Saturday, April 7, 2012
Evidence: Fetal Development
In footnote 94, Shenk talks about the impact of sound on the fetus and of research on the long-term effects. Exploring this idea, there were several examples cited such as Yo-Yo Ma the famous cellist who listened to classical music when he was in his mother's womb and ended up becoming the top cellist in the world. Other incidents included harsh sounds that resulted in violent responses from the fetus such as kicking, and then the same sounds eliciting different responses after the baby is born. Explore this idea of gene regulation during gestation. Why and how can the effect of sound during fetal development have an impact on responses from the human life after birth? In particular focus on the development of the fetus and at what stages this effect on genes could be taking place.
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During human gestation, the mother goes through three trimesters. The first trimester is where most of the embryo forms. It changes from a small blastocyst to an embryo with developing bodily organs. By this time the main organs have sprouted. During the second trimester, the organs are typically visible but still developing. The fetus, however, is growing and active. The third trimester is primarily growth and is where the mother goes into labor and the baby is born (Campbell).
ReplyDeleteThere are many hormones that help to regulate gene expression during the pregnancy. Progesterone, HCG, estrogen, etc. In the beginning of the pregnancy, HCG is used to regulate the progesterone and estrogen levels. It alters the gene expression to produce more proteins and blood to supply the new embryo. The main hormone, progesterone, regulates the genes and helps to turn on the genes that make more mucus and white blood cells to fight infection and protect the embryo from illnesses (http://www.babyzone.com/pregnancy/your-body-during-pregnancy/pregnancy-understanding-your-hormones_71084-page-2). Estrogen alters gene expression in the breasts so it may produce milk to prepare for the birth of the baby and provide food. The last hormone, oxytocin, regulates the contractions of the mother through positive feedback until the baby is born. These hormones regulate gene expression by turning on and off genes to produce certain proteins to help the pregnancy along whether it is to feed the embryo, protect it, or reduce discomfort for the mother.
The development of the fetus happens during the second trimester of this phase. By this time, the baby has developed ears and is able to respond to the outside environment as well as music being played. Scientists have claimed that music “activates neurons in many regions of the brain simultaneously” (99 Shenk). During the second trimester, the baby responds to this music by actively moving around. Certain music, such as Mozart and Bach are complex in musical structure and therefore open different neural pathways in the brain to improve spatial reasoning later in life for the child (http://www.educationoasis.com/resources/Articles/building_babys_brain.htm). These new pathways made can help to create new pathways for connecting neurons to help the memory in a child. This is why it is said that playing classical music will make the baby smarter. Some children have the memory of the music even after birth and are able to respond to the same songs they heard in the womb. This collective memory is later used for the child to enhance his or her learning capability by increasing his or her memory span because of the previously introduced neuron pathways. Babies that listened to complex music in the womb were shown to have increased cognitive skills, language capabilities, and motor skills (http://www.livestrong.com/article/494633-the-effects-of-music-on-prenatal-babies/).
Shenk quotes Giselle E. Whitwell, who states that music is a “pre-linguistic language which is nourishing and stimulating to the whole human being, affecting body, emotions, [and] intellect” (Shenk 285). This pre-linguistic language, he says, goes on to “engrave” our minds so that those exposed to music in the womb are more apt at languages or may have more musical inclinations once born, such as in the case of Yo-Yo Ma (Shenk 94).
ReplyDelete“Scientists have found that music stimulates more parts of the brain than any other human function”, and this stimulation can provide many future benefits for the developing fetus (http://www.npr.org/2011/06/01/136859090/the-power-of-music-to-affect-the-brain). For example, the human brain associates music with memories, and music has been used in therapy to help those with brain damage or with Alzheimer’s. If a baby has been exposed to music’s therapeutic qualities early on, he/she can reap the benefits from before birth. For example, “researchers have found a correlation between music and brain development. Playing music is known to stimulate brain development by promoting the development of neural synapses, that is, the building up of brain cell connections. The more developed the neural synapses; the better developed the brain on both the intelligence and physical levels. There will be a quicker grasp of language, improved motor movements and better spatial understanding.” (http://www.brighthubeducation.com/infant-development-learning/38665-music-and-baby-development/). Neural synapses are connections made in the brain that “analyze and interpret sensory input, taking into account the immediate context and the animal’s experience” (Campbell 1048). In this case, the experience of listening to music is integrated into the baby’s brain circuitry; although in the past it was thought that babies could remember things for only a few months, it was found that babies “remember tunes they were played in the womb for as much as a year after birth” (http://abcnews.go.com/Health/story?id=116610&page=1#.T4ZHxKsS2Ag). It is clear that music has a deeper impact on the baby’s brain than other memories and environmental influences do. Music is strengthening the way that the brain makes its intercellular connections, so gene expression is more efficient: “the vast majority of neurons in the brain are interneurons, which make only local connections” (Campbell 1048). If these local connections were weak, the brain would not be able to communicate with the body as a whole but rather only body parts near it; stronger intercellular connections strengthen the baby not only in terms of mental and linguistic skills but also motor skills (http://voices.yahoo.com/the-effects-music-babies-womb-afterward-1917926.html). Stronger structure means more efficient function.
Fetuses’ mature hearing begins to develop during the last three months of pregnancy; “five weeks before birth, the cochlea- the spiral-shaped part of the inner ear responsible for hearing - is usually mature” (http://www.dailymail.co.uk/sciencetech/article-1364120/Unborn-babies-played-music-womb-remember-melodies-born.html). Therefore, the majority of the studies citing effects of music on fetal development examine effects of playing music in the last few weeks of pregnancy. However, “four month old fetuses can respond in very specific ways to sound” already (Snek 286), such as by kicking. Environmental factors such as music could be playing a part in epigenetic gene expression that has not been proved yet, altering brain circuitry that we have not even noted yet; after all, “the first trimester is the main period of organogenesis”, and so during this time “the embryo is most susceptible to damage” or other outside influence (Campbell 1014). While Christina said that most people think playing classical music will make a baby smarter (the “Mozart effect”), in reality “the pace of the music was more important than the style”, and it is about exposing the baby to different rhythms more than the composer or style (http://news.bbc.co.uk/2/hi/health/1432495.stm).
ReplyDeleteIn addition, on a purely musical level in looking towards the future, it is possible that early exposure to music can activate a version of imprinting in humans. Imprinting is “the formation at a specific stage in life of a long-lasting behavioral response to a particular individual or object”, and can only occur during a sensitive period (Campbell 1126). In humans, this can be seen in how all humans are born with the capacity to have absolute pitch, but “that it gets activated only in those who are exposed to enough tonal imprinting at a very early age” (Shenk 94). The baby’s gestation period and early months can form this sensitive period. However, overall it is important to note that solely relying on genetic alterations due to music exposure ignores the reality of GxE. Environment is critical: there is a high correlation between professional musicians and absolute pitch (AP), but “this is not cause and effect. Rather, the correlation exists because both are so frequently a product of early musical training” (Shenk 290). Likewise, Yo-Yo Ma’s early exposure to music helped him, but his intensive training and passion were also key to his success.
Vivian Wang (vivian.wang9895@gmail.com)