THE FORMATION OF FALSE MEMORIES LOFTUS AND PECKRILL (1995)

Transcription

1 THE FORMATION OF FALSE MEMORIES LOFTUS AND PECKRILL (1995)

2 Bell Ringer Eyewitness Testimony Prior to viewing this clip, what is your opinion on eyewitness accounts? Why?

3 MEMORY Your memory is your mind s storehouse, the reservoir of your accumulated learning The persistence of learning over time through the storage and retrieval of information

4 MEMORY INFORMATION PROCESSING Encoding the processing of information into the memory system Storage the retention of encoded information over time Retrieval the process of getting information out of memory storage

5 Bell Ringer Think back to the last time you went to the grocery store. How well can you describe the person who was ahead of you in the check-out line? How many details do you remember about the person? Could you recognize them on the street if you passed this person? Watch this Ted Talk with our Elizabeth Loftus, our author!

6 PRO-ACTIVE INTERFERENCE It occurs when something you learned earlier (the old memory) interferes with your ability to create a new memory Example: You have been using a certain cell phone for a considerable time period. You are quite habituated with its functions and keys. And now you purchase new one and you initially find difficulty.

7 RETROACTIVE INTERFERENCE It occurs when new learning or new information interferes with the recall of something you learned earlier (the old memory) Example: You change your cell number and after some time you have memorized your new number, if you are asked to recall your previous number, you may not be able to recall it easily.

8 METHODOLOGY False memories... Yikes! SAMPLE: 3 males and 21 females Age range: 18 to 53 years Recruited by University of Washington students A pair of individuals a subject and the subject s relative Primarily parent-child pair or sibling pair The relative member of the pair had to be the one who had knowledge about childhood experiences of the subject

9 METHODOLOGY MATERIAL: A five-page booklet containing a cover letter with instructions for completing the booklet and schedule of interviews The booklet contained four short stories about childhood events of the subject provided by the relative Actually three of the stories were true One was false about child getting lost The order of events was always same in all booklets The false event was presented in the third position The relative member of the pair had to be the one who had knowledge about childhood experiences of the subject Each event was presented in a single paragraph Remaining page was left blank for the subject to reproduce his memory

10 METHODOLOGY EXAMPLE OF A FALSE EVENT: (for a 20- year old Vietnamese American woman who grew up in Washington) You, your mom, Tien and Tuan all went to the Bremerton K-Mart. You must have been five years old at the time. Your mom gave each of you some money to get a blueberry Icee. You ran ahead to get into the line first, and somehow lost your way in the store. Tien find you crying to an elderly Chinese woman. You three then went together to get an Icee.

11 METHODOLOGY Interviewed the relative to obtain 3 events that happened to the subjects between 4 to 6 years of age The stories were not to be family folklore or traumatic events Also, information about a plausible shopping trip to a mall or large departmental store was obtained Where the family would have shopped when the subject was five years old. Which members of the family usually went along on a shopping trip What kinds of stores might have attracted the subject s interests Verification that the subject had not been lost in a mall around age of five

12 METHODOLOGY Using the information false event was created that had following features: Lost for an extended period Crying Lost in a mall or large department store at about age of 5 Found and aided by an elderly woman Reunited with the family.

13 Reflective Article: We can implant entirely false memories 1.Divide out in your groups based on hair length. Longest hair=1; shortest hair=4 All ones will move to the side of the room to by the podium. All fours move to the side of the room by the windows. Based on your number, you will answer the following questions: 1. Repression is the idea that you hide memories away in your unconscious. To what extent do you agree with this idea of memory forgetting? 2. To what extent do you agree with the idea of motivated forgetting? If you tried hard enough, do you think you could forget a memory? 3. What do you think the effects of a drug that allows people to forget will do to our society? 4. Have you ever experienced a psuedomemory? In other words, remembered something that when you told, perhaps your parents, you found that this didn t really happen? Explain. After your groups answer the questions, you will return to your original group and share your responses. Each person in the group should have all four answers written down at the end.

14 Bell Ringer In New Jersey, Rules Are Changed on Witness IDs 1.Divide out in your groups based on hair length. Longest hair=1; shortest hair=4 All ones will move to the side of the room to by the podium. All fours move to the side of the room by the windows. Based on your number, you will answer the following questions: 1. Create an argument for why the law in New Jersey should not have changed. 2. Assess the impact you think the change will create when jurors decide the guilt of a suspect. 3. Develop an alternative plan to assess the reliability of eyewitness testimony prior to a jury hearing from the witness. 4. What do you think the maximum amount of passed time should before we must exclude eyewitness testimony?

15 METHODOLOGY Subjects were told that the study is about childhood memories and how and why people remember some things and not others. They were told to read the events in booklets and write what they remembered about each event. If event not remembered, they write I do not remember this. After completing the booklet, mailed back to the researchers

16 METHODOLOGY Subjects were called and scheduled for two interviews If convenient, interview would take place at university, otherwise over telephone First interview - one or two weeks after receipt of booklet Second interview one or two weeks after first interview Interviewers were 2 females

17 METHODOLOGY In 1 st interview, subjects were reminded of each event and asked to recall as much as they could. Later, subjects rated their memory for the event on a scale of 1 to 10. 1=not clear at all, and 10=extremely clear Subjects then rated the confidence on 5- point scale that if given more time to think, they would be able to recall more details 1=not confident, and 5=extremely confident

18 METHODOLOGY After 1 st interview, subjects were not to discuss events with relatives Subjects were told to try to remember more details for the next interview 2 nd interview was as same as 1 st interview, they recalled events, and rated on clarity and confidence scales. They were debriefed in the end and were asked to choose which of the 4 events was false Apologies for the deception and explanation why it was necessary

19 RESULTS Memory for true events: In total, there were 72 true events 49 out of 72 (68%) were remembered in booklet This percentage held constant in 1 st and 2 nd interview

20 RESULTS Memory for false events: Total 24 false events 7 out of 24 (29%) were remembered, either fully or partially in booklet Partial memories mean remembering parts of event + speculations about how and when it happened During 1 st interview, one subject claimed she did not remember this, dropping the number from 7 to 6 (25%) of the events were remembered fully or partially. In 2 nd interview, the percentage held constant

21 Bell Ringer Childhood false memories Create a set-up for an experiment that you would test to determine if you can plant false memories. What would you test? (In other words, what memory would you choose to plant in someone's head?) Discuss with your group and you will report your groups decision.

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23 RESULTS Number of words used to describe memories: The mean word length of descriptions of true memories was The mean word length of descriptions of false memories was 49.9 these findings are based on the descriptions of 7(29%) of the subjects who produced partial or full memories of false events in their booklets

24 RESULTS Clarity ratings for events: The clarity ratings for the false events were tended to be lower The mean clarity rating for the true events was 6.3 in both 1 st and 2 nd interview The mean clarity rating for the false events was 2.8 in 1 st interview and 3.6 in 2 nd interview

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26 RESULTS Confidence ratings: Confidence ratings were lower for false events. For true events, rating in 1 st interview was 2.7 and in 2 nd interview it was 2.2 For false events, it was 1.8 in 1 st interview and 1.4 in 2 nd interview.

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28 RESULTS When asked to choose false event after debriefing: 19 subjects correctly identified the false event as getting-lost memory.

29 CONCLUSION These findings reveal that people can be led to believe that entire events happen to them after suggestions to that effect. These findings provide an existence proof for the phenomenon of false memory information. Memory can be altered via suggestion. People can be led to remember their past in different ways and they can even be led to remember entire events that actually did not happen to them

30 Reflective Clive Wearing- Man without a memory