July 5th: Stephanie Azzarello, Amelia DeLise, and Gavin McIntyre

In our reading of Broca’s 1861 Remarks on the Seat of the Faculty of Articulated Speech, we were given a firsthand account of how Pierre Paul Broca came to discover the area of the brain now known as Broca’s area. 

While working at the Bicetre Hospital/Hospice, Broca came into contact with a patient known at the time as “Tan” because for the past 21 years of his life the only word he could articulate was “tan”.  Broca learned that when Tan had been admitted to the hospital 21 years earlier, he was only suffering from what come to be called Broca’s aphasia, an inability to produce speech.  During the most recent 10 years of his hospitalization, Tan also began to suffer from paralysis in his right arm, followed by paralysis in his right leg, and vision loss in his left eye.  After meeting the patient, Broca concluded that the problem must lie within the left hemisphere of the brain, since function of the arms and legs was known to be contralateral.  Upon Tan’s death, Broca performed an autopsy on Tan’s brain and found extensive damage to the left hemisphere, which included a large hole in the frontal lobe at the third frontal convolution.  He concluded that this area of the brain must be responsible for speech and that Tan’s aphasia resulted from this damage.

Not long after Broca’s discovery, a German neurologist named Carl Wernicke found another area of the brain involved in language processing. In 1874 Broca initially believed that he had discovered the area responsible for all speech related processes, however with Wernicke’s discovery it became clear this is not the case.  Whereas Broca’s area is involved with the production of speech and language, Wernicke’s area is involved in the comprehension of speech.  Damage to Wernicke’s Area, which is “located in the posterior third of the upper temporal convolution of the left hemisphere of the brain” (encyclopedia Britannica), causes individuals to experience trouble understanding language.  While people may speak fluently and form words correctly, the words are often devoid of meaning or context, creating nonsense phrases, often referred to as "word salad" when attempting to express their thoughts. Other less minor complications include things like generally vague language and the use of superfluous words when trying to express simple ideas.

Photo of Elizabeth Tower and the Palace of Westminster taken from the top of the London Eye

 Click here for a visual representation of Broca's area and Wernicke's area!

Timeline: 1861-- Paul Broca discovers what we now know as Broca's area.

References:

Benjamin, L. T. (2014). A Brief History of Modern Psychology(2^nd ed.). Hoboken, NJ: Wiley.

Broca, P. (1861b). Remarques sur le siége de la faculté du langage articulé, suivies d'une observation d'aphémie (perte de la parole). Bulletin de la Société Anatomique, 6, 330-357. Retrieved from http://psychclassics.yorku.ca/Broca/aphemie-e.htm

Wernicke's Aphasia. (n.d.). Retrieved July 5, 2015, from https://auditoryneuroscience.com/wernicke_aphasia

Wernicke area. (n.d.). Retrieved July 5, 2015, from http://www.britannica.com/science/Wernicke-area