Thursday, June 10, 2010

Colorless Green Ideas Sleep Furiously*

In 1861, a patient known only by Tan, as that was the single word he was able to clearly speak, underwent an autopsy. The French physician performing the procedure, Paul Broca, identified damage to a specific region on the left side of Tan’s brain. Broca concluded that the affected area was where the brain cells responsible for producing speech were located. It turns out that Broca was correct, and this region of the brain that controls speech production is now called Broca’s area. Patients that speak in a broken, choppy, or very limited capacity often do so because of damage to Broca’s area. These patients are said to have Broca’s aphasia. An example of this debilitating condition can be seen here.

Aphasia is essentially a term used to describe any language impairment. Aphasias can be expressive in nature, like in the case of Broca's, but sensory aphasias are also commonly encountered. A sensory aphasia causes individuals to no longer understand the meaning of language and is often due to neurological damage in a specific brain region known as Wernicke’s area.

A contemporary of Broca, a German physician named Carl Wernicke (pronounced Vern-nick-key), was also interested in how brain disease affects speech and language. His research identified the specific area of the brain responsible for processing the meaning of language, an area now known as Wernicke’s area. While patients with Wernicke’s aphasia do not lose the ability to speak, they do lose the ability to understand the meaning of language. A Wernicke's aphasiac will babble unintelligibly, and speak using a jumble of meaningless phrases, described as a “word salad”. An example of Wernicke's aphasia can be seen here.

It is doubtful that you would be unaware of having an aphasia as symptoms are obvious and include:

  • inability to pronounce words, not due to muscle paralysis or weakness
  • inability to name objects
  • poor enunciation
  • inability to repeat a phrase
  • persistent repetition of phrases
  • agrammatism (inability to speak in a grammatically correct fashion)
  • dysprosody (alterations in inflexion, stress, and rhythm)
  • speaking in incomplete sentences
  • inability to read
  • inability to write
June is Aphasia Awareness Month - you can now consider yourself aware but for more information, look to the National Aphasia Association.


*Noam Chomsky's famous example of a word salad. It demonstrates that randomly chosen words that while arranged in a phrase that appears to give them meaning, actually carry no significance.

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8 comments:

  1. The symptoms listed above match up well with our general population. I think we need help.

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  2. That is very compelling and rich. I had a headache the other day, and I thought I "Broca my brain." Good too no their was a diffrent prognoses, methinks.

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  3. I often struggle with nominal aphasia, and lose nouns all the time.

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  4. I used to get aphasia on Thursday nights, but it cleared up.

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  5. I have a very creative "word salad" when I hand out with my close friend vodka

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  6. Interesting post Ryan. Is language always on the left side of the brain? Does it have anything to do with the left brain/right brain research?

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  7. Great question Robyn:

    The majority of the "right brain/left brain" stuff is a joke. The idea that there are right brain vs left brain thinkers is not supported by neuroscience research and is not taken seriously by scientists. Language areas are located in the brain's left hemisphere, but I am unaware of any other difference between the two halves.

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  8. Very interesting and well written, once again

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