Category: News and Views
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."
that, is amazing! I can't even comprehend how that's possible. That's a true gift.
wow! that is amazing.
I remember watching him on TV. It was pretty amazing.