14 - Eyewitness Memory

Question 1

What is the misinformation effect?

Answer 1

Exposure to incorrect information about an event after it has occurred often causes people to incorporate this misinformation into their memories

Question 2

What are three ways to encounter post-event information?

Answer 2

1. Leading questions about the event (smashed/hit car)
2. Hearing about the event from the media (white van, snipers in blue car)
3. Hearing about the event from other witnesses

Question 3

Describe research that demonstrates how leading questions about the event can lead to misinformation?

Answer 3

Participants shown film of traffic accident

Asked how fast they were going when the cars smashed/hit each other

One week alter, participants in the smashed condition were more than twice as likely to recall broken glass, when there was none

Question 4

Describe research that demonstrates how hearing about an event through the media can lead to misinformation?

Answer 4

Participants shown pictures of shoplifting incident

Then read brief summary of the crime, which including some incorrect details

Participants incorporated the incorrect details from the summary into their memories

Question 5

What are the two types of co-witness information and what did the eyewitness survey reveal?

Answer 5

Direct transfer
Indirect transfer (through police officer)

Eyewitness Survey

• majority of witness’ report discussing event with a co-witness
• Main reason: providing information
• more witnesses reported they had been encouraged by the police to discuss event with co-witnesses

Question 6

What does the research on comparing ways to encounter misinformation reveal about type of informations effects?

Answer 6

Stimulus; crime video
1st delay; 1 week
Post-event information; leading questions, media report, indirect co-witness information, co-witness discussion, control
Results;
- no effect of post-event information type on memory accuracy for control
- For accurate information; direct and indirect co-witness MORE accurate
- For misleading information, direct and indirect co-witness LESS accurate

People really take on the information when it comes from a co-witness either indirectly or directly

Question 7

Research was conducted to see if informing people about the misinformation effect would mitigate co-witness information, what did it find?

Answer 7

Stimuli; crime video (two versions)
1st delay; 20 minutes
Memory elaboration: different-video group (misled), same-video group (not misled), no diffusion
2nd delay; 1 week
Warning (general, specific, none)
Individual memory task, free recall, recognition questionnaire and identification

Results;

• for misled items, misled ppts less accurate
• for neutral, misled ppts more accurate
• misled reported more accurate propositions and more misinformation.

Warning had no effect

Question 8

What are the main theories explaining the misinformation effect?

Answer 8

Modification of the Memory

• Alteration Theories
• Co-existence Theories

Social and Demand Facors
- Response Bias

Question 9

What do the alteration theories of misinformation believe?

Answer 9

Original information doesn’t exist because;

• vacant spot explanation: misinformation is accepted because individual failed to encode information
• overwriting explanation: post-event information overwrites original memory
• blend explanation: Ps encode misinformation as the original information, resulting in blend

Implications:

• try to prevent people from getting misinfomation in the first place
• warnings about misinformation doesn’t seem to work
• no matter how hard they try, they can’t access original correct information

Question 10

What do the co-existence theories of misinformation believe?

Answer 10

Both memory for the original event and misinformation are stored and each memory is capable of being recovered. Original memory is not replaced, but is less accessible than the subsequent misleading information.

Perhaps owing to; recency effect, retroactive interference (what we learn after the fact can make it difficult to access what we originally learned)

Implications;

• original memory trace is there, just need to ask the right questions to be able to access correct information.
• can never really say if a memory is there or not

Question 11

What do the social and demand factors of misinformation believe?

Answer 11

Response Bias in favour of post-event information

Due to recognition test procedure

• Ps who don’t remember/notice critical detail in the original event AND are not given any misinformation reply at change rate
• Ps who DO get misinforamtion, have no reason to doubt misinformation presented to them
• But, even when asked free recall some people still note misinformation

Question 12

What factors decrease susceptibility to misinformation effect?

Answer 12

They make a public statement about what they witnessed
There is less time between witnessing the event and presentation of misinformation
The misinformation blatantly contradicts what was originally witnessed
Source of the misinformation is not credible

They are forewarned they may encounter misinformation (but has to be told straight away)

Question 13

What factors increase susceptibility to misinformation effect?

Answer 13

Age (young and old)
Hypnosis
Suggestibility
Misinformation is repeated
Misinformation is peripheral

NOT SEX AND IQ

Question 14

What are the limitations of research on the misinformation effect?

Answer 14

Ethical constraints of laboratory research

Ecological validity of lab findings