PSY 368 Human Memory Semantic Memory cont. Reconstructive Memory

PSY 368 Human Memory

Semantic Memory cont.Reconstructive Memory

Announcements

• Data from Experiment 3 due April 9 (Mon)• Experiment 3 Report due April 16

• If you missed the details of the Experiment, I included them again at the end of this lecture

• Optional reading for Monday is posted on Blackboard site (Media Library: Optional Readings):• Einstein, et al (2005) Prospective Memory article • Dr. Dawn McBride will be our speaker

Exam 2• … was hard!

• The mean % was 67.7%.

• The range of scores was from 41% to 92%

• So when interpreting your score, think “good job” if in the 80s and 90s and ‘okay’ if in the mid 60s to 70s.

• It was harder than I expected, so I am thinking about offering an additional, one-time-only extra credit option. I’ll get the details hammered out this weekend (probably another article and focus questions kind of thing)

Summary of Semantic Memory

• Semantic memory = knowledge• Some evidence for a separate system• Early models suggested hierarchical network - cognitive

economy• Results suggest no strict hierarchy or cognitive

economy• But current network models suggest loosened hierarchy

(spreading activation)• Other ideas: compound cues, prototypes, exemplars,

schemas

• What kind of impact is there of this organization on retrieval of memories?

• Alternatives to Spreading activation models• Examine mechanisms of priming and extent to explain of priming

effects

• Make predictions about performance in memory retrieval tasks

• Generally they are mathematical models that predict sets of results based on strength of cue associations

• There are a lot of models to choose from (see “optional chapter” for details)• In SAM (Search of Associative Memory), a matrix of association among cues

and memory traces, which are called images• Cues are assembled in a short-term store, or probe set, which is the match against all

item in memory

• In TODAM (Theory Of Distributed Associative Memory), to-be-remembered items are represented as vectors of features• Sum of vectors, convolution

• The resulting scalar can be mapped into familiarity and, in turn, into response time and accuracy

Compound Cue Models

Semantics as Exemplars

• Instance theory: each concept is represented as examples of previous experience (e.g., Medin & Schaffer, 1978; Hintzman, 1986)

dog

• Make comparisons to stored instances• Typically have a probabilistic

component• Which instance gets retrieved for comparison

Semantics as Prototypes

• Prototype theory: store feature information with most “prototypical” instance (Eleanor Rosch, 1975)

chaircouc

h

tabledesk

1) chair1) sofa2) couch3) table::12) desk13) bed::42) TV54)

refrigerator

bed

TV

refrigerator

Rate on a scale of 1 to 7 if these are good examples of category: Furniture


• Prototype theory: store feature information with most “prototypical” instance (Eleanor Rosch, 1975)

• Prototypes: • Some members of a category are better instances of the

category than others• Fruit: apple vs. pomegranate

• What makes a prototype?• Possibly an abstraction of exemplars

• More central semantic features• What type of dog is a prototypical dog?

• What are the features of it?

• We are faster at retrieving prototypes of a category than other members of the category


• The main criticisms of the theory• The model fails to provide a rich enough representation of conceptual

knowledge • Vague: How can we think logically if our concepts are so vague?

• Flexibility: How do our concepts manage to be flexible and adaptive, if they are fixed to the similarity structure of the world?• features have different importance in different contexts

• what determines the feature weights

• Individual differences: If each of us represents the prototype differently, how can we identify when we have the same concept, as opposed to two different concepts with the same label?

• Does membership = similarity?: Why do we have concepts which incorporate objects which are clearly dissimilar, and exclude others which are apparently similar?

• Before we start talking about constructive (integrative) and reconstructive memory, let’s do a demonstration.

• I will present you with a long list of words, which I’ll later test your memory for.

Demo

queen

crown

castle

England

throne

ruler

prince

royalty

power

hill

valley

climb

summit

top

molehill

peak

plain

glacier

butter

food

eat

sandwich

rye

jam

milk

flour

jelly

thread

pin

eye

sewing

sharp

point

prick

thimble

haystack

steal

robber

crook

burglar

money

cop

bad

rob

jail

shoe

hand

toe

kick

sandals

soccer

yard

walk

ankle

Name as many state capitals as you can

(1) Vermont

(2) New York

(3) North Carolina

(4) Alaska

(5) California

(6) Texas

(7) Maine

(8) Missouri

(9) Colorado

(10) Florida

(11) Washington

(12) Virginia

(13) New Mexico

(14) Oregon

Write Y or N for each word below to indicate if you saw it in the list (Y) or not (N)

