Case studies

• Multi store model of memory (MSM)


  • Patient HM (suffered from epilepsy and underwent brain surgery to removing his hippocampus
  • Following this surgery, HM could remember events and some information and details from before the surgery (LTM) but he could not form new memories (STM could not be transferred to LTM)
  • His episodic memory was affected whereas his semantic and procedural memory was not
  • This shows that the brain uses separate regions for STM and LTM
• Working memory model (WMM)


  
  

  PATIENT KF, SHALLICE & WARRINGTON 1970

  
  

  • KF suffered a brain injury after which his STM was severely damaged
  • KF struggled to process verbal/auditory information but his ability to recall visual information was unaffected
  • This is evidence that there are different slave systems in the working memory which code for verbal/auditory information and visual information
• Forgetting - interference 


  BADDELEY & HITCH 1977

  • Rugby players asked to recall names of teams they had played against over one season
  • Players who had played in the most games had the worst recall
  • The researchers found that the later, more recent games had interfered with recall of the earlier games
  • The use of real players recalling real games gives this study good ecological validity
• Negative effect of anxiety on recall (weapon focus effect)

  JOHNSON & SCOTT 1976

  • Pps were made to believe that they were taking part in a lab study
  • While sitting in waiting room, pps in low-anxiety condition heard a causal conversation and see a man walk out with a pen
  • Other pps overheard heated argument and see a man walk out with a blood covered knife
  • 49% of pps who saw man carrying pen correctly recalled him
  • 33% of pps who saw man carrying knife correctly recalled him
  • Anxiety decreased the reliability of recall on EWT
• Positive effect of anxiety on recall 


  YUILLE & CUTSHALL 1986

  • 21 pps witnessed an actual shooting of a shop owner in Canada
  • 13 took part in the study and were interviewed 4 months later
  • Their reports were compared to the police reports at the time
  • Accuracy was determined on how many details they remembered and also asked to rank their stress levels at the time of incident
  • 88% pps who were very stressed were accurate
  • 75% pps who were less stressed were accurate