Overview%20of%20Memory%20Research

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Overview of Memory Research
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Modal Memory Model
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Basic Distinctions

• STM
• short term memory
• limited capacity
• limited duration
• holding available recent and relevant information
  in a temporary store
• LTM
• long term memory
• unlimited storage
• relatively permanent
• store for episodic and semantic memory

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Modal Model of Memory(Atkinson Shiffrin, 1968)

• Short-term memory is a limited capacity store for
  information -- place to rehearse new information
  from sensory buffers
• Items need to be rehearsed in short-term memory
  before entering long-term memory
• Probability of encoding in LTM directly related
  to time in STM

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a memory test...

• TABLE

CANDLE
MAPLE
SUBWAY
PENCIL
COFFEE
TOWEL
SOFTBALL
CURTAIN
PLAYER
KITTEN
DOORKNOB
FOLDER
CONCRETE
RAILROAD
DOCTOR
SUNSHINE
LETTER
TURKEY
HAMMER
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Serial Position Effects
nodistractor task
distractor task

• In free recall, more items are recalled from
  start of list (primacy effect) and end of the
  list (recency effect)
• Distractor task (e.g. counting) after last item
  removes recency effect

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Serial Position Effects

• Explanation from Modal Memory Model
• Early items can be rehearsed more often
• ? more likely to be transferred to long-term
  memory
• Last items of list are still in short-term memory
  (with no distractor task)
• ? they can be read out easily from short-term
  memory

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Encoding Retrieval Effects
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Levels of Processing(Craik Lockhart, 1972)
Modal Memory Model ? time in rehearsal buffer
determines memory strength Levels of processing
effect The way information is processed affects
recall. Deeper levels of processing (e.g.,
emphasizing meaning) leads to better recall ?
encoding effect
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Encoding Specificity Principle

• Recollection performance depends upon the
  interaction between the properties of the encoded
  event and the properties of the retrieval
  information
• Example
• context dependent effects information learned in
  a particular context is better recalled if recall
  takes place in the same context

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Godden Baddeley (1975)

• Memory experiment with deep-sea divers
• Deep-sea divers learned words either on land or
  underwater
• They then recalled the words either on land or
  underwater

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Mood Congruence

• Easier to remember happy memories in a happy
  state and sad memories in a sad state.
• Teasdale Russell (1983) subjects study
  positive or negative words in normal state. Test
  in positive or negative induced states.
• ? mood primes certain memory contents

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State-dependent recall

• Does physical state matter?
• Eich et al. (1975) study while smoking normal
  or marijuana cigarette. Test words under same or
  different physical condition

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Spacing effects

• Memory is better for repeated information if
  repetitions occur spaced over time than if they
  occur massed, one after another.
• Experiment study 48 words, 24 of which are
  repeated. Spacing interval varied from 1,2,4,8,20
  to 40 presentations.
• Results better memory for items with greater
  spacing.
• Explanation based on encoding specificity
  principle spaced items can be encoded in
  multiple ways ? more likely to be retrieved

Melton Schulman, 1970
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Working Memory
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Views on Short-Term memory

• Millers memory span (7 2 discrete slots)
• Short-term memory activated long-term memory
• Baddeleys theory of working memory
• Set of slave systems rehearsing and working on
  information
• Working memory capacity
• Measures focus of attention with distracting
  tasks

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Baddeleys working memory theory

• Concept of working memory brief, immediate
  memory of material we are currently processing
• Working memory is not a passive store-house such
  as short-term memory it is more like a work
  bench where material is constantly handled,
  combined and transformed

Visuo-spatial sketchpad
Phonological Loop
Central Executive
Long-term memory
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Phonological Loop(a.k.a. articulatory loop)

• Stores a limited number of sounds number of
  words is limited by pronunciation time, not
  number of items
• Experiment
• List 1 Burma, Greece, Tibet, Iceland, Malta,
  Laos
• List 2 Switzerland, Nicaragua, Afghanistan,
  Venezuela, Philippines, Madagascar
• Typical results list 1 ? 4.2 words list 2 ?
  2.8 words