(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

• Count up your correct Yes responses


Critical theme words - False memories• Count up your false Yes responses• Pay particular attention to the ones in

brown

Demo

• The task that we just did is called the DRM task• (Deese, 1959; Roediger & McDermott, 1995)

• It is designed to create false memories • We’ll return to discussing this procedure later in

the lecture

Remembering larger chunks

• How do people acquire and remember ideas• Not individual sentences, but integrated

semantic ideas

Semantic Integration• How do people acquire and remember ideas• Not individual sentences, but integrated semantic ideas

Bransford & Franks (1971)

• Each idea grouping consisted of 4 separate simple propositions (a simple relationship between 2 concepts)• The ants in the kitchen at the sweet jelly that was on the table.

• The ants were in the kitchen• The ants ate the jelly• The jelly was sweet• The jelly was on the table

• Whether subjects responded OLD or NEW was not related to whether the sentence was old or new

• Confidence in memory was NOT related to accuracy

• Subjects “remembered” seeing complex sentences that captured the meaning of the simple sentences• The ants in the kitchen ate

the sweet jelly on the table

• The simple sentences were integrated into one sentence that captured the story’s gist

Semantic IntegrationBransford & Franks (1971)

• A composite memory • We store separate bits of info together to

the extent those bits are related to each other (semantic relatedness)

• Using what we already know (schemata & scripts) to understand new experiences in a conceptually-driven fashion

• Drawbacks: May lead to distortions when we try to remember and may not be technically accurate

• Advantages: Content accuracy is enhanced and thus we can remember complex, meaningful events

Bransford & Franks (1971)

Semantic Integration

• Scripts and schemas:• Knowledge is packaged in integrated

conceptual structures. • Scripts: Typical action sequences (e.g., going to the

restaurant, going to the doctor…)• Schemas: Organized knowledge structures (e.g.,

your knowledge of cognitive psychology).

• Enable us to predict events, make sense of unfamiliar circumstances, organize our own behavior

• Act as filters to perception & recall

Schema Theory

Schema Theory

?The mind takes in the impoverished sensory input and matches it to a schema derived from past experience. The schema is used to ‘fill in the blanks’ in the input and to give it a meaning. Your ability to ‘see’ what’s there depends on your having an appropriate schema.

• Restaurant Script

Schema Theory

• 73% of respondents reported these common events when going to a restaurant:• Sit down• Look at menu• Order• Eat• Pay bill• Leave

• 48% also included:• Enter restaurant• Give reservation

name• Order drinks• Discuss menu• Talk• Eat appetizer• Order dessert• Eat dessert• Leave a tip

Bower, Black, and Turner (1979)

• People also tend to fill in missing details from scripts and schemas if they are not provided (as long as those parts are typical).

Schema Theory


Schema Theory

• When people see stories like this:Chief Resident Jones adjusted his face mask while anxiously surveying a pale figure secured to the long gleaming table before him. One swift stroke of his small, sharp instrument and a thin red line appeared. Then an eager young assistant carefully extended the opening as another aide pushed aside glistening surface fat so that vital parts were laid bare. Everyone present stared in horror at the ugly growth too large for removal. He now knew it was pointless to continue.


Schema Theory

• And you ask them to recognize words that might have been part of the story, they tend to recognize material that is script or schema typical even if it was not presented.

• Which of the following words appeared in the story?Chief Resident Jones adjusted his face mask while anxiously surveying a pale figure secured to the long gleaming table before him. One swift stroke of his small, sharp instrument and a thin red line appeared. Then an eager young assistant carefully extended the opening as another aide pushed aside glistening surface fat so that vital parts were laid bare. Everyone present stared in horror at the ugly growth too large for removal. He now knew it was pointless to continue.

• Scalpel• Assistant• Nurse• Doctor• Operation• Hospital

• When people are told the script or schema that is appropriate before hearing some material they tend to understand it better than if they are not told it at all or are told it after the material.

Schema Theory

Rocky slowly got up from the mat, planning his escape. He hesitated a moment and thought. Things were not going well. What bothered him most was being held, especially since the charge against him had been weak. He considered his present situation. The lock that held him was strong but he thought he could break it. He knew, however, that his timing would have to be perfect. Rocky was aware that it was because of his early roughness that he had been penalized so severely - much too severely from his point of view. The situation was becoming frustrating; the pressure had been grinding on him for too long. He was being ridden unmercifully. Rocky was getting angry now. He felt he was ready to make his move. He knew that his success or failure would depend on what he did in the next few seconds.

