The multi-store model of memory: sensory register, short-term memory and long-term memory. Features of each store: coding, capacity and duration.

What is the Multi-Store Model of Memory?

• Proposed by Atkinson and Shiffrin.
• Memory consists of separate stores.
• Information passes through stores in sequence.

What is the Flow of Information in the MSM?

• Input enters sensory register.
• Attention transfers information to STM.
• Rehearsal transfers information to LTM.
• Retrieval brings information from LTM back to STM.

What is the Sensory Register?

• Temporary memory store holding sensory information.
• Information encoded according to sense.

Sensory Register — Coding

• Information encoded according to sense.
• Visual information stored in iconic memory.
• Auditory information stored in echoic memory.

Sensory Register — Capacity

• Very large capacity.

Sensory Register — Duration

• Very brief duration.
• Iconic memory lasts less than 0.5 seconds.
• Echoic memory lasts around 2–3 seconds.

What is Short-Term Memory (STM)?

• Temporary memory store.
• Limited capacity and duration.

STM — Coding

• Mainly acoustic coding.
• Information stored by sound.

STM — Capacity

• Capacity around 7 ± 2 items.

STM — Duration

• Duration around 18–30 seconds without rehearsal.

What is Long-Term Memory (LTM)?

• Permanent memory store.
• Potentially unlimited duration and capacity.

LTM — Coding

• Mainly semantic coding.
• Information stored by meaning.

LTM — Capacity

• Potentially unlimited capacity.

LTM — Duration

• Potentially lifelong duration.

Baddeley — Aim

• Investigated coding in STM and LTM.

Baddeley — Procedure

• Participants learned acoustically and semantically similar/different word lists.
• Recall tested in STM and LTM.

Baddeley — Findings

• STM mainly coded acoustically.
• LTM mainly coded semantically.

Jacobs — Aim

• Investigated STM capacity.

Jacobs — Procedure

• Participants recalled sequences of numbers and letters.

Jacobs — Findings

• STM capacity around 7 items.
• Digit span larger than letter span.

Peterson and Peterson — Aim

• Investigated duration of STM.

Peterson and Peterson — Procedure

• Participants remembered trigrams.
• Prevented rehearsal by counting backwards.

Peterson and Peterson — Findings

• Recall declined rapidly after around 18 seconds.
• Supports short STM duration.

Bahrick et al. — Aim

• Investigated duration of LTM.

Bahrick et al. — Procedure

• Tested memory of classmates using yearbooks.

Bahrick et al. — Findings

• Participants recognised faces and names decades later.
• Supports potentially lifelong LTM.

MSM Evaluation — Research Support

• Research supports different coding, capacity and duration in memory stores.
• Supports existence of separate memory stores.

MSM Evaluation — Oversimplified STM

• MSM assumes STM is one single store.
• Working Memory Model suggests STM has multiple components.

MSM Evaluation — Oversimplified Rehearsal

• Rehearsal not always needed for transfer to LTM.
• Some memories transferred without repetition.

MSM Evaluation — Real World Application

• Improved understanding of memory problems.
• Useful in education and cognitive psychology.