Here's a language.
And here's a brain.
And this is a brain on language?
Just look at this brain!
In case you're not up to date on all the science,
there's a whole lot going on here.
There are neurons and glial cells, capillaries
and myelinated axons, all this anatomy.
But the sexiest stuff to focus on has been
the nerve cells in your cerebral cortex.
That's this outside layer here - the inside
looks whitish, this stuff looks grey, hence
the terms "white matter" and "grey matter".
The first real evidence of the brain's role
in language came not from observing "normal"
brains using language, but from damaged brains.
This started back in the 1800's, when pioneering
researchers dissected the brains of aphasiacs.
The Ancient Greek word ἀφασία simply
means 'speechlessness'.
Patients suffering from aphasia have head
injuries that disrupt their abilities to understand
or to produce speech.
It turns out that specific linguistic difficulties
were associated with lesions in specific parts
of the cortex.
The logic involved in pinning down these language
centers of the brain is pretty simple: if
someone doing action A has a healthy region
B, but someone else who has damage to region
B can't do A, then it looks like region B
is necessary for action A.
In 1861, the French surgeon, ahem...
Paul Broca, began to study the brains of aphasiacs
and hunted down just such a region apparently
crucial for speech production, a region we
today call Broca's area.
Inspired by Broca's findings, a German doctor
and anatomist named Carl Wernicke went and
found another region, this one linked to linguistic
understanding.
As you might have guessed, that region is
called Wernicke's area.
A little sidenote for you anatomy buffs or
anyone looking for extra credit.
Today's most widely used system for cutting
the brain into regions was proposed by another
German anatomist, Korbinian Brodmann.
This outer surface of the brain we've been
admiring has over two dozen of these Brodmann
areas.
Broca's corresponds to Brodmann areas 45 and
44, while 22 is home to Wernicke's area.
Both of these regions are most likely in your
left hemisphere.
With all the technological leaps forward we've
made in brain imaging since Broca's day, looking
inside the brain to see what's lighting up
where has obviously become even more important.
But don't let the aphasiacs mislead you.
What we're searching for inside the brain
isn't necessarily straightforward.
The way researchers speak about it, it's not
as if neuroimaging gives us the exact brain
location of language or of love or any other
human concept.
Instead, we get to see the areas of the brain
- the activation of the actual brain cells
- that are involved in performing a task.
These days, there are two fields that tackle
our topic of the day (which is "language and
the brain" in case you've forgotten).
The first one, neurolinguistics, makes an
entire discipline out of the kind of research
we've been chatting about.
Psycholinguistics, a related field, takes
on general questions like "how do humans acquire
language?" and "how do humans speak & understand?",
with a focus on the role of the mind in these
activities.
The two fields inform each other, meaning
that there is a high degree of interdisciplinarity
here.
With all this stuff about the brain going
through... your brain... think for a minute
about two 20th-century models of language.
In model #1, human language is a collection
of behaviors that are conditioned by external
stimuli.
Verbal behavior - language - that gets a favorable
response will be reinforced and repeated.
This is a perspective called Behaviorism,
and it places the brain in a background role.
Model #2 is a very popular linguistic model
of language, a model that dominated linguistics
during the second half of the twentieth century.
Known as Nativism, it holds that language
is an innate mental faculty.
Grammar isn't just a linguistic concept anymore,
it's actually born into every healthy human
brain.
But instead of marginalizing the brain by
focusing on external behavior and operant
conditioning, and instead of bringing linguistics
to the brain by mapping grammatical concepts
to brain areas, perhaps we could be a little
more considerate of what the brain is actually
doing when we articulate our understanding
of language.
Yes, being that specific with our familiar,
general, academic terms will require a bit
more intellectual muscle than ignoring the
brain or slapping stickers like "language",
"grammar", "speech" onto some part of your
cortex.
But consider it an invitation to get to know
your brain, and your brain on language, a
bit better.
