Edexcel GCSE Psychology: Memory
Topic 2: Memory — How does your memory work?
Paper 1 | Compulsory | 16 marks
This topic explores how memory works as a system, examines two major theories that explain how we store and recall information, and looks at what happens when memory is damaged. It is also one of the topics most likely to feature in the 9-mark essay question on Paper 1.
How memory works
Memory is the system by which we take in, store and retrieve information. The process follows three stages: input (information enters the system through our senses), processing (the information is encoded so it can be stored) and output (the information is retrieved when needed).
There are three key processes to understand:
Encoding: converting information into a form that can be stored in memory.
Storage: holding information in the memory system over time.
Retrieval: recovering stored information when it is needed.
Memory can also be described in terms of its duration (how long information can be held) and capacity (how much information can be held at any one time).
The Multi-Store Model of Memory (Atkinson and Shiffrin, 1968)
Atkinson and Shiffrin proposed that memory is made up of three distinct stores that information passes through in sequence.
The sensory register is the first point of entry. All information from our senses arrives here but it decays very quickly unless we pay attention to it. Once attention is directed at information, it passes into short-term memory.
Short-term memory (STM) has a limited capacity of approximately 5 to 9 items (Miller, 1956) and a duration of around 15 to 30 seconds without rehearsal. If information is rehearsed sufficiently it is transferred to long-term memory.
Long-term memory (LTM) has an essentially unlimited capacity and can hold information for a lifetime. Information in LTM can be retrieved back into STM when needed.
Evaluation
One strength is that the model is supported by experimental research. Peterson and Peterson (1959) demonstrated that STM has a limited duration by showing that participants forgot information quickly when rehearsal was prevented. This supports the idea that STM and LTM are separate stores.
One weakness is that the model is considered reductionist. It reduces the complex process of human memory to a simple input-output system and does not account for why some things are remembered better than others based on personal meaning or emotional significance.
A second weakness is that the model oversimplifies LTM, treating it as a single store. Later research suggests LTM contains different types of memory, such as memory for facts versus memory for skills, which the original model does not explain.
The Theory of Reconstructive Memory (Bartlett, 1932)
Frederic Bartlett argued that memory is not a passive recording of events but an active process of reconstruction. When we remember something, we do not play back an accurate record. Instead, we rebuild the memory using our schemas — the mental frameworks we have built up from prior knowledge and experience.
This means that memory is influenced by what we already know, what we expect to find, and the cultural context we bring to an experience. When details do not fit our existing schemas, we tend to change them to make the memory feel more coherent and familiar.
Bartlett identified four ways in which memory becomes distorted during recall:
Omission: details that do not fit our schema are simply left out.
Rationalisation: unfamiliar elements are changed to make the memory feel more logical and consistent.
Familiarisation: unfamiliar words, names or concepts are replaced with more familiar equivalents.
Transformation: the overall structure or emphasis of a memory shifts to better fit existing expectations.
Evaluation
One strength is that Bartlett's theory has strong ecological validity. He tested memory using real stories and images rather than artificial laboratory tasks, which means his findings reflect how memory works in everyday life.
One strength is that the theory has important real-world applications. Reconstructive memory has been used to understand how eyewitness testimony can be unreliable, which has had a significant impact on the criminal justice system and police interviewing techniques.
One weakness is that Bartlett's methodology was not rigorous. He interpreted participants' reproductions himself without standardised procedures, which makes his findings subjective and difficult to replicate reliably.
One weakness is that the theory is also considered reductionist in a different way. By focusing only on the role of schemas, it does not account for the role of the senses and structural memory stores in the way that the Multi-Store Model does.
Amnesia
Amnesia refers to significant memory loss, usually caused by brain injury, illness or surgery.
Retrograde amnesia is the loss of memories that were formed before the damage occurred. A person with retrograde amnesia may be unable to recall events from their past.
Anterograde amnesia is the inability to form new memories after the point of damage. A person with anterograde amnesia can remember the past but cannot retain new information.
The most famous case study is that of Patient HM (Henry Molaison), who had surgery to remove his hippocampus to treat severe epilepsy. Following surgery, HM developed profound anterograde amnesia — he could no longer form new long-term memories, though his memories from before the operation remained largely intact. This case provided important evidence that the hippocampus plays a critical role in transferring information from STM to LTM.
