types of LTM

• STRENGTH:

  • Evidence from famous case of HM (Henry Molaison) and Clive Wearing.
  • Episodic memory in both men was severely impaired due to brain damage and infection
  • But their semantic memory was relatively unaffected
  • They still understood the meaning of words
  • IE: HM could not recall having stroked a dog half an hour earlier but did not need the concept of dog being explained to him
  • Their procedural memory was intact they could both walk, speak and Clive Wearing could still play the piano
  • Evidence supports Tulving's view that there are different memory stores in LTM
• LIMITATION:

  • Studying people w brain injuries can help researchers to understand how memory is supposed to work normally
  • But clinical studies aren't perfect
  • Major limitation is the lack of control of variables
  • Brain injuries experienced by pp were usually unexpected
  • The researcher had no way of controlling what happened to the pp before + during the injury
  • The researcher has no knowledge of the pp's memory before the injury
  • Without this its difficult to judge exactly how much worse it is afterwards
  • Lack of control limits what clinical studies can tell us about diff types of LTM
• LIMITATION

  • Conflicting research findings linking types of LTM to areas of the brain
  • IE: Bucker and Peterson 1996 reviewed evidence regarding the location of semantic and episodic memory
  • Concluded that semantic memory is located on the left side of the pre-frontal cortex and episodic memory on the right
  • However other research links the left prefrontal cortex with encoding of episodic memories and the right prefrontal cortex w episodic retrieval (Tulving 1994)
  • Challenges any neurophysiological evidence to support types of memory as there is poor agreement on where each type is located