In the Argument, David Shenk argued that specific brain regions adapt according to relevant tasks. This could be seen in Eleanor Maguire’s 1999 brain scans of London cabbies, which showed enlarged regions in the brain that control spatial awareness (Shenk 67). How do these changes affect the cabbies genes? Will this have any effect on the genes inherited from a cabbie? Relate this to the relationship between Mozart’s upbringing and his inherited genes from his musical father. What do Maguire’s’ conclusions prove about the GxE dynamic, and what does this show about our use of the word ‘talent’? Is there such thing as having a ‘talent’ or a ‘gift’?
Michaela Margolis (mmargolis989@gmail.com)
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ReplyDeleteThe changes in the areas of the brain that control spatial awareness are the result of the "turning on" of the cabbies' already present genes. All human beings have the same genetic makeup in their DNA, but it is the manner of expression, which creates this variation and ability to grow and change. It is true that not everyone has this enlargement, and that it is especially prominent in the brains of cabbies, which demonstrates the plasticity of the brain. To begin, the area of the brain that enlarges is the hippocampus, which is where the "consolidation of information from short-term memory to long-term memory and spatial navigation" occur; in layman's terms, it handles information processing and memories (www.wikipedia.org/hippocampus). Stated by Maguire in her research paper, the volume of the hippocampus in nonhumans is known to vary as a function of the demands placed on spatial memory (http://www.fil.ion.ucl.ac.uk/Maguire/Maguire2006.pdf). Specifically, Maguire noticed the front part of the hippocampus was smaller, while the back was larger; the structural difference showed how function related to structure because it was this change in size that created the division between the long memory of the drivers to regular people.
ReplyDeleteIt is both a combination of environmental factors and genetic factors that influence the growth, which ties into the overall theme of regulation in biology, where "regulatory mechanisms switch genes on and off in reponse to environmental stress" (AP Biology Course Book). This is because the cabbies are constantly working on learning "The Knowledge," rather than memorizing it - they learn it because they want to commit it to their long-term memory rather than memorize using short-term and forget. Constant navigation and the stress of absorbing so much information causes growth in the hippocampus to accommodate the frequent usage. Over time, the cabbies who succeed find themselves with an enlarged hippocampus; however, it should be noted that no other parts of the brain became reduced. The other parts of the brain remained normal, indicating no change, which demonstrates how genes specifically turned on to allow for growth of the hippocampus due to environmental stress. However, because of the environmental factor, there will be no effects on the genes inherited from a cabbie. Their children will not demonstrate superior memory skills or have enlarged hippocampuses just because their father had them. When they are born, the children are in a sense, "a blank slate" - their brain growth is normal and until more environmental factors come in, the growth is relatively normal. Hypothetically, if a cabbie were to start training their children from a young age to learn "The Knowledge," then it is possible that their hippocampus will be enlarged like their fathers - possibly even more since the brain of a child has more plasticity due to the body's rapid growth during youth! After all, cabbies with over 40 years of driving experience had the largest hippocampuses, so a child being taught at a young age would have more years of experience in memorization.
(Diana Liao, dianaliao3@gmail.com)
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ReplyDeleteThis demonstrates the growth mentality as people shouldn't believe they are limited to what they are born with; in fact, some taxi drivers were surprised to learn they had brain growth - they considered themselves "unintelligent" and were shocked to hear their brain was enlarged. Maguire concludes her research regarding the brain's growth with the environment and genetics as "a mixture of both" (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1140382/).
Regarding Mozart, he is a product of heavy environmental factors that affected his genetics. Mozart was born normally like anyone else, yet it is because he was brought up in a family of talented musicians, especially with such a devoted father, that he developed his musical talents. It is even stated in Shenk's book in the Evidence that while Mozart was considered special and "talented" as a child, it was only much later in his teenage years that he wrote an actually "talented" piece of music. In his youth, he was special due to his upbringing, yet he didn't have "talent" besides his unique skills in playing, which he received from his family's musical influence. Like Jordan, Yo Yo Ma, and many other "talented" people, there is no such thing as an innate "talent" or "gift", but rather it is the amount of practice and devotion put into a skill that causes genes to turn on/off to allow for growth.
(Diana Liao, dianaliao3@gmail.com)