Flashcards in HM MIlner Deck (23):
What happened to him when he was 7 years old and what did he suffer from after the incidence?
- Hit by a cyclist while crossing the street when he was 7
- Sustained a serious head injury
- Suffered from epileptic attacks + incapacitated from his seizures;
- could not live a normal life, medicine did not help
Who was the first neurosurgeon who attempted surgery on him and what did he do?
He removed tissue from the medial temporal lobe including hippocampus
Who was the neuropsychologist who took over the case and till when?
Till he died in 2008
Describe his behaviour after his surgery
- He forgot daily events almost as soon as they occurred
- He remembered childhood very well,
- personality unchanged,
- no general intellectual impairment but
- could recall little from the 12 years before operation
What did he primarily suffer from?
Anterograde amnesia (couldn't remember things that happened after the operation)
What strategies did Milner primarily use?
She used method triangulation by:
- Psychometric testing: IQ testing was given to HM. His results were above average.
- Direct observation of his behaviour;
- Interviews with both HM and with family members.
- Cognitive testing: memory recall tests as well as learning tasks - such as reverse mirror drawing.
What did Corkin perform on HM and when?
What did he find?
- an MRI to determine the extent of the damage done to HM's brain
- In 1992 and then 2003
- parts of HM’s temporal lobe including the hippocampus had the most damage.
what type of knowledge could he not acquire? (2)
and what does this suggest?
- episodic knowledge (memory for events)
- semantic knowledge (general knowledge about the world)
that the brain structures that were removed from his brain are important for the transfer of information from short-term to long-term memory.
What else did researchers find about his behaviour? (1)
and what does this indicate? (2)
he was able to remember his house and could draw a picture of the floor plan of his new home.
-indicates that he was able to form a cognitive map of the spatial layout of his house.
-may mean that this type of memory is not encoded in the same way as semantic or episodic memories.
What did they find about motor skill memories?
procedural memories, were well maintained
e.g. he knew how to mow a lawn.
Where did he show improvements`?
performance of new skills such as reverse mirror-drawing in which he had to acquire new eye-hand coordination.
Although he showed improvement on the skill over time, he never remembered learning the skill.
How does this study explain the role of the hippocampus
Damage to the hippocampus explains the problem of transferring short-term memory to long-term memory as this is the area where the neurotransmitter acetylcholine is believed to play an important role in learning and formation of memories.
What conclusion can we draw about memory systems?
memory systems in the brain constitute a highly specialized and complex system.
What conclusion can we draw about the role of the hippocampus?
plays a critical role in converting memories of experiences from short-term memory -> long-term memory.
What conclusion did researchers draw about short term memory?
short-term memory is not stored in the hippocampus as HM was able to retain information for a while if he rehearsed it.
What conclusion can we draw about the role of the medial temporal lobe?
Since HM was able to retain some memories for events that happened long before his surgery it indicates that the medial temporal region is not the site of permanent storage but rather plays a role in the organization and permanent storage of memories elsewhere in the brain.
What conclusion can we draw about implicit memory
Implicit memory contains several stores - for example, procedural memory, emotional memory and skills and habits. Each of these areas is related to different brain areas.
What type of study was this and what does it reveal about the strength of it?
longitudinal - over 50 years!
Strong because change could be observed over time.
Limitation of case studies
but in this case what is used to confirm findings?
they cannot be easily replicated.
several other case studies of patients like HM - for example, Clive Wearing - which confirm the findings.
Limitation of this study
Some of the study was retrospective in nature-
that we do not have a lot of data on HM's actual cognitive abilities before the accident.
Limitation of medication used to treat his epilepsy
may have resulted in some of the damage, but this is not highly relevant as it is the damage to specific parts of the brain that is important.
High ecological validity, no variables were manipulated and HM was observed in his natural environment.