case studies of brain damaged patients Flashcards
What are case-studies?
In-depth investigations of a single person, group or event
They use a range of methods and can gather quantitative and qualitative data
HM
HM suffered amnesia following brain surgery for epilepsy, resulting in severe impairment to his LTM (as he couldn’t create new memories) whilst his STM was largely intact
William Scoville removed his hippocampus, a brain structure within the temporal role which consolidates memories from STM to LTM
It reduced his seizures but resulted in memory loss
HM as a case study
Throughout his life, HM was studied and the results contributed to a greater understanding of memory
- Both qualitative and quantitative data was gathered
- his memory was tested using recall tests, along with IQ, perception and general knowledge
- he completed tasks such as tracing routes through mazes on paper and drawing a five pointed star
- his brain was scanned when technology advanced
- he was interviewed, the qualitative data gathering in-depth information about thoughts and feelings. He was able to describe his childhood memories but he lacked context for them (how long ago they happened). He could not explain where he lived or who cared for him
Clive Wearing
Suffered long-term memory impairment following encephalitis (inflammation of the brain causing damage to the structures), but his short-term memory store remained unaffected (30 seconds)
He was unable to transfer information from STM to LTM, demonstrating that they are separate
KF
KF suffered brain damage from a motorcycle accident that damaged his STM (digit span of 1) but LTM was normal
KF struggled to process auditory information but his visual was unaffected
Supports WMM (phonological loop and VSSP process different types of info)
Case studies - support cognitive theories
P - a strength of case studies such as HM is that they can be used to support cognitive theories of memory, such as the MSM
E - for example, HM experienced severe impairment to his LTM whilst his STM remained largely intact (duration 30 secs), meaning that he couldn’t make new memories after the operation as he suffered from anterograde amnesia
T - This supports the theory that STM and LTM are separated stores and are affected differently
Case studies - generalisability
P - A weakness of using case studies in cognitive psychology is that the pps are unique in the nature of their brain injury so have limited generalisability
E - for example, HM’s surgery to treat his epilepsy would’ve affected his brain so his structure would be different to other individuals who have had their hippocampus removed. It is also possible that his memory may have been affected before the surgery as a result of epilepsy medication and seizures
T - therefore conclusions must be generalised with caution as they are not representative of the wider population
Case studies- variety of methods
P - A further strength is that case studies can use a variety of research methods to gather qualitative and quantitative data
E - HM’s memory was tested using recall tests, tracing routes through mazes on paper and drawing a five- pointed star, his brain was scanned and he was interviewed about his childhood memories
T - therefore findings and conclusions can have high internal validity as the numerical data is supported by in-depth descriptions
Case studies - practical issues
P - case studies have practical issues if they are conducted over a long period of time
E - HM’s case study gathered huge amounts of data which would’ve taken time to conduct and analyse, so would cost more than a snapshot study (short term). Researchers may be very invested in the study and may get to know a pp well over such a long period of time so this raises issues about the ability for researchers tomorrow remain objective for such a long time
T - therefore there are practical issues with conducting case studies
Case studies - conclusion
Despite limitations. Studying unique individuals leads to further research on larger samples of participants. Several case studies, such as HM and KF, have provided invaluable evidence for cognitive theories of memory which can benefit society, for example dementia care which stimulates the use of ST and LT memory
