Example Essay: Research methods (case studies) in the biological approach

Travis Dixon Biological Psychology, Research Methodology, Revision and Exam Preparation 2 Comments

Psychologists use unique case studies like SM and HM to understand localization of function.

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Essays on research methods and ethical considerations are the hardest to write in IB Psychology exams. Here is an example essay on the use of case studies in the biological approach. Notice how the essay has a good balance between explaining the method (central argument), using studies (supporting evidence) and explaining limitations (counter-arguments). 

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Evaluate the use of one or more research methods used to study the brain and behaviour.  
One research method used to study the brain and behaviour is the case study method. Case studies are often conducted on people with unique brain damage in specific areas of the brain. These studies allow psychologists to draw conclusions about localization of function. Examples include SM’s and HM’s case studies on the amygdala and hippocampus respectively. While they can be valuable methods, there are also limitations to using case studies which will be evaluated in this essay. Question is restated in opening line. This guarantees 1 mark for Criterion A.  Introduction outlines the entire scope of the essay.
Case studies are in-depth investigations of an individual, small group or organization. They rely on the use of a number of different methods, both quantitative and qualitative to gather data. This includes observations, questionnaires, interviews and tests. In studies on the brain and behaviour, researchers find participants with damage to particular areas of the brain. They employ a range of methods to gather data on the individual’s behaviour. Any behavioural differences observed between the individual and “healthy” controls allows researchers to draw conclusions about the role of the damaged areas of the brain in that particular behaviour. Case study is defined and explained, including how and why they’re used for this specific topic.
For example, Feinstein et al. (2011) conducted a case study on SM,  a patient with bilateral amygdala damage (damage to amygdalae on both sides of the brain). This was due to a genetic condition. In this study, the researchers exposed SM to a range of fear-inducing stimuli, including going to an exotic pet store, visiting a haunted house and watching scary films. SM displayed a lack of fear in response to these stimuli. They also used questionnaires and interviews to gather data about her life-experiences. These revealed that SM is often in situations involving danger and she has had her life threatened numerous times (e.g. she lives in a dangerous neighborhood and continually walks home through dangerous areas and she was in an abusive relationship). The comparison made between SM and other participants in the study, as well as the qualitative observations and quantitative self-report data gathered, enabled the researchers to conclude that one function of the amygdala is to enable us to experience fear. Knowledge is shown of the study through detailed description of relevant details.  Terminology is used appropriately.    The conclusion focuses on the method and lesson on the applications of the study.
This study highlights the benefits of case studies like SM to study localization. Previous studies on the amygdala relied on animal studies using lesioning. This has ethical issues, they also might not be generalizable to humans, they’re conducted in artificial environments, and the monkeys cannot verbalize their experiences of fear. SM is a valuable case study because it is rare to find someone with damage just in the amygdala (since it’s buried deep within the brain). The results from the data gathered on SM allowed researchers to show the role of the amygdala in fear. Further explanation linking the study to the question.
Another classic case study on localization was conducted by Milner and Scoville who began studying HM after he had an operation to remove his hippocampus. This was to prevent his seizures that were life threatening. The operation was successful but the side-effect was that HM had severe anterograde amnesia. Milner began conducting a series of tests on HM to understand his amnesia. For example, she conducted interviews with his parents and recorded details like he could not remember where their new house was and always went to their old house (where they lived before the surgery) and he was always asking where things were. She gave him memory tests like asking him to hold information in his mind (his working memory) for a long period of time by rehearsing it. If he was uninterrupted, he could do this, but as soon as he stopped thinking of the number it was forgotten. This was further evidence to show that he lost the ability to create new long-term memories. HM’s study is a significant one in psychology because it was the first to demonstrate the role of the hippocampus in memory formation. He was the subject of study for many decades after up until his death. A second study helps support the argument further.  It might be argued that this study serves to repeat the point already being made from the previous study. However, it does provide a better example of the benefits of case studies in terms of humans being able to verbalize their experiences (a strength compared to animal studies).
This is another study that demonstrates the value of case studies. It would be unethical to deliberately damage the hippocampus in a human for experimental purposes and animals cannot verbalize their memories so we can only study their behaviour. Therefore, HM provided valuable information on the role of the hippocampus in the cognitive process of memory.
Both SM and HM’s study demonstrate the value of case studies for understanding localization of function. They can support animal studies by allowing us to study humans in an ethical manner using an array of methods. However, there are still some limitations with case studies including ethical issues. The unique nature of HM’s and SM’s brain damage highlights the importance of anonymity – if the researchers were to publish their full names they might have had unwanted attention from the public and from the media. However, there is a potential issue with granting anonymity. Should other psychologists have access to HM and SM to study as well, or is it the right of the researchers to keep their personal details private? For HM, they must have given his details to some other psychologists, as many people met and studied him over the years. However, some have accused the researchers of protecting HM’s identify for their own fame. This raises an interesting question of the ethics of granting anonymity to rare and potentially highly valuable case studies of patients with brain damage to protect their privacy at the expense of offering other psychologists the opportunity to conduct studies that could further create new knowledge. Critical thinking is shown through the evaluation .    The limitation is explained in detail.   More knowledge is shown about the study in question.
Another issue with these case studies is that they are only one single individuals. Could these results be generalizable based on such a miniscule sample? SM’s brain damage was the result of a genetic condition but perhaps this condition also influenced her fear response. Perhaps it wasn’t just her amygdala damage. HM had epilepsy before the operation and the epilepsy might also affected his memory. People with epilepsy do suffer from memory problems (possibly because of acetylcholine which is associated with both memory and epilepsy). This being said, numerous brain imaging studies and animal studies support the case studies conclusions that the amygdala is responsible for fear and the hippocampus for memory formation. However, this highlights the limitation of case studies – by themselves they can provide possible explanations of localization but they are only really strong sources of evidence when supported by other studies but by themselves they are limited. A second limitation is explained in detail with specific reasons why the results of the case studies might not be generalizable.    The focus is redirected back to the method, not just the individual studies.
In conclusion, while SM’s and HM’s case studies demonstrate the benefits of using case studies to research the brain and behaviour, they do have certain ethical and validity issues. (1050 words approx.). Relevant conclusion. 
Mr Dixon’s Marks:A 2/2B 5/6C 5/6D 5/6E 2/2 19/22

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