Shenk continuously mentions the importance of practice throughout his argument, and specifically emphasizes that "[There is] emerging evidence that extended practice has profound effects on...muscles, nerve systems heart and circulatory system and brain" (Shenk 251). Why is practice so important to Shenk's argument? What are specific examples of changes that may occur to the specific parts of the body given in the quote that show the change practice can have? Use accurate support for your examples and incorporate an biological theme that pertains the the effects of practice.
Joseph Hugener (jah1112@comcast.net)
It is a common phrase that practice makes perfect. Success takes hard work and, especially in athletics, long hours of practice are required to master the skills one is trying to use in competition. Anders Ericsson defines the “…minimum amount of deliberate practice necessary to raise any novice to level of expert as ten years or 10,000 hours” (http://www.science20.com/sports_are_80_percent_mental/does_practice_make_perfect_sports). Many scientists believe that the mental and physical changes that occur as a result of this extended time of practice are pivotal to becoming and expert in any given field. Ericsson writes “[there is] emerging evidence that extended focused practice has profound effects on, and can influence virtually every aspect of, the human body, such as muscles, nerve systems, heart and circulatory system, and the brain” (Ericsson et al., eds., The Cambridge Handbook of Expertise and Expert Performance, p. 59.). Practice and physical repetition physically change the way our bodies and minds function.
ReplyDeleteOne of he major changes that we see as a result of practice in mental. But is the only way to practice by physically doing an act? According to a study done by a team at Dartmouth’s Department of Psychological and Brain Sciences, groups of people that either got to watch and practice a dance routine or only got to watch the dance routine had similar brain activity in the Action Observance Network (AON) and both were able to preform the same routines with similar accuracy. This shows that practice is not only the physical act but also the mental act of watching what one is trying to accomplish. (http://www.science20.com/sports_are_80_percent_mental/does_practice_make_perfect_sports). Other mental changes occur as a result of extended physical activity. Long hours of practice increase neurogenesis or the formation of new neurons. This process of neurogenesis occurs in the hippocampus and it is thought that the mild stress produced by practice “stimulates an influx of calcium, which activates transportation factors in existing hippocampus neurons. The transcription factors initiate the expression of the BDNF (Brain-Derived Neurotrophic Factor) gene, creating BDNF proteins that act to promote neurogenesis” (http://serendip.brynmawr.edu/bb/neuro/neuro05/web2/mmcgovern.html). An increase in the number of neurons in the brain will help quick thinking and fast reflexes during athletic competition. Practice also helps to increase consistency. A study done by a group of Stanford electrical engineers shows that the reason for somebody to make a physical error after hours and hours of practice of that physical act starts in the brain. Before a physical action is begun, the brain prepares for that action. However, the brain cannot prepare the same way each time and therefore, sometimes errors in the physical action occur. The study shows that after many hours of practice, the brain will eventually increase its ability to prepare for physical activity and preform that activity with consistency. David Shenk writes “The brain drives the brawn. Even among athletes, changes in the brain are arguable the most profound…” (Shenk, 251).
To be continued
Aaron Appelbaum (aaronbaron580@aol.com)
Continuation from above...
ReplyDeleteSome of the changes that occur in the body as a result of increased practice occur in the muscles. Not only do the muscles gain strength and endurance from continued use but the muscles work with the brain to form muscle memory. “Muscle memory can best be described as a type of movement with which the muscles become familiar over time” (http://www.wisegeek.com/what-is-muscle-memory.htm). Increasing muscle memory occurs with lots of repetition of a movement and it allows an athlete to have fast and subconscious movement as a result of a stimulus in a game. The development of muscle memory shows the theme of the relationship between structure and function. Muscle memory can occur without thinking. The brain is able to communicate with the muscle with out consciously thinking about it. This means that the structure of the muscles and the way that they are connected to the neurons in the brain are conducive to memory of an action and the development and advancement of specific muscle movements. Lots of practice also changes the heart. Long-term aerobic exercise, which comes with the long hours of practice necessary to become an expert, will thicken the wall and increase the size of ones heart. The muscle it self will grow stronger. This is necessary for physical activity (http://www.livestrong.com/article/127016-short-longterm-effects-exercise/).
