How does the multi-store model explain the structure of memory?
The multi-store model of memory: sensory register, short-term memory and long-term memory. Features of each store: coding, capacity and duration.
Covers AQA 4.2 the multi-store model (Atkinson and Shiffrin): the sensory register, short-term and long-term memory, and the coding, capacity and duration of each store.
Reviewed by: AI editorial process; not yet individually human-reviewed
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What this dot point is asking
AQA wants you to describe the multi-store model (MSM) and the coding, capacity and duration of each of the three stores, with evaluation. The exam skill is to reproduce the figures and supporting studies accurately, to keep STM and LTM coding the right way round, and to evaluate the model's claim that the stores are unitary.
The three stores
The multi-store model describes memory as a single linear flow through three separate stores. Information from the environment first enters the sensory register, which is modality-specific (a separate store for each sense, such as the iconic store for vision and the echoic store for sound). If the information is attended to, it passes into short-term memory; if it is not attended to, it decays almost immediately. Within short-term memory, information is kept alive through maintenance rehearsal (repeating it), and with enough rehearsal it is transferred into long-term memory. Information in long-term memory can be retrieved back into short-term memory when it is needed. The model therefore makes attention the gateway into STM and rehearsal the gateway into LTM, which is one of its testable and criticised claims.
Coding, capacity and duration
The three stores differ on three features that the specification names directly. Coding is the format in which information is stored: Baddeley found that STM relies mainly on acoustic coding (we confuse similar-sounding words in STM) while LTM relies mainly on semantic coding (we confuse similar-meaning words in LTM). Capacity is how much can be held: Miller's "magic number" and Jacobs' digit-span work put STM at about seven items, plus or minus two, while LTM is potentially unlimited. Duration is how long it lasts: Peterson and Peterson found STM lasts about 18 to 30 seconds without rehearsal, while Bahrick's study of recognising old classmates from yearbooks showed LTM can last a lifetime. Knowing the supporting researcher for each feature is what turns a list into a top-band answer.
Evidence and limitations
Studies of patients such as HM and Clive Wearing support separate STM and LTM stores. However, the model is criticised for treating STM and LTM as single, unitary stores, which the working memory model and types of LTM challenge.
The strongest support comes from case studies of brain-damaged patients who can have one store impaired while the other is intact, which implies the stores are genuinely separate. HM, who lost the ability to form new long-term memories after surgery, retained a working short-term memory, showing STM and LTM are distinct. The main criticism, however, is that the model is too simple in treating both STM and LTM as single, unitary stores. The working memory model shows that STM is not one store but several components, and the case of patient KF (who had poor verbal STM but intact visual STM) cannot be explained by a single STM. Similarly, the research on types of long-term memory (episodic, semantic and procedural) shows LTM is not unitary either. A further criticism is that the model overstates the role of maintenance rehearsal: Craik and Lockhart argued that it is the depth or elaboration of processing, not just the amount of repetition, that determines whether something enters LTM.
Exam-style practice questions
Practice questions written in the style of AQA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
AQA 20194 marksOutline the coding, capacity and duration of short-term memory and long-term memory.Show worked answer →
A 4-mark item testing the technical features. Markers want the figures and the supporting researchers where possible.
Short-term memory is coded mainly acoustically (Baddeley), has a capacity of about 7 plus or minus 2 items (Miller; Jacobs' digit span), and a duration of about 18 to 30 seconds without rehearsal (Peterson and Peterson). Long-term memory is coded mainly semantically (by meaning, Baddeley), has a potentially unlimited capacity, and a duration of up to a lifetime (Bahrick's study of yearbook recognition).
A full-mark answer gives the coding, capacity and duration for both stores with the correct figures, and ideally names a supporting researcher for each feature. The classic error is reversing the coding of STM (acoustic) and LTM (semantic).
AQA 20216 marksOutline the multi-store model of memory and explain one limitation of it.Show worked answer →
A 6-mark item, roughly 4 AO1 and 2 AO3.
Outline: the multi-store model (Atkinson and Shiffrin, 1968) describes memory as a linear flow through three stores. Sensory information enters the sensory register; if attended to, it passes to short-term memory; if rehearsed (maintenance rehearsal), it passes to long-term memory; and it is retrieved back into STM when needed.
Limitation: the model treats STM and LTM as single, unitary stores, but evidence contradicts this. The working memory model shows STM has several components, and patient KF had poor verbal STM but intact visual STM, which a single STM store cannot explain. A full-mark answer outlines the three-store flow and develops one limitation with evidence. Simply describing the stores without evaluation loses the AO3 marks.
Related dot points
- The working memory model: central executive, phonological loop, visuo-spatial sketchpad and episodic buffer. Features of the model: coding and capacity.
Covers AQA 4.2 the working memory model (Baddeley and Hitch): central executive, phonological loop, visuo-spatial sketchpad and episodic buffer, with coding and capacity.
- Types of long-term memory: episodic, semantic and procedural.
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Sources & how we know this
- AQA A-level Psychology (7182) specification — AQA (2015)