Critically Discussing Amnesia Case Studies: Brain Memory Mechanisms

This essay critically evaluates the contribution of case studies of human amnesia to understanding the brain mechanisms of memory, highlighting the significance of cases like H.M. and Clive Wearing. It discusses different types of memory (explicit, implicit, short-term, long-term) and amnesia (anterograde, retrograde, psychogenic, organic) and their impact on memory functions. The essay emphasizes how these case studies provide valuable insights into the roles of brain structures like the hippocampus in memory consolidation, the distinction between short-term and long-term memory, and the separability of memory stores. It also addresses the limitations of generalizing from case studies and reinforces the importance of the hippocampus in long-term memory, concluding that these studies offer crucial information despite their limitations. Desklib provides access to similar solved assignments and resources for students.

Neuroscience:
Critically discuss the contribution
of case studies of human amnesia
to our understanding of the brain
mechanisms of memory.

The contribution made by the case studies of human amnesia to understanding
the brain mechanisms of memory are significant. Memory comprises of four sub
components. The first component is a central executive system that works for attention
control (Payne, 2020). The second is a phonological loop which performs the work of
storage and manipulation of verbal materials. A visual spatial sketchpad is the third
component which finds its use in object and spatial information. The fourth component
is an episodic buffer which stress information. In other words, memory is the ability of an
individual to remember. The present essay critically evaluates the contribution of case
studies of human amnesia in developing understanding of brain mechanisms of
memory.
Memory is divided into long and short term which are further bifurcated into
explicit and implicit. The explicit memory comprises of episodic and semantic memory.
Implicit memory consists of procedural and non- associative learning (Jonin and et.al.,
2018). The procedural memory is further bifurcated into priming and associative
learning. Amnesia is regarded as partial or total loss of memory. This be the result of
shock, brain illness injury and psychological disturbance. Amnesia can be organization
and psychogenic. Organic amnesia is caused due to a shock or injury to brain.
Psychogenic amnesia, on the other hand, is caused due to psychological trauma. The
most common form of amnesia is post traumatic amnesia (PTA) which is caused by
sever head trauma and leads to an inability to keep a track of the ongoing activities
(MacPherson and Della Sala, 2019). Extreme trauma to head may lead to long term
amnesia which leads to inability to recall old memories and encode new ones. In case
of retrograde amnesia, consolidation of recent memories is disrupted due to damage to
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the hippocampus. More severe damage as is the case in anterograde amnesia may
lead to continued problems with consolidation.
There are various advantages of studying case studies. They consume less cost
and time and prove to be a boon when there is limited exposure data. For example,
case studies of Clive Wearing and H.M. have been a great source of information and
developed understanding about memory and ways in which brain works (Elward and
Vargha-Khadem, 2018). Rich quality of data has been provided by these case studies
which assisted in understanding memory processes of brain. The main advantage of
case studies is that these help the researchers in examining the cause and effect of
injuries of brain. These also help in knowing the effects that injury has on memory.
These features make the case studies occupy an important place in psychological
research.
Case studies of human amnesia contributed significantly to understanding of the
brain mechanisms of memory (Szabo and et.al., 2020). Henry Gustav Molaison (HM)
had severe epilepsy from 10 years. In the year 1953, he underwent bilateral removal of
medial temporal lobe. He suffered from severe anterograde amnesia and some
retrograde amnesia. However, the working memory and motor still learning was
preserved. This case study was widely studies as due to the removal of majority of
hippocampus, it function could be tested without the impact of other confounding
impairments. Despite several psychologists and neurologists studying H.M., there was
no difference observed and every day of testing was similar to the first (Blumenthal and
et.al., 2017). Along with various amnesic symptoms, it was found that H.M.’s existing
procedural memories were intact and even new procedural memories can be formed.
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The contribution of HM case study to understanding brain mechanisms is
important. It provided evidence for separate long term memory (LTM) and short term
memory (STM). Further, the case study also assisted by providing evidence for long
term memory stores that are separable. These are the episodic, procedural and other
memory stores (Shallice, 2019). The procedures related to distributed memory functions
could also be understood with the help of H.M. case study. In addition to this, H.M. case
study provided evidence for the key role that temporal lobe structures play in
consolidating memories and transferring them to long term store. With this case study, it
