PSY 368 Human Memory

PSY 368 Human Memory

Reconstructive Memory cont.

Announcements

• Experiment 3 Report due April 16 • If you missed the details of the Experiment, I

included them in the lectures last week

• Interaction of Episodic and Semantic Memory (Exp 3) (Download detailed instructions form Blackboard)

• Modification of Anderson, Bjork, & Bjork (1994)• (see Blackboard Media Library Optional Readings to

download a pdf of this paper if you want to read more)

• Question: Can the retrieval of some items impact the retrieval of others?• e.g., Suppose that you are studying for a test. You

decide to study half the material. Does studying half the material have an impact on the half of the material that you didn’t study?

Experiment 3

• Interaction of Episodic and Semantic Memory (Exp 3)• Scoring:

Experiment 3 Results

Class Avg. Data

Practiced # recalled 4.6

% (divide # by 6) 77.2%

Non-practiced # recalled

2.9

% (divide # by 6) 47.7%

Control # recalled 6.4

% (divide # by 12) 53.5%“drinks – v”, “weapons – s”, “drinks – r”, “weapons – r”, “drinks – g”, “weapons – t”

Don’t count “beer”, not

on list

• Interaction of Episodic and Semantic Memory (Exp 3)• Scoring:


ANOVA resultsF(2,118) = 59.49

comparisons:

Practice vs control

t(59) = 8.9, p < .05

Non-practice vs control

t(59) = -2.0, p < .05

General conclusions: Evidence for “retrieval induced forgetting.” Items within the same category as those studied, that weren’t studied were worse than controls. May be due to inhibition of items following spreading of activation.

*

*

• Interaction of Episodic and Semantic Memory (Exp 3)


General conclusions: Evidence for “retrieval induced forgetting.” Items within the same category as those studied, that weren’t studied were worse than controls. May be due to inhibition of items following spreading of activation.

beer

ale

rumbourbon

whiskey

ginvodka

False Memories

• Memory is reconstructive• Sometimes we may “remember” things that never

actually happened• And for these “false memories” we may be as confident in

them as we are with actual memories• We are surprisingly unaware of how unreliable our

memory can be and overly confident in the accuracy of our memories

• Overconfidence comes from two factors:• Source Memory: Memory of the exact source of the information

(original event, later information, or general knowledge of the situation)

• Processing Fluency: The ease with which something is processed or comes to mind (remember “sleep” too easily for you to have imagined it)

False Memories

• Why do we study them?• Real World Implications

• Perceptual illusions, can give better understanding of “normal” processes

• DRM procedure• Eyewitness testimony credibility• Recovered memories issue

False Memories

Roediger & McDermott (1995) study• DRM paradigm (Deese, 1959; Roediger &

McDermott, 1995)• Creates false memories in the lab• DEMO (like the task that we saw Schacter give

Alan Alda)

False Memories• A week ago I gave you a long list of words to remember

(1) haystack (13) airplane (25) rye (37) thief(2) sandals (14) flow (26) melody (38) hill(3) fright (15) pretty (27) spider (39) power(4) weather (16) ankle (28) music (40) butter(5) sharp (17) awake (29) girl (41) foot(6) hot (18) doctor (30) bread (42) father(7) creek (19) frame (31) sweet (43) jagged(8) king (20) jelly (32) stream (44) door(9) thread (21) top (33) soft (45) throne(10) shoe (22) jazz (34) river (46) money(11) winter (23) sugar (35) jail (47) mountain(12) tide (24) needle (36) glacier (48) steal



Studied list words - Accurate memories



Studied list words - Accurate memoriesCritical theme words - False memories

False Memories

Roediger & McDermott (1995)

• Recall: ~ 40% recalled “sleep”

• Recognition: Remembering the lure (sleep) during recall strengthened participants memories of the lure during recognition• Participants claimed to

“remember” the lure rather than merely “know” it had been on the list

DRM Paradigm

• How strong is this effect?• Recent studies indicate it is very robust

• Replicated may times

• Explicit warnings fail to eliminate the effect• May see a reduction in the effect

• As the number of list items increases, rate of false recollection increases (Robinson & Roediger, 1997)

• Young children are less susceptible to DRM paradigm• Have not yet developed associations

• But they are easily influenced by suggestive questioning

• Older adults are more susceptible to the illusion• Rely more on gist than verbatim traces

False Memories

• Look at the original list (different order now)

• So what is going on in the DRM task?• The lists rely on properties of semantic association