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Phonological Similarity

• Note most working memory tasks involve serial
  recall
• Short-term memory worse for phonologically
  similar items ? interference in phonological loop

man mad cap can map
pen rig day bar cup
big huge broad long tall
old late thin wet hot
(Baddeley, 1966)
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Reading rate determines serial recall

• Baddeley (1986) tested recall for five words
  varying from 1 to 5 syllables.
• 1 syllable wit, sum, harm, bay, top
• 5 syllables university, opportunity, aluminum,
  constitutional, auditorium
• Reading rate seems to determine recall
  performance
• Phonological loop stores 1.5 - 2 seconds worth of
  words

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Working memory and Language Differences

• Different languages have different syllables per
  digit
• Therefore, recall for numbers should be different
  across languages
• E.g. memory for English number sequences is
  better than than Spanish or Arabic sequences

(Naveh-Benjamin Ayres, 1986)
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Problems with Baddeleys theory

• Pronunciation time does not always predict recall
  very well

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Problems with Baddeleys theory

• Even with long delays, memory span does not
  decrease much
• Underspecified processes and representation
• Serial recall requires memory for the order of
  items ? how is order information stored?
• How does central executive work?
• How does interference in phonological loop work?

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Long-Term Memory Systems
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Are there multiple LTM memory systems?

• How do you learn a new skill?
• How do you learn a new fact?
• How about learning about an event?
• Is there one long-term memory (LTM) system for
  these types of knowledge or are there multiple
  LTM systems?

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Squires Taxonomy of memory
MEMORY
EXPLICIT
IMPLICIT
SEMANTIC (facts)
EPISODIC (events)
PROCEDURAL (skills)
PRIMING (perceptual, semantic)
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Implicit and explicit memory

• Implicit memory
• past experiences influence perceptions, thoughts
  actions without awareness that any info from
  past is accessed
• Explicit memory
• conscious access to info from the past
• (I remember that.. )
• -gt involves conscious recollection
• -gt term often used synonymously with episodic
  memory

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Explicit Implicit MEMORY TESTS Look at the
following words. I will test your memory for
these words in various ways.
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SPONGE CANDY DOLPHIN PACKAGE POSTER
LICORICE ZEBRA SECTION CAMOFLAGE MISTAKE PORTAL
KNAPSACK COFFEE QUAIL ALPINE HANDLE PANTRY CARPE
T EAGER CELLO PRESSURE LLAMA ORIOLE ACRID
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EXPLICIT TEST OF MEMORY RECALL WRITE DOWN THE
WORDS YOU REMEMBER FROM THE LIST IN THE EARLIER
SLIDE IMPLICIT TEST OF MEMORY WORD
FRAGMENTS ON THE NEXT SLIDE, YOU WILL SEE SOME
WORDS MISSING LETTERS, SOME WORD FRAGMENTS AND
SOME ANAGRAMS. GUESS WHAT EACH WORD MIGHT BE.
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Implicit Memory Tasks

• Word-fragment completion is an implicit memory
  task.Fragments are (often) completed with words
  previously studied in the absence of an explicit
  instruction to remember the word
• Amnesiacs often showed spaired implicit memory ?
  dissociation suggest different systems for
  implicit and explicit memory systems

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HM Amnesic

• Severe epilepsy, treated with surgery to
  bilaterally remove medial temporal lobes,
  including hippocampus
• Operation 9/1953, 27 years old

HIPPOCAMPUS MEDIAL TEMPORAL LOBES
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HM Amnesic

• Operation 9/1953, 27 years old
• Tested 4/1955, age 29
• Reported date as 3/1953, age of 27
• No memories since operation
• IQ better than pre-op (112)
• Fewer seizures

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HM Amnesic

• Profound failure to create new memories
• Cant find new home (after 10 mos.)
• Cant remember new people, names, tasks
• Events/People since operation
• Language essentially frozen in 50s
• Exceptions Ayatollah, rock n roll

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HM Amnesic

• Mirror tracing task, Milner, 1965

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HM Amnesic

• Mirror tracing task, Milner, 1965
• improvement in H.M.
• no conscious recollection of previous training
  episodes

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HM Stem-completion

• Graf et al. (1984)
• Study word list (table, garden,umbrella)
• Test
• - free recall
• - cued recall complete word stem with word from
  study list
• umb____ ??
• - word stem completion complete word stem with
  first word that comes to mind
• gar___??

