Case Study Of Brain-damaged Patients

Question 1

What happened to HM in 1953 which led to him becoming the most studied individual in psychological research?

Answer 1

At the age of 27, HM had his hippocampus surgically removed in the hope to alleviate the severe symptoms of his epilepsy, which he developed after he fell of his bike as a child. After the surgery, HM was diagnosed with anterograde (can’t store new information in STM) and retrograde (loss of information from events occurring in the past) amnesia. His STM remained normal but he was unable to transfer any new information into his LTM.

Question 2

What did they find with regards to HM’s intelligence and personality after the operation?

Answer 2

• His personality remained the same

- His IQ improved from 104 to 112

Question 3

Who conducted the case study and carried out the majority of research on HM after his brain damage?

Answer 3

Milner- gathered many in depth data. Conducted recall tests, neurological examinations, formal tests and experimental procedures.

Question 4

What additional research findings were found relating to HM’s memory?

Answer 4

• Procedural memory appeared to be intact= he could still learn new motor skills e.g star mirror task, but couldn’t remember that he had learnt this skill
• largely unable to form new episodic memories
• STM remained the same in comparison to control participants, but for a shorter amount of time (20 seconds)

Question 5

What do the case studies of HM conclude about memory?

Answer 5

• Semantic memories are not related to the hippocampus= we know this as his maths skill were still okay and recognised Kennedy on a half dollar and knew he was assassinated
• Procedural memories aren’t related to hippocampus, but instead the cellebelum= we know this as he improved in the star mirror task
• The hippocampus is responsible for committing episodic memories to long term memory= HM couldn’t do this

Question 6

Evaluate the case study of HM.

Answer 6

STRENGHTS:

P: High reliability
E: Over the many years that HM was examined, many tests and experiments took place which all used standardised procedures. For example, the mirror task was conducted by Milner and was repeated several times, using the same process.
E: This means conclusions from this test are trustworthy and can be compared, giving reliable results for other scientists to analyse and replicate the same test on other individuals accurately.

P: High application to real life
E: The extreme and intense studying of HM for several years produced a lot of very analytical data. Neurological examinations as well as formal tests and experimental procedures were all carried out on HM to deepen our understanding of memory and progress psychological research.
E: Scientists now have a much clearer and more detailed explanation of how the brain works, and how memory works including how crucial the hippocampus is for the functioning of memory. All of this knowledge can be used by other scientists to not make the same mistake that William Scoville did

WEAKNESSES:
P: Low generalisability
E: HM was just one individual who had a very extreme case of epilepsy, and underwent surgical operation to remove his hippocampus, both things which aren’t very common
E: This therefore means the findings of the study may be difficult to generalise because this unique case is not representative of the wider population

P: Low internal validity
E: Due to the unexpected result of the surgery (memory loss), no tests or data was collected before hand to show an effect of the surgery. This therefore means it’s difficult to confidently say the removal of the hippocampus is what purely caused HM’s memory loss, as scientists didn’t have any data of HM before hand
E: This therefore means it’s harder to establish a trustworthy relationship between the IV (hippocampus removal) and the DV (memory loss) because we don’t know if there were any other extraneous variables, for e.g the fact he had epilepsy, which may have influenced the severity of the memory loss