open another big nut: what is "seeing"
exactly? Even 
without the ability to detect light, Armagan is coming
incredibly close to 
it, admits Pascual-Leone. We can't know what is actually
being generated in 
his brain. "But whatever that thing in his mind is, he is
able to transfer 
it to paper so that I unequivocally know it's the same
object he just felt," 
says Pascual-Leone.

"We normally think of seeing as the taking in of objective
reality through 
our eyes. But is it?"In his own life, too, Armagan seems to
have a 
remarkable grasp of space. He seldom gets lost, says his
manager Joan 
Eroncel. He has an uncanny sense of a room's dimensions. He
once drew the 
layout of an apartment he had only visited briefly, she
says, and remembered 
it perfectly nine years later.

We normally think of seeing as the taking in of objective
reality through 
our eyes. But is it? How much of what we think of as seeing
really comes 
from without, and how much from within? The visual cortex
may have a much 
more important role than we realise in creating expectations
for what we are 
about to see, says Pascual-Leone. "Seeing is only possible
when you know 
what you're going to see," he says. Perhaps in Armagan the
expectation part 
is operational, but there is simply no data coming in
visually.

Conventional wisdom suggests that a person can't have a
"mind's eye" without 
ever having had vision. But Pascual-Leone thinks Armagan
must have one. The 
researcher has long argued that you could arrive at the same
mental picture 
via different senses. In fact he thinks we all do this all
the time, 
integrating all the sensations of an object into our mental
picture of it. 
"When we see a cup," he says, "we're also feeling with our
mind's hand. 
Seeing is as much touching as it is seeing." But because
vision is so 
overwhelming, we are unaware of that, he says. But in
Armagan, 
significantly, that is not the case.

I sit across from the source of all this mystery and I ask
him about the 
birds he loves to paint. They are brightly coloured and
exotic and I wonder 
aloud how he knows how to depict them. He tells me about how
he used to own 
a parakeet shop. "They come to your hand," he says. "You can
easily touch 
them." He pauses and smiles and says: "I love being
surrounded by beauty."


http://www.newscientist.com/channel/being-human/mg18524841.700

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