Information encoded by meaning and linked to what you already know is much more likely to be stored for a long time.
Memory · processes of memory
Storing and finding memories
Long-term memories are stored in an organised way, linked by meaning, a bit like a filing system.
Retrieval works best with a cue: a place, a smell, a picture or the first letter of a word.
A memory can be stored but not found. "On the tip of my tongue" is a retrieval problem, not a lost memory.
Quick check
?Ayo learns a door code by saying it over and over under his breath. How is he encoding it?
Quick check
?Zara reads a page of her textbook while thinking about the weekend. The next day she can't recall a single fact from it. Which process most likely failed?
Your answer
?You know your old teacher's name and you recognise it when a friend says it, but you can't bring it to mind yourself. Which process has failed?
Mission check
?A number's gone in seconds; a joke lasts years. What's different?
You held the number only as a sound, for a few seconds. The joke you understood: you encoded it by its meaning and linked it to things you already knew, so it was stored in long-term memory and could be retrieved years later.
Mission 2
You see everything for a split second. What decides what you keep?
Make a guess: You see everything for a split second. What decides what you keep?
Memory · the multi-store model
Three stores in a line
Atkinson and Shiffrin's (1968) multi-store model says memory is made of three separate stores.
Information flows from the sensory register to short-term memory (STM) to long-term memory (LTM).
Attention moves information from the sensory register into STM. Anything not attended to is lost.
Rehearsal (repeating it) keeps information in STM; enough rehearsal transfers it to LTM.
To use a memory, it is retrieved from LTM back into STM.
Memory · the multi-store model
Encoding, capacity and duration
Each store differs in how it encodes information, how much it holds and how long it lasts.
Store
Encoding (coding)
Capacity
Duration
Sensory register
Same form as the sense (images, sounds)
Very large
Under a second for sights, about 2 seconds for sounds
STM
Mainly acoustic (sound)
About 7 ± 2 items
About 18–30 seconds without rehearsal
LTM
Mainly semantic (meaning)
Unlimited
Potentially a lifetime
Quick check
?Mia hears a 12-digit order number once. When she tries to repeat it straight away, she gets only the first seven digits. Which feature of STM explains this?
Key studyMemory · the multi-store model
Peterson and Peterson (1959)
Aim
To find out how long information lasts in STM when rehearsal is prevented.
Method
Lab experiment; 24 psychology students saw a trigram (three consonants, e.g. CHJ), then counted backwards in threes from a three-digit number for 3, 6, 9, 12, 15 or 18 seconds before recalling it.
Results
About 80% of trigrams were recalled after 3 seconds but only about 10% after 18 seconds.
Conclusion
Without rehearsal, information is lost from STM very quickly; STM has a short duration.
Strength
Standardised procedure with tight control, so it can be replicated to check reliability.
Weakness
Trigrams are meaningless, so low ecological validity; counting numbers may have displaced the letters rather than letting them decay.
Calculate
?Your class repeats Peterson and Peterson's task. 25 students each recall one trigram after 18 seconds of counting backwards, and 3 get it right. What percentage recalled the trigram correctly?
Sort it
?Is each point a strength or a weakness of the multi-store model?
Tap a statement, then tap the group it belongs in. Then press Check.
Mission check
?You see everything for a split second. What decides what you keep?
Attention decides. Your sensory register holds almost everything for a split second, but only what you pay attention to passes into short-term memory; the rest is lost. Rehearsal then decides what makes it into long-term memory.
Mission 3
He forgets a visitor in minutes but still plays piano. How?
Make a guess: He forgets a visitor in minutes but still plays piano. How?
Memory · amnesia and the brain
Losing memories before and after
Amnesia is a loss of memory, usually caused by brain damage, e.g. a head injury, a stroke or a brain infection.
Retrograde amnesia: losing memories from before the damage.
Anterograde amnesia: being unable to form new long-term memories after the damage.
A person can have both types at once.
Memory · amnesia and the brain
The symptoms
The two types cause different everyday problems.
Symptom
Anterograde amnesia
Retrograde amnesia
New memories after the damage
Can't be formed: forgets people, events and conversations within minutes; repeats questions
Can be formed as normal
Memories from before the damage
Mostly kept
Lost, especially those from just before the damage
Short-term memory
Works, for a few seconds
Works
Skills (procedural memory)
Usually kept; new skills can still be learned with practice
Usually kept
Quick check
?After falling from a horse, Priya can't remember the ride or anything from the week before it. She does remember the name of the nurse she met this morning. Which type of amnesia does she show?
Memory · amnesia and the brain
What amnesia tells us about memory
In anterograde amnesia, STM still works but new information can't reach LTM. This suggests STM and LTM are separate stores, a strength of the multi-store model.
But skills usually survive while memories of events are lost. This suggests LTM is more than one store, a weakness of the model's single LTM.
Sort it
?Which type of amnesia does each person show?
Tap a statement, then tap the group it belongs in. Then press Check.
Your answer
?What is the name for the type of amnesia in which a person cannot form new long-term memories after brain damage?
Mission check
?He forgets a visitor in minutes but still plays piano. How?
Memory isn't one system. His brain damage stopped new memories of events forming (anterograde amnesia), but his procedural memory for skills was spared, so his piano playing survived.
Mission 4
Retell a strange story over months and it changes. Who edits it?
Make a guess: Retell a strange story over months and it changes. Who edits it?
Memory · reconstructive memory
Memory is rebuilt, not replayed
Memory is not a recording. Each time you recall something, you reconstruct it from stored fragments plus what you know.
This is Bartlett's (1932) Theory of Reconstructive Memory: memory is an active process.
