Memory
• The multistore or stage theory
– three types of processing
– three stages
• Factors that influence retrieval from LTM
• Mnemonics
• Recognition and recall
• Cue efficiency
• Three types of LTM
• Forgetting
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Memory
• Memory Encoding
• Structure of knowledge
– Characteristics of memory
– models
• feature set
• hierarchical
• spreading activation
• propositional net
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Stage Model
• Three types of processing
– encoding - acquisition -converting information into a
code
– retention - storage
– retrieval - accessing information
• Three stages
– Sensory Register
– STM (working memory)
– LTM
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Sensory Register
• Encoding
– exposure leads to maintenance of sensory code
• Retention
– 200 - 300 msec.
– unprocessed sensory data
• Retrieval
– Icon and Echo
– Sperling’s partial report technique
• can report 3 -5 items before the rest fades
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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STM
• Encoding
– attention (selected)
– usually do acoustic recoding
– e.g. phone numbers and visual vs. acoustic
confusions (T for E, but not F for E)
• Retention
– ~30 sec.
– memory span task (7 +/- 2)
– 8th item displaces 1st
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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STM
– Serial position effect
• primacy effect
• recency effect
– rehearsal = refreshing the acoustic code
– how to study time decay
– “chunks” - the largest meaningful units
• Retrieval
– Sternberg’s serial search - each item adds 40 msec.
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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LTM
• Encoding
– information represented in many codes
• Retention
– three types of LTM
• semantic
• episodic
• Procedural
• Retrieval
– forgetting - storage failure or retrieval failure?
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Factors That Influence Retrieval
• Organization
– making connections
• Context
– state dependent learning
• Interference
– retroactive - new interferes with old
– proactive - old interferes with new
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Factors that Influence Retrieval
• Emotional factors
– rehearse strong emotional situations
– anxiety causes extraneous thoughts
– Freud’s repression
• actively block unpleasant experiences
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Mnemonics
Method of Loci
Set of Loci
Driveway
Grocery list items
Grapefruit
Garage door
Tomatoes
Front door of house
Coat closet
Chair
TV
Dining table
Lettuce
Oatmeal
Sugar
Coffee
carrots
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
Images
Grapefruit instead of rocks
along driveway
Tomatoes splattered on
garage door
Lettuce leaves for awning
Oatmeal oozing out of door
Bag of sugar as throw pillow
Juan Valdez on TV
Legs made of carrots
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Mnemonics
Peg-word system
Numbered pegs
List of words
Image
One is a bun
Cup
Two is a shoe
Three is a tree
Four is a door
Five is a hive
Six is sticks
Flag
Horse
Dollar
Brush
Pan
Seven is heaven
Clock
Eight is a gate
Nine is a vine
Pen
Paper
Ten is a hen
shirt
Hamburger bun with smashed
cup
Running shoes with a flag
Horse stranded in tree
dollar bill tacked to front door
Queen bee brushing her hair
Boiling pan full of cinnamon
sticks
St. Peter checking clock at
gates of heaven
Pens as the pickets in a fence
Newspapers as the blossoms
on a vine
Baked hen wearing a flannel
shirt
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Mnemonics
• Key word system
– often used for learning Foreign Language vocabulary
– e.g. pared - red wall, nino - nine year old
• Bizarre imagery
– combine items into an interactive bizarre image
• Letters of the alphabet
– does it start with?
• Acronyms and short rhymes
– roy g. biv
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Recognition
• Compare perceptual input with memory
representation
– response based on “feeling” of familiarity
– may or may not be able to identify
• Factors that influence recognition
– similarity of input to representation
– prior experience (frequency and recency)
– expectation and context
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Recognition
• Often automatic (fast with no conscious effort)
• Sometimes triggers a more controlled search
– “Don’t I know you from somewhere?”
• Multiple choice tests (sometimes)
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Recall
• Two steps
– generate potential targets
– recognize which targets are correct
– e.g. try recalling state capitals
• Most difficulties occur in generating potential targets
– called retrieval
– cue dependent
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Recall
• Successful retrieval depends upon
– efficient memory organization
– strategy for search
• Failures are often due to
– lack of associations
– bad cues (inappropriate associations)
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Cue Effectiveness
• Associative strength
– frequency of co-occurrence
– free association norms (salt - ?)
• Encoding Specificity
– Tulving and Thomson
– cue is most effective if it was specifically encoded with
the target
– distinctiveness and elaboration
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Cue Effectiveness
• Experiment to compare association strength and
encoding specificity
– All participants are given pairs of weakly associated
words to memorize e.g. hat-girl; key-dog
– Two groups for recall
• group one is given the same weak associates as
cues e.g. hat-?; key-?
• group two is given the strong associates (not
previously presented) e.g. boy-?; cat-?
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Cue Effectiveness
• Outcome
– group one with the previously associated cue did
better; given the cue they specifically associated with
the target
• How does this experiment relate to the difference
between episodic and semantic memory?