• Words that are similar in meaning or co-occur in language are associates

False Memories

• So what is going on in the DRM task?• Two main theoretical accounts

• Activation/Monitoring Theory• Fuzzy Trace Theory

• Status of the debate: mixed results, with each theory having some support

False Memories

• Activation-Source Monitoring Theory: Two components• Part I. Activation

• Lure is consciously or unconsciously activated• Activation is automatic • High activation results in false recollection

power

castle

jewel

ruler

prince

throne

royalty

England

crown

queen king

• Part II. Source Monitoring• Memories for imagined

events are attributed to other source• Participants think they studied items they thought about

• Increased familiarity

False Memories

• Fuzzy-Trace Theory• Information is encoded in two formats in parallel

• Gist – meaning based representation• Longer lasting representations

• Verbatim – details • Are not as well preserved

• More sensitive to interference effects

• List memory = verbatim + gist• Lure memory = gist only

• The verbatim memories for all items may not be there so rely on gist, which may include the lure (since it is consistent with the general gist)

Eyewitness Testimony

• Eyewitness Testimony• Reconstructive memory

• Schema driven errors

• Effect of leading questions


• Persuasiveness • Most persuasive form of evidence

• Eyewitnesses believed ~80% of the time (Loftus, 1983)

• Juries cannot tell the difference between an accurate and an inaccurate witness• Accurate witness believed 68% of time• Inaccurate witness believed 70% of time

Type of Evidence

% guilty votes

Eyewitness testimony

78

Fingerprints 70

Polygraph 53

Handwriting 34

Eyewitness Testimony• Persuasiveness

• Juries cannot tell the difference between an accurate and an inaccurate witness

• Wells et al. (1998)• Studied 40 people who were convicted but later cleared

by DNA• In 90% (36) of the cases, there was false eyewitness

identification• Rattner (1988)

• Studied 205 wrongfully convicted defendants• 52% were due to inaccurate eyewitness testimony

• Brandon and Davies (1973)• Described 70 cases of people wrongfully convicted due

to inaccurate eyewitness testimony


• Persuasiveness • Experimental studies

• Buckhout (1975)• Simulated crime on a TV newscast• 2,145 callers• 14.7% were accurate

• Buckhout (1974)• Staged assault on professor in front of 141

students• 7 weeks later, students shown line-up of six

photographs• 40% identified attacker• 36% identified bystander• 23% identified person not there


• What do witnesses report?Attribute % Reporting % Accurate

Gender 99.6 100

Height 91.2 44

Clothing (upper body) 90.8 58

Clothing (head) 89.6 56

Build 84.4 57

Weapon 76.4 71

Clothing (pants) 73.6 53

Age 62.4 38

Type of speech 46.8 84Fashsing, Ask, & Granhag (2004)


• Schema Driven Errors• Witnesses to crimes filter information during

acquisition & recall• Their schematic understanding may influence how

info is both stored & retrieved• Distortions may occur without the witness realizing,

based on things like:• Past experiences

• Assumptions about what usually happens

• Stereotypes & beliefs about crime & criminals


• Experimental Evidence: Interference paradigms• Information presented after an event can lead to

distortions• Post-event information can be incorporated into the

original memory• Misinformation effects

• Repeated questioning about an event can enhance recall of certain details and induce forgetting of others (also increases confidence in memory of the event)

• Repeated exposure to misinformation strengthens memory about the misinformation

• Are even found when participants are warned that misleading information might be presented


• Effect of leading questions on recall• Leading questions introduce new information • Leading info may activate wrong schemas in witness‘

mind• Consequently, witness may recall events incorrectly

• Most affected by leading Qs when:• Witness believes questioner knows more than them• Witness does not realize they may be misled• Leading information is peripheral, not central• Leading information is not blatantly incorrect


• Effect of leading questions on recall

Loftus & Palmer (1974)• Showed film of car accident• Estimated speed• How fast were the cars going when they ____ into each

other? (smashed, hit, collided, etc)• ‘Smashed’ led to higher speed estimates

• Did you see a/the broken headlight?• ‘The’ produced more affirmative (incorrect)

responses

Smashed 40.8 mphCollided 39.3 mphBumped 38.1 mphHit 34.0 mphContacted 31.8 mph


• Loftus, Miller, & Burns (1978)• Saw slides of car turning to hit a

pedestrian• Either saw stop or yield sign

• Effect of misleading information on recall

• Asked questions including:• “Did another car pass

the red Datsun while it was at the ____ sign?” (consistent vs. inconsistent)


• Loftus, Miller, & Burns (1978)

• Effect of misleading information on recall

Consistent “… while it was at the stop sign?”

Inconsistent) “… while it was at the yield sign?”

Consistent “… while it was at the yield sign?”

