Unit 10: Memory
Why memory is built in stages, why it fades on a predictable curve, and why every act of remembering is also an act of rebuilding.
7 topics · 24 questions
Each topic is a path, not a menu: work down it in order and every question builds on the one above. Click any of them to watch the answer draw itself.
Encoding, Storage, and Retrieval
- How it worksHow does information move from encoding to storage to retrieval, and where does forgetting actually happen along that path?
- Going furtherWhat happens to retrieval when a memory was encoded in one mood or place and you try to recall it in a completely different one?
- Common mistakeWhy isn't forgetting always a storage failure rather than a retrieval failure?
Your turn1 of 2
Someone tries hard to recall a name and simply cannot, and later assumes the information about that name must never have been stored in memory at all. A student wonders where along the path from encoding to storage to retrieval forgetting actually tends to happen. How does information move through these three stages, and where can forgetting occur?Working Memory's Limited Capacity
- How it worksHow does working memory hold a small amount of information active through rehearsal before it decays or gets stored?
- Worked exampleFind how chunking turns the twelve letters F B I C I A I R S U S A into four memorable chunks instead of twelve items.
- Common mistakeWhy isn't working memory the same thing as long-term memory running at a smaller scale?
Your turn1 of 2
A string of 30 letters is grouped into meaningful chunks averaging 4 letters each. Find how many chunks result.The Serial Position Curve
- How it worksHow do the primacy effect and the recency effect combine to draw a U-shaped serial position curve?
- Worked exampleFind what happens to the recency effect, but not the primacy effect, when recall is delayed by 30 seconds of distraction.
- Going furtherWhat happens to the serial position curve when the list is read aloud twice as slowly?
Your turn1 of 2
On a grocery list read aloud once, people tend to recall the first few and the last few items much better than the items in the middle, producing a U-shaped curve when recall is plotted by position. A student assumes there must be one single mechanism responsible for both ends of this curve at once. How do the primacy effect and the recency effect combine to draw this shape?The Forgetting Curve
- How it worksHow did Ebbinghaus's forgetting curve reveal that memory loss is steepest right after learning and then levels off?
- Worked exampleFind roughly what percentage of freshly memorized material survives after one day versus after one week, based on Ebbinghaus's original curve.
- Common mistakeWhy doesn't spacing out your studying just take more total time than cramming for the same result?
- Going furtherWhat happens to the forgetting curve when the same material is reviewed again right before it would have been forgotten?
Your turn1 of 2
According to Ebbinghaus's forgetting curve, roughly 49 percent of freshly memorized material survives after one day, and roughly 22 percent survives after one week. Find how many more percentage points are lost between one day and one week.Long-Term Potentiation
- How it worksHow does long-term potentiation strengthen a synapse when two neurons fire together repeatedly?
- Going furtherWhat happens to a memory's strength when a drug blocks long-term potentiation right after the memory is formed?
- Ties togetherHow does neurons that fire together wire together connect long-term potentiation to how any habit gets built?
Your turn1 of 2
Two neurons that repeatedly fire together end up with a strengthened connection between them, one that responds more strongly the next time the first neuron fires. A student assumes such a lasting change must require adding an entirely new physical connection between the two cells from scratch. How does long-term potentiation actually strengthen a synapse when two neurons fire together repeatedly?Memory as Reconstruction
- How it worksHow does the brain rebuild a memory each time it's retrieved instead of replaying a fixed recording?
- How it worksHow does the wording of a single question, like asking how fast cars were going when they smashed versus hit, change what someone later reports remembering?
- Worked exampleFind why participants told a car smashed into another rated broken glass in a filmed accident that never actually showed any broken glass.
- Common mistakeWhy isn't memory like a video recording that plays back exactly what happened?
- Going furtherWhat happens to an eyewitness's confidence in a false memory once it has been altered by a leading question?
Your turn1 of 2
Researchers asked participants how fast two cars were going when they 'smashed into' each other versus when they 'hit' each other, after showing the same filmed accident to everyone. Participants who heard 'smashed' reported higher speed estimates than those who heard 'hit,' even though everyone saw the exact same footage. A student assumes the specific wording of a question should not be able to change an already-formed memory. How does the wording of a single question change what someone later reports remembering?Flashbulb Memories
- How it worksHow does a surge of emotional arousal make the brain feel like it's burned a memory in with perfect vividness?
- Common mistakeWhy isn't a flashbulb memory's vividness proof that it's more accurate than an ordinary memory?
- Ties togetherHow does the unreliability of flashbulb memories connect to the same reconstruction process behind eyewitness testimony?
Your turn1 of 2
People often report remembering exactly where they were and what they were doing when they heard shocking news, with a striking sense of vividness and confidence, as though the moment were burned permanently into memory. A student assumes this vivid, burned-in feeling must come from some special, more reliable memory system reserved for shocking events. How does a surge of emotional arousal produce this feeling of vivid, burned-in memory?