Although the results of physical practice are usually associated with athletic competition, the 10,000 hours of practice necessary for expertise also holds true for many other activities such a musical excellence. Becoming a top musician requires the same type of specialized practice and focus as becoming great in athletics. Hundreds of hours are required for one to be able to be able to learn about proper posture, and technique. One must constantly explore new realms of music composition in order to familiarize oneself with all different forms and styles of music. Practice is required for one to develop an ear to hear proper intonation. Muscle memory also applies to the mastery of music. Practicing the correct posture and finger placement on an instrument will eventually come subconscious but it is the constant practice and repetition of these moves that allows for the muscle memory. In order for one to become great at any activity from athletics to music to chess, the proper preparation and practice is necessary for one to be able to achieve at the highest level.
Aaron Appelbaum (aaronbaron580@aol.com)
The fact that practice can physically change the body is vital to Shenk's argument that superior genes do not determine superior traits because the changes caused by practice show that ability is not an unchangeable constant. A person can improve his or her abilities over time with lots of practice because practice stimulates changes in gene expression that over time, which causes changes in phenotypes. K. Anders Ericsson, who Shenk cites as the source of this idea in the quote in the prompt, argues that deliberate practice is the only factor that affects expertise, not “experience, reputation, and perceived mastery of knowledge and skill” (http://onlinelibrary.wiley.com/doi/10.1111/j.1553-2712.2008.00227.x/full) This is also important to Shenk's argument because it shows that a superior environment does not automatically determine skill level either. Improved ability is caused by a person's interactions with his or her environment through deliberate practice and the effects on his or her body.
ReplyDeleteShenk states that “in musculature, we are not all created equal. Although on average, human beings have about a fifty-fifty mix of slow and fast-twitch muscle fibers, some are born with differing proportions” (309). However, in an article for Scientific American, Jesper Andersen asserts that muscle fibers can change size and type, a property called muscle plasticity. There are two main types of muscle fibers: fast-twitch and slow-twitch fibers. Fast-twitch fibers contract very quickly but for only a short amount of time, and they can get ATP either from aerobic respiration of glycolysis. Fast fibers that get ATP from glycolysis are called type IIx fibers and are glycolytic fibers, and fast fibers that get ATP from aerobic respiration are called type IIa fibers and are oxidative fibers. Slow-twitch fibers don't contract as quickly as fast-twitch fibers, but they can sustain contractions for much a much longer time, and they get ATP from aerobic respiration. Andersen explains that during repeated weight training, fast IIx fibers change into fast IIa fibers because “In those fibers the nuclei stop expressing the IIx gene and begin expressing the IIa” (http://www.learningmethods.com/downloads/pdf/muscle,.genes.and.athletic.performance—scientific.american.sept.2000.pdf). This change allows weight lifters to get a quick burst of strength so that they could lift the weight, but the burst lasted longer because aerobic respiration is a more efficient way to provide muscles with ATP than glycolysis and can be sustained for a longer time. There has been little evidence to suggest that slow-twitch fibers can change into fast-twitch fibers, but all muscle fibers can become thicker with practice. Andersen gives the example that “weight training can increase the cross-sectional area of the muscle covered by fast fibers without changing the relative ratio between the number of slow and fast fibers in the muscle,” so a person who was born with fewer fast-twitch fibers than slow-twitch fibers can still be a sprinter if he or she practices regularly. Muscle fibers cannot divide like cells to form new muscle fibers, and so instead of growing muscle mass by dividing cells, muscle mass grows by increasing the amount of myofibrils in each muscle fiber. Exercise stimulates a change in gene expression by putting stress on a muscle, which activates muscle trigger signaling proteins that then cause the expression of the genes for myosin and actin, the two proteins that make up the sliding filament model for muscle contraction. The myosin and actin proteins are then used to build another myofibril in the muscle fiber. In this way, deliberate practice and exercise of specific muscles in specific ways can help a person with mostly slow-twitch fibers strengthen his or her fast-twitch fibers if he or she wants to become a sprinter (http://www.learningmethods.com/downloads/pdf/muscle,.genes.and.athletic.performance--scientific.american.sept.2000.pdf). (continued next post)
Adele Padgett adele.padgett@gmail.com
Cardiac muscle, like skeletal muscle, is striated because its thick filaments made of myosin and thin filaments made of actin are arranged in an organized pattern. The fibers in cardiac muscle can become stronger and thicker with practice in the same way that the fibers in cardiac muscle become thicker. Deliberate practice for the heart means any exercise that takes a person to his or her maximum heart rate. As the heart becomes stronger, resting heart rate decreases because stroke volume increases because the heart is able to pump more blood to the body in each contraction of the left ventricle. Maximum heart rate also increases because like any skeletal muscle, exercise increases speed and strength of the heart. Increased maximum heart rate and stroke volume allow an individual to exercise longer and harder because the heart pumps more efficiently. Therefore, as a result of increased cardiac fitness due to regular aerobic exercise, a person can perform a more intense and longer workout, showing how ability can increase with practice.
