Unformatted text preview: to a disembodied beak
with no mother attached.
Why does a chick think a scientist waving a beak is a mother
seagull? Well, the goal of vision is to do as little processing or
computation as is necessary for the job on hand, in this case
for recognizing mother. And through millions of years of evolution, the chick has acquired the wisdom that this long thing
with a red spot always has a mother attached to it, rather than
a mutant pig or a malicious ethologist. So it can take advantage of the statistical redundancy in nature and assume “Long
yellow thing with a red spot equals mother,” thereby simplifying the processing and saving a lot of computational labor.
That seems fair enough. But what Tinbergen found next is
that he didn’t even need a beak. He took a long yellow stick
with three red stripes, which looked nothing like a beak—and
that’s important—and the chicks pecked at the stick even more
than they would have pecked at a real beak. They preferred it
to a real beak, even though it didn’t resemble a beak. Tinbergen had stumbled on a superbeak—an ultrabeak. So the
chick’s brain goes, “Wow, what a sexy beak!”
Why does this happen? We don’t know exactly, but obviously
there are neural circuits in the visual pathways of the chick’s
brain that are specialized to detect a beak as soon as the chick
175 the internet and the university hatches. They fire upon seeing the beak. Perhaps because of
the way they are wired up, they may actually respond more
powerfully to the stick with the three stripes than to a real
beak. Maybe the neurons’ receptive field embodies a rule such
as “the more red contour the better.” And so even though the
stick doesn’t look like a beak—maybe not even to the chick—
this strange object is actually more effective in driving beak detectors than a real beak. And a message from this beak-detecting neuron goes to the emotional limbic centers in the chick’s
brain, giving it a big jolt and the message “Here is a superbeak.” The chick is absolutely mesmerized.
All of which brings me to my punch line about art. If herring
gulls had an art gallery, they would hang a long stick with three
red stripes on the wall; they would worship it, pay millions of
dollars for it, call it a Picasso, but not understand why—why
they are mesmerized by this thing even though it doesn’t resemble anything. That’s all any art lover is doing when buying
contemporary art: behaving exactly like those gull chicks.
In other words, human artists through trial and error,
through intuition, through genius, have discovered the figural
primitives of our perceptual grammar. They are tapping into
these and creating for the human brain the equivalent of the
long stick with three stripes. And what emerges is a Henry
Moore or a Picasso.
The advantage with these ideas is that they can be tested experimentally. It is possible to record from cells in the fusiform
gyrus of the brain that respond powerfully to individual faces.
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- Summer '09
- artful brain