OverviewBroca's area also known as the Broca area can be found in the frontal left lobe. One of its most important functions include the production of speech. Studies of chronic aphasia have implicated the essential role it plays in various speech and language functions. Various language tasks have shown activation patterns on an fMRI. Research indicates that its function can shift to nearby areas in the brain if the Broca area is slowly deteriorating due to brain tumors. Patients who developed tumors that destroyed the area were still able to speak relatively well.
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Broca's area is in the left frontal lobe of the brain. It is near the bottom of the frontal lobe. Broca's area controls your speech. Since your speech is controlled here, if you damage this area you will have speech issues.
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Broca's area deals with forming words. Speech can be affected if there is damage to this part of the brain. You could be born with this damage or you could damage it in someway during your life. People with the same damage can be affected differently, some are not affected at all.
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Pierre Broca found Broca's area. He was a physician who was interested in evolution and comparative anatomy. His interests changed from when he first became a doctor to when he died.
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WHY |
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He was interested in the anatomy of the brain. He wanted to find where speech came from. Broca had heard of people with speech issues and wanted to find out more about them and why they had those issues. When these people died he performed autopsies to find why they had speech issues.
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Broca discovered where speech came from by comparing people's brains. He would look at someone who had no speech issues and then look at someone who had speech issues. He would look at people brain damage and find where the damage occurred and why.
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Pierre Broca found Broca's area in 1861. He also found Leborgne in 1861. This is kind of the start of his research. He preformed an autopsy on Leborgne and found a lesion in Broca's area. He found other people with speech issues and did autopsies on them. He found that they had issues in that area too, this supported his findings.
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Function
It was assumed that the primary role of Broca's area was more devoted to manage production than to language comprehension. Evidence has surfaced however that demonstrates that Broca's area also plays a significant role in language comprehension. Patients who have lesions in this area show inability to use synaptic information to determine the meaning of sentences and were also unable to speak correctly. Recent fMRI experiments and a number of neuroimaging studies have implicated the involvement of Broca's area in the processing of complex sentences and ambiguous sentences. Recent experiments have also indicated that the area is involved in various cognitive and perceptual tasks. When observing meaningful hand shadows resembling moving animals activation occurs in the frontal language area which shows that Broca's area plays a role in interpreting the action of others. Activation of Broca's area can be seen in many neuroimaging studies when representing meaningful hand gestures. Another recent study shows that word and gesture are related when looking at its motor goal and intention. This helps to explain why people who use sign language also suffer from language deficits. Language development in terms of evolution can also be seen here because of the fact that gesture aspects are translated into words. The somewhat essential role of the Broca's area in speech production has been questioned since it can be destroyed while leaving language mostly in tact. In one case a computer engineer had a slow-growing tumor that was removed. The removal of the tumor destroyed the left inferior and middle frontal gyrus, the head of the caudate nucleus, the anterior limb of the internal capsule, and the interior insula. However, minimal language problems arose. Minor problems such as the inability to create complex sentences including more than two subjects, multiple conjunctions or reported speech. The researchers explained these problems as due to working memory problems.
Clinical Significance
Multiple studies have revealed that those who stutter have an underactive Broca's area. Aphasia is an acquired language disorder affecting modalities such as writing, reading, speaking, and listening and results from brain damage. Patients with expressive aphasia also known as Broca's aphasia are individuals who cannot say what they want to say. They are more or less unable to generate fluent speech. They can usually comprehend words and sentences with a simple structure. Other problems that arise can include problems with fluency, articulation, word-finding, word repetition, and producing and comprehending complex grammatical sentences, both orally and in writing. There are multiple "types" of aphasia and each are characterized by a different set of language deficits. Those who have expressive aphasia tend to retain good spoken language comprehension while other types can leave patients without ant ability to understand spoken language. People with expressive aphasia may also struggle less with reading and writing than people with other types. Individuals who have expressive aphasia tend to have a good ability to self-monitor their language output while others are entirely unaware of their language deficits.
Broca and his patients
BROCA-Pierre Paul Broca was born in Sainte-Foy-la-Grande, Gironde, France on June 28, 1824. He became a physician, surgeon, anatomist, and anthropologist. Broca wasn't just interested in finding what part of the brain controls speech, he was also interested in cancer pathology, evolutionary psychology, and more. Broca's legacy is finding where speech is controlled. He found people with lesions in the frontal lobe who had speech issues. He tested different patients that supported his findings. Broca's signature is on the Eiffel Tower.
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LEBORGNE (TAN)
Leborgne was a patient of Broca's. He was almost completely unable to produce any words or phrases. He was able to receptively repeat the word "tan" however. A lesion was discovered in the surface of his frontal lobe after his death. |
LELONG
Lelong was another patient of Broca's. He was also unable to speak clearly. He could only say five words. "yes", "no", "three", "always", and "lelo" (a mispronunciation of his own name). After his death an autopsy revealed a lesion in the same region of lateral frontal lobe as in Leborgne. These two cases led Broca to believe that speech was localized to this particular area. |
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