Encoding, storage & retrieval

Memory is the mental process of taking in, keeping and getting back information. AQA splits it into three processes:

• Encoding — turning information into a form memory can hold. It can be visual (images), acoustic (sounds) or semantic (meaning).
• Storage — holding the information over time.
• Retrieval — getting the information back out when you need it.

Key idea: short-term memory tends to encode acoustically, while long-term memory tends to encode semantically (by meaning).

Which process is which?

The multi-store model (Atkinson & Shiffrin)

The multi-store model of memory (Atkinson & Shiffrin, 1968) describes memory as three separate stores that information flows through:

• Sensory register — brief store for information from the senses; very short duration; lost unless you pay attention.
• Short-term memory (STM) — limited capacity (about 7 items) and short duration (about 18–30 seconds); kept going by rehearsal.
• Long-term memory (LTM) — potentially unlimited capacity and very long duration; information gets here through repeated rehearsal.

Evaluation: a strength is strong supporting evidence (e.g. the serial position curve). A weakness is that it treats STM and LTM as single, simple stores, which later research says is too simple.

What keeps information in STM?

Murdock's serial position curve

Murdock (1962) gave participants lists of words and asked them to recall as many as they could in any order. Plotting the chance of recalling a word against its position gave the serial position curve:

• Primacy effect — words at the start were recalled well because there was time to rehearse them into LTM.
• Recency effect — words at the end were recalled well because they were still in STM.
• Words in the middle were recalled worst — too late to rehearse, too early to still be in STM.

Why it matters: the two separate effects support the idea that STM and LTM are separate stores, backing up the multi-store model.

Explaining the recency effect

Sort the memory stores

Tap a feature, then tap the store it best describes. (Some belong to all three.)

Bartlett: reconstructive memory

Bartlett (1932) argued that memory is not a perfect recording but is reconstructive: we actively rebuild memories and change them to fit what we already know (our schemas).

• In his War of the Ghosts study, British participants read an unfamiliar Native American folk tale and retold it later.
• They changed details to fit their own culture — shortening the story, dropping unfamiliar parts and swapping in familiar ideas.
• This showed memory is influenced by expectations and prior knowledge, not just stored word-for-word.

Link: reconstructive memory helps explain why eyewitness testimony can be inaccurate — people fill gaps with what they expect to have happened.

Factors affecting accuracy: interference & context

AQA asks you to explain factors that affect how accurate memory is:

• Interference — other memories get in the way. Similar information learned before or after can disrupt recall.
• Context — we recall better when the situation matches the one in which we learned (context-dependent memory).
• Reconstruction — as Bartlett showed, schemas can distort what we remember, especially for unfamiliar events.

Match each idea to the right term

Tap a description on the left, then its matching key term on the right.

Applying reconstructive memory

Evaluating the multi-store model

Examiners reward evaluation. For the multi-store model:

• Strength: supported by evidence such as Murdock's serial position curve and case studies of brain damage.
• Weakness: it is too simple — it treats STM and LTM as single stores, when research shows several types of each.
• Weakness: it over-emphasises rehearsal; we clearly remember some things without rehearsing them.

A closer look at long-term memory

Long-term memory is not one single store. Psychologists distinguish, for example:

• Episodic memory — personal events and experiences.
• Semantic memory — facts and general knowledge.
• Procedural memory — skills, like riding a bike.
• This variety is one reason the simple multi-store model is criticised.

The big ideas to know

You've covered the whole AQA Memory topic — the model, the evidence and why memory can be unreliable. Press Finish to see your score.