Long-Term Memory Overview: Varieties of LTM. Encoding into LTM. Retrieval from LTM. Implicit Memory. Memory as Reconstruction.

How does memory work?

1. Human memory works by recording a static, permanent record of past events. Although some events or event details may be forgotten, the things we remember are an accurate reproduction of what really happened.

2. Human memory reflects changes in the mind & brain driven by experience. Although what we remember is often related to the events in our past, most memories are a reconstruction and thus contain a number of errors and distortions.

Two classically opposing points of view...

How does memory work?

Memory as reproduction.• Warehouse or video-camera metaphor.• Remembering is like searching through

a warehouse; and when the right memory is 'found', we re-experience it.

• Narrative or story-telling metaphor.• Remembering is an active process of

recreating the past by using current info, inferences, & plausible guesses.

Memory as reconstruction.

How can we decide between these two points of view?

Two classically opposing points of view...

Amazing Feats of Memory…

Akira Haraguchi can recite pi from memory to 100,000 decimal places.

Andi Bell can remember the order of 520 randomly presented cards after just 20 minutes of study.

Kim Peek (the real Rain Man) can recall the content of 12,000+ books & the zip code of every US location US.

"And as the evidence started to come in, and I was told it wasn’t him, it was still just conclusive to me that this had been the rapist. And so as time goes on, I think that my mind will always see Ronald Cotton".

"He looked exactly like the man. His mannerisms, his voice, his height, his weight -- it all just added up in my mind".

Amazing Failures of Memory…

Amazing Feats…

Amazing Failures…

Is memory a reproduction of the past, or only a reconstruction?

How can we decide between these different points of view?

The Deese, Roediger, McDermott (DRM) Paradigm

The effect is difficult to avoid, making it similar to many perceptual illusions.

The effect appears to occur at encoding with the critical lure (e.g., sleep) being repeatedly activated by each of the study words. cf. Spreading Activation in Semantic Memory.

The "modern classic" false memory paradigm. based on the work of Deese (1959), recently

updated by Roediger & McDermott (1995).

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Studied Critical Lure UnrelatedLureItem Type

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ortio

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Old

Res

pons

esThe Desse, Roediger, McDermott

(DRM) Paradigm

Spreading Activation Account of DRM Effect

Schema: An organized piece of

knowledge (framework) that represents what's typical about a person, place, or thing.

Script: An organized

knowledge framework that represents how an event typically unfolds.

Schemas & Scripts

Schemas often help us by reducing the need to remember schema-consistent info; and by increasing memory for schema-inconsistent info.

Effects of Schemas on Memory

However, schemas can also produce false memories for schema-consistent events that never happened.

If schema active during encoding, the effect may be irreversible.

S's read list of memories - one is false, but plausible.

S's then interviewed about the various "memories".

25% "remembered" false event.

1st interview: “I have no clue. I have never heard that one before.”

2nd interview: “It was an outdoor wedding, and I think we were running around and knocked something over like a punch bowl or something and made a big mess and of course got yelled at for it.”

False Memories for Autobiographical Events

Elizabeth Loftus

Imagination Inflation

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Found $10

Bad Haircut

Stuck in tree

Won a pet

Saved by lifeguard

Emergency room visit

Broke window

Called 911Did Not ImagineImagined

Percent of subjects with increasing confidence that event occurred

Can just imagining something make you remember it later as an actual event?

Subjects rated the likelihood of 40 childhood events

2 weeks later asked to imagine they had experienced some of those events.

Subjects then repeated the likelihood task.

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Number of Imaginations

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ortio

n of

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se A

larm

sThe more you imagine something, the more likely

you are to "remember" it happening later on.

Imagination Inflation

Spreading Activation (e.g., the DRM effect).

The Origins of False MemoriesFrom Internal Processes:

Schemas & Scripts.

Imagination Inflation.

Misinformation Effects (RI & PI).

From External Information:

Priming (e.g., from photos or criminal line-ups).

Source Confusion.

Loftus & Palmer (1974)Misinformation Effects

Subjects watch video of a traffic accident.

