Broca’s Aphasia

The first language area within the left hemisphere to be discovered is called Broca’s Area, after Paul Broca.  Broca was a French neurologist  who had a patient with severe language problems:  Although he could understand the speech of others with little difficulty, the only word he could produce was “tan.”  Because of this, Broca gave the patient the pseudonym “Tan.”  After the patient died, Broca performed an autopsy, and discovered that an area of the frontal lobe, just ahead of the motor cortex controlling the mouth, had been seriously damaged.  He correctly hypothesized that this area was responsible for speech production.



Physicians called the inability to speak aphasia, and the inability to produce speech was therefore called Broca’s aphasia, or expressive aphasia.  Someone with this kind of aphasia has little problem understanding speech.  But when trying to speak themselves are capable only of slow, laborious, often slurred sequences of words.  They don’t produce complete sentences, seldom use regular grammatical endings such as -ed for the past tense, and tend to leave out small grammatical words. 



It turns out that Broca’s area is not just a matter of getting language out in a motor sense, though.  It seems to be more generally involved in the ability to deal with grammar itself, at least the more complex aspects of grammar.  For example, when they hear sentences that are put into a passive form, they often misunderstand:  If you say “the boy was slapped by the girl,” they may understand you as communicating that the boy slapped the girl instead.