Memory – Module 27Memory – Module 27 Forgetting and Memory Forgetting and Memory

ConstructionConstruction

General Psych 1General Psych 1

April 12, 2005April 12, 2005

Class #21Class #21

SOURCE AMNESIASOURCE AMNESIA

• Remembering something but Remembering something but attributing it to the wrong sourceattributing it to the wrong source

• We may recognize someone but have We may recognize someone but have no idea where we saw that personno idea where we saw that person

Poole and Lindsay (1995, Poole and Lindsay (1995, 2001)2001)

•““Mr. Science” had real Mr. Science” had real interactions with preschoolers…interactions with preschoolers…

•Three months later, parents read Three months later, parents read stories to the children stories to the children

•These stories were about the children These stories were about the children and Mr. Science – some which were and Mr. Science – some which were true, others that were nottrue, others that were not

The “Mr. Science” The “Mr. Science” experiment…experiment…

• Results:Results:– Children sometimes reported that events Children sometimes reported that events

happened to them when the only time they happened to them when the only time they had ever heard about them was during the had ever heard about them was during the previous interview a month earlierprevious interview a month earlier

– For some children, simple exposure to a For some children, simple exposure to a yes-no question about an event they did yes-no question about an event they did not experience was suggestive enough for not experience was suggestive enough for them to report it as real a month later them to report it as real a month later

Eyewitness TestimonyEyewitness TestimonyHow accurate is an How accurate is an

eyewitness testimony?eyewitness testimony?

Perception:Perception: we can only remember is perceived which a.) depends on our attention level at the time and b.) also may depend n top-down processing. (our past experiences

influencing perception..Retroactive interference:Retroactive interference: (old memories influencing new memories) Something new and this might cause something old to be

forgotten..Integration:Integration: might involve an integration of

old memories with new memories.

Things Involved:

Loftus and Palmer (1974)

--attempted to find out how accurately we remember the details of a complex event (like a traffic accident)

-memory reconstruction of automobile destruction

-looked at the interaction between language and memory

Loftus and Palmer (1974)Experiment 1

--45 subjects watched 7 films depicting a traffic accident

-They were asked to give a written account of what they had just seen and answer several questions…….

There was a key question “About how fast (MPH) were the cars

going when they hit each other?”In each group the word hit was changed with

either smashed, collided, bumped or contacted…

So what we have is………So what we have is………

5 Groups of 9 people5 Groups of 9 people Group 1: hit Group 2: smashed Group 3: collided Group 4: bumped Group 5: contactedWhich word do you think elicited the fasted MPH

answers?

Or did it matter at all which word was used?

Results……….

Verb Avg. Speed

Hit

Smashed

Collided

Bumped

Contacted

Loftus and Palmer (1974)Experiment 2

--150 subjects watched one film depicting a multiple car accident.

-Subjects were divided into three groups and were asked to give a written account of they had just seen and then answer several questions

The key question……..

Group 1: “About how fast (MPH) were the cars going when they smashed into each other?”

Group 2: “About how fast (MPH) were the cars going when they hit each other?

Group 3: Participants in this group were not interrogated about vehicular speed.

What do you think the results were???????

Results………

Verb Avg. Speed

Smashed

Hit

Experiment 2 (Con’t)

-One week later…………… -without viewing the film again

subjects were asked several questions

-somewhere in this serious of questions is the critical question,

“Did you see any broken glass?”

Results…………

Response Grp: 1 Grp: 2 Control

YES

NO

Loftus and Palmer’s Theory…..

2 types of information goes into one’s memory concerning a complex occurrence

-The first is an internal type of infoone’s initial perception of the event

-The second is an external type this is supplied to them after the factOver time both of these memories become

intergraded giving us only one memory but it’s different from the first one

Loftus and Palmer Theory (Con’t)--The subject first forms an internal representation of

the accident-Then the experimenter provides the external

information ( “smashed”)-When these 2 pieces of information are intergraded,

the subject forms a memory of the experiment that was even more severe then it in fact was

Example: Broken glass is more likely in severe accidents so the subject is more likely to say that it was present

Loftus and palmer’s Theory (Con’t)

-When the experimenter say’s “smashed” he is effectively labeling the accident

-It is natural to conclude that the label “smashed” causes a shift in memory representation of the accident

-The shift in memory is basically caused by the verbal label

-So much that most subjects mentioned that they were extremely confident in their predictions

Be Careful How You Phrase Things………………………………….

