MEMORY: factors effecting accuracy of EWT - misleading information

Key study : Loftus and Palmer 1974 - experiment 1

procedure

• 45 students were shown 7 films of different traffic accidents

• after each film the particpants ere given a questionnaire which asked them to describe the accident and then answer a series of specific questions about it

• one critical question - about how fast were the cards going when they hit one another?

• one group of participants were given the verbs smashed, collided, bumped or contacted in the place of the word hit.

• this critical question was a leading question because it suggested the answer that a participant might give

findings

• results suggested that leading questions affect response given by participants

• - smashed average speed estimate = 40.8mph

• contacted being the lowest = 31.8mph

Loftus and palmer 1974 - experiment 2

procedure

• leading question may bias a participants response or may actually cause information to be altered before it is stored

• tested this - a new set of participants was divided into 3 groups and shown a film of a car accident lasting 1 minute

• again asked questions about speed

• participants were then asked to return one week later when they were asked a series of 10 questions about the accident

• including another critical question - did you see any broken glass?

• there was no broken glass in the film but presumably, those who thought the car was travelling faster might be more likely to think that there would be broken glass

findings

• leading question did change the actual memory a participant had for the event

• smashed verb - yes=16 no=34

• hit verb - yes =7 no=43

• control - yes=6 no=44

post event discussion conformity effect

memory of an event may also be altered or contaminated through discussing events with others and/ or being questioned multiple times

Fiona gabbert and colleagues 2003 - partipcants were in pairs where each partner watched a different video of the same event so that the each viewed unique items

pairs in one condition were encouraged to discuss the vent before each partner individually recalled the event they watched - 71% of witnesses who had discussed the event went in to mistakenly recall items acquired during the discussion

post event discussion - repeat interviewing

• each time eyewitness is interviewed there is a possibility that comments form the interviewer will become incorporated into their recollection of events

• it is also the case that an interviewer may use leading questions and thus alter the individuals memory for events.

• this is especially the case when children are being interviewed about a crime

what is eyewitness testimony?

• the evidence provided in court by a person who witnessed a crime, with a view to identifying the perpetrator of the crime

eyewitness memory - extra info

3 stages

• witness encodes into LTM details of the event and the persons involved. encoding may be only partial and distorted, particularly as most crimes happen very quickly, frequently at night and sometimes accompanied by rapid, complex and often violent action

• witness retains the information for a period of time - memories may be lost or modified during retention (most forgetting takes place within the first few minutes of retention interval) and other activities between encoding and retrieval may interfere with the memory itself.

• the witness retrieves the memory from storage. the presence or absence of appropriate retrieval cues

AO3 supporting evidence

there has been considerable support for research not he effect of misleading information

for example, Loftus conducted a memorable study involving a cut out of bugs bunny (braun et al 2002). College students who had Disneyland as children were asked to evaluate advertising material about Disneyland containing misleading information about bugs bunny (not a Disney character) or Ariel (not introduced at the time of their childhood.

Participants assigned to the bugs or Ariel groups were most likely to report having shaken hands with these characters than the control group (no misleading information)

this shows how powerful misleading information can be in creating an inaccurate (false) memory

AO3 - EWT in real life

loftus’ research suggested that EWT was generally inaccurate and hence unreliable, but other researchers have criticised her research for its lack of ecological validity

lab experiments such as those carried out by Loftus may not represent real life because people don’t take the experiment seriously and/ or they are not emotionally aroused in the way they would be in a real accident.

Yuille and Cutshall 1986 also found that witnesses to an armed robbery in Canada gave very accurate reports of the crime four months after the event despite initially being given two misleading questions -

suggesting that the influence of misleading questions may be less significant in real life scenarios in EWT than Loftus’s research suggests especially when events are emotionally significant.

AO3 - individual differences

a criticism of research investigating EWT concerns individual differences of witnesses

an eyewitness typically acquires information from two sources, from observing the event itself and from subsequent suggestions (misleading information).

a number of studies have found that, compared to younger subjects, elderly people have difficulty remembering the source of their information, even though their memory fro the information itself is unimpaired. As a result, they become more prone to the effect of misleading information when giving testimony

this suggests that individual differences, age in particular, are an important factor when assessing the reliability of EWT.