"Classic Model" of Language
Link
http://neurosciencenews.com/broca-and-wernicke-are-dead-its-time-to-rewrite-the-neurobiology-of-language/
Brief Summary
This article focuses on addressing how the “Classic Model” of language function—the Broca’s area and Wernicke’s area—is not viewed as the most supported theory anymore. Researchers conducted a survey in which they were attempting to determine the whether the Classic Model is the best available theory, which only 2% of the scientists and medics reported as being the case. This model creates the idea that the Broca’s area and Wernicke’s area are connected via a single tract, so these are the only areas that can be deemed responsible for the overarching concept of language. According to modern findings, there are multiple tracts connecting the two regions—the uncinate fasciculus, the inferior front-occipital fasciculus, the middle longitudinal fasciculus and the inferior longitudinal fasciculus. There is also the belief that language function can be found in areas of the frontal, parietal, and temporal lobes, as well as the medial hemisphere, the basal ganglia, thalamus, and cerebellum. The fear with this is that there can be the lack of the account of language-related symptoms due to complications within these regions of the brain because neuropsychology and neurology students are only being presented with the “Classic Model”. If we abandon trusting the “Classic Model” then we may be opening up the door for further theoretical advancement.
Tie to Psychology
The concept of localization encourages the belief that the brain can be viewed as different parts that serve different functions. This idea first arose when Paul Broca had patients who suffered a speech impairment; when he examined their autopsies he found that they were missing part of their brain in the frontal lobe which was the area responsible for generating the movement to create speech. This would now be identified as Broca’s area—the part of the brain pertaining to speech production. Other cases of localization exist such as Fritsch and Hitzig stimulating a specific area within the frontal lobe—later identified as the motor cortex—with the results of involuntary movements from the dogs such as responses in the dogs’ leg muscles. In the end, localization cannot be used as a solid idea of how the brain functions because many functions are spread across multiple parts of the brain. This article attempts to address that the “Classic Model” of language function—the Broca’s area and Wernicke’s area—is not the best way to view the concept of language. The author provides the modern findings that state the presence of language function in other tracts as well as multiple other areas of the brain. If there are other areas that are helping compose language functions, why is it that Paul Broca’s patients were unable to produce speech? We discussed that when some parts of the brain are damaged that other areas can pick up some of the slack, so why did that not happen with the patients missing Broca’s area? If the answer pertains to the idea that Broca’s area is the only area in the brain that can produce speech, then why do we not support localization? There is the idea that multiple tracts and parts of the brain work together for language function but certain functions can only be produced by certain parts of the brain. It is interesting that we do not fully support localization despite the fact that we divide the brain into different parts that identify with certain functions. Some functions are widely distributed across many regions but others are concentrated in one area alone.
http://neurosciencenews.com/broca-and-wernicke-are-dead-its-time-to-rewrite-the-neurobiology-of-language/
Brief Summary
This article focuses on addressing how the “Classic Model” of language function—the Broca’s area and Wernicke’s area—is not viewed as the most supported theory anymore. Researchers conducted a survey in which they were attempting to determine the whether the Classic Model is the best available theory, which only 2% of the scientists and medics reported as being the case. This model creates the idea that the Broca’s area and Wernicke’s area are connected via a single tract, so these are the only areas that can be deemed responsible for the overarching concept of language. According to modern findings, there are multiple tracts connecting the two regions—the uncinate fasciculus, the inferior front-occipital fasciculus, the middle longitudinal fasciculus and the inferior longitudinal fasciculus. There is also the belief that language function can be found in areas of the frontal, parietal, and temporal lobes, as well as the medial hemisphere, the basal ganglia, thalamus, and cerebellum. The fear with this is that there can be the lack of the account of language-related symptoms due to complications within these regions of the brain because neuropsychology and neurology students are only being presented with the “Classic Model”. If we abandon trusting the “Classic Model” then we may be opening up the door for further theoretical advancement.
Tie to Psychology
The concept of localization encourages the belief that the brain can be viewed as different parts that serve different functions. This idea first arose when Paul Broca had patients who suffered a speech impairment; when he examined their autopsies he found that they were missing part of their brain in the frontal lobe which was the area responsible for generating the movement to create speech. This would now be identified as Broca’s area—the part of the brain pertaining to speech production. Other cases of localization exist such as Fritsch and Hitzig stimulating a specific area within the frontal lobe—later identified as the motor cortex—with the results of involuntary movements from the dogs such as responses in the dogs’ leg muscles. In the end, localization cannot be used as a solid idea of how the brain functions because many functions are spread across multiple parts of the brain. This article attempts to address that the “Classic Model” of language function—the Broca’s area and Wernicke’s area—is not the best way to view the concept of language. The author provides the modern findings that state the presence of language function in other tracts as well as multiple other areas of the brain. If there are other areas that are helping compose language functions, why is it that Paul Broca’s patients were unable to produce speech? We discussed that when some parts of the brain are damaged that other areas can pick up some of the slack, so why did that not happen with the patients missing Broca’s area? If the answer pertains to the idea that Broca’s area is the only area in the brain that can produce speech, then why do we not support localization? There is the idea that multiple tracts and parts of the brain work together for language function but certain functions can only be produced by certain parts of the brain. It is interesting that we do not fully support localization despite the fact that we divide the brain into different parts that identify with certain functions. Some functions are widely distributed across many regions but others are concentrated in one area alone.
This is a very interesting article. I remember in the beginning of the semester when we discussed the accuracy of localization as being only semi-accurate. This was because the brain is so complex and not just one brain area contributes to a particular function, especially complex functions. Hearing and language are complex processes. It doesn't really surprise me that researchers are finding evidence to support other brain areas being involved with language. Language isn't just hearing something and responding to it. It involves emotion which we learned that the right hemisphere of the brain is involved with. Language also involves the planning of speech (PFC) knowing what to say and how to say it (tone of voice). It also draws from your memory- knowing what's appropriate to say, past experiences, etc. Language is so complex that Wernicke's area and Broca's area cannot possibly account for all the aspects of language. Those two areas contribute to production of speech (Broca) and comprehension (Wernicke)of speech which is important to language, but other brain areas that contribute should be acknowledged. It's good to move away from this single tract model since it does not account for other important aspects of language.
ReplyDeleteI think that the human brain is capable of so many extraordinary things. I agree that we should look past localization and expand all the different aspects of language, as Elizabeth mentions above. I think that the most important part of speech besides actually talking is the prosody behind it. If I'm upset and my friends ask me how I am I could say "I'm fine" but from the prosody in my voice my friends would know for sure that I am not fine. The Wernicke-Geshwind Model does not clearly display every aspect and part of the brain that goes along with speech because it is a very localized theory that speech and response goes through only 4-5 steps. If we expand the model we could include that the angular gyrus by combining the information from the emotion we see on the other persons face, and then sending it to be processed by different parts for emotion, and then understand what the person actually said in Wernicke's area, and then the prefrontal cortex will plan what to say back to the person, and then Broca's area will respond. This kind of model gives a more thorough representation of what would be happening. Of course, the order of the steps would be different, but just a general idea. I think it is time to kick out the old, and start fresh and see what we can find.
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