Week 4 Constructive Theories of Long Term Memory

When I was younger I could remember anything,
whether it happened or not.
--Mark Twain

Memory as a videotape recorder

Hypnotic Memory Retrieval

• Hypnotized subjects are told that the mind is much like a videotape. That they will be able to rewind the tape, freeze the frame, zoom in on details and so on.
• Produced some amazing successes (Reiser, 1980).
• Controled laboratory studies have produced mixed results. Increase in both hits and false alarms and increase in the confidence of false alarms.

Penfield(1969)

• Treating epileptic patients
• Used weak electric current to map brain function
• Found that applying current to certain parts of the brain produced what seemed like recollective experiences to patients.
• Sometimes these recollective experiences were quite vivid. One patient who claimed to be remembering a song from childhood stated, "...[I]t was not as though I were imagining the tune to myself. I actually heard it."

Memory as a jigsaw puzzle: Constructive Theories of Memory

Basic claims

• Our memories are far from perfect. Often times we forget things
• To make up for this deficit, we fill in gaps in our memory with what seems plausible
• While this is often useful it sometimes leads to errors.

Information sources used for memory construction

• Information retained from the original event.
• Prior Knowledge (Schemas)**
• What you learn later (Postevent information)**

Barlett(1932)

• Bartlett saw memory as a tool which people use to construct meaning.
• Thus memory does not simply passively record facts; rather memory combines fact and interpretation in a constructive way such that the two become indistinguishable.
• In some of Bartlett's research he had them listen to an unfamiliar story called War of the Ghosts and then later attempt to recall the story.
• He found that people's recall tended to show systematic distortions
  • Unfamiliar things dropped out altogether
  • Other things were elaborated on or extended
• Bartlett proposed that these systematic distortions reflected the use of schemas in storing and retrieving information.

Memory perspective as evidence for the constructive nature of memory

• Field memories versus observer memories
• Robinson & Swanson found that 75% of all people experienced at least some memories from the observer perspective
• In a sample of autobiographical memories from different stages of people's lives they found that close to half of all memories were observer memories.
• Observer memories must be constructions since they do not match the original perceptual input.

Schematic Memory Effects

Schema plus correction Models

• Not all information gets put into long term memory
• What is stored is a pointer to a schema plus any deviations from that schema
• This results in great economy of storage since all the details needn't be explicitly stored.

Evidence consistent with Schema plus correction models

• Predictions of Schema plus correction models
  • Memory for atypical actions should be extremely good because there are explicit tags indicating that they are true.
  • Memory for typical actions should be poor because they are not explicitly indicated. Rather the entire script is pointed to. Thus there should be alot of false alarms and only slighty more hits for typical information.
• Experiments by Graesser and others(c.f.Smith & Graesser, 1981)
  • Subjects listen to a story about some common event like going to a dentist.
  • The story mentions several actions typical of going to a dentist (like reading a magazine in the waitingroom) and several actions which are atypical of going to a dentist (like missing the spit sink).
  • On later tests subjects show better memory for the atypical actions and sometimes falsely recall typical actions which never happened.
• Occurs for more naturalistic events as well like memory for the actions of a professor giving a lecture(Nakumura, Graesser, Zimmerman & Riha, 1985), memory for objects in a room(Brewer & Treyens, 1981), memory for testimony given in court(Smith & Studebaker, 1996), memory for parts of objects(Lampinen & Faries, in prep).

Do Schemas influence the encoding of information or the retrieval of information?

• The influence of delay on errors(Dooling & Christiansen,1977)

  She was a problem child from birth. She was wild,
  stubborn and violent. By the time she turned eight she
  was still unmanageable. Her parents were very concerned
  with her mental health. There was no good institution for
  her problem in the state. Her parents finally decided to take
  some action. They hired a private teacher for her.

