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									Section 5. Memory

                    1. What is memory?

                         memory subsystems
                         memory processes

                    2. Memory subsystems

                         sensory memory
                         short-term (working) memory
                         long-term memory

                    3. Memory processes

                         levels of processing theory
                         amnesic syndrome/LTM subsystems

                    4. Representation of information in memory

                         analog vs. propositional representation

                    5. Mnemonics

                    Terms to know for this section


                          Reisberg - pp. 123-167 (memory structures), 168-210 (memory
                processes), 394-439 (visual memory), 256-303 (theories of memory
         organization), 304-345 (concepts), 211-255 (memory problems)
5.1 What is memory?

                 Functional definition: Memory is the retention of potentially usable
                 information over some period of time.

                 Memory subsystems - organization of memory into component parts

                       sensory memory
                       short-term memory
                       long-term memory

                 Memory processes - the activities that occur in memory

                       encoding - transduction

                 retrieval - relationship to encoding
5.2 Memory subsystems

                  The spatial metaphor for memory - items in memory are like objects located
                  in a space that must be searched for retrieval to take place.

                  Problem - If we search memory to retrieve information, why is it sometimes
                  so easy to say that we don't know something? (Would it not be necessary to
                  search everywhere in memory to confirm that we did not know something?)

                  Characteristics of memory subsystems -

                        capacity - how much information?
                        duration -how long does the information last?
                        representation - what kind of information is retained?
                        information loss - how does forgetting occur?
                        decay/interference (retrieval failure)

                  The modal (3-store) model of memory (Atkinson & Shiffrin, 1968)
5.2 continued

                1. Sensory memory

                     high capacity
                     short duration
                     uncoded, precategorical representation
                     information loss through interference

                Sperling' s (1960) experiments - visual sensory memory - iconic memory
5.2 continued

                2. Short-term memory (STM)

                        limited capacity - 7+2 chunks (Miller, 1956)
                        short duration - limited by rehearsal?
                        visual/auditory/etc. codes
                        information loss through interference

                interaction between sensory information and information from long-term

                chunk - a meaningful unit of information



                        visual STM (deGroot, 1965) - expert vs. novice chess players
                        phonological STM - Conrad (1964) - visual letter confusions are
5.2 continued

                3. Long-term memory (LTM)

                      unlimited capacity?
                      unlimited duration?
                      abstract, highly-organized representation
                      information loss due to retrieval failure
                      importance of rehearsal

                Evidence for the distinction between STM & LTM: Recall task; stimuli =
lists of

                interference task / rate of presentation manipulation

                serial position curve

                      primacy effect
                      recency effect

                Control processes - rehearsal, encoding, etc.

                Rundus & Atkinson (1970) - Rehearsal processes in free recall: A
                procedure for direct observation
         Rehearsal was the primary mechanism considered for the transfer of
         information from STM to LTM within the context of the modal model.
         & Atkinson utilized a verbal protocol in which subjects spoke aloud while
         learning a list of words that were to be recalled later. They showed that
         from the beginning of the list received more rehearsals than items from later
         in the list. Except for items at the end of the list, the number of rehearsals
         was correlated with the number of words recalled.
5.2 continued

                Criticisms of the modal model -

                     over-simplified - suggested that STM and LTM were each unitary
                     memory stores
                     role of rehearsal exaggerated

                Revisions to the modal model -

                Working memory (Baddeley & Hitch, 1974; Baddeley, 1986)

                augmented version of STM (based, in part, on neuropsychological
                evidence) -

                     modality-free central executive
                     articulatory loop (phonological store + articulatory production
                     visual-spatial sketch pad
5.3 Memory processes

                  Alternatives to the modal model assume a unitary store that is equivalent to
                  LTM and in which STM is equivalent to temporarily activated regions of
                  Thus, this type of model uses an activation metaphor. In addition, less
                  emphasis is placed on rehearsal as a mechanism for adding information to
                  LTM. As an alternative, more emphasis is placed on how subjects encode
5.3 continued

                1. How does the type of encoding affect the retrieval of information?

                levels of processing theory (Craik & Lockhart, 1972)

                      the level or depth of processing of information affects its
                      deep processing creates more robust memories than shallow

                shallow processing -
                Is the word in capital letters?

                deep processing -
                Would the word fit in the sentence? "He met a ___ on the


                In general, recognition memory performance was best (80%) for words that
                received deep processing whereas performance was worst (20%) for words
                that received shallow processing.

