types of long term memory

• episodic memories

  • stores events (episodes) from our lives
  • Eg = your most recent visit to the dentist, the breakfast you ate this morning
  • key features: (they are complex)
  • They are time-stamped
  • They involve several elements
  • You have to make a conscious effort to recall them
• semantic memories

  • Stores our knowledge of the world
  • Eg = meaning of words, the taste of something
  • Key features:
  • not time-stamped
  • Less personal, more about facts/knowledge we all share
• procedural memories

  • Stores memories for actions and skills
  • Eg = driving a car, playing tennis
  • Key features:
  • Recall occurs without awareness or effort
  • Skills/actions become automatic with practice
  • Explains the step-by-step procedure is hard because you do it without conscious recall
• strength = case study evidence of different types of LTM

  • Clinical studies of amnesia (HM and Clive Wearing) showed both had difficulty recalling events that had happened to them in their pasts (episodic memory)
  • But their semantic memories were relatively unaffected (eg HM did not need the concept of ‘dog’ explained to him)
  • Procedural memories also intact (eg Clive Wearing still played the piano)
  • Supports the view that there are different memory stores in LTM becuase one store can be damaged but other stores are unaffected
• counterpoint to case study evidence

  • Researchers lack control in clinical case studies = they do not know anything about the person‘s memory before brain damage
  • => clinical studies are limited in what they can tell us about different types of LTM
• limitation = conflicting findings about types of LTM and brain areas

  • Buckner and Peterson = reviewed research findings and concluded that semantic memory is located in the left prefrontal cortex and episodic with the right prefrontal cortex
  • BUT other studies (eg Tulving et al) = have found that semantic memory was associated with the right prefrontal cortex and the reverse for episodic memory
  • This challenges any neurophysiological evidence to support types of memory as there is poor agreement on where each type might be located
• strength = helping people with memory problems

  • Memory loss in old age is specific to episodic memory = it is harder to recall memories of recent experiences although past episodic memories are intact
  • Belleville et al = devised an intervention for older people targeting episodic memory, which improved their memory compared to a control group
  • Shows that distinguishing between types of LTM enables specific treatments to be developed
• extra evaluation = distinction between episodic and semantic memories

  • Tulving = recently said episodic memory is a ‘specialised subcategory’ of semantic - an intact semantic memory can function with a damaged episodic but not vice versa
  • BUT = Hodges and Patterson found that some patients with Alzheimer’s disease can form new episodic memories but not semantic ones
  • => episodic and semantic memories are closely related but ultimately different from of LTM