In your essay, it is important that you are able to link research evidence to specific theoretical claims. Case studies of people with acquired brain injuries have been particularly useful in providing support for one of MSM’s key claims, but the same studies have also highlighted some of the weaknesses of this model.
What is a case study?
Case studies allow us to gather in-depth information on areas where it may be impossible to carry out experiments. Clearly, from an ethical standpoint we cannot deliberately injure someone purely to see what behavioural and cognitive changes may result! Instead, scientists often make use of naturally occurring cases where someone has an acquired brain injury, meaning they were functioning perfectly well beforehand, i.e. they have been involved in an accident, had an illness that has affected their brain or undergone surgery for a tumour or to treat epilepsy, for example.
Case studies focuses on an individual or small group and use information from a variety of sources including medical and educational reports and records, interviews, standardised tests and observations, and so on to gather a wide range of detailed information. The use of multiple research methods is known as method triangulation.
Case studies generally lack control as the injury was naturally occurring, this said, they can inspire more scientific studies that are able to examine cause and effect.
As you may recall from the localisation topic, case studies focusing on people who have sustained brain damage allow researchers to explore the function of various brain regions through examining the impact of the damage on their behaviour and cognitive functioning.
Can you think of any scientific weaknesses of such studies?
Often there is no valid evidence of the person’s skill level prior to the brain injury, and therefore it is not possible to conclude with certainty that the brain injury has caused any issues the person appears to have, as these problems may have pre-dated the injury. This is clearly not always the case but worth bearing in mind 😉
The table below details three case studies conducted with people with brain injuries. Case studies like these indicate that there are different memory stores but perhaps it is too simple to think that there are only three stores, memory for different types of information seems to be situated in different areas. This is shown by HM and Clive Wearing’s unaffected procedural memories.
|Participant and researcher||Description||Skills affected|
Reported by Baddeley (1993)
|Clive Wearing was chorus master of London Sinfonietta, BBC radio producer and world music expert. A virus attacked and destroyed his hippocampus and also damaged other areas of cortex. Lives in a snapshot of time, constantly believing he has just woken up from unconsciousness||Normal STM but unable to lay down new information in LTM, some LTM left unaffected as remembers who is wife is and other skills like playing piano and conducting.|
Reported by Blakemore (1988)
|HM had suffered very bad epilepsy from age 16. At 27 he had surgery to remove his hippocampus from both sides of brain, this cured the epilepsy but had terrible side effects. He had no problem recalling information stored prior to the surgery but severe memory deficits for events happening after surgery.||Similar to Clive wearing: normal STM, e.g could hold verbal info for 15 seconds and longer if allowed to rehearse but could not transfer it to LTM store and if he could, he was unable to access and retrieve it, his memory for new motor skills seems unaffected.|
Reported by Shallice and Warrington (1970)
|KF is one of the few reported cases of damage to STM. KF had a motor bike accident which damaged the left parieto-occipital region of the brain.||LTM recall was unaffected but STM badly affected, e.g could only recall 1-2 items in digit span task instead of usual 7+/-2. On recency effect tasks recall was as low as 1 item. Some STM tasks performed better than others|
Use the worksheet above to find out more about these three case studies and think about how they could be used to support or refute the claims made by Atkinson and Shiffrin’s multistore model, i.e. that there are three separate memory stores through which information flows in a linear fashion, that short and long term memory are single (unitary) stores.
Find out more about the case of Clive Wearing using these clips from youtube:
HM – Henry Molaison
One interesting aspects of the HM case study is that although it is claimed HM was incapable of laying down new long term memories (anterograde amnesia) over time it was shown that he was able to learn a new skill; mirror drawing.
Learn more about HM with this podcast form the BBC: https://www.bbc.co.uk/programmes/b00t6zqv
Practice drawing stars like HM: Click below and scroll down to “Milner Research Replication”.
Practice what you know about the HM case study and how it relates to MSM using this quizizz: https://quizizz.com/admin/quiz/5f74661a1bb349001ba0a3a5
The Case of KF
To learn more about the case of KF why not check out one of the original papers about this patient here :
Case study of KF Original Paper: warrington1969
A clip of Warrington talking about KF
The following worksheet demonstrates how the case study of KF exemplifies all the key features of the case study as a research method in psychology, but is also useful for adding to your detailed knowledge of the aim, procedure, findings and conclusions of the study itself.