                Problems with levels of processing theory -

                      what level of processing does the orienting task utilize? How can
                      depth be assessed independently of memory performance?
                      relation between orienting task and memory task (Morris, Bransford,
                      & Franks, 1977 - semantic/rhyme encoding task; standard/rhyme
                      recognition tasks).
5.3 continued

                2. What happens when we remember something?

                1. Retrieval cues

                retrieval of information is based on the concept of retrieval cues

                What is a retrieval cue? …anything that could serve to activate relevant or
                associated information in memory

                Sometimes the cues are supplied to you, as in a recognition memory task
                (such as multiple choice exam). In that case, in that case you are assumed to
                require only some type of decision process to evaluate the information
                evoked by the cues.

                Alternatively, you have to supply the cues yourself, as in a recall task (such
                an essay exam). Here you must supply both retirival cues and evaluate the
                relevance of the information evoked.

                2. Encoding specificity principle (Tulving, 1982)

                the similarity between the information available at the time of encoding and
                the time of retrieval determines memory performance

                +similarity(encoding; retrieval) —> +memory

                      state-dependent learning (mood / drugs)
                      physical context (Godden & Baddeley, 1975) - wet vs. dry learning,
                      wet vs. dry testing
         3. Limits on the use of recall and recognition task

         doctrine of concordance (Tulving, 1989)

         Tacit assumption of many memory researchers that generally there is
         similarity "…between what people know, how they behave and what they
         experience. Thus conscious awareness is required for, and therefore
         accompanies, the acquisition of knowledge, or its retrieval from the
         store; retrieved knowledge guides behaviour, and when this happens,
         people are aware of the relation between the knowledge and the behaviour."
5.3 continued

                3. Amnesia and LTM subsystems

                Evidence from cognitive neuropsychology may be useful when considering
                memory structures and processes.

                Background information…

                      syndrome - a group of symptoms that collectively characterize a
                      specific condition or disease
                      amnesic syndrome (source - Korsakoff' s syndrome, head injuries,
                      & strokes)

                - anterograde amnesia generally present (a lack of memory for events after
                the trauma)

                - retrograde amnesia sometimes present (a lack of memory for events
                before the trauma)

                - amnesics generally have normal intelligence

                - generally intact STM

                - patients can usually learn certain things after the onset of amnesia

                What abilities do amnesics retain? (residual learning capacity)

                      most have good STM performance
                      most can learn to do tasks involving motor skills (but may be slower
                      learning than normals).

                Patient H.M. & broken drawings
     amnesics are susceptible to perceptual priming (repetition priming) -
     conscious awareness vs. performance

Theories of amnesia and memory must account for the abilities that
amnesics have lost and those that they retain.
5.3 continued

                Theories of amnesia and memory must account for these effects.

                Theories of memory and amnesia

                1. episodic vs. semantic memory (Tulving, 1972)

                      episodic memory - contextual memory (autobiographical knowledge)
                      semantic memory - factual knowledge that is independent of the
                      setting in which it was originally learned

                Originally, amnesics were believed to have an impaired episodic memory
                system but an intact semantic memory system.

                Are episodic & semantic memory really two separate memory processes?
                Probably not. Amnesics usually exhibit intact episodic and semantic
                for events learned prior to their amnesia.

