LongTerm Memory

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Long-Term Memory
Focusing on Memory Encoding

• Brandon Beltz
• Mar 9, 2005

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Lecture Outline

• Long-term memory
• Declarative (explicit)
• episodic
• semantic
• Nondeclarative (implicit)
• Memory Encoding
• Factors that help
• Rehearsal
• Organization of information
• Visual imagery
• Depth of processing
• Elaboration
• Mnemonic devices (an application of the previous
  factors)
• Emotional arousal
• Factors that do not help as much as we think
• Repetition
• Intention to learn
• Why do we encode information the way we do?
• Prior knowledge

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Memory The Big Picture
W. W. Norton
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Declarative versus Nondeclarative Memory

• Declarative (explicit)
• LTM knowledge that can be retrieved and then
  reflected on consciously.
• Knowledge can be declared verbally.
• Nondeclarative (implicit)
• Knowledge that can influence thought and behavior
  without any necessary involvement of conscious
  awareness.

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Memory The Big Picture
W. W. Norton
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Episodic versus Semantic Memory

• Episodic
• Autobiographical memory-- stores personally
  experienced events (e.g., your mothers maiden
  name).
• Semantic
• Stores general world knowledge (e.g., concepts
  and categories).

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Memory Encoding
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What Determines What We Encode in Memory?

• Factors that help
• Rehearsal
• Organization of information
• Visual imagery
• Depth of processing
• Elaboration
• Mnemonic devices (an application of the previous
  factors)
• Emotional arousal

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Rehearsal

• A deliberate recycling of STMs contents.
• Why do we rehearse information?
• Increases probability information will be
  transferred to long-term memory.

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Studies of Rehearsal and Serial Order Effects

• Primacy effect mostly dependent on of
  rehearsals
• the first items in a list get the best and most
  rehearsal.
• Rundus (1971)

Serial Order Effect
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Organization of Information

• The structuring or restructuring of information
  as it is being stored in memory.
• Example Category clustering experiment that
  follows.

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Remember the following words for later free
recall

• horse
• knife
• fork
• lion
• tiger
• spoon

• hour
• apple
• club
• tent
• flute
• snow

Did you organize the words in this list into
similar categories?
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How does organization of information relate to
chunking and recoding?

• We are able to re-organize separate pieces of
  information into a larger structure or hierarchy.
  
• How might this relate to you (students), me
  (instructor), and the information we encounter in
  this class?

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Visual Imagery

• The mental picturing of a stimulus that affects
  later recall or recognition.
• Study of visual imagery.
• Schnorr and Atkinson (1969)
• Participants studied paired word associates
• (e.g. dog-book)
• Methods of encoding
• Rote repetition
• Forming visual images of words.

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Paired associates study phase rote repetition
condition

• book-canoe
• rat-phone

• rose-sock
• corn-door

Remember these word pairs by repeating them in
your mind
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Paired associates test phase rote repetition
condition

• book-?
• rat- ?

• rose- ?
• corn- ?

What is the second word in the pair?
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Paired associates study phase visual imagery
condition

• book-canoe
• rat-phone

• rose-sock
• corn-door

Remember these word pairs and form a mental image
of the words during study
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Paired associates test phase visual imagery
condition

• book-?
• rat- ?

• rose- ?
• corn- ?

What is the second word in the pair?
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Visual Imagery Results

• Imagery condition did much better at remembering
  the second word when cued with the first word.

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Dual Coding Hypothesis(Paivio, 1971)

• Concrete words (book, canoe) can be stored twice
  in long-term memory, once as a word, and once as
  a visual image.
• Abstract words (justice, idea, cognition) can be
  retrieved in only one way.
• Hence, concrete words are remembered better than
  abstract words due to the dual coding of them.

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Depth of Processing

• Memory is determined by the manner of processing
  not by how long information stays in the system.
• Depth refers to the degree of semantic
  involvement.
• Craik and Lockhart (1972)
• Alternative to rehearsal and STM

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Studying Depth of ProcessingCraik and Watkins
(1973)

• The orienting task
• Is it an animal? dog
• Is it in upper case? TABLE
• In first question, dog requires semantic
  processing
• In second question, table does not.
• People will remember the word dog better than
  the word table.
• Deep processing (semantic) leads to strong LTM
  traces.
• Shallow processing leads to poor LTM traces.

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Challenges to Depth of Processing

• Is this a circular explanation for memory
  performance?
• Effects using recognition instead of recall.
• The Congruity effect (better memory for yes
  over no words, even if both were processed
  deeply).

