H. M Flashcards
Why did H.M have a partial lobotomy?
he cracked his skull in an accident as a child which caused him to have seizures
What effects did the partial lobotomy have on his memory?
lost most of his memories from the past decade
he was unable to form new memories
Which part of H.Ms brain was removed?
the hippocampus
Why were lobotomies thought to be successful?
It was thought mental functions were strictly localised to corresponding areas of the brain.
They had been successfully done to reduce seizures in psychosis
What were the results of H.Ms lobotomy?
The seizures had disappeared?
He had no change in his personality
What did H.Ms case study teach us about memory?
It proved that there was a distinction between long-term and short-term memory and that each uses different brain region.
H.M’s basal ganglia
he still learnt how to play tennis
he improved on the star tracing task
H.M’s hypothalamus
couldn’t identify feelings of tiredness / hunger
H.M’s Parahippocampal Gyrus
impaired - couldn’t identify smells
learnt what an astronaut was
H.M’s hippocampus
couldn’t improve on maze task
What happened to his early episodic memory?
it was still intact
What happened to his recent episodic memory?
it was impaired
what happened to his semantic memory?
it was partially intact but also impaired
what was the aim of the case study?
to investigate the extent of H.Ms memory deficits and how they relate to his brain damage
what was the sample for the case study?
One adult male, H.M., aged 27
he suffered from both retrograde amnesia (loss of memories before his operation) & anterograde amnesia (loss of memories after his brain operation)
maze task
HM attempted to trace the correct route through the maze with his finger.
he had 252 attempts at the task
H.M. never showed any improvement
star tracing task
1962 - he had to copy a five pointed star by drawing between the lines of a template.
he could only see a reflection of the star and his hand in a mirror
made fewer mistakes on each attempt
Day 1:
- started with 30 errors
-20 on second attempt
-10 on 7th attempt
Day 2:
-started with 25 errors
-immediately dropped to fewer than 10
Day 3:
-made fewer than 5 mistakes each time
describe HM’s memory
forgot all new experiences after about 30 seconds
remembered a lot of information from before his 16th birthday
consistent personality
reinforcement and punishment tests using electric shocks
these tests were abandoned
he had huge tolerance for electric shocks and barely noticed ones that normal people found painful
he also had difficulty noticing feelings of tiredness and hunger
conclusions about STM & LTM
there is a clear difference between them
the hippocampus plays a vital role in transforming short term memories into long term memories, as HM could not do this
