Weird Memory Effects Kimberley Clow [email protected]

Weird Memory Effects

Kimberley Clow

[email protected]

http://instruct.uwo.ca/psychology/130/

Outline

• Reproductive Memory• Schemas

– Scripts

• Technical vs. Content Memory• False Memories• Repressed / Recovered Memories• Flashbulb Memories

Context Effects on Comprehension

• Earlier words prime proper interpretation of later words.– A common example of semantic priming.

• Primed– The kids’ first arithmetic lesson taught them

to count– The vampire was disguised as a handsome

count.

• Ambiguous Target– We had trouble keeping track of the count

Memory is NOT Exact!

• Reproductive Memory– A highly accurate, verbatim recording of an event

• Reconstructive Memory– Remembering by combining elements of

experience with existing knowledge

• In “The Princess Bride”, does Inigo tell Vizzini– You say that so often, I do not think it means

what you think it means– You keep using that word, I do not think it means

what you think it means

The Seven Sins of Memory

Bartlett’s War of the Ghosts• English students told a Native Indian

story• Memory for the story tested across time

– Omissions and normalization

• Results indicated that memory is reconstructive– Leveling

• making story simpler

– Sharpening• overemphasizing certain details

– Assimilating• changing details to fit what we think

Scripts

• What is your Restaurant script?– What happens

first?– And then?– And then?

Recognition

• Which of the following sentences was/were shown earlier?– The ants were on the table– The ants ate the jelly on the table– The old car pulled the trailer– The car climbed the steep hill

Technical vs. Content Accuracy

• Technical Accuracy– Recalling or recognizing exactly what

was experienced– Generally quite poor

• Content Accuracy– Recalling or recognizing the meaning

or content of what was experienced– Generally quite accurate

Recall

Car Accident

Loftus & Colleagues

• Estimate how fast the cars were going– When they “hit”

each other– When they

“smashed” each other

• Did you see the broken glass?

Why Does This Happen?

• Possible Explanations– Memory Impairment– The Response Bias

Explanation– Source Misattribution– Misinformation

Acceptance

Lost in the Mall

• Can you produce false memories through suggestion?– Asked to write about 4

memories• 3 real• 1 false (lost in mall)

– When told one was incorrect, picked one of the real memories

Lost Again

• Replicated on a group of people– What memories did people remember?

• 7 out of 24 remembered the false event

– How are the events remembered?• True memories described more• True memories rated more clear• False memories’ clarity increased over

time

– Can they choose the false memory?• 19 out of 24 figured out which was false• Process of elimination?

One Person’s False Memory...• “I vaguely, vague, I mean this is very vague, remember the

lady helping me and Tim and my mom doing something else, but I don't remember crying. I mean I can remember a hundred times crying..... I just remember bits and pieces of it. I remember being with the lady. I remember going shopping. I don't think I, I don't remember the sunglasses part.“

• "Well, it can't be Slasher, 'cause I know that he ran up in the...the chimney and I know that that cat got smashed and I know that we got robbed so it had to be that mall one.”

• "..I totally remember walking around in those dressing rooms and my mom not being in the section she said she'd be in. You know what I mean?"

Individual Differences

• Some people are more susceptible to misinformation than others– 7 out of 24 participants

• People high at risk for misinformation acceptance have– Poor general memory– High scores on imagery vividness– High empathy scores

Recovered Memories of Abuse

• A person remembers today, that 20 years ago, someone sexually abused them

• Traumatic memory was repressed and is now recovered– often under hypnosis in therapy

• Validity of recovered memories?• Empirical evidence for Freudian

repression?

Model of Recovered Memories?

Questions

• Is there evidence for repressed memories?– Much evidence that emotional events

are remembered better, not forgotten• Post-traumatic stress disorder

– Are these memories real or false?

• If there is repression, how does it differ from normal forgetting?

Evidence for Suppression?• Learned 40 unrelated

word pairs– ordeal-roach

• Respond Condition– Think of the word paired

with ORDEAL…

• Suppression Condition– Do NOT think of word

paired with MEASURE…

• Memory for target words decreased with the number of suppressions

Evidence?• Most cases are unclear

– Susan Nason murder• Eileen Fanklin: “I remember my father did it.”• George Franklin denies it and no evidence

links him

• Research reports 4 cases with reasonably good evidence that– A memory for abuse was recovered– The remembered event actually

happened– The event was previously forgotten

Recovered Memories

• Recovery Experiences– Sudden– Startling– Emotional– Initiated by related retrieval cues

• encoding specificity?

• Forgetting– May have been over-estimated– Prior remembering not as emotional

Counter Example• Adults recall of horrific abuse at hands

of Satanists– Murder, torture, sexual abuse, eating babies

• FBI could find no evidence– Dissociative Identity Disorder (DID)?– Repressed memory?

• Therapists used highly suggestive techniques– drugs, hypnosis, suggest that there might

be non-remembered abuse

• Therapy led to false memories?

Physically Possible?

• A possible physiological explanation of repression– Stress release of glucocorticoids (steroid

hormones)– Glucocorticoids kill hippocampal neurons– Hippocampus brain area related to memory

• Hippocampus reduced in abused vs. non-abused women– Same for post-traumatic stress disorder– BUT no direct evidence links glucocorticoids

to repression of traumatic memories.

To Sum Up

• Repressed Memories– More questions, than answers– Child abuse and sexual assault are big

problems that are very traumatic• Some evidence that memories of such abuse can

be forgotten and then recovered

– Memories can also be inaccurate or manufactured

• Especially when under hypnosis or otherwise being given suggestions or directed questions

– Can’t tell if a memory is true or false without independent corroboration

Consequences of Memory Effects• Think of how all of this might affect the

courts, and specifically eye witness testimony– Schema effects, false memories, repressed

memories, recovered memories

• Memory is suggestible: – people’s memory can be altered and

influenced by the knowledge they have when they encounter the information, and by the information they encounter afterwards

• Is there anything we can do to minimize these effects?

Cognitive Interview• Encourage eyewitness to produce her own

memory cues and minimize direct questions • Get her to mentally recreate the context of

the crime– environmental and internal (e.g., mood state) info

• She should report everything she can remember– even if info is fragmented

• Alter how the info is reported– List details in various orders– List details from various perspectives

Flashbulb Memories• Flashbulb memories are

– Vivid– Detailed– Long-lasting– Memories we will “never

forget”– Personally meaningful

• Personal Examples– Your first date– The death of someone

close to you

Princess Diana

Six ‘Canonical’ Categories• Write an account of a flashbulb

memory– Place

• where were you?

– Ongoing event• what were you doing?

– Informant• who told you / how did you find out?

– Affect in others – Own affect– Aftermath

Accuracy of Flashbulb Memories

• Neisser & Harsch (1992)– Ask people to remember

what they were doing when they first heard about the Challenger shuttle explosion

– Asked them again 2½ years later

– Measured the similarity of both memory reports

• Same memory reported very differently over time

January, 1986

• “I was in my religion class and some people walked in and started talking about the [explosion]. I didn’t know any details except that it had exploded and the school teacher’s students had all been watching, which I thought was so sad. Then after class I went to my room and watched the TV program talking about it and I got all the details from that.”

September, 1988

• “When I first heard about the explosion I was sitting in my freshman dorm room with my roommate and we were watching TV. It came on a news flash and were we both totally shocked. I was really upset and went upstairs to talk to a friend of mine and then I called my parents.”