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Long-Term Memory: Episodic

Kimberley Clow

kclow2@uwo.ca

http://instruct.uwo.ca/psychology/130/

OutlineWhat is Episodic Memory?– Autobiographical Memory

EbbinghausMemory Stages– Encoding– Storage– Retrieval

Interactions Between Stages– Depth of Processing– Strategies

Recap

This is the mental model of memory that has developed over the last few lectures

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Long-Term Memory

ExamplesWhat did you eat for breakfast this morning? What was the first university class you attended? What was the name of your fourth grade teacher?What was the name of your first best-friend?What colour was your bedroom when you were 6 years old?

Leftovers from thanksgiving dinner

The history of theatre

Ms. Jarvis

Richie

Blue

Autobiographical MemoryPrimarily interpretations about an eventInformation about– the location of an event– temporal information about the date of occurrence

of an event– the actors, actions, and locations– context-specific sensory and perceptual attributes– imagery

Contains the experience of rememberingDuration of the memory can last for years

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Types

Personal Memory– image-based representation of a single unrepeated

eventAutobiographical Fact– identical to personal memory, except that the

memory is not image-basedGeneric Personal Memory– similar to personal memory, except that the event is

repeated or a series of similar events occur and are represented in a more abstract form

Accuracy

"Memory is a complicated thing, a relative to truth, but not its twin“

• Barbara Kingsolver

Accuracy of autobiographical memories– Factual information:

• .88 correlation among family members– Emotions and attitudes:

• .43 correlation among family members

What Memory System?

Who Wants to be a

Millionaire?

This is Your Life

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Ebbinghaus

Criticism

He excluded meaning from the stimuli– We have a great tendency to impose

meaning even on the most meaningless stimuli

• e.g., mentally turning BEF into BEEF– If memory is studied in absence of

meaning, can this tell us how memory normally functions?

• When we do have access to meaning • When do we use mnemonics and other

strategies?

Stages of Memory

Three different stages of processing– Encoding– Storage– Retrieval

Recollecting episodic memories is determined by the interaction of encoding and retrieval processes– How we input material will determine how well we

can output it

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Encoding

Depth of Processing– Shallow processing

• Physical features

– Deep processing• Meaning

Memory is affected by the way information is encoded– Not just whether it is in the system– How was it encoded into the system?

Experimental Evidence

Study Phase– Visual

• Does the word contain a letter E?

– Phonemic• Does the word rhyme

with train?

– Semantic• Is it a type of animal?

Test Phase

Not Just the Kind of Processing

Manipulation of sentence contexts– Target: TOMATO

• Simple– She cooked the …

• Medium– The ripe … tasted

delicious• Complex

– The small lady angrilypicked up the red …

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Criticisms

Circular Arguments– Deep vs. shallow not well defined– If result is good memory processing must

have been deep instead of shallowRecall vs. RecognitionDoesn’t explain why some codes are better than others– Why difference for yes vs. no response?

Doesn’t explain context effects

Encoding Specificity

Study word pairs– Encode based either

on meaning or sound• Meaning

– Is the target related to the word CAT?

• Sound– Does the target rhyme

with the word CAT?

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ENCODEMEANING

ENCODESOUND

MEANING CUESOUND CUE

Context Effects

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ENCODE ONLAND

ENCODEUNDERWATER

RETRIEVE ONLANDRETRIEVEUNDERWATER

0102030405060708090

SAD ENCODING HAPPYENCODING

SAD RETRIEVAL

HAPPYRETRIEVAL

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PLACEBOENCODING

DOPE ENCODING

PLACEBORETRIEVALDOPERETRIEVAL

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ENCODEMEANING

ENCODESOUND

MEANING CUESOUND CUE

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Two Types of Context

Intrinsic context– Has direct impact on the meaning of the to-

be-remembered item• strawberry-JAM vs. traffic-JAM

Extrinsic context– Situation has indirect effect on the to-be-

remembered item• Mood and state dependent learning

– learn words on land or 20 ft under water

Cautionary Note!

Change of environmental context affected recall, but not recognition

Encoding specificity may more generally be thought of as transfer-appropriate processing

Transfer-Appropriate Processing– memory performance is determined by the

degree of similarity between the cognitive operations performed at encoding and those performed at retrieval

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When Episodic Memory Fails…His face

is familiar...

HEY BUDDY,I MISSED YOUSO MUCH....

Encoding Strategies

Rehearsal– Type I– Type II

Mnemonics– Single Use– Multiple Use

OrganizationImagery

Mnemonics

Three principles:1. Material to-be-learned is structured and

integrated into a preexisting memory framework

2. Material to be remembered must be practiced to form distinctive traces

3. Mnemonic device can be used for both encoding and retrieval by providing effective cues

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Single Use MnemonicsAcronyms– ROY G. BIV

Rhymes– i before e, except after c

Phrases– Spring forward, fall back– Never Eat Shredded Wheat– My Very Earnest Mother Just Served Us Nine Pizzas

Personal Meaning– My student Kate reminds me of Kate Blanchet playing

Galadriel

Multiple Use Mnemonics

The Method of Loci– Dates back to Ancient Greece.

Peg-Word Technique– Taking advantage of pre-existing associations

• “This old man, he played one…”

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Imagery

Many mnemonics use visual imagery– Do the method of loci and peg words work

because of their visual basis?Imagery aids learning– Deeper encoding?– Better storage?– Easier retrieval?

Retrieval

Types of tasks used to test retrieval:– Relearning Task

• Ebbinghaus– Paired-Associate Learning– Recall

• Free recall• Serial recall• Cued recall

– Recognition

Paired-Associate Learning Task

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Forgetting

Reasons for Forgetting– Decay– Interference– Retrieval Failure

Important Terms– Availability– Accessibility

Availability vs. AccessibilityTwo groups studied same list of 48 items – Items were preceded by the appropriate name of

the category– Participants were told that they only had to

remember the items themselvesAt recall one group free recall, the other group cued recallResults: – Free recall group: 40 percent– Cued recall group: 62 percent

So information can be available but not accessible

Other Influences

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And …Targets presented with weakly associated cue– glue-CHAIR

When asked to RECOGNIZE– if target is in a new context recognition may fail

• fail to recognize table-CHAIR

When given cued RECALL with original associate cue, now successfully remember– glue-?

New associate better cue for remembering item than the item itself!– Don’t remember chair when they see chair with

table, but can recall chair when they only see glue

Dissociation?Patient H.M.– Episodic & semantic memory prior

to surgery intact, but cannot form new memories

Patient E.D.– Semantic memory is impaired yet

episodic memory for the same period is intact

Patient K.C.– Episodic memory processes

disrupted, but semantic memory processes in tact

Not good evidence

Good evidence