How The Environment Can Affect One Physiological Process

Neuroplasticity
Break down what the question is asking you… what does the command term want you to do? Discuss: Offer a considered and balanced review that includes a range of arguments, factors or hypotheses. Conclusions should be presented clearly and supported by appropriate evidence (studies).

Paragraph 1 – Rephrase question to focus answer. Identify the physiological process you will write about, and which environmental condition effects it. Give background info and define concepts if not commonly known. Eg. General explanation of how enriched/deprived env affects neuroplasticity. Paragraph 2 – Explain Rosenzweig and Bennett’s study (AMFE) and link to q. Briefly outline how Kolb’s research supports this. Clearly link findings to how the environment effects physiological processes at the end of the paragraph. OR ALTERNATIVELY Paragraph 2 and 3 – Explain Maguire’s study (AMFE) and link to q. Explain how case study of Genie shows effect of alternate environment. Offer a considered and balanced review of how the environment effects physiological processes. Paragraph 5 – Conclusion. Ensure you link your answer back to the specific question asked using evidence (research) to support your conclusion.

Discuss one example of how the environment can affect one physiological process. One physiological process that is affected by the environment is brain plasticity. Brain plasticity is the brain’s ability to reorganize itself by forming new neural connections throughout life. High levels of stimulation (social interaction) and numerous learning opportunities at the appropriate times lead to an increase in the density of neural connections. This is called dendritic branching because the dendrites of neurons grow in numbers and connect with other neurons. The level of density can be a result of the environments effects. An enriched environment can stimulate neural connections and increase dendritic branching. One study that suggests that an enriched environment involving numerous learning opportunities can affect neural plasticity is Maguire et al (2000). Maguire et al. were attempting to demonstrate the plasticity of the brain.

Maguire et al. set out to discover whether morphological (changes in form and shape) changes could be detected in the healthy human brain associated with extensive experience of spatial navigation. Their prediction was that the hippocampus would be the most likely brain region to show changes. To test this prediction the researchers decided to study London taxi drivers because they rely heavily on spatial navigation skills in their working lives. London taxi drivers have to undertake extensive training known as “The Knowledge” and during this time they have to acquire a vast spatial memory of the roads of central London. All of the taxi drivers were described as having healthy general medical, neurological, and psychiatric profiles. Control participants were selected from the structural MRI scan database at the same unit where the taxi drivers were scanned.

Participants below 32 and above 62 years of age were excluded as were females, left-handed males, and those with any health problems. Voxel-based morphology (VBM) was used in this study to measure the density of grey matter in the brain. VBM provides a three dimensional measurement of volume of an area. The scans of the 16 taxi drivers and 16 age-matched controls were compared. The first main findings of the research were that the posterior hippocampi of taxi drivers were significantly larger relative to those of control subjects and that the anterior hippocampal region was larger in control subjects than in taxi drivers. The second main finding was that hippocampal volume correlated with the amount of time spent as a taxi driver. Maguire et al. argue that this study demonstrates the plasticity of the hippocampus in response to environmental demands.

They argue that the posterior hippocampus stores a spatial representation of the environment and that in the London taxi drivers the volume of the posterior hippocampus expanded because of their dependence on navigation skills. This study suggests that the changes in hippocampal grey matter, at least on the right, are acquired. This finding indicates the possibility of local plasticity in the structure of the healthy adult human brain as a function of increasing exposure to an environmental stimulus. The study is an example of a quasi or natural experiment because the researchers are comparing the data of taxi drivers and non-taxi drivers. The researchers have no control of this variable as it is naturally occurring. One issue that may affect the reliability of the results is the trial was conducted on London cab drivers that had to pass “the knowledge” where as in other cultures the necessity to learn routes might not be as high if cab drivers were able to rely on GPS devices for directions.

This suggests that the study may not be able to be reliably reproduced in other cultures producing the same results. Another issue with this study is that it was conducted only on male participants. Females were not represented in this study which means that the study is not generalizable to women. The study while it may not be generalised to females and may not be generalised to other cultures the results are reliable within Britain and its male population. Another study that purposes that brain plasticity can be affected by an enriching environment is the case of Genie as describe by Curtis (1977). Genie was socially and emotionally deprived for the first 13 years of her life. Genie had no knowledge of self-identity, social skills, or interaction with relationships. In 1970 when Genie was removed from her parents’ neglectful environment and moved to the Children’s Hospital and given an enriching environment by her doctors Genie began to develop her brain and skills. Speech therapists were involved in helping Genie increase her vocabulary skills and non-verbal communication skills. Genie explored her new environment with curiosity and her own language.

She began to form relationships and began repeating words. She was learning how to communicate her anger by waving her hand with a finger in the air, representing the level of anger she was feeling. As her verbal communication increased, Genie could describe past events of things that happened at a time before she knew language. She had her own words for her emotions, colors, and shapes. Attending a nursery school and institute for the deaf, Genie was learning how to interact with the world. This case shows that children need constant care, love, and attention so their brains develop correctly. If the child is malnourished, neglected, or abused during infancy and adolescent years, this can affect the development of the brain. However, learning is still a possibility after the adolescent years. Genie was a remarkable girl who used non-verbal communication to connect with others. This ability to develop alternative ways to communicate shows her brains neuroplasticity.

The case of Genie is an extreme case and is not replicable due to ethical concerns of patient wellbeing. This does affect our ability to generalize to a wider population however. Other issues with Genie’s case study were that there was a great deal of background information on Genie’s living conditions missing due to the death of her father and her mother’s unwillingness to cooperate. This lack of information may impact of the validity of how much ability to change and develop Genie had. If she did learn to speak as a young child and then stopped would be different to her newly learning the skill as a teenager. Another issue is that that treatment and monitoring was only implemented for 4 years. There was no longitudinal study of effects or results.

This study still does however demonstrate Genie’s ability to adapt, building new/stronger neural pathways and brain plasticity in an enriched environment. The studies by Maguire et al and Curtis both demonstrate how being in an enriched environment, one where opportunities for learning are stimulated and supported, can affect brain plasticity and dendritic branching for the best. Maguire et al showed the plasticity of taxi drivers’ hippocampi in response to environmental demands of spatial skills. Curtis described how Genie was able to develop new/stronger neural pathways and brain plasticity in an enriched environment even after being in a deprived environment for so long.