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Paul Broca and "Tan"

Paul Broca is one of the most influential neuroscientists best known for his patient, Tan. Well, his name wasn't really Tan. His name was Louis Victor Leborgne, and his incredibly unusual neurological disorder settled a debate about the location of language capabilities in the brain.

In 1861, Leborgne approached Broca at the Bicetre Hospital to receive surgery for a leg infection. Leborgne had suffered from several medical conditions prior to his surgery; he had epilepsy at a young age and subsequently lost his ability to produce fluent speech.

It was Leborgne's language disorder that really caught Broca's attention. Leborgne could think properly, but whenever he tried to communicate with Broca and verbalize his thoughts, all that came out of his mouth was the meaningless word "tan." For this reason, many scholars of neuroscience simply refer to Leborgne as "Tan".

Broca realized that he could learn about our language capabilities by studying Leborgne's brain. At the time, there was much debate about whether certain functions of the brain were localized to certain areas, or if the all areas of the brain were identical. Up until Broca's discovery, neuroscientists believed that the two cerebral hemispheres were identical in structure and function.

Upon his death, an autopsy of Leborgne's brain revealed deterioration of a certain area in his left frontal lobe, as seen in the images below. Over the next several years, Broca identified many similar patients who had damage to their left frontal lobe along with a deficit in producing fluent speech. This specific area linked to speech impairment became known as Broca's area. The associated language problem, involving a deficiency in the ability to produce fluent language, became known as Broca's aphasia.


Image result for broca's areaImage result for broca's area


Broca's findings regarding fluent speech production have made him very well-known in the history of neuroscience.

Neuroscientist Carl Wernicke made another significant discovery about speech production that further supported the notion of cerebral dominance and localized functions of the brain. Read more about Wernicke in this blog post.
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Image Credit:
(1) “Broca's Area - Lateral View.” Wikimedia Commons, 2 May 2014, upload.wikimedia.org/wikipedia/commons/b/b4/Broca%27s_area_-_lateral_view.png.

(2) “Broca's Area - Anterior View.” Wikimedia Commons, 2 May 2014, upload.wikimedia.org/wikipedia/commons/d/d0/Broca%27s_area_-_anterior_view.png.

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