MSM

Multi-Store Model (MSM)

Proposed by Atkinson & Shiffrin, describes memory as three separate stores—sensory register, short-term memory (STM), and long-term memory (LTM)—through which information passes.

Sensory Register

Receives stimuli from the environment through different senses (e.g., iconic memory for visual info) and transfers information to STM if attention is paid.

Capacity of Sensory Register

Very large.

Duration of Sensory Register

Less than 1 second.

Short-Term Memory (STM)

A temporary memory store where information is held if attended to; it has limited capacity and duration.

Capacity of STM

Approximately 7 ± 2 items (Miller, 1956).

Information Coding in STM

Acoustically (by sound).

Duration of STM

About 18 seconds unless rehearsed.

Movement from STM to LTM

Maintenance rehearsal keeps info in STM, and prolonged rehearsal can transfer it to LTM.

Long-Term Memory (LTM)

A permanent memory store with unlimited capacity and potentially lifelong duration.

Information Coding in LTM

Semantically (according to meaning).

Retrieval from LTM

It is transferred back to STM through retrieval when needed.

Evidence Supporting Separate STM and LTM

Baddeley (1966) found STM errors were mostly acoustic, LTM errors mostly semantic, showing different coding.

Case Studies Supporting MSM

HM could not form new LTM but had intact STM, showing STM and LTM are separate stores.

Limitation of Artificial Stimuli in Research

Lab studies use meaningless digits/letters, reducing mundane realism and external validity.

Patient KF's Challenge to MSM

He had poor recall of auditory STM but intact visual STM, suggesting STM is not unitary.

Limitation of Rehearsal in MSM

Craik & Watkins (1973) showed elaborative rehearsal (linking info to meaning) is more effective than maintenance rehearsal for creating LTM.

Clive Wearing's Case

He could not form/retrieve episodic LTM but could remember procedural skills, showing LTM is not unitary.

Main Strength of the MSM

It distinguishes between separate memory stores and has research and case study support.

Main Limitation of the MSM

It oversimplifies memory, ignores multiple types of STM and LTM, and underestimates the role of meaning in memory formation.