Aim
to understand the link between the hippocampus and memory
Background information
Henry Molaison (HM) suffered an accident, aged 7, resulting in a serious head injury
started to suffer from epileptic seizures, aged 10
couldn't control bodily functions due to seizures, aged 27
medication did not help
had an experimental surgery by neurosurgeon, William Scoville
tissue from temporal lobe was removed, including hippocampus
Procedure
Method triangulation
Psychometric testing
Direct observation of HM’s behaviour
Interviews with both HM and family members
Cognitive testing
MRI Scans
Findings
retrograde amnesia (memory of events before operation) diminished
anterograde amnesia (memory of past decade) diminished
unable to form episodic knowledge and new semantic knowledge
retained spatial memories
had a capacity for working memory
procedural memories (motor skills) maintained
Conclusion
hippocampus plays a critical role in converting short-term memory into long-term memory
short-term memory and long-term memory uses different brain region
implicit memory contains several stores
Strengths
Longitudinal study
High ecological validity
Utilisation of method triangulation reduces research bias and enhanced validy of results
Weaknesses
Difficult to replicate + limited generalisation (case study)
Retrospective elements limited availability of pre-accident cognitive data
Potential confounding effects of epilepsy medication on brain damage
Lack of control variables in naturalistic setting may introduce confounding factors