Memory – Module 27 Forgetting and Memory Construction General Psych 1 April 12, 2005 Class #21

SOURCE AMNESIA

• • Remembering something but attributing it to the wrong source We may recognize someone but have no idea where we saw that person

Poole and Lindsay (1995, 2001)

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“ Mr. Science” had real interactions with preschoolers…

• Three months later, parents read stories to the children • These stories were about the children and Mr. Science – some which were true, others that were not

The “Mr. Science” experiment…

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Results:

– Children sometimes reported that events happened to them when the only time they had ever heard about them was during the previous interview a month earlier – For some children, simple exposure to a yes no question about an event they did not experience was suggestive enough for them to report it as real a month later

Eyewitness Testimony How accurate is an eyewitness testimony?

Things Involved:

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

Integration: might involve an integration of old memories with new memories.

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………

5 Groups of 9 people

Group 1: hit Group 2: smashed Group 3: collided Group 4: bumped Group 5: contacted Which 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 Smashed Hit Avg. Speed

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 YES NO Grp: 2 Control

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 info one’s initial perception of the event -The second is an external type this is supplied to them after the fact Over 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…

Loftus and Palmer’s Theory Real 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 Bias

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

Platz & Hosch (1988)

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

• Accurate IDs: • • • • Clerk Race: White Black Mexican Customer Race White Black 58% 42% 57% 37% 65% 23% Mexican 37% 43% 59%

How can someone make a false identification?

• • • False ID’s may result from improper acquisition or storage as well as the construction of the lineup and instructions given to witnesses can lead to problems with retrieval Line-up Construction – Usually 4-8 innocent people fitting the general description Witnesses often assume or are explicitly told that the culprit is in the lineup

Improper acquisition…

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Acquisition:

– This is the learning stage – when things are encoded -- noticing and attending to the information – Affected by physical factors (e.g., lighting, disguises, distance), limited time, and fear

Much can lead to a mistaken identity…

• Weapon-focus effect – An eyewitness’s diminished ability to subsequently identify a perpetrator when a weapon was used in a crime (Shaw & Skolnick, 1994)

Weapon-focus effect

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

Easterbrook Hypothesis

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Easterbrook (1959)

– Narrowing of attention during emotional events • Does this remind you of anything we mentioned during earlier class on classical conditioning?

False Memory Syndrome

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Kihlstrom (1996)

– Defines this syndrome as a condition in which a person's identity and interpersonal relationships are centered around a memory of traumatic experience which is objectively false but in which the person strongly believes

Improper storage…

• • Loftus and Palmer theory applies here Someone’s words can often distort memories