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HM Stem-Completion
Free Cued Completion Recall Recall
HM No memory for studying of list
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Learning to Miror-Reverse Read
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Amnesics can learn to mirror-reverse read and are
sensitive to repetitions
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Spared implicit memory in anterograde amnesia

• Claparede study (1911).
• Patient never remembered having met Claparede
  (doctor) before
• Claparade offers handshake with pin hidden in his
  hand
• Next time, patient has no explicit memory of
  painful event (or doctor)
• Still, patient refuses to shake hands and offers
  explanation sometimes pins are hidden in
  peoples hands

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Implicit/ Explicit Memory with Normals

• Jacoby (1983)
• Study conditions
• generate give antonym to hot - ...
• context study word in context hot - COLD
• no context ... - COLD
• At test
• Explicit memory test recognition memory
• Implicit Memory test Speed up on perceptual
  identification test how much faster can you
  identify a word flashed 40ms on screen when you
  have studied word before?

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Results
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Knowledge Memory
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How well do people recall events?

• Memory is not just reproductive
• We do not recall the original event exactly
• Memory for events is often reconstructive
• We construct a memory by combining elements from
  the event with our existing knowledge.

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What does a penny look like?
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Memory for Details vs. Gist

• Memory is better for meaningful, significant
  features than for details of language or
  perception, suggesting that we have knowledge
  representations based on our interpretations of
  meaning.
• Representation for meaning
• Propositional representations
• Semantic Networks
• Schemas
• Scripts
• Latent Semantic Analysis (LSA)

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Evidence for Schemas

• A simple demonstration experiment
• I am going to show you a picture of a graduate
  students office. Just take a look at it for a
  while

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Now write down all the things you can remember
Potential responses Chairs Desk Table Boxes Bott
le of wine Picnic basket Books Skull
Brewer Treyens (1981) 30 of subjects
(falsely) recalled that books were present
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Story Retelling involves Schemas

• Bartlett (1932) told a native American story war
  of the ghosts to one subject
• This subject tells story to the next subject, and
  so on (method of serial reproduction)
• What happens during retelling of story from
  memory?

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War of the Ghosts

• excerpt One night two young men from Egulac
  went down to the river to hunt seals and while
  they were there it became foggy and calm. Then
  they heard war-cries, and they thought "Maybe
  this is a war-party". They escaped to the shore,
  and hid behind a log. Now canoes came up, and
  they heard the noise of paddles, and saw one
  canoe coming up to them. There were five men in
  the canoe, and they said ....

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Typical Results

• Gist remains intact -- the main plot and sequence
  of events
• Omission Errors
• Quite a bit of material is omitted (e.g. the name
  Egulac) and minor events
• Normalization Errors
• Additional info was added to make the story more
  coherent
• As Ss recalled/retold the story more and more, it
  tended to warp over time.

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Memory for Event Sequences

• John was hungry
• He went into a restaurant and ordered a sandwich
• He paid his bill and left
• Question Did John eat his sandwich? From whom
  did he order a sandwich? What was the bill for?
• None of the answers is stated in the sentences
  but are based on inferences

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Scripts

• Inferences are based on representations for
  stereotyped sequences of actions ? scripts
• A restaurant script

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Evidence for Scripts

• Bower et al. (1979)
• Ss. study a sequence of events
• when an event is out of order, Ss might correct
  the order to the stereotypical order
• E.g., restaurant story where bill is paid first
  is remembered in correct order (bill is paid
  last)
• Some events are (incorrectly) filled in based on
  inference
• Suggests Events encoded with respect to general
  script

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Schemas Scripts Implications

• Information from specific events is combined with
  general knowledge
• Experience shapes scripts
• Scripts guide recall
• Advantages Disadvantages