Types of long term memory Flashcards
Who proposed that there are different types of LTM?
Tulving (1985)
What is episodic memory?
this refers to our ability to recall personal life events (episodes). It includes memories of when the events occurred, and of the people, objects, places and behaviours involved
What is semantic memory?
this long-term memory store contains our knowledge of the world. This includes facts and our knowledge of what words and concepts mean
What is procedural memory?
this long-term memory store is for our knowledge of how to do things. It is our memory for learned actions or motor skills
Features of the episodic memory
Can be expressed verbally (recalled with conscious effort) – available for conscious inspection (explicit)
Time-stamped – with reference to time and place
May be less resistant to amnesia/forgetting i.e. more likely to be forgotten
More likely to involve the storage of emotional content in memory such as how we felt at the time
Generally based on an individual’s subjective experience
Features of semantic memory
Can be expressed verbally (recalled with conscious effort) – available for conscious inspection (explicit)
Not time-stamped
May be less resistant to amnesia/forgetting i.e. more likely to be forgotten
Less likely to involve the storage of emotional content in memory
Are objective facts about the world
Features of procedural memory
Difficult to explain verbally (recall without conscious awareness) – unavailable for conscious inspection (implicit)
Not time-stamped
May be more resistant to amnesia/forgetting i.e. less likely to be forgotten
Supporting evidence - case of HM and what it shows
HM underwent brain surgery to relieve his epilepsy which involved removing his hippocampus. When his memory was assessed in 1955 (when he was 31), he thought it was 1953 and he was 27. His LTM was tested over and over again but never improved with practice. He would read the same magazine repeatedly without remembering it. He couldn’t recall what he had eaten earlier the same day. However, he performed well on tests of immediate memory span (a test of STM).
This supports Tulving’s view that there are different memory stores in LTM. One store can be damaged but other stores are unaffected. This is clear evidence that nor only are there different types of LTM, but that they are stored in different parts of the brain.
Supporting evidence - brain scans, and what it shows
There is evidence from brain scan studies the different types of memory are stored in different parts of the brain. Tulving et al. (1994) got their participants to perform various memory tasks while their brains were scanned using a PET scanner. They found that episodic and semantic memories were both recalled from the prefrontal cortex. The left prefrontal cortex was involved in recalling semantic memories. The right prefrontal cortex was involved in recalling episodic memories.
This supports the view that there is a physical reality to the different types of LTM within the brain. It has also been confirmed many times in later research studies, further supporting the validity of this finding.
Real world application and what it shows
Being able to identify different aspects of LTM allows psychologists to target certain kinds of memory in order to better people’s lives. Research has found that episodic memories could be improved in older people who had a mild cognitive impairment. The trained participants performed better on a test of episodic memory than a control group.
Episodic memory is the type of memory most affected by mild cognitive impairment, which highlights the benefit of being able to distinguish between types of LTM – it enables specific treatments to be developed, supporting the external validity of the theory.
Weakness - declarative memory and what it shows
Others have disagreed with the division of three LTM stores. They accept that procedural memories represent one type of LTM. But they argue that episodic and semantic memories are stored together in one LTM store that they call declarative memory (i.e. memories that can be consciously recalled). Procedural memories are non-declarative.
It is important to get these distinctions right so that any treatments that are developed are effective and so that the theory is valid i.e. it accurately explains the differences between types of LTM. As such, we cannot be confident about the validity of the division of LTM into three stores.