ReplyDeletePractice also leads to changes in the brain. In one example, Shenk explains that to become a cab driver in London, a person has to memorize and know how to get around all the roads in London, which is a very complex and disorganized city. Neurologist Eleanor Maguire did MRI scans of London cab drivers' brains and found that “experienced taxi drivers had a greatly enlarged posterior hippocampus—the part of the brain that specializes in recalling spacial representations” (35). Because the data show that the cab drivers who had been driving longer had larger hippocampuses, the results “suggest that the changes in hippocampal gray matter are acquired” (35). The hippocampus is part of the limbic system in the brain, which is associated with emotion, motivation, olfaction, behavior, and memory. As Aaron wrote, the hippocampus is also very important in neurogenesis, the formation of new neurons, and new neurons are very important in quick thinking and fast reaction time. This is because more having more neurons in the brain allows more connections to be made. Connections in the hippocampus are often related to memory. The hippocampus in particular plays a major role in memory. Short term memories are stored in the cerebral cortex, but they are accessed through temporary links formed in the hippocampus. When short term memories are converted into long term memories, lasting connections form in the cerebral cortex to replace the temporary links in the hippocampus (Campbell 1077 and 1079). As the taxi driver study reflects, the hippocampus is also involved in spacial memory. The posterior hippocampus is involved in recalling already learned spacial information, and the anterior hippocampus is involved in encoding and forming memories of new spaces. Maguire and her team believe from their results that “the mental map of the city is stored in the posterior hippocampus and is accommodated by an increase in tissue volume” while the anterior hippocampus helps with “a further fine-tuning of the spacial representation of London, permitting increasing understanding of how routes and places relate to each other (Shenk 199). The taxi drivers' interactions with their environment (driving their taxis around London) led to formation of new spacial memories by increasing the strength of already present neural connections or forming new synaptic connections in the hippocampus. The ability to form new connections or get rid of old unused ones is neural plasticity (Campbell 1079).
Adele Padgett adele.padgett@gmail.com
Another study showed that from second to third grade, the way children think about math and do math problems changes completely. Second graders approaches easy problems like 3 + 1 = 4 and “complex” problems like 8 + 5 = 13 in the same way, as shown by scanning the children's brains in an MRI while they were doing to math problems. The third graders approached the easy problems differently, possibly because they could recall them from previous experience with the problems encoded as memories in the left dorsolateral prefrontal cortex, “a brain region important for working memory” (http://www.sciencenews.org/view/generic/id/330726/title/A_year_adds_up_to_big_changes_in_brain). In the MRI, this region was shown to be more active in third graders than in the second graders when both groups were doing easy problems. Although the style of math classes and normal development probably cause some of the changes in thinking about math problems from second to third grade, “training and skill acquisition” play a major role too, says developmental psychologist Ann Dowker from the University of Oxford in England. The children's brains form new synaptic connections in the left dorsolateral cortex in response to the environmental influence of practicing math in school, and by third grade, most children have improved their addition skills.
ReplyDeleteAll the examples of specific body parts that have changed due to practice reflect the theme of the relationship between structure and function. To make the muscles more functional and efficient during exercise, the structure of the muscle changes due to changes in gene expression by switching the type of muscle fiber to adapt to the specific type of exercise being performed, or by forming new myofibrils to make muscle fibers stronger. Cardiac muscle adapts to function more efficiently during exercise by changing the structure of its muscle fibers in the same way as skeletal muscle. The structure of taxi drivers' hippocampal regions changed in response to practice to make more connections and to grow bigger so that taxi drivers were able to remember a map of London. The' brain structure of third graders' left dorsolateral cortexes changed by making synaptic connections to store working memory of simple math problems because of continued practice with addition problems.
Adele Padgett adele.padgett@gmail.com