Lecture on Memory and the Multi-Store Model

Introduction to Memory

• Earliest memories often between ages 3-5; many are "incomplete" and not fixed in time.
• Memories are often about oneself and emotional, e.g., falling down stairs.
• Understanding memory models helps in storing new information and improving recollection.

The Multi-Store Model (Atkinson and Shiffrin, 1968)

Key Concepts:

• Displacement: When STM (Short-Term Memory) becomes full and new info pushes out old info.
• Interference: New info overwrites older info, e.g., a new phone number overwriting an old one.

Sensory Memory:

• Holds information in immediate environment briefly in sensory registers.
• Types of sensory registers:
  • Iconic (visual)
  • Echoic (sound)
  • Gustatory (taste)
  • Olfactory (smell)
  • Tactile (touch)

STM (Short-Term Memory):

• Capacity: 7±2 items
• Duration: Less than 30 seconds
• Temporary and limited

LTM (Long-Term Memory):

• Duration: Over 30 seconds to a lifetime
• Potentially limitless in information storage

Processes:

• Rehearsal: Encodes info from STM to LTM
• Retrieval: Accesses stored memories from LTM

Evaluation of the Multi-Store Model

Strengths:

• Evidence supporting separate memory stores, e.g., amnesia cases show distinct short and long-term memory.
• Provides understanding of STM structure and process, aiding further research.
• Supported by primacy and recency effect experiments, e.g., Ben Murdock's study.

Weaknesses:

• Overemphasizes rehearsal for LTM transfer; does not consider other means such as emotional significance.
• Suggests only one type of LTM, though cases like Clive Wearing show multiple types.
• Oversimplified, not considering the impact of relevancy and nature of information.

Evidence for the Multi-Store Model

Peterson & Peterson Study

Aim:

• Investigate effects of interference on recall and impact of rehearsal.

Sample and Procedure:

• 24 psychology students participated.
• Standardized instructions with recall tasks involving trigrams and interference (e.g., counting backwards).

Results:

• Rapid decay of information from STM over intervals up to 18 seconds.

Conclusion:

• STM has limited duration; rehearsal is key for retention.

HM Case Study (Milner 1966)

Background:

• HM suffered anterograde amnesia post-surgery, studied by Brenda Milner.

Key Findings:

• Memory systems are specialized.
• Hippocampus crucial for converting experiences from STM to LTM.
• STM not stored in hippocampus; evidence of multiple memory stores.

Evaluation:

• Longitudinal study over 50 years with high ecological validity.
• Method triangulation used, providing comprehensive insights.
• Case study limitations include difficulty in replication and retrospective data issues.

Conclusion and Theory Evaluation

• Multi-Store Model provides foundational understanding of memory but may be reductionist and oversimplistic.
• Studies show the importance of rehearsal and the role of the hippocampus, supporting the model’s structure.
• However, other memory theories suggest more complexity, e.g., Working Memory Model.