PrisonWrestling

Other

?

Schema Theory

Every Saturday night, four good friends get together. When Jerry, Mike, and Pat arrived, Karen had just finished writing some notes. She quickly arranged the cards and stood up to greet her friends at the door. They followed her into the living room and sat down facing each other. They began to play. Karen's recorder filled the room with soft and pleasant music. Her hand flashed in front of everyone's eyes and they all noticed her diamonds. They continued for many hours until everyone was exhausted and quite silly. Jerry made his friends laugh as he theatrically took a bow, entertaining them all with the wildness of his playing. Finally, Karen's friends went home.

Playing music

Playing cards

Other

?

Schema Theory

Schema Theory

• Potential “down-side” of schemata• Memory is not a direct record of what was witnessed• What is encoded and how it is retrieved depends on:

• Information already stored in memory• How this info is understood, structured and organized

• Reconstructive retrieval• Refers to schema-guided construction of episodic memories

that alter and distort encoded memory representations.• Reconstruction levels by losing details, assimilates by

normalizing to fit expectations, and sharpens by embellishing details.

• Bartlett (1932) • Read unfamiliar story “War of the Ghosts”• Then the subjects “re-told” the story• Looked at progressive changes in what

subjects remembered about the story• Remembered differently depending on

expectation

Schema Theory

• Bartlett (1932)

Schema Theory

• Bartlett (1932)

Schema Theory

• Omissions:

• Poor recall for many of the details (specific names, or events)

• Minor events were omitted (recall for main plot and sequence of events was not too bad)

• Shorter than the original

• Normalizations:

• Tendency to add and alter the stories to make them more conventional or reasonable (top-down processing)

• When recalled by UK PPs:• Some details

changed• More consistent

with ‘Western’ schema

Proportions of text propositions recalled after varying retention intervals (adapted from Bergman & Roediger, 1999)

Schema Theory

• Conclusions:• Human memory for this type of

material is NOT reproductive• A highly accurate, verbatim recording of an event

• Rather, it is reconstructive• Altered during BOTH storage and retrieval• Combining elements from the original material

with existing knowledge

• Bartlett (1932)

Reconstructive Effects

• Knowledge about a theme of a passage improves peoples memory for the passage• Providing a theme can also distort recall

Sulin & Dooling (1974)• Subjects read identical stories about:

• Carol Harris (fictitious) or Helen Keller• “Problem child from birth, wild, stubborn, violent…”

• Asked to identify if sentences were the same, nearly the same, or different from the story

Reconstructive Effects

• Knowledge about a theme of a passage improves peoples memory for the passage• Providing a theme can also distort recall

Sulin & Dooling (1974)• Subjects who read the Keller paragraph rated

sentences as the same more frequently when they matched their existing knowledge about Keller• Even though the original paragraph did not contain such

info• 1 week later: “Was she deaf, dumb, and blind?”

• 5% of Harris group said yes• 50% of Keller said yes

• The Keller groups’ “memory” of these stories was influenced by their knowledge of Keller

False Memories

• Memory is reconstructive• Errors of omission

• Transience, absent-mindedness, blocking

• Errors of commission • Misattribution, suggestibility, bias

• Why do we study them?• Like perceptual illusions, can give better

understanding of “normal” processes• Eyewitness testimony credibility• Recovered memories issue

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


• Interference paradigm• Information presented after an event can lead to

distortions• Post-event information can be incorporated into the

original memory• Misinformation effect

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

• Repeated exposure to misinformation strengthens memory about the misinformation

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


• 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


• 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


• Effect of leading questions on recall

• 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


• Loftus, Miller, & Burns (1978)• Saw slides of car turning to hit a pedestrian• Saw stop or yield sign• “Did another car pass the red Datsun while it was at

the ____ sign?” (consistent vs. inconsistent)• Recognition test for correct photo of car with sign

• Effect of misleading information on recall


• Loftus, Miller, & Burns (1978)• Misinformation effect: People incorrectly claim to

remember the misinformation (the yield sign) Immediate

Consistent 75%Inconsistent 40%

2 week delayInconsistent 20%

• Effect of misleading information on recall

Misattribution & Misinformation

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

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

memory

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 stop sign because it was actually in the picture?