Harris (1973)

• In-class experiment…In-class experiment…

Loftus and Palmer’s TheoryReal Life Implications

•Can a therapist , police officer, lawyer, or anyone else who repeatedly suggests something actually distort the truth?

- What about a child witness?

Own Race BiasOwn Race Bias

• Are people better at recognizing Are people better at recognizing faces that are of the same race as faces that are of the same race as themselves?themselves?

Platz & Hosch (1988)Platz & Hosch (1988)

• El Paso, TX convenience store clerks asked to El Paso, TX convenience store clerks asked to identify customers from lineups…identify customers from lineups…

• Accurate IDs:Accurate IDs:

ClerkClerk                                           Customer RaceCustomer Race• Race:                      White          Black          MexicanRace:                      White          Black          Mexican• White                      58%              42%              37%White                      58%              42%              37%• Black                       57%              65%              43%Black                       57%              65%              43%• Mexican                  37%              23%              59%Mexican                  37%              23%              59%

How can someone make a How can someone make a false identification?false identification?

• False ID’s may result from improper False ID’s may result from improper acquisition or storage as well as the acquisition or storage as well as the construction of the lineup and instructions construction of the lineup and instructions given to witnesses can lead to problems given to witnesses can lead to problems with retrievalwith retrieval

• Line-up ConstructionLine-up Construction– Usually 4-8 innocent people fitting the Usually 4-8 innocent people fitting the

general descriptiongeneral description• Witnesses often assume or are explicitly Witnesses often assume or are explicitly

told that the culprit is in the lineuptold that the culprit is in the lineup

Improper acquisition…Improper acquisition…

• Acquisition: Acquisition: – This is the learning stage – when things This is the learning stage – when things

are encoded -- noticing and attending to are encoded -- noticing and attending to the informationthe information

– Affected by physical factors (e.g., Affected by physical factors (e.g., lighting, disguises, distance), limited lighting, disguises, distance), limited time, and feartime, and fear

Much can lead to a mistaken Much can lead to a mistaken identity…identity…

• Weapon-focus effectWeapon-focus effect– An eyewitness’s diminished ability to An eyewitness’s diminished ability to

subsequently identify a perpetrator subsequently identify a perpetrator when a weapon was used in a crime when a weapon was used in a crime (Shaw & Skolnick, 1994)(Shaw & Skolnick, 1994)

Weapon-focus effectWeapon-focus effect

• When a criminal pulls out a gun, a When a criminal pulls out a gun, a razor blade, or a knife, witnesses are razor blade, or a knife, witnesses are less able to identify that culprit than less able to identify that culprit than if no weapon is presentif no weapon is present– This is due to agitation at the sight of a This is due to agitation at the sight of a

menacing weapon and witnesses’ eyes menacing weapon and witnesses’ eyes are drawn to weaponsare drawn to weapons

Easterbrook HypothesisEasterbrook Hypothesis

• Easterbrook (1959)Easterbrook (1959) – Narrowing of attention during emotional Narrowing of attention during emotional

events events

• Does this remind you of anything we Does this remind you of anything we mentioned during earlier class on classical mentioned during earlier class on classical conditioning?conditioning?

False Memory SyndromeFalse Memory Syndrome

• Kihlstrom (1996) Kihlstrom (1996) – Defines this syndrome as a condition in Defines this syndrome as a condition in

which a person's identity and which a person's identity and interpersonal relationships are centered interpersonal relationships are centered around a memory of traumatic around a memory of traumatic experience which is objectively false but experience which is objectively false but in which the person strongly believesin which the person strongly believes

Improper storage…Improper storage…

• Loftus and Palmer theory applies Loftus and Palmer theory applies herehere

• Someone’s words can often distort Someone’s words can often distort memoriesmemories