memory research - Wilson et al - CW Flashcards
(18 cards)
Background
People with amnesic syndrome often experience varying degrees of memory loss includes forgetting age etc etc but when someone in unaware of time, date and surrounding = dementia .
However according to Kopelman its rare for someone to complete forget who they are in neuronal disease
Two types of distorted memories
1) Faulty episodic memory, memories of past events that are incorrectly recalled. Might be recalled as being in a different time or place or may have remembered things that never actually happened
2) Faulty semantic memory, knowledge and understanding of things can be inaccurate
Definition of delusions
False beliefs that the person who is experiencing them fully believes in, and will not listen to others who argue that it cannot be correct. Preoccupying and those who have damage to their memory = delusions part of faulty semantic memory.
Define consciousness
Organism awareness of its own self and surroundings and its ability to respond to environmental factors
Aim
report on case of CW who suffered from rare severe condition on anterograde and retrograde amnesia . Researchers had recorded neuropsychological assessments of his brain and psychological experiences.
Sample
CW who was born in UK in 1938, outstanding musicians and musical scholar and leader of London sinfonietta.
Method
Longitudinal single case study covering 21 years. The research gathered both qualitive and quantitative data.
Materials
- neuropsychological tests such as IQ tests, tests of verbal fluency, and a digit span test to test long-term and short-term memory
- MRI scan to see amount and location of damage in his brain
Outline of the study
March 1985, CW developed an influenza type illness, symptoms include: headache, fever. Several days later, he was diagnosed with HSVE and given medication which probably saved his life.
Virus already destroyed parts of his brain.
Neuropsychological assessment
- CW was referred to Barbara Wilson in Oct 1985. He had already been assessed and the report found that he was experiencing ‘ extremely severe episodic memory deficits, some semantic memory impairments but his immediate memory span was normal. This means his memory for autobiographical events was very damaged . He was unable to recall many details about his life before the illness. Also unable to create new memories. His memory for facts and knowledge had some damage but his ability to remember a small amount of information over a short amount of time was normal.
- CW was assessed in Nov 1985. His verbal and performance IQ tests were found to be within the ‘ average ‘ range. However, CW was an extraordinary gifted mean before his illness so this score is likely to be poorer than he would have scored before his illness.
-His short term memory was found to be normal but his long term memory was severely impaired .
- He also still showed impaired semantic memory when asked ‘ what is a scarecrow ‘, he responded ‘a bird that flies and makes funny noises’
Magnetic resonance imaging (MRI) scanning
- in 1991, CW had his first MRI scan. The scans were rated by three independent experts who all agreed that there was significant abnormalities in hippocampal formations, amygdala, mammillary bodies, temporal poles and substantia innominate. There was also other abnormalities in many other brain areas such as the left fornix and the left media frontal cortex.
- CW given a second MRI scan 15 years later in 2006
- second brain scan showed there was very little change . It also revealed that CW had extension damage to his temporal cortices . As the scans show, the damage was greater on the left than the right.
- over 21 years CW was given numerous assessments.
Results showed that he always scored zero on
tests of delayed recall. This means that if he was
given new things to learn, he was completely
unable to recall them after a delay, showing that
he could not form new semantic memories. This is
evidence for anterograde amnesia.
He did, however, recall who he was, where he went
to school, where he studied music and that he had
married his wife.
In summary, his memory remained largely
unchanged over the 21 years of the study.
CW’s auditory hallucination
In 1990, CW developed an auditory hallucination. His
wife, Deborah, reported that CW thought he could hear
his music being played. This hallucination persisted
and he still ‘hears’ his music played several times a
week. It is quite common for auditory hallucinations
to be familiar songs that are repeated over and over.
This suggests that left over memory traces play a
part in the creation of hallucinations.
Results
CW was found to have:
severe brain abnormalities
both retrograde and anterograde amnesia
the inability to form new memories
decreased performance and verbal IQs (although
these were classed as ‘normal’, CW was
exceptionally talented before his illness)
some loss of semantic memory
a severely damaged episodic memory.
CW’s beliefs about his consciousness
According to Wilson et al., CW did not appear to accept
that he had a problem with his memory. Instead CW
insisted that his memory problems were due to the
fact that he had not been conscious since his illness.
When he was challenged on his belief about his
consciousness, for example, by being shown previous
entries in the diary that he kept, or a videotape of him
conducting his choir (which he was recorded doing for
a television documentary after his illness), he would
say that he wasn’t conscious at the time of doing it.
Wilson et al. questioned whether CW was suffering from a
delusion. However, they decided against this, as he wasn’t
experiencing other psychiatric features of delusions.
Lacking autobiographical consciousness
According to Damasio (2000) consciousness is made
up of three parts. The first part is the proto self, that
we are not consciously aware of. The second part is
the core consciousness which only requires short
term memory where a person is aware that their
thoughts are their own and can respond to emotion.
The third stage – and highest form of consciousness
of retrograde and anterograde amnesia. Therefore,
CW didn’t actually gain anything from taking part in
this research.
#
Wilson et al. suggest that CW has core
consciousness – he is aware that his thoughts are
his own. However, the severe brain damage has
meant that he was virtually unable to create new
autobiographical memories. For example, if his wife
came to visit him, he was unable to create this as a
memory so that each time he saw her it was as if it
was the first time since his illness. His memories
of his past life before his illness are also very
limited. Therefore, according to Damasio’s theory of
consciousness, CW has very limited ‘autobiographical
self’.
Conclusions
CW’s sense of ‘self’ was disrupted by his memory
disorder.
The viral infection herpes simplex encephalitis can
result in brain damage.
Brain damage can result in both retrograde and
anterograde amnesia.
Brain damage can significantly affect memory.
Provides support for the Multi-store Model. It
suggests that both short-term memory and long-term
memory have separate stores. The Multi-store
Model would also suggest that CW is unable to use
elaborative rehearsal or maintenance rehearsal in
order for the information to pass into LTM.
Criticisms
CW was repeatedly tested over 21 years, which
may have caused him psychological distress. The
authors state that CW was given neuropsychological
tests on many occasions over the 21 years of the
study. Although CW would have been unable to
remember these tests, was it ethical to use him
repeatedly as a test subject? Although CW might have
been able to provide consent, given the extent of his
brain damage, he may not have truly understood
what they were planning to do and how often.
The tests that Wilson et al. describe were not
designed to actually help CW or to find ways to
help him. They were simply used to repeatedly test
his memory ability to gain a better understanding
Criticisms
CW was irritated at having his belief in his own
consciousness questioned. This obviously caused
him some psychological harm at those brief
moments in time. It can be argued that it was
unethical to cause him irritation even in those short
moments, given how difficult life must be for him.
Confidentiality was not maintained. Although
the authors refer to the participant as CW, they
do identify him by his full name and give enough
personal background details to make it very clear
who CW actually is. Therefore, his identity was not
kept private.
It is hard to generalise the results to other people
because of the extent of the damage to his brain.
Obviously, CW’s case is highly unusual. Considering
the extent of the damage to his brain, it is difficult
to pin-point how the exact areas of the brain that
were damaged were linked to his retrograde
and anterograde amnesia. Wilson et al. mention
a patient of Damasio, known as David, who had
similar brain damage to CW. However, David did
not report thinking that he had just woken up or
had not been conscious before. Therefore, the
results of Wilson’s single case study may not be
useful for generalising to the wider population to
understanding how our memories work.