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Elaboration

• Elaboration addition of extra material or
  details
• Elaboration Study
• Bradshaw and Anderson (1982)
• Participants heard sentence about a famous person
• Elaboration Conditions
• Original sentences only
• Some heard relevant information to original
  sentence
• Others heard irrelevant information to original
  sentence.

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Elaboration Study Results
Original Sentences Only
Irrelevant Elaboration
Relevant Elaboration
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Elaboration Study Results

• Elaboration has to be relevant to what you are
  trying to remember to improve deep processing and
  memory performance.

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Mnemonic Devices

• The Method of Loci
• (Dates back to Ancient Greece)
• The Peg-word Technique

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Three Mnemonic Principles

• Provide an organization for learning.
• By means of visual images and rhymes, which form
  durable and distinctive memory traces.
• Guide retrieval by providing effective cues for
  retrieving the information.

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The Method of Loci
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The Peg Word Technique
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Emotion and Memory

• Emotional arousal affects ability of recall
• Cahill (1995)
• Flashbulb memories
• September 11th examples
• What are some of your earliest memories?
• What feelings are associated with them?

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Enhanced memory associated with emotional
arousal(Cahill, 1995)

• Told two different stories (accompanied by
  slides) to participants
• Two stories were similar in beginning and end
• They differed in middle part
• Neutral story in middle
• Emotional arousal story in middle

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Emotional Arousal and Memory (Cahill, 1995)
Neutral Story Arousal Story
Shared lines in both stories
Different lines- Emotional arousal!
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Results Emotional Arousal and Memory (Cahill,
1995)
Stories differed in middle part
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Flashbulb Memories

• A very rich, very detailed memory that is encoded
  when something emotionally salient happens.
• Like the flash of a camera which enhances
  photographs.

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Studies of flashbulb memories

• Often test peoples memory of nationally salient
  events
• e.g. Kennedy assassination, Challenger explosion,
  Fall of the Berlin Wall, etc.
• People tested for accuracy of information
  surrounding event.
• What year did the Berlin Wall come down?
• People tested for accuracy of autobiographical
  information surrounding event.
• Where were you when you first heard about the
  Berlin Wall?
• The difficulty as a researcher is comparing
  flashbulb memory changes over the long-term.
• Where were you when you heard of 9/11?

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Impact of time and emotion for memories of Sep
11, 2001(Smith, et al., 2003)

• Conducted survey of Canadian undergraduate
  students 1 week and 6 months after Sep 11, 2001.
• Asked autobiographical questions.
• location, activity, informant, time, and the
  presence of others.
• Asked questions about details of the terrorist
  attacks itself.
• The time of day of the first attack in New York
• Total number of terrorists involved
• Name of the city and airport the two airplanes
  that struck the towers departed from.
• Temporally order the following six events the
  crash into the North tower, the crash into the
  South tower, the crash into the Pentagon, the
  fall of the South tower, the fall of the North
  tower, and the plane crash in Pennsylvania.
• Students rated how confident they were in their
  answers.
• Students rets how emotionally aroused were
  about event.
• e.g. Relatives involved etc.

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Results Impact of time and emotion for
memories(Smith, et al., 2003)

• Autobiographical memories and event memories are
  differentially influenced by traumatic events
  over time.
• Memory for Autobiographical details
• Unaffected either by emotional arousal or the
  passage of time.
• Memory for Event itself
• Arousal improves memory accuracy
• However, accuracy significantly declines over
  time
• Memory for autobiographical info more consistent
  than memory for event information.

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Other studies of flashbulb memories

• OJ Simpson Trial
• Shmolck, Buffalo and Squire (2000)
• Found that over time, memories do contain major
  distortions.
• Many details were reported, seemingly like a
  snapshot, but were incorrect.

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What Determines What We Encode in Memory?

• Factors that dont help as much as we might
  think
• Intention to learn
• Repetition of items

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Intention to Learn(Hyde and Jenkins, 1973)

• Does the fact a person has an intention to
  learn affect memory performance?
• Depth of processing study. Participants saw lists
  of words and were asked to process
• Shallow Determine whether the word had the
  letter a or q in it?
• Deep Rate the pleasantness of the word.
• E.g. daisy might have high pleasant rating,
  grave might have low pleasant rating.
• Afterwards participants were tested
• Intentional memory tests
• Inform subjects that they will be tested.
• Incidental memory tests
• Subject not told they will be test on materials
  they are dealing with.

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Depth of Processing versus Intention to
Learn(Hyde and Jenkins, 1973)
80 60 40 20 0
Percent Correct
Shallow Processing
Deep Processing
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Do you really believe a persons intention to
learn has little effect on memory?

• What are some possible confounds of this study?