Inconsistent) “… while it was at the stop sign?”

AccuracyImmediate

Consistent 75%Inconsistent 40%

2 week delayInconsistent 20%

• Recognition test for correct photo of car with sign

Misattribution & Misinformation

• Genuine alteration for the original memory may be only one part of the memory distortion explanation

• Three important effects:• Overconfidence in the accuracy of the memory• Source misattribution• Misinformation acceptance

• Source Misattribution• The inability to distinguish whether the original

event or some later event was the source of the information (misremember what we have experienced)

• Did I remember the word “sleep” because it was actually in the list ?

OR• Because I thought about the word when I heard the

list?


• Misinformation Acceptance:• Accepting additional information as having

been part of an earlier experience without actually remembering that information (form memories on the basis of suggestion from some other source)

• Do I remember the car speeding because it was?

OR

• Because the policeman said it was?

• Tendency grows stronger as more time elapses


Recovered Memories

• A person remembers a traumatic event from many years ago

• The memory was “repressed”, but is now recovered in therapy• Intentional forgetting of painful or traumatic

experiences• Little empirical evidence for this type of

forgetting (could have the opposite effect)

Recovered Memories

• In 1986, Nadean Cool, a nurse’s aid in Wisconsin, sought therapy from a psychiatrist to help her cope with her reaction to a traumatic event experienced by her daughter

• Psychiatrist used hypnosis and other suggestive techniques to uncover buried memories of abuse that Cool herself had experienced

Recovered Memories

• Cool became convinced that she had repressed memories of• having been in a satanic cult• eating babies• being raped• having sex with animals• being forced to watch murder of her 8-year-old friend

• Cool came to believe that she had more than 120 alter personalities: children, adults, angels, duck

Recovered Memories

• Cool eventually came to believe that false memories had been implanted

• Cool sued psychiatrist for malpractice

• in March, 1997, after 5 weeks of trial, her case was settled for $2.4 million

Recovered Memories

• Increasing numbers of people believe that they were sexually abused as children, but repressed the memory until it was later recovered, often with help of therapist• 1990’s: A big spike in cases of people in therapy recovering

memories of childhood sexual abuse • “Courage to Heal”: General premise that we were all abused as

children, we need help to remember • Even if there is no evidence and we have no recollection of being abused

• Therapies included…• Hypnosis (uses imagery, suggestive questioning, & repetition)

• Guided Imagery (for now, just imagine that you were abused by your father)

• Drug Therapies (sodium amytal, mostly)

Recovered memories

• Could some of the recovered memories be false?

• If it is possible to create false memories, then some recovered memories might be false

• Stakes are high• must find justice and safety for victims of abuse;

must prevent perpetrators from harming others• must protect individuals from false charges that

can destroy their lives

Recovered memories• Recovered Memory

• all memories recovered in therapy should be taken seriously

• False memories are rare• If raise doubts, betray children and

support pedophiles

• Pseudomemory• Memories recovered in therapy should

be viewed with skepticism• False memories can be manufactured

by naïve/unscrupulous therapists• Many false accusations

Recovered memories

• Loftus’s “shopping mall” studies• asked subjects to try to remember childhood

events that had been told to researchers by their parents, older siblings, or other close family members

• 3 events were real; 1 event (getting lost in a shopping mall at age 5) was false

• 29% “remembered” false event

Recovered memories• Hyman and colleagues (reported in Loftus,

1997)• asked college students to recall childhood

experiences told to the researchers by their parents• each subject given one false event (either an

overnight hospitalization for a high fever and ear infection or a birthday party with pizza and a clown)

• during first interview, no one “remembered” false event

• during second interview, 20% “remembered” false event

Recovered memories

• McNally (2003) – review of several studies

• Identified 4 groups• Repressed memory• Recovered memory• Continuous memory• Control

Recovered memories

• McNally (cont.)• No differences in terms of personality traits between

continuous & control• Repressed scored higher than all other groups in

terms of negative affectivity• Repressed also reported more dissociative & PTSD

symptoms• Repressed & recovered scored higher in terms of

fantasy proneness

Recovered memories

• Recovered are more likely than control to develop FM in laboratory paradigms

• Clancy et al. (2002)• Ss reported being abducted by aliens• Exhibited robust FM effects

Recovered memories

• Brief Summary• Both extreme positions of “children always lie” and

“children never lie” are wrong• Most children do recollect accurately most of what

they have seen or observed• Some children will say something happened when

it did not• Like adults, children can be influenced to report an

event in a certain way, depending on the frequency of suggestions and the insistence of the person making them

Documents

PSY 368 Human Memory