AP® Psychology review sheet from Aim for Five (aimforfive.com/psych/units/2/2-5)
Unit 2 · Topic 2.5
2.5 Storing Memories
Memory storage keeps information over time. Sensory, short-term, working and long-term memory differ in how long they last, how much they hold and what they contain. Elaborative rehearsal keeps information better than simple repetition, and storage can be disrupted by amnesia, Alzheimer's disease and the normal gaps of infantile amnesia.
Key terms
- sensory memory
- short-term memory
- long-term memory
- maintenance and elaborative rehearsal
- retrograde and anterograde amnesia
- infantile amnesia
Comparing the memory stores
Short-term memory and working memory overlap. Short-term memory describes temporary storage, while working memory describes active work with that information. For the exam, think of working memory as short-term memory in action.
| Store | How long it lasts | How much it holds | What it's for |
|---|---|---|---|
| Sensory memory | Under a second for sights (iconic); a few seconds for sounds (echoic) | A lot, but very briefly | A quick, detailed copy of what your senses take in |
| Short-term memory | Roughly 15 to 30 seconds without rehearsal | About 7 items (newer estimates are closer to 4 chunks) | Holding what you're paying attention to right now |
| Working memory | As long as you keep actively using it | Limited, like short-term memory | Actively processing information, like doing math in your head |
| Long-term memory | Minutes to a lifetime | Essentially unlimited | Storing knowledge, skills and experiences |
Keeping information: two kinds of rehearsal
Maintenance rehearsal is simple repetition, like saying a phone number over and over until you dial it. It keeps information in short-term memory as long as you keep repeating, but it isn't very good at moving information into long-term memory.
Elaborative rehearsal means connecting new information to its meaning or to things you already know. To remember that the hippocampus forms new memories, you might picture a hippo on a campus, studying hard to remember everything. Because it involves deeper, semantic processing (2.3), elaborative rehearsal leads to much better long-term retention.
Autobiographical memory and superior memory
Autobiographical memory is memory for the events of your own life. Information linked to yourself is especially memorable, which is why connecting a concept to your own experience is such a strong study strategy.
A very small number of people have highly superior autobiographical memory (HSAM). Given almost any date from their adult lives, they can recall what day of the week it was and what they did. Researchers think this may point to biological differences in how memories are stored. Interestingly, people with HSAM aren't usually better than others at memorizing lists or facts; their advantage is mostly for personal events.
When storage breaks down
A memory trick: anterograde amnesia affects memories going forward (new ones), and retrograde affects memories going backward (old ones).
- Retrograde amnesia: losing memories formed before an injury or illness. A person in a car accident may not remember the hours or days before the crash.
- Anterograde amnesia: being unable to form new long-term memories after an injury or illness, often from damage to the hippocampus. The person may remember their childhood but forget a conversation minutes later.
- Alzheimer's disease: a progressive brain disease that destroys neurons over time. It usually begins with trouble forming new memories and gradually affects older memories, language, reasoning and eventually daily functioning. It is linked to a loss of neurons that produce acetylcholine.
- Infantile amnesia: most people can't recall events from before about age 3 or 4. This is a normal developmental limitation, likely because the brain structures and language skills used to store lasting episodic memories aren't yet mature.
Worked examples
Try each one yourself first, then open the solution.
- Example 1
Retrograde or anterograde?
After surgery that damaged his hippocampus, a patient remembers his wedding from 20 years earlier and still knows how to play the piano, but he can't remember his nurse's name even though she introduced herself many times. What type of amnesia is this, and what does the piano evidence show?
Show the solutionHide the solution
- Step 1: He can't form new explicit memories after the damage: that is anterograde amnesia.
- Step 2: His older memories (the wedding) are intact, so this is not mainly retrograde amnesia.
- Step 3: His piano skill is procedural (implicit) memory, which doesn't depend on the hippocampus in the same way. So implicit memory can survive when the ability to form new explicit memories is lost.
Answer: Anterograde amnesia; his intact piano playing shows procedural (implicit) memory is stored separately from new explicit memory.
- Example 2
Evaluating a case study
A researcher studies one woman with HSAM in great depth and concludes that 'people with better memories have different brains.' Evaluate this conclusion based on the research design.
Show the solutionHide the solution
- Step 1: Identify the design: a case study, which is an in-depth look at one person.
- Step 2: Strength: it gives rich detail about a very rare ability that couldn't be studied in a large sample.
- Step 3: Limitation: results from one person may not generalize to others, and a case study can't show cause and effect.
- Step 4: A better conclusion would be tentative: her case suggests biological differences might be involved, which larger studies would need to test.
Answer: The conclusion goes too far: a single case study can suggest ideas but can't be generalized to all people or prove what causes superior memory.
Common mistakes
- Reversing retrograde and anterograde amnesia. Anterograde means you can't form new memories; retrograde means you lose old ones.
- Saying maintenance rehearsal is the best way to study. Repetition keeps information active, but elaborative rehearsal is what builds lasting long-term memories.
- Treating infantile amnesia as a disorder. It's a normal part of development that nearly everyone experiences.
On the exam
- Expect to compare memory stores by duration, capacity and content, often from a scenario.
- Storage topics often use case studies, so be ready to name a case study's strengths and its limits for generalizing.
Connected topics
Videos
Check yourself
4 questions on 2.5 Storing Memories. Pick an answer to see if you got it, and why.
Which study strategy would most likely help a student remember the meaning of the word "benevolent" for the longest time?
| Delay between the flash and the tone | Mean letters correctly reported from the cued row (out of 4) |
|---|---|
| 0 seconds | 3.3 |
| 0.3 seconds | 2.4 |
| 0.6 seconds | 1.8 |
| 1.0 second | 1.5 |
Hypothetical experiment. Participants saw a grid of 12 letters (three rows of four) for 50 milliseconds. A high, medium or low tone then signaled which row to report. Participants could not know in advance which row would be cued.
When the tone sounded right away, participants reported about 3.3 of the 4 letters in the cued row. Because they could not know in advance which row would be cued, this suggests that just after the flash, they had access to about
The drop in letters reported as the delay grows best supports which conclusion about this kind of memory?
After a car crash in which she suffered a concussion, Mei cannot remember the hour before the crash. Since then, she has had no trouble remembering new events from day to day. Mei is showing
0 of 4 answered