• Only half of the subjects were told that this story was about Helen Keller.
• Later subjects were presented sentences which some of which were not in the story but which were consistent with it being about Helen Keller:"She went on to help others overcome their handicaps.", "A book was written about her life.", "She eventually learned how to communicate."
• Subjects were either tested the same day they heard the story or one week later. There were more false alarms one week later than there were after only a day which is consistent with a view of schemas operating at retrieval.
• Time of schema activation: Reconstructive theories predict that schema consistent false alarms should occur whether the schema is activated before or after encoding.
  • Schema before condition: Subjects were told ahead of time that this story was about Helen Keller.
  • Schema after condition: Subjects were told right before the test that this story was about Helen Keller.
  • No Schema: Subjects were never told who this story was about.Test items
  • False alarms occurred whether the schema was presented before the story or after the story

Postevent information

Suggesting inconsistent event details: Loftus, Miller and Burns(1978)

PHASE I: Subjects watch color slides of an auto/pedestrian accident, in which a car stops at a sign before plowing into a pedestrian.


PHASE II: Subjects were asked a series of misleading questions including the critical questions...


Misleading: Did another car pass the red Datsun when it stopped at the yield sign?


Unbiased: Did another car pass the red Datsun when it stopped at the corner?


PHASE III: Subjects are given a forced choice test in which they choose between one of two slides. One alternative was the original slide which they saw in the slide presentation. The other slide was an identical slide in which the stop sign was replaced with a yield sign.

Suggesting the presence of non-existent items: Loftus(1975)

PHASE I: Subjects presented fast paced film of a car travelling down a country road. The country road did not contain a barn


PHASE II. Subjects were asked a series of questions including one of these two.


Misled condition: "How fast was the white sports car going as it passed the barn on the country road?"


Neutral condition: "How fast was the white sports car going as it travelled along the country road?"


PHASE III. Test: Question: Was there a barn on the country road?


Memory Blending: Loftus (1977)

PHASE I: Subjects see a film in which a green car drives past an accident scene.


PHASE II. Subjects were asked a series of questions including one of these two.


Misled condition: "Did the blue car that drove past the accident have a ski rack on the roof?"


Neutral condition: "Did the car that drove past the accident have a ski rack on the roof?"


PHASE III. Test: Subjects are asked to pick the color of several items (including the car) out of a color wheel. Subjects tended to pick a bluish-green color.

Do false memories seem real?

Anecdotal accounts

• Loftus & Doyle (1992)
• Neisser (1982)
• Piaget

Flashbulb Memories

• Flashbulb Memories are characterized as being vivid, almost perceptual memories of one's personal circumstances upon hearing of a surprising and consequential event (Assassination of Kennedy, Space Shuttle Explosion, Personal Tragedy)
• Several studies have demonstrated that flashbulb memories sometimes contain inconsistencies (Neisser & Harsch, 1992; McCloskey, Wible & Cohen, 1988)
• Since flashbulb memories are vivid almost perceptual memories then vivid almost perceptual memories must sometimes be in error.

Source monitoring accounts of human memory.

• How do people distinguish between what they really saw and what they imagined.
• Johnson & Raye (1981) has suggested the reality monitoring framework to account for how people do this.
• Memory includes
  • Perceptual details
  • Memory for cognitive operations
  • Memory for contextual information
  • Memory for emotions
• Subject decides whether memory is of a real experience by comparing the number of perceptual, contextual, emotional and cognitive details. Large numbers of perceptual details indicate real experience. Large number of cognitive operations indicate created memory.
• Errors happen
  • Loss of detail. Memory has few details of any type but information still seems familiar. So you have to make a guess about its source.
  • The wrong kinds of details. Memory for imagined event contains perceptual details. Leads you to believe it is a memory for an actual event.

Source Monitoring errors in Postevent Information Studies

• Zaragoza & Lane (1994)
  PHASE I: Subjects watch slides of an office theft
  

  PHASE II: Later they read a summary of the slides
  

  MISLED: A calculator is mentioned
  

  CONTROL: No calculator is mentioned

  
  

  PHASE III: Subjects take a special source monitoring test. For each object on the test they must decide:
  

  Was it in the slides?
  Was it in the summary?
  Was it in both?
  Was it in neither?
  