                2. declarative vs. procedural memory (Cohen & Squire, 1980)

                      declarative memory - "knowing what"; includes episodic and
                      procedural memory - "knowing how"; performance of skilled actions
                      that do not require conscious awareness of recollection

                Cohen & Squire (1980) argue that amnesics have an impaired declarative
                memory but an intact procedural memory.

                However, 1) some amnesics are able to acquire declarative knowledge, 2)
                most tasks incorporate a mix of declarative and procedural memory.

                3. explicit vs. implicit memory (Schacter, 1987)

                      explicit memory - information available to conscious recollection
                      implicit memory - information unavailable to conscious recollection;
                      not usually tested in traditional measures of memory

                Support from experiments - compare recall/recognition w/ word fragment
                completion/perceptual performance

                      normals (Jacoby & Dallas, 1981)
                      amnesics - performance is often close to normal in implicit memory
                      tasks whereas performance is generally worse than normal in explicit
           memory tasks


           descriptive rather than explanatory
      Conclusion? No one theory of memory accounts for all aspects of memory
      performance in amnesics and non amnesics. Nor is it likely that memory
      be neatly dichotomized as in these theories. Instead, memory is more like a
      series of integrated systems that contains some of the characteristics of the
      theories described here.
4. Representation of information in memory

                     Basic questions

                           What is a representation?
                           In what form is information represented in memory?
                           How is information organized so it can be efficiently used?

                     A representation re-presents or stands for something. It is a transformation
                     of information in one form to another form that preserves characteristics of
                     the original information.

                     Understanding the representation and processing of information are the two
                     basic goals of cognitive psychology.

                     Fundamental characteristic of all representational systems - there is less
                     information contained in the representation than in the thing being

                     Internal representations (Mental representations)

Propositions                                    Analog
1. Discrete symbols                             1. No discrete symbols
2. Explicit, needs symbol for relation          2. Implicit, no separate symbol for relation
3. Clear rules of combination for types of      3. No clear rules of combination or symbol
   symbol                                          types
4. Abstract                                     4. Modality-specific
5.4 continued

                Propositions vs. imagery

                Imagery - analog representation based on visual information; manipulation
                of visual information

                      mental rotation (Shepard et al.)
                      image scanning (Kosslyn et al.)

                Propositions - a language-like representation of an event. e.g., predicate

                      Predicate (arguments); e.g., ON(BOOK, TABLE)

                Does one form of representation have priority over other forms? Can one
                form of representation be reduced to another form?

                Pylyshyn' s criticisms of imagery

                      Images can' t just be 'pictures in the mind' s eye.' e.g., If an image has
                      a missing part, it is usually a meaningful part that is missing. This is
                      necessarily true of a picture.
                      If the 'mind' s eye' perceives images, what kind of images does it use?
                      …an infinite regression.
                      Images can be reduced to propositions. (images ® propositions)
                      Results from imagery experiments are due to demand characteristics.

                Kosslyn' s response

                      The idea that images are the same as pictures is a 'straw man' .
                      Propositional accounts of image data are cumbersome.
                      Images have distinct characteristics that make them different from
                      propositional representations.

                Kosslyn' s theory/model of imagery

                1. images are represented in a special spatial medium that has the following

                      limited extent of medium
                      area of highest resolution at centre
                      medium has 'grain' that obscures fine detail in small images
                      once an image is generated it begins to fade
2. Imaginal information is often linked to corresponding propositional

3. Generating images involves both imaginal and propositional information.

Evidence for Kosslyn' s theory/model

      experimental - e.g., image tracing task (granularity)
      neuropsychological - e.g., dissociation between imaginal and
      propositional information
5.4 continued

                Concept organization

                Why do we have concepts?

                      cognitive economy
                      generalization (recognition of novel things )
                      recognition of the relationship among instances

                Theories of conceptual organization

                1. Defining-attribute view (Classical view)

                Basically, a concept has defining attributes that determine the members of a
                concept. Defining attributes are also known as properties or features.

