Functional dissociation occurs when one cognitive function is impaired while another remains intact. Research on amnesia patients shows they often have a perfectly normal STM capacity ( items) and duration (up to 30 seconds), but a severely impaired LTM.
Support for the MSM comes from the fact that if memory were a single unified store, damage would likely affect all aspects of memory equally. The fact that CW could hold a conversation (using STM) but forget it immediately after (failure of LTM transfer) proves the stores are separate.
Biological localization in research identifies the hippocampus as a critical structure for transferring information from STM to LTM. Damage to this area, as seen in CW, prevents the consolidation of new declarative memories.
Procedural memory refers to the unconscious memory of skills and how to do things, such as playing an instrument or riding a bike. Research shows that this type of memory is often preserved in amnesiacs even when their episodic memory is destroyed.
Declarative memory involves the conscious recall of facts (semantic) and events (episodic). Wilson et al. found that while CW lost his declarative memory, his procedural memory for playing the piano remained at a professional level.
Implications for the MSM: This research suggests that the 'Long-Term Memory' store in the original MSM is likely more complex than a single unit, containing multiple sub-systems for different types of information.
| Feature | Anterograde Amnesia | Retrograde Amnesia |
|---|---|---|
| Definition | Inability to create new memories | Loss of pre-existing memories |
| MSM Relation | Failure of transfer from STM to LTM | Failure of retrieval from LTM |
| Temporal Focus | Future/Post-injury events | Past/Pre-injury events |
| Example | Forgetting a person met 5 minutes ago | Forgetting one's own wedding day |
Use as Evidence: When asked to evaluate the Multi-Store Model, always use the Wilson et al. (2008) study as 'supporting evidence' for the existence of separate stores. Explain exactly how the preservation of STM alongside the loss of LTM proves they are distinct.
Identify the Limitation: Use the same research to 'criticize' the model by pointing out that the MSM is too simplistic. Mention that the preservation of procedural memory (skills) suggests LTM is not one single store as the original model claimed.
Terminology Precision: Ensure you distinguish between 'duration' (how long) and 'capacity' (how much) when describing CW's STM. His duration was normal for STM (up to 30s) but his LTM duration was effectively zero for new information.
Methodological Critique: Remember that case studies have low 'population validity.' Because CW's brain damage was so unique and severe, we must be cautious about assuming every human brain works exactly the same way.