Gaps are filled with what seems likely, so memories change without you noticing.
Memory · reconstructive memory
Schemas
A schema is a mental framework of knowledge and expectations about something, e.g. what happens at a birthday party.
How schemas form: through experience and culture (repeated events, what we see and are told). New experiences update them.
How schemas shape memory: we recall what fits, leave out what doesn't, turn the unfamiliar into the familiar and add details we expect.
Key studyMemory · reconstructive memory
Bartlett (1932)
Aim
To see whether people's schemas, built from their culture, change how they recall an unfamiliar story.
Method
20 English university students read a Native American folk tale, "The War of the Ghosts", twice, then recalled it after 15 minutes and repeatedly over months and years (repeated reproduction).
Results
Recalls became shorter; strange and supernatural details were left out or explained away; details changed to fit English culture, e.g. "canoes" became "boats" and "hunting seals" became "fishing".
Conclusion
Memory is reconstructive: people use schemas to fill gaps and make an unfamiliar story make sense to them.
Strength
A meaningful story is closer to everyday memory than lists of words.
Weakness
Participants weren't told to be accurate, so some changes may be guesses; small, one-culture sample.
Quick check
?Volunteers wait two minutes in a dentist's waiting room, then are asked to list what was in it. Several list a fish tank and a pile of magazines. There was a fish tank, but no magazines. What best explains the magazines?
Memory · reconstructive memory
Reductionism and holism
Reductionism: explaining behaviour by breaking it into simple parts or one cause. Such a theory is reductionist.
Holism: explaining behaviour by looking at the whole person and all factors together. Such a theory is holistic.
The multi-store model is reductionist: three boxes and arrows.
Reconstructive memory is more holistic: it includes culture, experience and meaning. But it is also called reductionist: it explains memory through schemas alone, ignoring the brain.
Sort it
?Is each point a strength or a weakness of the Theory of Reconstructive Memory?
Tap a statement, then tap the group it belongs in. Then press Check.
Mission check
?Retell a strange story over months and it changes. Who edits it?
Your own mind edits it, without you noticing. Each time you recall the story you rebuild it using your schemas, so strange details are dropped or changed into familiar ones, and the story becomes shorter and more like what you already know.
Mission 5
Same crash, but asked "hit" or "smashed". Why do memories differ?
Make a guess: Same crash, but asked "hit" or "smashed". Why do memories differ?
Memory · accuracy of memory
Leading questions
A leading question suggests the answer, e.g. "Did you see the knife?" rather than "Did you see a knife?"
Information met after an event (questions, other people's stories, news) can blend into your memory.
The memory is distorted, and the witness doesn't realise.
In experiments, asking how fast cars "smashed" rather than "hit" led to higher speed estimates, and more people later "remembered" broken glass that wasn't there.
Memory · accuracy of memory
Schemas and witnesses
Witnesses don't take in every detail, so they fill gaps from their schemas: what usually happens, or what a "typical" robber looks like.
This can add details that never happened, or change ones that did.
Eyewitness accounts can decide court cases, so these errors matter.
A witness can be confident and still wrong.
Memory · accuracy of memory
False memories
A false memory is a memory of something that didn't happen, or happened differently. It feels just as real as a true memory.
False memories can be created by suggestion: leading questions, other people's accounts, imagining an event, or images and adverts.
Each time a memory is rebuilt, new information can get into it.
Quick check
?A police officer wants an accurate account from a witness to a car accident. Which question is most likely to distort the witness's memory?
Sort it
?Is each point a strength or a weakness of research into leading questions and false memories?
Tap a statement, then tap the group it belongs in. Then press Check.
Mission check
?Same crash, but asked "hit" or "smashed". Why do memories differ?
The question changed the memory. A leading word like "smashed" is information after the event, and it gets blended into the memory when it is rebuilt, so the witness may now recall a faster, more violent crash, and even details that weren't there.
Recap
Big ideas
Information processing runs from input to output; the processing in between is encoding, storage and retrieval.
Information can be encoded acoustically, visually or semantically; encoding by meaning makes long-term storage much more likely, and cues help retrieval.
The multi-store model has three stores, sensory register, STM and LTM, which differ in encoding, capacity and duration.
Attention moves information into STM; rehearsal keeps it there and transfers it to LTM.
Peterson and Peterson (1959) showed that STM lasts only seconds when rehearsal is prevented.
Retrograde amnesia is the loss of memories from before brain damage; anterograde amnesia is being unable to form new long-term memories after it.
Amnesia can destroy memory for events while sparing short-term memory and skills (procedural memory).
Amnesia supports separate STM and LTM stores, but suggests LTM is more than one store.
Memory is an active process: we reconstruct memories from fragments and our schemas, so recall can change without us noticing.
Schemas form through experience and culture and shape what we recall: we leave out, change and add details to fit what we expect.
The multi-store model is reductionist; the reconstructive theory is more holistic, though it can also be called reductionist.
Memory can be distorted after the event: leading questions and other information blend into the memory, and schemas fill gaps, sometimes creating false memories that feel real.
Schemas influence eyewitness memory, which is strong evidence for the Theory of Reconstructive Memory.
🏆
Mini-lesson complete!
⭐⭐⭐
You've worked through Memory for Edexcel GCSE Psychology (1PS0). 🎉
Mission 1A number's gone in seconds; a joke lasts years. What's different?
Mission 2You see everything for a split second. What decides what you keep?
Mission 3He forgets a visitor in minutes but still plays piano. How?
Mission 4Retell a strange story over months and it changes. Who edits it?
Mission 5Same crash, but asked "hit" or "smashed". Why do memories differ?