Key studies
Bartlett (1932) — War of the Ghosts
Aim: to investigate whether memory is reconstructive and whether cultural schemas distort recall.
Procedure: 20 British participants read a Native American folk story called War of the Ghosts twice. The story was deliberately chosen because it contained unfamiliar cultural concepts and names. Participants were asked to reproduce the story at intervals ranging from 15 minutes to almost 10 years later.
Results: participants gradually changed the story over successive reproductions. Unfamiliar terms were replaced with familiar ones (for example, "canoes" became "boats"), details were omitted, and the story became shorter and more coherent with British cultural expectations.
Conclusion: memory is not a faithful recording of events but is reconstructed over time, shaped by existing schemas.
Strengths: used a realistic task (recalling a story) rather than artificial laboratory materials, which improves ecological validity. The long-term nature of the study shows how memory distortion develops over time.
Weaknesses: Bartlett interpreted results subjectively, meaning different researchers might have reached different conclusions. The sample of 20 British participants limits how far the findings can be generalised.
Peterson and Peterson (1959) — short-term retention of individual verbal items
Aim: to investigate the duration of short-term memory.
Procedure: 24 student participants were shown trigrams (three-consonant combinations such as BKW) and then immediately asked to count backwards in threes from a given number, to prevent rehearsal. They were asked to recall the trigram after intervals of 3, 6, 9, 12, 15 or 18 seconds.
Results: recall dropped sharply as the interval increased. After 3 seconds, around 80% of trigrams were recalled correctly. After 18 seconds, recall fell to approximately 10%.
Conclusion: the duration of STM is very short (around 15 to 18 seconds) without rehearsal.
Strengths: the study used standardised procedures and controlled conditions, making it reliable and replicable.
Weaknesses: the use of trigrams is an artificial task that lacks ecological validity. Students may also have been familiar with psychological research, which could affect how they responded.
Issues and debates: reductionism and holism
Reductionism is the idea that complex behaviour or mental processes can be best understood by breaking them down into simpler component parts.
Holism is the view that behaviour and mental processes can only be fully understood by looking at the whole picture, including the context, individual differences and personal experience.
The memory topic is a useful lens through which to explore this debate.
The Multi-Store Model of Memory is widely considered to be reductionist. It breaks memory down into separate stores with fixed properties and describes information processing as a simple linear system. Critics argue this does not capture the richness and complexity of how real human memory works.
Bartlett's Theory of Reconstructive Memory can be seen as more holistic. Rather than reducing memory to a mechanical system, Bartlett acknowledged that memory is shaped by individual schemas, personal background and cultural experience. His qualitative approach also considered each participant's unique recall rather than averaging across groups.
The debate raises an important question: is it more useful to study memory in controlled, measurable ways (reductionist) or to capture the full complexity of memory as it functions in real life (holistic)? Most psychologists would argue that both approaches are valuable and that neither alone gives the complete picture.
Key terms
Encoding: converting information into a form that can be stored in memory.
Storage: holding information in the memory system over time.
Retrieval: recovering stored information when it is needed.
Duration: how long information can be held in a memory store.
Capacity: how much information a memory store can hold at any one time.
Sensory register: the first stage of the Multi-Store Model, where all incoming sensory information is briefly held.
Short-term memory: a limited capacity, short duration memory store that holds information for around 15 to 30 seconds without rehearsal.
Long-term memory: a potentially unlimited store that can hold information for a lifetime.
Rehearsal: the process of repeating information to keep it in STM and transfer it to LTM.
Schema: a mental framework built from prior knowledge and experience that shapes how we interpret and recall information.
Reconstructive memory: the idea that memory is an active process of rebuilding rather than a passive playback of stored information.
Retrograde amnesia: loss of memories formed before brain damage occurred.
Anterograde amnesia: the inability to form new long-term memories after brain damage.
Reductionism: the view that complex behaviour can be understood by breaking it down into simpler components.
Holism: the view that behaviour can only be fully understood by considering the whole picture rather than isolated parts.
Looking for revision resources for this topic? The Memory Knowledge Organiser covers all of the above in a format designed for efficient revision.