H.M case study multi store model
What was the strengths
provided supporting evidence for the MSM. method triangulation increases the validity of the study it was a case study which provided rich qualitative information about H.M that could not have been acquired in any other way. The HM study had high ecological validity because it was a real-life experiment and not just a lab simulation
What were the results of the operation?
After the operation for epilepsy, his short term memory remained intact. However after the accident, HM's long term memory had been damaged as he was unable to form new memories. He couldn't transfer new information into his long term memory. He could not acquire new episodic knowledge and semantic knowledge, while his procedural memory was intact (memories in the form of motor skills) Diagnosed with anterograde amnesia Despite being able to remember people he had known long ago, new people he had encountered were like strangers to him.
how does the study of HM support the localization of the brain?
Another test that shows procedural memory must be localized in a different part of the brain than the hippocampus was the star tracing task. Milner asked HM to fill in a star with a pencil by looking at a mirror reflection of his hands and the paper star. This is a difficult task and HM struggled the first time. He completed this task every day for one week and by the seventh day he was very adept at filling in the star. He was impressed with his ability to do this, because he had no recollection of ever trying to do it before. The researchers were able to conclude that while his episodic memory was damaged, he was able to acquire and develop new skills. This further supports localization of brain function because it demonstrates how motor skill learning (procedural memory) must require a different part of the brain to other types of memoRY
RESEARCH METHOD OF CASE STUDIES
Case studies are considered a qualitative research method, however quantitative data may be collected as well The data provided may be more valid, meaning that the data is more useful, meaningful and accurate than other research method the data collected is not restricted in any way; when the researcher reveals something interesting, following up every opportunity and taking further measurements leads to a much more comprehensive and valid set of findings taking an ideographic approach such as this (looking carefully at individual differences) can provide hypotheses which can be tested in more scientific ways in the future, also it may be that a case study is the only way to practically and ethically look at such an issue. The findings of case studies are not deemed to be generalizable by many quantitative researchers, the study reflects the uniqueness of one individual and thus generalisation to others may be unjustified Reliability is difficult to establish as the exact circumstances are impossible to recreate Researchers may develop more personal relationships with participants may result in subjective data or different behaviour of participants and researchers Results of case studies are affected by the researcher's interpretationsmay be subjective and influenced by the researcher's beliefs, values, and opinions May cost a lot of time, effort & money due to the amount of data and time of a case study ------In depth information would not be able to be collected by using other research methods (e.g. experiment, survey etc.).
background of Henry Molaison
H.M fell off his bike when he was aged 7 and sustained a serious head injury. At 27 he became so incapacitated by his seizures that he could not lead a normal life. As a result, with the approval of himself and his family, neurosurgeon Scoville performed dubious experimental surgery that removed tissue from the medial temporal lobes on each side of his brain, including the hippocampus. This consequently resulted in Henry suffering from anterograde amnesia- he was no longer able to transfer information from short term memory to long term memory, and could not retain new information for longer than 30 seconds.
What is triangulation? And what does it involves?
Triangulation involves using multiple data sources, multiple researchers or multiple research methods in an investigation to reach a richer understanding of a behaviour or cognitive process for example in this case study methods including . interviews . cognitive testing . direct observation of behaviour . psychometric testing
What are the limitations of the case study?
it cannot be replicated, it was a unique circumstance that cannot be repeated due to ethical reasons. ethical criticisms was dubious informed consent, consent was obtained from a person who was profoundly amnesiac; whose mental incapacity precluded his understanding what he was consenting to. the findings of the case study is not applicable to everyone, therefore lacking generalisability the researcher may be intensely involved in the gathering of data. may lose their objectivity, potential researcher bias. however this was avoided with triangulation.
What are explicit memories?
memories that are consciously available such as facts and personal experiences. it is information that we intentionally recall and articulate.
What could be concluded from these results, specifically regarding the role of the hippocampus?
that the part removed accidentally from his brain is important for the formation of long term explicit memories It was found from the MRI scan that the brain damage was spread through the hippocampus, amygdala and other parts close to the hippocampus. Damage of the hippocampus explains the problem of transferring short term memory to long term memory the researchers concluded that the hippocampus plays a critical role in converting memories of experiences from STM to LTM. since H.M was able to retain memories of events that occurred before his surgery, it indicates that the role of the hippocampus is not the site of permanent storage, but rather plays a role in the organisation and permanent storage of memories elsewhere in the brain.
overall conclusion
therefore, as Henry Molaison's previous long term memories were intact, but he could not form new long term memories, the case study of HM provides evidence for the MSM which states that the STM and LTM are separate storage areas in the brain, and that information moves in a serial manner from STM to LTM. The fact that HM and other people with amnesia have deficits in some types of memory but not others, provides evidence for multiple memory systems with distinct brain regions. thus indicating to scientists that the medial temporal region with the hippocampus is not the site of permanent memory storage in itself. It seems to play a role in memory consolidation and then organized storage in another part of the brain.