Overview
This lesson explains the Atkinson and Shiffrin Multi-Store Model of Memory (1968), describing its structure, process, and key evaluations.
The Multi-Store Model of Memory
- Atkinson and Shiffrin (1968) proposed the Multi-Store Model, describing memory as a linear sequence of stores.
- The model comprises sensory memory, short-term memory (STM), and long-term memory (LTM).
- Each store differs in coding (how it processes info), capacity (how much it can hold), and duration (how long it retains info).
- Sensory memory briefly holds environmental stimuli from our senses (iconic = visual, echoic = auditory).
- Sensory memory has a large capacity, but very short duration unless attention is paid to the info.
- STM receives info paid attention to, has a duration of 18–30 seconds, a capacity of 7±2 items (Miller), and uses acoustic coding (Baddeley).
- Maintenance rehearsal keeps info in STM; prolonged rehearsal transfers info to LTM.
- LTM is coded semantically, has potentially unlimited capacity (Miller), and unlimited duration (Bahrick).
- Retrieval moves info from LTM back to STM for use.
- Forgetting can occur via decay (sensory, STM), displacement (STM), and interference or retrieval failure (LTM).
Evaluation of the Multi-Store Model
- Research support: Baddeley showed STM and LTM use different coding (acoustic vs. semantic); Peterson & Peterson (STM duration) vs. Bahrick (LTM duration) show stores have distinct properties.
- Limitation: Research often uses artificial materials (digits, nonsense syllables) unlike real-life memory, reducing ecological validity.
- Limitation: Evidence (e.g., patient KF) suggests more than one STM type (visual and auditory), challenging the model's single-STM store.
- Limitation: Model oversimplifies memory; later research shows multiple LTM stores (facts, actions, events) and more than one rehearsal type.
Key Terms & Definitions
- Coding — The way information is processed and represented in memory (acoustic in STM, semantic in LTM).
- Capacity — The amount of information a memory store can hold.
- Duration — How long information can be retained in a memory store.
- Maintenance rehearsal — Repeating information to keep it in STM.
- Prolonged rehearsal — Rehearsing information long enough to transfer it into LTM.
- Retrieval — Accessing information from LTM to use in STM.
- Decay — Fading of information over time if not used.
- Displacement — When new info pushes out older info in STM due to limited capacity.
- Interference — When old and new memories compete, causing forgetting.
- Ecological validity — The extent to which research findings reflect real-life situations.
Action Items / Next Steps
- Review Memory Lesson One for definitions, research studies, and more evaluation points.
- Pause and summarize model structure and evaluation points in your own notes.
- Check your textbook for additional or alternative evaluation points.