                      the meaning of a concept is the conjunction of a set of attributes
                      each attribute is singly necessary and jointly sufficient for an item to
                      be considered a member of a concept

                      explanation for singly necessary and jointly sufficient:

                             singly necessary = each characteristic must be present
            for the object to belong to the category
            jointly sufficient = only these characteristics (and no
            others) are required for the object to be considered a
            member of the category


     definition of a bachelor - male, unmarried, adult

     Is Mr. Smith a bachelor

            age (beyond adulthood) unimportant
            size unimportant
            hair colour unimportant

     clear-cut boundaries exist between items that are members of the
     concept and those that are not members
     all members of a concept are equally representative
     concepts are nested within superordinate concepts

A model of the defining-attribute view

Collins & Quillian (1969) semantic network

     hierarchical organization

     characteristics as defined above
     hierarchy is searched in response to inquiries about concept
     membership (search times are related to hierarchical distance)
     hierarchy is searched in response to inquiries about concept
     attributes (search times are related to hierarchical distance)

Supporting evidence…

     sentence verification task
     "Is a canary a bird?"faster than "Is a canary an animal?"
     "Does a canary fly?"faster than "Does a canary have skin?"
Problems with the defining-attribute view

     some attributes are more important for determining concept
     membership than others
           Feature listings for 2 concepts
     all members of a concept are not treated equally (typicality)
             Typicality ratings for birds (Rips, Shoben, & Smith,
      difficulty in determining the defining attributes of concepts (family
              Family resemblance analysis (Rosch & Mervis, 1975)
      concept membership is not always clear-cut (fuzzy boundaries)

predictions based on the nesting of concepts are not always confirmed (e.g.,
"Is a chicken a bird?"vs. "Is a chicken an animal?")
5.4 continued

2. Prototype theory

Designed to account for the problems associated with the defining attribute
model, such as typicality effects and fuzzy concepts (compare with work on
prototype theory in perception, section 4).

What is a prototype? A representation that captures the central tendency of
a set of similar items. It can be a) a summary description that is an
abstraction of many instances, or b) a collection of the 'best instances' of a

      there is no set of necessary and sufficient attributes
      concept boundaries are fuzzy
      instances are graded according to typicality
      concept membership is defined by similarity to the concept' s

Supporting evidence…

      apparent universality in the categorization of colours
      typicality ratings are good predictors of classification times
      typical concept members are listed first
      children generally learn about typical concept members first
      typical members tend to serve as cognitive reference points
      family resemblance scores can be calculated and typical members
      tend to have the highest scores

Are some levels of abstraction in prototype theory more important than

Rosch et al. (1976)

      specific objects - slotted screwdriver, Robertson screwdriver, Phillips
      screwdriver, etc.
      basic level - screwdriver
      superordinate level - tool

Individuals tend to use basic level category terms.

Tanaka & Taylor (1991) - Object categories and expertise: Is the basic level
in the eye of the beholder?

Problems with prototype theory

      not all concepts have prototype characteristics - deals best with
      concrete concepts, not abstract concepts
      does not incorporate information about the relationship among
      concepts (pets & fish; pet fish)

does not account for the coherence of concepts - Why do members of a
concept group together? It is not just similarity - we can form arbitrary
concepts (women, fire, & dangerous things; things in a yard sale, etc.).
5.4 continued


                How is information about individual concepts combined?

                How does the collective organization of information about individual
                concepts allow us to deal with everyday situations?

                schema - structured cluster of concepts (plural schemas or schemata);
                coined by Bartlett (1932)

                Early work on schema - Bartlett

                Subjects read story with non-Western construction (War of the Ghosts);
                recall story at later date. Subjects impose a Western organization on the
                information contained in the story.

                Subjects' recall was affected by their expectancies; memory was
                reconstructed according to past experiences.

