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Long before Descartes famously declared,
"I think, therefore I am,"
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and long after that,
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scientists and philosophers alike
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have puzzled over what they call
the mind-body problem.
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Is the mind some separate, non-material
entity piloting a machine of flesh?
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Or if it's just a particularly elusive part
of our physical body,
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how can it translate the input of our
animal senses
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into the seemingly non-physical
experiences that we call thoughts?
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But though the answers have been
debated endlessly,
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new research suggests that
part of the problem lies
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in how we pose the question
in the first place,
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assuming a distinction between our
sensory perception and our ideas
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that may not really be there.
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The traditional model of our mental
function
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has been that the senses provide
separate data to our brain
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which are then translated into the
appropriate mental phenomena:
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visual images into trees, auditory
experiences into bird songs, and so on.
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But occasionally,
we have come across people
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whose senses seem to mingle together,
allowing them to hear colors,
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or taste sounds.
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Until recently, the common understanding
was that this phenomenon,
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called synesthesia,
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was a direct connection between the
parts of the brain
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responsible for sensory stimuli such as
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seeing the color yellow immediately
upon hearing the tone of b flat.
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But newer studies have
shown that synesthesia
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is actually mediated through our
understanding
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of the shapes, colors and sounds
that our senses apprehend.
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In order for the cross-sensory
experiences to occur,
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the higher level ideas and concepts
that our minds associate
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with the sensory input must be activated.
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For example, this shape can be seen as
either the letter "s" or the number "5,"
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and synesthetes associate each with
different colors or sounds
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based on how they interpret it
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despite the purely visual stimulus
remaining identical.
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In another study, synesthetes created
novel color associations
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for unfamiliar letters after learning
what the letters were.
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So because it relies on a connection
between ideas and senses,
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this mental phenomenon
underlying synesthesia
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is known as ideasthesia.
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Synesthesia only occurs in some people,
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although it may be more common
than previously thought.
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But ideasthesia itself is a
fundamental part of our lives.
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Virtually all of us recognize the color
red as warm and blue as cold.
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Many would agree that bright colors,
italic letters and thin lines
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are high-pitched,
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while earth tones are low-pitched.
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And while many of these associations
are acquired through cultural exposure,
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others have been demonstrated even
in infants and apes,
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suggesting that at least
some associations are inborn.
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When asked to choose between two
possible names for these shapes,
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people from entirely different cultural
and language backgrounds
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overwhelmingly agree that "kiki"
is the spiky star,
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while "bouba" is the rounded blob,
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both because of the sounds themselves
and the shapes our mouths make
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to produce them.
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And this leads to even more
associations
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within a rich semantic network.
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Kiki is described as nervous and clever,
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while bouba is perceived as lazy and slow.
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What all of this suggests is that our
everyday experiences
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of colors, sounds and other stimuli
do not live on separate sensory islands
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but are organized in a
network of associations
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similar to our language network.
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This is what enables us to
understand metaphors
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even though they make no logical sense,
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such as the comparison of snow
to a white blanket,
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based on the shared sensations of
softness and lightness.
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Ideasthesia may even be crucial to art,
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which relies on a synthesis of
the conceptual and the emotional.
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In great art, idea and aesthesia
enhance each other,
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whether it's song lyrics combining
perfectly with a melody,
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the thematic content of a painting
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heightened by its use of
colors and brushstrokes,
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or the well constructed plot of a novel
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conveyed through perfectly
crafted sentences.
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Most importantly, the network of
associations formed by ideasethesia
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may not only be similar to
our linguistic network
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but may, in fact, be an integral part of it.
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Rather than the traditional view,
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where our senses first capture
a collection of colors and shapes,
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or some vibrations in the air,
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and our mind then classifies them as a
tree or a siren,
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ideasthesia suggests that the two
processes occur simultaneously.
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Our sensory perceptions are shaped by
our conceptual understanding of the world.
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and the two are so connected that one
cannot exist without the other.
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If this model suggested
by ideasthesia is accurate,
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it may have major implications
for some of the biggest
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scientific and philosophical issues
surrounding the study of mind.
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Without a preexisting concept of self,
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Descartes would not have had an "I"
to attribute the thinking to.
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And without a preexisting network of
interrelated and distinct concepts,
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our sensory experience of the world
would be an undifferentiated mass
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rather than the discrete objects
we actually apprehend.
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For science, the task is to find where
this network lies,
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how it is formed, and
how it interacts with external stimuli.
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For philosophy,
the challenge is to rethink
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what this new model of consciousness means
for our understanding of our selves
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and our relation to the world around us.