Cognitive Psychology: Long-Term Memory

Types of Long Term Memory

Tulving (1985) proposed that the Multi-Store Model (MSM) view of Long Term Memory (LTM) was too simplistic and suggested that there are 3 separate stores within the LTM:

• Episodic memory
• Semantic memory
• Procedural memory

Episodic Memory

• Refers to the ability to recall personal events (episodes) from our lives.
• Memories are 'time stamped.'
• Memory of a single episode includes specific details, the context of the event, and associated emotions.
• Requires a conscious effort to recall.

Semantic Memory

• Stores our knowledge of the world, including facts and information.
• Memories are not 'time stamped.'
• A vast collection of material is constantly being added to.

Procedural Memory

• Stores memory for actions and skills; how we remember to physically do things.
• Memories often become automatic and are difficult to describe.

Explicit vs. Implicit Memory

• Explicit/Declarative Memory: Memory with conscious recall (Episodic and Semantic).
• Implicit/Nondeclarative Memory: Memory without conscious recall (Procedural).
• Autobiographical Memory (AM) is a special kind of Episodic Memory about particular life events that have personal significance.
• Flashbulb memories are vivid & detailed recollections of where we were and what we were doing (Brown & Kulik, 1977).

Tulving’s Explanation of LTM (1972)

Tulving proposed a disassociation between semantic and episodic memories based on:

• Time + Spatial referencing (encoding & storage)
• Time/Temporal referencing – relates to when something occurs
• Spatial referencing – relates to where something occurs
• Is data input fragmented or continuous?
• Retrieval & forgetting

Semantic Vs Episodic Differences

Definition:

• Semantic: Mental encyclopedia / Knowledge of facts
• Episodic: Mental diary
  Example:
• Semantic: E.g. Capital city of France is Paris
• Episodic: Memory of an event e.g. birthday party
  Time + Spatial referencing - Is input fragmented or continuous?
• Semantic: Independent of time and spatial (location) referencing. Input is fragmented e.g. two facts independently learnt and later pieced together
• Episodic: Dependent on time and spatial referencing – linked to the time and place in which they occurred. Input is continuous
  Retrieval & Forgetting
• Semantic: Retrieval not dependent on context to aid recall. Retrieval possible without learning – can be based on inferences, generalization, rationality
• Episodic: Retrieval uses cues and context which are encoded at the point of learning. Forgetting - Susceptible to transformations from schemas e.g., leading questions and post event discussions (Reconstructive memory theory)

Strengths

• Supporting Evidence: Case studies like HM and KC show that damage to one LTM store does not affect others.
• Brain Scans: Evidence from brain scans supports the view that there are different memory stores in the LTM. Tulving et al (1994) found that episodic and semantic memories were recalled from different areas in the prefrontal cortex.

Weaknesses

• Credibility: Case studies may not be generalizable due to the uniqueness of each case.
• Other Explanations: Cohen and Squire (1980) argue that semantic and episodic memories are stored together in one declarative memory store.
• Other Explanations: Tulving viewed episodic memory as a specialized sub- category of semantic memory.

Application

• Belleville et al (2006) demonstrated that episodic memories could be improved through training.
• Cognitive Interview techniques of contextual reinstatement and report everything. Successful application of CI in gaining accurate EWT suggest Tulving’s LTM theory has some pragmatic validity.