When explaining the “’savant
syndrome’” (89), Shenk says that if the left side of the brain is impaired by a structural error, the
right side can, in some cases, functionally compensate for error, making the person affected a
savant. When a brain is not functional in one hemisphere, how can ones
environment encourage the body to enhance the focus on the functional hemisphere?
Is there a relationship between the
onset of “savant syndrome” and the proposed GxE model of gene expression and
why would it be selectively advantageous for such an enhancement or development
to occur in an individual with a malfunctioning left hemisphere(relate your response
to the idea of biodiversity and the concept of a selective advantage)? Also, how
does this enhancement begin and proceed in relation to the different forms of
cell communication as referred to in chapter 11 of Campbell.
-Jesse Pukshansky (jesse.pukshansky@gmail.com)
The inability of one of the brain’s hemispheres to function often leads to “temporary savant-like tendencies” and Shenk refers to the idea of brain plasticity to explain the emergence of savant skills since plasticity allows the brain “to recruit other other areas to be put to use” (89). In terms of the environment, savants develop because there are certain stimuli that can trigger the use of one hemisphere of the brain more than the other hemisphere of the brain. Savants with an inhibited left hemisphere can generate a greater sense of creativity when exposed to visual stimuli, such as art, since the right hemisphere (and its ability to generate visual stimuli and spatial skills) can “compensate heavily for the loss” (89). Without certain stimuli to compensate for the loss of one hemisphere, many people won’t generate savant skills. Savant syndrome is an offset for many people that have autism, which can be considered a genetic disorder. At the same time, the environment, as stated before, can stimulate the emergence of savant skills through stimuli. We can relate the combination of both genes and environment to the GxE model based on the prior knowledge of autism being partly induced by genetic variation and the environmental stress.
ReplyDeleteSavant syndrome can be considered a selective advantage that brings about a variation of organisms within the human species. While we can’t necessarily relate savant syndrome to increased reproduction, the emergence of the syndrome could be a means of ensuring a person’s survival. Since savant syndrome develops from a deteriorated or damaged hemisphere, the ability of the brain to adjust to missing parts can develop certain, unique skills with use of parts in the brain that are still available. Cell signaling can be stimulated in certain parts of the brain when the brain is lacking a certain structure (such as one of the hemispheres) for a specific function. The Campbell textbook talks about how the brain can increase the rate of firing an electrical signal along a nerve cell in synaptic signaling to produce a chemical signal that can generate proteins specific to a certain part in the brain. If either hemisphere could increase its rate of synaptic signaling, more proteins are produced for the hemisphere and the hemisphere is stimulated in functioning because there are more proteins for use.
We can relate the generation of savant syndrome to the biological theme of structure and function. When one of the hemispheres of the brain ceases to function, cellular adaptations are occurring in the brain due to the damaged structure. Nerve cells in the left hemisphere must function differently than the right hemisphere to explain the difference in the stimuli that the hemispheres receive and the position of the each hemisphere in the brain. Without a viable structure, a hemisphere’s functioning would stop while increasing the ability of the other hemisphere as seen in savants.
In Patricia Howlin’s journal article, “Savant skills in autism: psychometric approaches and parental reports,” Howlin demonstrates in an experiment with a group of savant men and savant women that stereotypes and social behaviors have caused savant skills to emerge with greater cognitive skill in men than women. Howlin’s experiment suggests that environmental stresses due to domestic influence can shape the development of savant skills in men and women and that the GxE development is plausible explanation for how the body develops its structures to function in specific tasks.
-Trish Chari (trishtennis@gmail.com)