The art of seeing without sight
New Scientist, 29 January 2005
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.
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.
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."