Case study HM

• Aim of HM case study?

  To investigate the impact of a surgical procedure on HM at the age of 27 that resulted in no new memories being stored.
• Method? for HM

  For over 55 years he completed different memory tests, interviews and Iq tests. He had an operation where his hippocampi were removed and couldn’t form any new memories after his operation
• Results of HM?

  He could recall everything prior to the surgery but couldn’t encode new memories. However he could learn new motor skills.
• Evaluation of HM

  A strength is that it was high in control as there was only one participant

  And also it had a standardised procedure over 55 years

  A weakness is the findings are not generalisable since case study involves one patient.

  Another one is he couldn't give informed consent as brain damaged
• Weakness 3 of HM (low reliability)

  HMS behaviours and responses are open to interpretation meaning the case study is highly subjective. This is a weakness as it means the study may be biased decreasing the reliability, as if it was repeated to check for consistencies researchers may have got different conclusions.
• Strength 3 of HM (Application)

  HM provided insights into the role of hippocampus in forming new memories. This is useful as it lead to more studies on memory and the findings are applied in hospitals and schools.
• Strength 2 of HM

  HM only participant in study which makes it easier to control his actions. This means the data gathered on his memory will be more accurate as due to the controls we'll know his inability to form new memories is due to brain damage alone increasing the validity of our findings on memory from the case study
• Strength 1 HM

  Extensive longitudinal data was collected over decades such as interviews and tests. This has contributed to our understanding of memory processes
• Weakness 2 of HM (limited view)

  Provides insights into memory however doesn't encompass full complexity of memory systems or the influence of other brain regions in memory processing.
• Weakness 1 of HM (low generalisability)


  HM was a unique individual with specific brain damage. This means findings from his case may not be representative of how memory is stored/lost in other individuals with memory problems, reducing the generalisability of the results on how memory works.
• HM retained the ability to learn new motor skills such as learning how to use a walking frame when he broke his ankle.
• HM shows LTM is a separate store as he can access information from before the surgery about his life but he can't create new long term memories supporting the idea that short term memories need to be transferred to long term memory in order to be retrieved later.
• HM can be considered useful as it allows us to understand how the hippocampus works in relation to STM and LTM that would otherwise be unethical to study. The study could be considered less useful as it hasn't been replicated due to the many years it took to complete, therefore we won't know if the findings from HM were reliable or not.