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

questions?

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

Overconfidence in Memory

• 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)

Overconfidence in Memory

• We are surprisingly unaware of how unreliable our memory can be and overly confident in the accuracy of our 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)


Studied list words - Accurate memories


Critical theme words - False memories

DRM Paradigm

• The lists rely on properties of semantic association

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

• Activation of a concept spreads to related concepts in the network

DRM Paradigm

• The lists rely on properties of semantic association

thief foot bread king mountain needlesteal shoe butter queen hill threadrobber hand food crown valley pincrook toe eat castle climb eyeburglar kick sandwich England summit sewingmoney sandals rye throne top sharpcop soccer jam ruler molehill pointbad yard milk prince peak prickrob walk flour royalty plain thimblejail ankle jelly power glacier haystack

DRM Paradigm

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

• 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)

Spreading Activation Model

Example

power

castlejewel

ruler

prince

throne

royalty

England

crown

queen

king

Theoretical explanations

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


• Activation-source monitoring• Memories for imagined events are attributed

to other source• Participants think they studied items they

thought about• Increased familiarity


• Fuzzy-trace theory• Information is encoded in two formats

• Gist - meaning• Verbatim - details

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

• Scripts

- We use knowledge about known events to fill in missing info


Individual differences

• 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

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

• Therapies included…• Hypnosis (uses imagery, suggestive

questioning, & repetition)• Guided Imagery (for now, just imagine that

you were abused by your father)• Body Work (recovering memories from your

muscles)• Drug Therapies (sodium amytal, mostly)

Recovered Memories• 1990’s: A big spike in cases of people in therapy

recovering memories of childhood sexual abuse • Often early abuse (e.g., infancy)

• “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

• San Diego Reader: Ads identifying symptoms of abuse• Headaches, depression, eating disorders, urinary tract

infections

Recovered vs. false memories

• Several techniques to recover memories also can create false memories• Hypnosis• Repeated retrieval attempts• Guessing (The courage to heal)• Imagination• Repeated exposure to stories of abuse

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

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

• 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


• Stimuli: 4 categories• Drinks, Weapons, Fish, Fruits• Six exemplars from each category• Write out category and exemplar on index cards

Experiment 3

• The full list of 24 items is in the detailed instructions

• Subjects: find 3 willing participants


• Procedure: 4 phases• Study phase: subs will study all categories and exemplars

• Shuffle all of the cards, read Study phase 1 instructions, present each card to subject for 3 seconds in random order

Experiment 3


• Procedure: 4 phases• Practice phase: subs will attempt to remember some of

the studied items (half from 2 of the categories) by coming up with exemplars with cues (category and first letter)• Give practice phase recall sheet to subject, Read practice

phase instructions to subject, give subs category and first letter (see ordered list in detailed instructions) and give them 15 secs to practice it before moving to next item

• “drinks – v”, “weapons – s”, “drinks – r”, “weapons – r”, “drinks – g”, “weapons – t”

Experiment 3


• Procedure: 4 phases• Distractor phase: complete a city generation task

• Read distractor phase instructions, Give distractor US Cities Task sheet

Experiment 3


• Procedure: 4 phases• Test phase: free recall of all studied items (by

category)• Read test phase instructions, give recall test response

sheets (1 for each of the 4 categories)• Give 30 seconds for recall for each category

Experiment 3


• Scoring:

Experiment 3

Subject #1 Data

Practiced # recalled

% (divide # by 6)

Non-practiced # recalled

% (divide # by 6)

Control # recalled

% (divide # by 12)


• Scoring:

Experiment 3

Subject #1 Data

Practiced # recalled 3

% (divide # by 6) 3/6 = 50%


% (divide # by 6)

Control # recalled

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


• Scoring:

Experiment 3

Subject #1 Data


% (divide # by 6) 3/6 = 50%


3

% (divide # by 6) 3/6 = 50%

Control # recalled

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

Don’t count “beer”, not

on list


• Scoring:

Experiment 3

Subject #1 Data


% (divide # by 6) 3/6 = 50%


3

% (divide # by 6) 3/6 = 50%

Control # recalled 6

% (divide # by 12) 6/12 = 50%“drinks – v”, “weapons – s”, “drinks – r”, “weapons – r”, “drinks – g”, “weapons – t”

Don’t count “beer”, not

on list

Documents

PSY 368 Human Memory Semantic Memory cont. Reconstructive Memory