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  • 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.

Here's a language. And here's a brain. And this is a brain on language?

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言語に関するあなたの脳。文法は頭の中にある?-- 言語学と論理学101 (Your Brain on Language: Is grammar inside my head? -- Linguistics & Logic 101)

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