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Repeated exposure to information

• All of us have been exposed to the U.S. penny
  thousands of times
• Penny recognition test
• (Nickerson Adams, 1979)
• Memory for the common penny quite bad.
• Less than half the people correctly identified
  its features.

On the heads side Does Lincolns head face
left or right? At the top does it say In God
We Trust or United States of America
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Repetition in short-term/ working
memory(Watkins, 1973)

• You will see a list of words
• Silently rehears the last word you heard that
  started with a g.

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Repetition in short-term/ working
memory(Watkins, 1973)

• radio
• giraffe
• nurse
• game
• dog
• nutcracker
• hotel
• squirrel
• giant
• rake
• stapler

Which g words did you see?
Increased number of intervening words increases
amount of time for repetition
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Repetition in short-term/ working memory

• In original experiment participants saw 27 lists
  with 21 words each.
• The subsequent memory tests were unexpected.
• Of course recall was low
• But one would think highly rehearsed words in
  lists would have better recall than less
  rehearsed items.
• Not the casethe time a word held in STM (and
  rehearsals) had little effect on LTM recall.

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Factors that dont help encoding as much as we
think

• There are many counter examples that show
  intention to learn and repetition do help
• However, it seems they help only in conjunction
  with the other factors we mentioned previously.

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Why Do We Encode Information as We Do?

• Prior Knowledge
• Reduces what we must remember
• Guides the interpretation of details
• Makes unusual things stand out

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Prior Knowledge Reduces What We Must Remember

• Use of Chunking Reduces Memory Load
• Study of expert chess players
• Chase and Simon (1973)
• Master level chess players and nonexperts asked
  to remember location of pieces on a chess board

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Prior Knowledge Chess Example

• Master players memory of location much more
  accurate
• Master players able to chunk pieces into larger
  meaningful units using their prior knowledge
• Helps reduce memory load

The red bishop is covered by the red knight
The red king is castled
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Prior Knowledge Chess Example

• However, in later studies, experts memory was no
  different than novices when the piece locations
  were illegal and did not fit standard
  chessboard templates
• Illustrates important role of relevant prior
  knowledge

Illegal chessboard
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Prior KnowledgeGuides the Interpretations of
Details

• Prior knowledge can be thought of as a set of
  related facts
• Facts can come in a packet known as a schema
  which can guide memory processes
• Schema A memory representation containing
  general information about an object or an event.
  It contains information representative of a type
  of event rather than of a single event
• Default value A characteristic that is a part of
  a schema that is assumed to be true in the
  absence of other information.
• Example unless one is told otherwise, one
  assumes that a dog is furry furriness is a
  default characteristic for dogs

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Prior KnowledgeGuides the Interpretations of
Details

• Schemas aid in interpreting ambiguities
• What does the following ambiguous paragraph refer
  to?
• The procedure is actually quite simple. First
  you arrange things into different groups. Of
  course one pile may be sufficient depending on
  how much there is to do. If you have to go
  somewhere else due to lack of facilities that is
  the next step, otherwise you are pretty well set.
  It is important not to overdo things. That is, it
  is better to do too few things at one time than
  too many. In the short run this may not seem
  important but complications can easily arise. A
  mistake can be expensive as well. At first the
  whole procedure will seem complicated. Soon,
  however, it will become just another facet of
  life. It is difficult to foresee any end to the
  necessity for this task in the immediate future,
  but then one can never tell. After the procedure
  is completed one arranges the materials into
  different groups again. Then they can be put into
  their appropriate places. Eventually they will be
  used once more and the whole cycle will then have
  to be repeated. However, that is a part of life.
• (Bransford and Johnson, 1972)

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Prior KnowledgeGuides the Interpretations of
Details

• In the previous paragraph accuracy was much
  improved if the subjects knew that the paragraph
  referred to washing clothes.

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Prior KnowledgeMakes Unusual Things Stand out

• Prior knowledge leads to expect what usually
  happens
• Knowledge about common situations postulated to
  be organized into scripts
• (Schank and Abelson, 1977)
• Script A type of schema that describes a series
  of events
• Example
• What to do in a restaurant
• Visiting the doctor
• Studies show that memory is best for
• Details that are not part of the script
• Details relevant to the goals of the script
• Bower, et al. (1979)

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Class announcement

• Much of the material of long-term memory will not
  be covered in the Ashcraft text.
• Additional readings for long term memory topics
• Chapters from Cognition The Thinking Animal,
  Willingham, 2004
• The readings are in my department mailbox which
  is located across the hall from room 2005 In
  David King Hall.
• Look for Beltz under the PhD students section.
• The readings are in a yellow folder marked psych
  317.
• Please return the readings to my mailbox as soon
  as you are finished copying them!
• There is a copy machine on the 3rd floor of David
  King Hall.