2.2.13 - case studies of brain-damaged patients Flashcards
what is a clinical case study?
a specific, in-depth study where multiple sources of data (qualitative and quantitative) are gathered about a unique person, group or situation
what are the aims of clinical case studies?
primary aim - help the participant
secondary aim - produce evidence and insights which can help people similar to the participant, or just people in general
how are case studies different from experiments?
in experiments, the results of the whole group are analysed statistically and conclusions are drawn from the performance of the ‘average’ participant, but in case studies the focus is much more on the individual person, group or situation
what happened to Henry Molaison (HM)?
he suffered a head injury at age 7 leading to epileptic seizures which increased in frequency and severity until they were potentially life-threatening by the time he was 27
Dr William Scoville performed surgery to alleviate the seizures in 1953, where HM’s hippocampus was removed
what is retrograde amnesia?
the inability to recall information previously stored in the LTM
what is anterograde amnesia?
the inability to store new long-term memories
what were the effects of the surgery on HM’s memory?
- developed anterograde amnesia - normal short-term memory but unable to form new long-term memories eg. never learned name of Milner
- developed retrograde amnesia - poor recall of years leading up to operation as he could only remember partial events after age 16, and virtually nothing after age 25
- was able to learn new skills but not remember learning them - was taught in 1962 by Milner to trace a line with a pencil while watching the pen and his hand in a mirror which he got better at with practice, but couldn’t remember learning task
what conclusions did Milner draw from the HM case study about the structure and functioning of memory?
- STM and LTM are distinct structures (HM’s STM was intact but LTM was damaged)
- LTM has two distinct systems - declarative memory for handling facts and events, and procedural memory for handling motor skills
strengths of case studies - in-depth understanding?
bring together lots of different data which offers rich understanding of cognitive function in more detail than an experiment would
strengths of case studies - change over time?
they often involve working with participants over an extended period of time, allowing researchers to see how cognition changes longitudinally
strengths of case studies - relationship between cognition and biology?
allow researchers to investigate the relationship between cognitive and biological processes because when you know exactly how the structure of the brain changed, and how this affected cognition, you can conclude they are related
strengths of case studies - test theories of cognitive processes?
studying brain-damaged patients allows us to identify where theories of cognition are correct or incorrect - HM’s cases suggested the MSM was correct in stating that STM and LTM are separate structures (suffered anterograde amnesia), but incorrect in stating that the LTM is a single unitary store (seems to consist of declarative and procedural memory)
weaknesses of case studies - generalisability?
the area and extent of brain damage in each clinical case is unique, so the resultant changes in cognition may be unique to the individual - the findings of clinical case studies can’t necessarily be generalised to non-injured people, or even other brain injury patients
weaknesses of case studies - nature of brain injuries?
brain injures can be widespread and their extent hard to assess, meaning conclusions about the relationship between brain function and cognition drawn from studying them may be incorrect
weaknesses of case studies - nature of participant’s memory?
we may not have information on the individual’s cognitive processes like memory before their injury - this means we can’t necessarily conclude that any abnormalities were caused by the injury, which could lead to incorrect assumptions about the relationship between brain function and cognition
what are some comparisons between experimental studies and clinical case studies?
experimental want typical pps, clinical want atypical pps
experimental look at performance across a group, clinical look at individuals
experimental have narrow focus (only usually look at effect of changing one variable), clinical have broad focus (look at effect of different interacting factors on cognitive functions)
what is qualitative data?
data which presents descriptions of findings in prose and provides detailed accounts of people’s experiences, feelings and beliefs
where is qualitative data often used in cognitive psychology?
in research based on case-studies of brain damaged patients - it can describe the patient’s functioning after suffering amnesia and give insight into their subjective experiences
what are different methods of gathering qualitative data?
unstructured or semi-structured interviews, questionnaires with open-ended questions, group discussions, speech analysis, literature reviews
what are strengths of qualitative data?
offers rich insights which may be missed when using quantitative methods
integral in understanding important issues like in health and clinical psychology - can address beliefs and feelings on questions like how patients experience palliative care
what are weaknesses of qualitative data?
data analysis and transcription takes a long time making it laborious and hard to conduct
has no standardised format so is criticised for being unscientific and too subjective
people argue it is more descriptive than explanatory
