Broca's area is the area of the brain responsible for speech production, language processing, and language comprehension, as well as controlling facial neurons. First discovered in 1861, this area was named after Pierre Paul Broca. Broca discovered the area after studying the brain of a patient with a speech impairment after his death.
This part of the brain is connected to the Wernick’s area of the brain by the arcuate fasciculus, which is a pathway made of neurons. It is found in the frontal lobe of the cortex, within the inferior frontal gyrus. It is comprised of two primary parts: the Pars triangularis and the Pars opercularis.
The Pars triangularis is located in the anterior portion of Broca's area. Researchers believe that this area of the brain is responsible for helping the human brain interpret different stimulus modes. It is also where verbal conducts are programmed in the brain.
The Pars opercularis is located in the posterior region of Broca's area. It is believed that this area supports only one stimulus mode, rather than multiple modes like the Pars triangularis. This portion is also thought to coordinate the organs used for speech in order to produce language. This conclusion has been drawn because the Pars opercularis is located near areas that are related to motor skills.
If this part of the brain is damaged, the person is said to suffer from Broca's area aphasia. This condition is also called expressive aphasia, nonfluent aphasia, or motor aphasia. A person suffering from this condition is unable to put together sentences that are grammatically complex. In addition, the sentences typically contain very few words related to content.
Despite the person’s difficulty in putting together sentences, a person with a damaged Broca's area is generally capable of comprehending language without a problem. In some cases, however, the person may have difficulty with understanding a few words used in a sentence with complex syntax. These individuals typically have damage only in the posterior portion of the area, a condition referred to as Wernicke’s aphasia. Those suffering from Wernicke’s aphasia may have somewhat normal speech, though it tends to be vague or even meaningless.
Individuals who stutter have also been found to have a smaller Pars triangularis and a decreased overall amount of activity in Broca's area. On the other hand, these individuals tend to have more activity in the right hemisphere of the area. It is believed that this increased activity is to compensate for the overall decrease.