Memory--retrieval

For later. . .

Try to remember these words. . .

• Measures of memory

• Relative difficulty of different measures of memory

• Role of cues in memory retrieval

• Retrieval and prior knowledge

Measures of memory

• Free recall

• Cued recall

• Recognition

• Savings in relearning

MeasuresFree recall: Minimal information from experimenter: experimenter simply says “Remember” and the contextis usually implied, occasionally described.Cued Recall: Experimenter also gives part of the information, or some related information.Recognition: The to-be-remembered information is presented, along with other stuff (distractors) and the subject must distinguish new from old.

Savings in relearning: Subject learns some material to a criterion, and the # of trials required is noted. Later subject relearns the material to the same criterion; if fewer trials are required, that is savings.

Difficulty

An important principle is this:Whether or not it appears that someone rememberssome material depends on the way that you measuretheir memory.

That is, it can appear that someone has forgotten somematerial, but if you give them a different test, it is clear that they remember it.

Measures--difficulty

In general, free recall is hardest, then cued recall, then recognition.

Shepard & Recognition memory

Subjects see 512 words, then take a 2-choice recognition test--get 88%

Subjects see 612 brief sentences (e.g., “The truck swerved to avoid the limping deer”), then take 2-choice recognition test--get 88%

Final experiment = colored pictures cut from magazines.

Shepard’s results

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Caveat

Although it’s true that recognition memory is usually very good, you have to bear in mind that the difficulty of a recognition task depends on the distractors.

SensitivityAlthough we can’t talk about the absolute sensitivity of free recall, cued recall, and recognition, we can talk about the relative sensitivity (usually). IN GENERAL

Free recall< cued recall< recognition.

Tulving & Pearlstone, 1966: Condition 1: Free recall, then cued recallCondition 2: Cued recall, then cued recallCued recall 50% more remembered than free.

Hart, 1965, 1967: When free recall fails, subjects recognize answer 50% of the time

Nelson, 1978 When recognition fails, subjects relearn the material faster than new material

Recognition more sensitive than free recall

Cued recall more sensitive than free recall

Savings more sensitive than recognition

Why the difference in sensitivity?

It feels like memory success is some combination of memory strength and the sensitivity of the test.

Tests are sensitive to the extent that they give you good cues.

Free recall: context (time and place)Cued recall: context + partial informationRecognition: context + all information

The importance of cues.

Try to recall the words to “Star Spangled Banner”

Does # of cues (sensitivity) explain everything?

No, what’s actually important is whether the cues make you think of material the same way at encoding and retrieval.

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Recognition Rhyming

Type of Test

Deep Encoding

Shallow Encoding

Rhyming

Meaning

Transfer Appropriate Processing

The importance of cues

We can extend transfer appropriate processing: cues are important not just if they are about sound (rhyming) vs. about meaning: they are important if they make you think about different things about material, even if all the cues concern meaning

Barclay et al.

This effect works even if you don’t change the word, but just emphasize different properties of the word!

E.g., “The moving men struggled to get the PIANO up the stairs.

Cue: something that makes music (avg. 1.6 words/10)Cue: something heavy (avg. 4.6 words/10).

We can take this effect one step further:if a recall cue is better at making you thinkas you did at encoding than a recognition cue,you should be better at cued recall than recognition.

Recognition failure of recallable words

Participants see word pairs:

glue: CHAIRground: COLD

They are told they need only remember the wordsin capital letters, but the other words might help.

Recognition failure of recallable words

They get two tests:

Recognition test:

CHAIR NURSE SHELL

Cued recall test:glue: ground:

Recognition failure of recallable words

Key finding: there are some words for which people fail to recognize the word, but then are able to recall it.

Why?

“glue-chair”

“chair”

The point: recognition failure of recallable words effect is consistent with the idea that different measures of retrieval lead to better or worse recall because they provide different cues, and the cues are more or less likely to make you think about material the way that you thought about it at encoding.

Test

Try to recall the word list that you heard at the start of the class.

Why do people remember “sleep?”

• They might think about “sleep” at encoding

• They know the list is composed of words related to sleep, so at retrieval, “sleep” seems like a plausible list member.

Retrieval & prior knowledge

We can generalize from this “sleep” example to say that memory is almost always a combination of the actual event plus relevant prior knowledge.

What type of prior knowledge?

Schemas

A memory representation of a type of event, characteristics generally true of the event, not of a specific event.

Schemas• What’s in your schema of a doctor’s visit?

Things that conflict with the schema are attended to and remembered. Things that are not part of the schema but are irrelevant are not.

Schemas

• Would it stand out if the nurse didn’t say “The doctor will be with you shortly” after leaving you in the exam room? Would you perhaps remember that she did say that week later?

At encoding: schemas make atypical things stand out, and they are memorable.At retrieval: schemas make it seem likely that typical things happened, even if they didn’t.

Most memory researchers believe that all memory is a reconstruction. You combine what happened with what you believe probably happened and that’s your memory.

Retrieval success varies with cues. Cues vary in the extent to which they make you likely to think about material the way you did at encoding.