  Saying either that the calculator was in the slides or that it was in both the slides and the summary would be source monitoring errors.
  

  MISLED subjects make more of these source monitoring errors than do CONTROL subjects.
  

  Lindsay(1990): Opposition Technique
  PHASE I: Subjects watch slides of an office theft
  

  PHASE II: Later they read a summary of the slides
  

  MISLED: A calculator is mentioned
  

  CONTROL: No calculator is mentioned

  
  

  PHASE III: Subjects take a test in which they are given a list of objects and they must decide for each object whether or not it was in the slides. Before they do so they are given special instructions
  

  Opposition instructions: The narrative included some objects which WERE NOT in the slides. Any object on this test which was mentioned in the summary DEFINITELY WAS NOT in the slides.
  

  Results: MISLED subjects are more likely to endorse items which were not in the slides even though they were explicitly told that any test item mentioned in the summary definitely was not in the slides.

Recollective Memory Paradigm (Tulving , 1985)

• Recognition memory is a two component process in which subjects can make correct recognition judgments in two distinct ways (Mandler, 1980; Jacoby & Dallas, 1981).
  • Conscious Recollection
  • Familiarity
• Subjects in these experiments are asked to distinguish between these two types of conscious experience when making their memory judgements. They are asked to indicate for each response whether they are making a remember or know judgement.
  • Remember judgements: Reflect conscious recollection.
    An association
    An image
    Position of the item
    Physical characteristics of item
    Personal significance
    A thought one had at the time
    
  • Know judgements: Decision made on some other basis, although theoretically know judgements are thought to reflect feelings of familiarity.

False Recollective Experiences

• Roediger & McDermott(1995)
  • Subjects were presented with lists of thematically related words. For instance, participants might listen to a list such as the following:
    butter
    food
    eat
    sandwich
    rye
    jam
    milk
    flour
    jelly
    dough
    crust
    slice
    wine
    loaf
    toast
    

  • After several such lists participants were asked whether they heard a related word "BREAD" which had never actually been presented.
  • Roediger found a false recollection rate of between 40-60% for these critical lures.

• Lampinen & Faries (1995)
  • Subjects listen to a story about a guy named Jack who performs several activities
    example: Scene #5 Taking his dog to the vets

    When Jack finished with his apartment, it was almost 4:00 and Jack had an appointment to take his dog Al to the vet for shots. Jack got Al's leash and whistled for Al to come. Al was an old dog and got up slowly and walked over to Jack and they walked out the door. Jack loaded Al into the car and drove the three blocks to the vet's office. They entered the office and Jack confirmed his appointment with the receptionist. Jack waited in the waiting room for the receptionist to call him. Jack showed the lady next to him all the tricks Al could do. When the receptionist called him, Jack took Al into the examination room where he met Dr. Jaccard. Dr. Jaccard examined Al, checking his teeth and listening to his heart. Dr. Jaccard took out a hypodermic needle and gave Al a shot as Jack held him down. Once they were done Jack went back out to the waiting room and paid the bill. Jack thought the receptionist was attractive, so he flirted with her for a few minutes. In the waiting room there were a lot of other animals, the most unusual one being a lizard. After Jack paid the bill, he went back home.

  • Later subjects are given a YES/NO recognition test for actions from the story. For each action they are asked to indicate whether the action was stated in the story.
    Typical Stated: Dr. Jaccard checked Al's Teeth.
    Atypical Stated: Jack showed the lady next to him all the tricks Al could do.
    Typical Unstated: Jack patted Al on the head to calm him down
    Atypical Unstated: Al had to stay at the vet's overnight

  • If they say it was stated they are asked whether they "Remember", "Know" .

  • Results: About 20% of all false alarms for typical actions were categorized by subjects as remember judgements. Also hits for atypical information were especially likely to be remember judgements.
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