STUDIES - Milner (1966) or HM Flashcards
1
Q
Introduction
A
- Longitudinal case study
HENRY MOLAISON (HM):
- Hit by a cyclist when child and had serious head injury
- After injury, developed epilepsy
- When older, epilepsy was very severe and couldn’t maintain normal life as he didn’t respond to medication
- Neurosurgeon performed experimental surgery where he removed his hippocampus
2
Q
Aim
A
- Better understand the effects that the surgery had on patient HM
3
Q
Procedure
A
Method:
- Case study
- Used triangulation: Direct observation, interviews, MRIs…
Variables:
- No variables as it was not an experiment
4
Q
Results
A
- IQ and personality intact
- Significant anterograde amnesia: Could not form new explicit memories like semantic or episodic
- No retrograde amnesia: Had access to memories prior to surgery (LTM), but it got worse as years passed
- Unable to transfer information from STM to LTM
- Had working memory: He was able to carry out a normal conversation
- Could create procedural memory: Showed progress in reverse mirror drawing
5
Q
Findings
A
- Hippocampus plays a critical role in transferring information from STM to LTM
- STM is not stored in hippocampus: Could retain information for a while if rehearsed
- LTM is not stored in hippocampus: Could remember events prior to surgery
- Different memory types (procedural, semantic, episodic…) are found in different brain areas: Lost semantic but not procedural for example
- Biological evidence that STM and LTM are located in different areas of the brain
6
Q
Evaluation - Strengths
A
- Longitudinal (<50 yrs): Allowed
1) Change to be observed over time
2) Usage of different methods (triangulation)
3) Formation of rich explanations - High ecological validity: No variables manipulated as HM. was observed in his natural environment
- High ethical standards: Informed consent, no deception, withdrawal from participation
7
Q
Evaluation - Limitations
A
- Low replicability: Hard to falsify due to its focus on one specific patient
- Sample bias: Patient was a male of a certain age, doesn’t allow generalisability to different genders, cultures, or ages
- Potential researcher bias: Due to longitudinal nature, could have expectations…
- Retrospective: Little data on HM’s cognitive abilities prior to accident so hard to see what was caused by surgery
— EXAMPLE: Unaware if medication had caused damage to brain (symptoms from medication or surgery?) - Ethical issues: Confidentiality and anonymity was not preserved as we know the name of the patient