Then asked "How fast were the cars going when they _______ each other?"

Group 1: "hit"

Group 2: "smashed into"

Later asked, "Did you see broken glass?"

34 mph

41 mph

14%

32%

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Hit Smashed Into

Leading Question Condition

Speed: mph Glass?: % yes

Loftus & Palmer (1974)Misinformation Effects

Loftus (1975)Misinformation Effects

Subjects watch slides or video of a traffic accident in which a car goes fails to completely stop at a stop sign.

Results show that a significant number of subjects later report seeing a yield sign in the original slides/video.

Then asked to either read a narrative about the event, or asked questions such as… "How fast was the car going it went past the yield sign?

Retroactive Interference (RI)

Control Condition

Interference from a recent event on memory for an earlier event.

Example: Trying to remember your previousaddress or phone number.

Event 1 - - - - - - - - - - - - - - - - - - - - Test for Event 1

Experimental (RI) Condition

Event 1 - - - - - - - Event 2 - - - - - - - Test for Event 1

Proactive Interference (PI)

Control Condition

Example: Parking in a new location, after parking in the same spot on previous occasions.

Experimental (PI) Condition

Event 1 - - - - - - - Event 2 - - - - - - - Test for Event 2

Interference from an earlier event on memory for a recent event.

- - - - - - - - - - - - - Event 2 - - - - - - - Test for Event 2

Subjects reminded of two real childhood events (obtained from parents).

Effects of reviewing photographs

Also "reminded" of a third event that never happened (putting Slime in their teacher's desk).

Subjects then rated whether they could remember any of these three events & rated the confidence in their memory.

Subjects shown the picture were more than twice as likely to "remember" the Slime event.

False Memories for Childhood Events

Half of the subjects made these ratings while viewing an old class picture.

Source Confusion Source Memory - memory for the origin of

information (e.g., imagination vs. reality; news show vs. radio; tabloid vs. newspaper)

The Sleeper Effect – remembering the content of a message but forgetting the (often unreliable) source.

Eyewitness TestimonyWhat leads people to make confident

false identifications? Implicit memory (priming)

from a photo, seen prior to identifying the person in a line-up.

Also, picking a suspect on the basis of general similarityvs. specific identity.

Eyewitness TestimonyHave you seen these people?

"that's the guy we thought it was"

Bobby Poole, the real rapist Identikit sketch

Ronald Cotton's photo, picked by

Jennifer Thompson

Ronald Cotton in line-up, picked by

Jennifer Thompson

• Schemas.

• Misinformation Effects (RI & PI).

• Imagination Inflation.

• Source Confusion.

• Priming.

"And as the evidence started to come in, and I was told it wasn’t him, it was still just conclusive to me that this had been the rapist. And so as time goes on, I think that my mind will always see Ronald Cotton".

"He looked exactly like the man. His mannerisms, his voice, his height, his weight -- it all just added up in my mind".

Eyewitness Testimony

Repressed/Recovered MemoriesConvicted of rape & murder on the basis of a memory recovered by his daughter, Eileen.

Eileen told a court in 1990 that she remembered seeing her father, 21 years earlier, rape her best friend, Susan Nason, and then beat her in the head with a rock.

"I remembered seeing Susan sitting there and seeing my father with the rock above his head," she said.

Franklin's conviction was overturned in 1995 whereupon he was released from prison after serving 6.5 years.

Intentional Forgetting (cf. repression).• under the right conditions, people can "learn to forget".

Recovered Memories or False Memories?

Psychotherapy as a recipe for false memory?• clients hypnotized or encouraged to imagine abuse.

• 12% of clinicians surveyed by APA reported treating patients forced to participate in satanic cults

– 1994 federally-funded research team concluded that satanic conspiracies in day care centers is a myth.

• Other recovered memories:

– Alien abductions– Past lives– Conspiracies– Fantastic stories of abuse

• People insist these "memories" are true because they are experienced vividly and with emotional force.

Repressed/Recovered Memories?