Types of LTM

• Who identified procedural memory?

  Cohen and Squire.
• What is procedural memory?

  • Memory for actions and skills
  • Requires practice to acquire, but no conscious awareness or effect to recall once learned
  • Remains intact for long periods of time without our ability to perform an action deteriorating
• Who identified declarative memory?

  Milner.
• What is declarative memory?

  Memory for facts, data and events.
• What are the two types of declarative memory?

  Episodic and semantic . Identified by Tulving.
• What is semantic memory?

  • Knowledge of facts/our understanding of concepts
  • No time-stamp (don't remember when we learnt it)
  • Not personal (no added meaning; doesn't revoke an emotional response)
  • Requires conscious effort to recall the information
• What is episodic memory?

  • Unique recollection of experiences and events from our individual lives
  • Psychologists describe episodic memories as being time-stamped (memories of specific occurrences)
  • Can recall lots of associated detail
  • Requires conscious effort to recall these memories
  • May evoke an emotional response
• What evidence does Clive Wearing supply for types of LTM?

  Suffers amnesia due to virus which attacked his CNS and destroyed parts of his hippocampus. Episodic and semantic LTM is disrupted. Unable to recall events in his life (e.g. what he ate for breakfast, getting married), but can remember some facts. However, has intact procedural memory - can still play piano, read music and sing.
• What evidence does Henry Molaison provide for types of LTM?

  Suffered epileptic seizures likely caused by childhood cycling accident. Surgeon removed tissue from hippocampus to control seizures. Combined effect of medication and surgery meant HM had no memories and couldn't form new memories either. Milner repeatedly gave him a task to trace a star from a mirrored reflection. Despite never making a conscious memory, he became progressively better with practice i.e. made a new procedural memory. Evidence for separation within brain or episodic/semantic memory from procedural memory.
• Strength for types of LTM - evidence from brain scans

  Tulving et al. Patients undertook different memory tasks requiring either semantic or episodic memory whilst having PET scans. Scans revealed activity in pre-frontal cortex on both types of tasks, however semantic memory tasks were performed in left brain and episodic in the right brain. Suggests a spatial separation within the brain for these two types of LTM supporting idea that there are distinct types of memory.
• Problem for types of LTM - lack of knowledge about brain damage

  When still alive, psychologists generally unsure about extent of their brain damage. If brain damage is more extensive than first thought, this can cast doubt as to where different types of LTM are located, and even if they are truly 'different' from one another.
• Problem for different types of LTM - differences due to extra rehearsal

  Some psychologists point out we tend to recollect memories from our own lives (episodic) more often than we do factual (semantic) memories. Episodic & semantic memories may only be more detailed because we think about them more often - additional detail in LTM for episodic memories is just a result of more rehearsal.