In frontal lobe lesions, a vast variety of behavioral and personality changes can occur. A millimeter can make all the difference. One particular lesion that has received a great deal of attention is damage to the Broca’s area, typically causing Broca’s aphasia. Another term for this condition is non-fluent aphasia. Those diagnosed with Broca’s aphasia are able to comprehend language, however their speaking and syntax abilities are severely limited.
Patrick McCaffrey, Ph.D. conducted research on this particular damage. According to McCaffery, the lesion that causes this aphasia occurs in the third frontal convolution (both the gyrus and the sulcus) of the left frontal lobe. In common cases, patients’ sentences are limited to four words, often in noun-verb combinations. Furthermore, repetition and word finding abilities are often impaired. Incidentally, Broca’s aphasia proves to be a very frustrating condition because patients are aware of their linguistic errors and disability, and there is absolutely nothing they can do about it. Additionally, writing skills are often limited while reading abilities remain relatively intact. Clearly, Broca's aphasia deserves the attention it receives.
A disorder that is often viewed as the opposite of Broca's Aphasia is Wernicke's Aphasia. Patients with Wernicke's Aphasis do not have the ability to comprehend language, but maintain the ability to generate grammatical speech. However, because they cannot comprehend language, their speech is generally incoherent.
ReplyDeleteBy conducting experiments that compare and contrast disorders that appear related as such, I think we have a stronger basis for exploring information than if we only had information on one disorder. Thus, we may be able to learn more about the mechanisms in the brain that affect our everyday actions and abilities.
One thing I would be curious to see is if having smaller lesions to only certain parts of Broca's produces different levels of Broca's aphasia severity. I know that certain brain regions, for example the insula, increase in complexity of processing in a posterior-to-anterior fashion. I wonder if a similar pattern might be seen in Broca's area - at least in the sense that some ares of it are responsible for certain parts of speech while others are responsible for different parts of speech.
ReplyDeleteIt is really amazing how the brain is so complex that a lesion in one area affects only parts of speech and language while others remain unaffected. The coding process for the different aspects of language in the human genome is something that would do a great deal of help to learn more about for patients such as these.
ReplyDeleteI agree with Ari's comment. A lot of people have accidents and completely lose the ability to generate speech. However, it is incredible that having a lesion in a specific area of the brain, like Broca's area, can partially "mess" up the ability to generate speech, but the person can still somewhat speak (limited), while fully understanding language. Faith's point about Wernicke's Aphasia is very interesting and worth looking into, since both conditions are similar yet somewhat opposite. Comparing both conditions and exploring them as pairs may lead to new findings.
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