case study of HM

• background of hm

  • born in 1926
  • age 7 knocked down by bicycle, had minor epileptic seizures at 10, major seizures at 12.
  • seizures so severe he stopped working, couldn’t live normal life.
  • monitored by William Scoville who offered experimental procedure of bilateral mesial temporal lobe resection (5cm removed and 2/3 hippo)
  • controlled epilepsy but had serious effect on memory.
• aim?

  find out effects of brain surgery on his functioning, particularly memory
• procedure?

  studied using various methods: observation, interviews, standardised IQ/memory test, MRI during lifetime and after death ect. took place between 1957-2008 (age 82).
• results? (affected memory)

  forgot daily events, underestimated own age, forgot names of people he was introduced to, couldn’t recognise hospital staff, couldn’t learn new words, severely impaired from recognising faces post surgery but unaffected faces in news before surgery
• what was HM unable to do?

  • unable to encode temporary short-term memory into long-term memory
• results? (unaffected memory)

  normal intelligence, same personality, remarkable attention so could carry convo, intact digit span, info available if actively rehearsed but lost if difficult to rehearse (STM not impaired), spatial memory intact as he could draw floor plan of house.