                Characteristics of schema

                      schema consist of relations, variables/slots, and values
                      relations can be of the form 'is-a,' 'eat,' 'cause,' etc.
                      variables contain other schema or concepts
                      values are the instances that fit the variables
                      schema contain general knowledge that can used in many specific
                      situations (e.g., 'restaurant schema' )
                      slots may have default values

                Theories of schema organization

                Schank & Abelson' s script theory

                A script is a type of schema that describes the actions that are part of
                stereotypical events.

                e.g., restaurant script

                                                          specific actions

                                                          walk into restaurant
                                                          look for table
                                         decide seat location
                                         go to table
                                         sit down

                                         get menu
                                         look at menu
                                         choose food
                                         server arrives
                                         order given to server
                                         order given to cook
                                         wait, talk!
                                         cook prepares food


script organization allows the efficient use of cognitive resources

criticisms - unprincipled (ad hoc); inflexible
5.4 continued

                Implications of schematic/reconstructive processes for memory

                  1.gist vs. verbatim recall
                  2.John Dean' s memory
                  3.eye-witness testimony - Loftus
                  4.enhancing eye-witness testimony
5.4 continued

                1. gist vs. verbatim recall

                      gist = meaning
                      verbatim = surface structure; exact wording

                      in general, memory for gist is maintained while verbatim
                      memory is lost

                Sachs (1967)

                He sent a letter about it to Galileo, the great Italian scientist.
                (test sentence)

                Galileo, the great Italian scientist, sent him a letter about it.
                (comparison sentence; different meaning)

                He sent Galileo, the great Italian scientist, a letter about it.
                (comparison sentence; same meaning, different word order)
5.4 continued

                2. John Dean's memory

                      who was John Dean? Richard Nixon' s counsel; Watergate
                      Neisser (1981) compared what he remembered during the Watergate
                      trial & Nixon' s tapes
                              systematic distortions
                              some of gist maintained - if information rehearsed in advance
                              or repeated
                              reflected Dean' s self-image (his recollection was that he
                              played a more central role than he did in reality)

                gist preserved across episodes - underlying tone that permeated multiple
                encounters with the same people, discussing the same topics
5.4 continued

                3. eye-witness testimony

                memory is subject to distortions that can occur at the time of encoding and
                distortions that can occur at the time of retrieval

                Loftus & Zanni (1975) - typical experiment

                      show people film of vehicles involved in accidents
                      test subjects:

                      "Did you see a broken headlight?" vs. "Did you see the broken
                      (no broken headlight was shown in the film)

                results: those asked "Did you see the broken headlight?"were twice as likely
                to report that the headlight was broken.
5.4 continued

                4. enhancing eye-witness testimony

                standard police interview

                open-ended questions - what happened? - short-answer questions about

                Cognitive interview (Fisher & Geiselman, 1987) - increase overlap between
                encoding & retrieval; increase number of retrieval paths

                   1.mentally reinstating the environmental and personal context
                   2.reporting everything, regardless of the perceived importance
                   3.recount events in a variety of temporal orders
          events from a variety of perspectives (e.g., the witness and
                      another significant figure in the event)

                      General mnemonics: if you can' t remember a name, how many
                      syllables, frequency of occurrence, ethnicity, etc.

                cognitive interview produces 25-35% more correct information than
                standard interview (also superior to other procedures, such as hypnosis).
5. Mnemonics

               PEMA - personal external memory aid

               Principles of mnemonics


               1. Acronyms





               2. Key word method

               foreign languages - link sound / meaning

               e.g., Russian: zronok (bell) - zero-oaks

               Atkinson (1975)

               120 Russian words / 3 sessions

                     control group retains 30% 6 weeks later
                     key word method retains 45% 6 weeks later

               3. method of loci


               spatial locations

               4. Peg word system


                                    one is a bun
                                         two is a shoe
                                         three is a tree
                                         ten is a hen

You have reached the end of section 5.

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