Long-Term Memory

• It has been proposed that there are three different types of LTM

  Episodic Memory

  Semantic Memory

  Procedural Memory
• Declarative

  Memories that can be recalled consciously
• Non-declarative

  Recall of information and events without requiring conscious effort
• Episodic memories (declarative)

  • Refers to our ability to recall life events or personal experiences known as 'episodes'
  • We remember the details, context and emotions, and make an explicit effort
  • Associated with the hippocampus and the temporal lobe
• Semantic memories (declarative)

  • Our factual memory about meaningful information
  • We make an explicit effort to recall
  • Associated with the temporal lobe
• Procedural memories (non-declarative)

  • Concerned with skills and 'how to do' behaviours/things.
  • Muscle-based memory which improves with practise and is resistant to forgetting
  • We make an implicit effort to recall
  • Associated with the cerebellum and limbic system
• Hippocampus- episodic

  Cerebellum and motor cortex- procedural

  Temporal lobe- semantic
• Supporting evidence- Tulving

  6 Volunteers injected themselves with a small amount of radioactive gold which was scanned to detect its location w/ a gamma ray detector
• Tulving

  Each participant performed 8 trials, involving 4 semantic and 4 episodic topics

  Participants would lie with their eyes closed and indulge in either episodic or semantic retrieval
• Tulving

  There was greater activation in the right prefrontal cortex (hippocampus in particular), when thinking about episodic memories

  Greater activation in the left prefrontal cortex, (temporal lobe) when retrieving semantic information
• Tulving

  Showed that semantic and episodic memories are formed and stored in different areas of the brain and are distinct from another

  However it is difficult to generalise the results, they lack external validity
• Herlitz

  1000 Swedish participants

  Found that females consistently performed better than males on tasks requiring episodic LTM

  There was no differences between males and females in semantic ability
• Case study of Clive W

  Viral encephalitis resulted in anterograde and retrograde amnesia which damaged his temporal lobe, frontal lobe (semantic memories) and eradicated his hippocampus (episodic memories)

  His declarative knowledge was poor

  He retained his cerebellum and therefore maintained his procedural memories, as he could play the piano

  Supports the LTM and the different stores
• Spiers

  Brain damaged patients with amnesia (147 cases)

  They all has poor declarative knowledge but none had issues with any procedural knowledge
• Milner

  Discovered that HM was able to learn to trace a shape using its mirror imagine and he could retain this skill

  He had no conscious recollection of ever doing the task before

  Appears that HM could use procedural memory to learn this skills but his declarative memory was damaged
• Debate

  • It has been suggested that the temporal cortex, including the hippocampus are used for both semantic and episodic memories
  • Damage to the temporal cortex seems to cause problems with both types of memory, suggesting they are located in the same place
• Application

  • Research like Godden and Baddeley has allowed us to understand the importance of context cues in retrieving long-term memories
  • Allowed for the development of dementia treatments such as cognitive stimulation therapy and the development of eyewitness testimony techniques
  • Allowed for better care of brain-damaged patients