Henry Molaison Flashcards
Who was HM?
He had the most studied brain when he died and helped the development of memory.
What was wrong with HM?
He suffered from severe epilepsy following a bicycle accident at the age of 9
He suffered from epileptic seizures for many years up to 27
What did HM do?
when he was 27 he underwent an operation by William Scoville where he removed his hippocampus.
what was the result of the operation?
The procedure reduced seizures and heled IQ but left him with severe memory loss.
What did he get diagnosed with?
anterograde and retrograde amnesia.
What did the two neuropsychologists realise when assessing the extent of his amnesia?
That the hippocampus was consolidating memories so his memories were eroding and the removal of it was irreversible
What is anterograde amnesia and how did it affect HM?
Inability to form new memories.
HM could still learn skills but had no memory of learning them.
What is retrograde amnesia and how did it affect HM?
the inability to retrieve memories.
He lost the ability to retrieve memories from 19months-11 years prior the operation.
He could retain certain info for 15 mins max.
What was the concern with the retrograde amnesia?
He may not have got it due to the operation but most likely by epilepsy medication and frequency of seizures prior to the operation.
What task did HM undergo?
A mirror task where we had to trace a shape (star) whilst looking into a mirror.
he did this 10 times.
What were the results of the task?
What does this show?
His performance improved each time even though he didn’t remember doing it.
This shows he can still learn new skills with procedural memory.
How does HM relate to MSM?
-he retained the ability to form short term memories which shows how LTM and STM are separate.
Also shows that damage to one memory store doesn’t affect the other.
-Maintenance rehearsal allows LTM to work better.
-hippocampus plays a crucial role in transferring info for STM to LTM.
How dos HM link to Tulving?
Supports assertion that memory types are functionally separate
He could only process procedural and episodic memory properly.
Shows that the hippocampus is essential for declarative memory.
How does HM link to Tulvings episodic memory?
He couldn’t recall new events or memories what happened after the procedure, only memories from before 27.
How does HM link to Tulvings semantic memory theory?
His semantic memory was partially impaired, he retained some old factual knowledge that was encoded before his surgery.
