AP Syllabus focus:
‘The multi-store model includes sensory, short-term, and long-term memory, shaped by automatic and effortful processing.’
Human memory is often explained as a flow of information through separate stores.
Diagram of the Atkinson–Shiffrin (multi-store) model illustrating how environmental input enters sensory memory, how attention moves information into short-term memory, and how rehearsal supports transfer into long-term memory. The arrows for retrieval and forgetting make the model’s core claim explicit: memory performance depends on control processes that regulate movement between stores. Source
The multi-store (Atkinson–Shiffrin) model emphasises structure, movement between stores, and how different types of processing influence what lasts.
Core idea: separate memory stores
The multi-store model
Multi-store model of memory: A model proposing that information moves through sensory memory, short-term memory, and long-term memory via processes such as attention and rehearsal.
The model assumes information must be encoded into a store, stored over time, and later retrieved. It also assumes different stores have different capacity (how much), duration (how long), and typical coding (type of information format).
Sensory memory: brief first holding area
What it does
Sensory memory: The immediate, very brief retention of sensory information (e.g., sights, sounds) before it either fades or is passed onward through attention.
Sensory memory is high-capacity but extremely short in duration. Most incoming input is lost unless selective attention transfers it into short-term memory. In the multi-store view, sensory memory is not “thinking”; it is initial registration.
Short-term memory (STM): limited active holding
Key properties
Short-term memory (STM): A limited-capacity store that briefly holds information, typically for seconds, unless it is actively maintained.
STM capacity is limited, so new information can displace older information. Without continued processing, contents decay quickly. In the model, rehearsal is the main mechanism that keeps information available and increases the likelihood of transfer to long-term memory.
Rehearsal and movement to LTM
Maintenance rehearsal (simple repetition) keeps material in STM longer and, in the classic model, helps push information into long-term memory. If attention shifts away and rehearsal stops, information is likely to be lost from STM.
Long-term memory (LTM): durable storage
Key properties
Long-term memory (LTM): A large-capacity store for information that can persist from minutes to a lifetime and can be retrieved back into conscious awareness.
LTM is described as having very large capacity and long duration. Retrieval brings information from LTM back into STM for conscious use, such as recalling a definition or recognising a person.
Automatic vs effortful processing in the model
Two routes that shape what is stored
Automatic processing: The encoding of some information with little or no conscious effort, often incidental to ongoing activity.
Automatic processing can lay down memories without deliberate rehearsal (for example, routine details). The multi-store model still treats these as entering memory through initial registration and later storage, even if the person does not intentionally try to learn them.
Effortful processing: Encoding that requires attention and conscious strategies, such as rehearsal or deliberate organisation.
Effortful processing increases the probability that information is stabilised in LTM because it involves sustained attention and active mental work. In the multi-store model’s terms, it strengthens the flow from sensory input to STM and from STM to LTM.
Common evaluation points (AP-relevant)
The model is useful because it clearly distinguishes stores and processes (attention, rehearsal, retrieval).
Serial position curve (percent recall by list position) showing higher recall for early items (primacy effect) and late items (recency effect). This pattern is often interpreted as consistent with the multi-store idea that early items benefit from rehearsal into long-term memory, while the most recent items can still be maintained in short-term memory at the time of recall. Source
A key limitation is that it can oversimplify STM and LTM as single “boxes,” even though memory performance suggests more complexity within each store.
FAQ
In the classic account, rehearsal mainly refers to repetition that keeps items active in STM and supports transfer to LTM.
Later interpretations broaden rehearsal to include more active strategies, but that moves beyond the model’s original simplicity.
Sensory memory loss is mainly due to rapid fading of the trace.
STM forgetting is often attributed to quick decay without rehearsal and to displacement when capacity is exceeded.
Findings that some brain injuries impair new long-term learning while leaving immediate recall relatively intact suggested separable systems.
Laboratory tasks also showed sharp limits in brief holding compared with more durable retention.
Not explicitly. The model still assumes information is registered and that some portion becomes stored, even if the person is not deliberately rehearsing it.
Automaticity mainly changes the effort and awareness involved, not the basic store structure.
Attention acts like a gate from sensory memory to STM, selecting a small subset of input for further processing.
Reduced attention (e.g., distraction) lowers the chance of STM encoding and downstream LTM storage.
Practice Questions
Outline how information moves through the multi-store model from sensory input to long-term memory. (3 marks)
1 mark: Sensory memory briefly registers incoming information.
1 mark: Attention transfers selected information into short-term memory.
1 mark: Rehearsal/effortful processing supports transfer to long-term memory (or prevents decay in STM long enough for encoding).
Explain the role of automatic and effortful processing in the multi-store model, including how each affects storage and later retrieval. (6 marks)
1 mark: Defines or accurately describes automatic processing as low-effort/incidental encoding.
1 mark: Links automatic processing to memory storage without deliberate rehearsal (can still reach LTM).
1 mark: Defines or accurately describes effortful processing as attention-demanding/conscious encoding.
1 mark: Links effortful processing to rehearsal/active strategies that increase transfer from STM to LTM.
1 mark: Explains retrieval as bringing information from LTM back into STM/awareness.
1 mark: Compares impact (effortful typically increases likelihood/strength of later retrieval more reliably than purely incidental encoding).