can be inferred that since short term memory is intact. The presence of hippocampus
(HC) is not crucial for STM. However, presence of HC is critical for formation of new
memories. Also, there is no requirement of HC for recalling established LTM (Cubelli,
2019). Furthermore, personality, judgement IQ and intelligence are unaffected by the
presence of HC. But, he presence of HC is important for the process of consolidation.
The case study of HM contributed to the understanding of explicit and implicit split of
amnesia.
Another case study by Claparade contributed to understanding related to
amnesic evidence. Every morning, neuropsychiatrist shook hands with amnesic patient.
One day, hand shake was done with a pin in hand which took the patient by shock. Next
day, the patient refused to shake hands but could not give any specific reason for it.
from this it could be analyzed that conditioned stimulus led to anticipation of shock
(Kapur and Kemp, 2019). This contribute to our understanding that for conditioning,
explicit memory or brain regions (HC) necessary for explicit memory are not required.
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Yarnell and lynch (1970) conducted a study on concussed American football
players. The players were asked questions immediately after the incident, they were
able to recall it. however, when asked questions after 3- 20 minutes after the incident,
the players were unable to provide any information (Perez Velazquez Nenadovic, 2021).
This study contribute to understand that psychological consolidation process is
disrupted by a blow to head. Hence, the process for memory to be retained permanently
is also disrupted.
The contribution of the case study of Clive Wearing can also be studied for
understating the brain processes of memory. Clive Wearing was a leading musicologist
who suffered widespread brain damage due to severe Herpes encephalitis (Baddeley,
2021). This affected the left temporal and frontal lobe areas. He suffered from both
anterograde and retrograde amnesia and episodic and semantic memories were
affected by it. but, the procedural memory was unaffected. The only person he could
recognize was his wife. No clear explanation could be provided for this memory. He can
retain information for only 10- 15 minutes. Wearing could be considered to develop a
profound case of total amnesia. He could only retain a memory of the las few seconds
(Rubin, 2021). It is due to this that every few seconds he feels that he has just woken up
from sleep.
The case study of Clive provides significant contribution to understanding the
brain processes of memory. It provided insight about the distribution of memory into the
brain. Further, by studying the case of Clive, it was found that memory is not localized to
hippocampus (Raaijmakers, 2018). The ability of Clive to play piano indicates that the
areas of brain which are related to procedural memory are intact. Also, it is seen that
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Clive provides a strong emotional response. This adds to the information that emotional
memory is not impaired (Fama, Pitel and Sullivan, 2012). This is the area of amygdala.
Though the case studies provide important information about the processes of
brain related to memory, it can be critically analysed hat these cannot be generalized.
This is because all the cases of amnesia are different (Kopelman, 2015). Also, the case
study of Clive could not explain the processes of brain of memory of basic things such
as eating, showing etc. which were intact. It could not explain whether these are
procedural or episodic memory (Ferguson and et al. 2019).
Double dissociation is referred to a situation which is characterized by location of
different cognitive abilities in different areas of brain. The case of HM is an example of
double dissociation between long and short term memory stores. Further the case of
Clive Wearing and HM both comprised of damage to hippocampus. Therefore, these
case studies provide a triangulating evidence and assisted in reinforcing the importance
of hippocampus in long term memory.
The case study of HM contributed to the hierarchical model of temporal lobe
function. The view asserted by this model was confirmed by the persistent emphasis on
hippocampus dysfunction that was evident in the case of HM. In this case, HM
repeatedly failed and could not recognize his friends and near neighbors. This indicates
that both verbal and non- verbal recognition was impaired. Therefore, it cannot be
concluded that in HM’s case there was relative sparing of recognition memory.
However, the notion of different brain structure was reinforced by the case of HM.
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As per the Multi Store Model by Atkinson, memory is divide into three unitary
stores and transfer of information takes place in a linear sequence. HM’s case study
supports this mode and provides further information on it. HM had marked problems in
long term memory after brain surgery. There are small number of personal and public
events that he remembers. However, the short term memory remains intact.
From the essay it can be concluded that case studies of HM and Clive provide
valuable information about the brain mechanisms of memory and amnesia. The
information provided by these case studies surpasses the demerits of using case
studies as a method of conducting research.
REFERENCES
Books and journals
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