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Three Types of LTM
• Episodic
– memory for events in your life
• Semantic
– knowledge base
• Procedural
– knowledge of how to do things
• Evidence that these are separate memory systems
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Episodic Memory
• Memory for specific events
• Reconstruction based on schemas and/or temporal
landmarks
• Hard to distinguish reconstruction from actual
memory
– intention to do something versus actually doing it
• Tagged with time, location, context, and mood
• Unique episodes are easier to distinguish than
everyday episodes
– e.g. brushing your teeth
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Episodic Memory
• Eye-witness testimony
– Elizabeth Loftus
– misleading post event information
• wording of questions
– traveled vs. careened
– standing vs. crowded
– inappropriate associations
• all mug shots get “associated” with the crime
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Semantic Memory
• Abstraction of common elements from a variety of
previous episodes
– data base of cognition
– has truth value
– concepts and their relationships
• Expert Performance
– influence of the amount of knowledge in a given field
– domain knowledge
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Expert Performance
• Voss et al. Baseball
– participants are put into two groups based on a test of
the rules of the game
• low and high knowledge group
– All participants are given a mid game description
– the high knowledge group had much better recall
• more detail and accurate sequence information
• Background Knowledge
– provides a framework
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Expert Performance
• De Groot
– expert vs. novice chess players
– brief exposure to chess pieces on a board either mid
game or random
– expert MUCH better than novices for replacing pieces
in a mid game configuration, but no better for random
placements
– knowledge provides “chunking” - see larger pattern
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Expert Performance
• Several studies done of college students and college
professors
– professors show better recall of journal articles
– professors evaluate research designs faster and more
effectively
– professors organize material in terms of major
theoretical ideas
• Experts have
– organizing frameworks and larger perceptual chunks
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Procedural memory
• Knowledge of how to do things
– knowledge used to carry-out various tasks
• Production rules
– specify which actions should be performed under a
particular set of conditions
– condition/action rules (if/then)
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Independence of the 3 Types of LTM
• Korsokoff’s syndrome
– loss of hippocampus (usually from alcoholism)
– no new episodic memory
– show semantic priming with no recall of prime word
• K.C.
– motorcycle accident damaged episodic but not
semantic memory
– can play chess but does not ever remember having
done so
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Independence of the 3 Types of LTM
• PET scans
– retrieval of personal episodes stimulates front part of
brain
– thinking about facts stimulates back part of brain
• Amnesia
– some cause loss of episodes but not facts
– others cause loss of facts but not episodes
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Forgetting
• Probably not decay of information
– loss of access
• Retroactive and proactive interference
– degree of interference varies with degree of similarity
• Theories of interference
– response competition
• learn another response to the same cue
– unlearning
• when old association is incorrect (science “facts”)
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Forgetting
• Failure of retrieval cues
– use wrong cue
– use incorrect search strategy
– better cue can overcome a memory block
• Minimizing forgetting
– practice the retrieval (automatize)
• State dependent learning
– environmental cues
• room
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Forgetting
• State dependent learning
• color
• underwater
• drug states (alcohol, caffeine)
• place in text book
• context (people, place)
• Mood congruency (Bower)
– more likely to recall information same as mood
• hypnosis, readings, Velten induction, music, recall
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Memory Encoding (Learning)
• Information translated into a representation in
memory
• verbatim memory (word for word)
– poems, plays
• gist memory
– general or main idea
• intentional learning
– effortful
– conscious strategies
– set up retrieval cues
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Memory Encoding (Learning)
• Incidental learning
– unconscious
– effortless
– by product of cognitive processing
– often used as a research tool
• Craik and Tulving’s Levels of Processing Model
– recognition increases as the level of processing
induced by the task increases
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Levels of Processing
• Assumptions
– memory trace is a by product of perceptual analysis
• what is remembered depends upon what was
attended to
– quality of retention depends on what is encoded
• encoding meaning produces the best retention
• Use incidental memory to test the model
– avoid the confounds of conscious strategies
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Levels of Processing
• Four conditions in the experiment
– Is the word in all capital letters?
(visual)
– Does the word rhyme with _____ ? (acoustic)
– Is it an animal?
(categorical)
– Can it fit in the following sentence? (most specific)
• Each condition represents a deeper level of
processing
– visual is most shallow and sentence task is most
deep
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Levels of Processing
• Findings of surprise recall task:
– the more deeply the words are processed the more
words are recalled
– more words are recalled from the sentence than any
other condition.
– least number of words recalled from the visual
condition
• However
– memory depends on the recall task
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Levels of Processing
–
–
–
–
If ask “which words were presented in capital letters?”
then visual group has the highest score
depends on recall cue
encoding specificity
• Why is semantic encoding generally better?
– Elaboration hypothesis
• more elaborate encoding therefore more cues
– Distinctiveness
• deeper levels specify more limited number of
words
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Levels of Processing
– e.g. any word can be presented in capital letters,
there are fewer animals, and very few words can take
the place in a specific sentence
– the unique features aid the memory search
• unusual words and weird pronunciations are easier
to recall - more distinct
• Elaboration increases distinctiveness
– Begg recall of word pairs
– use word pairs that are either similar (beer-wine) or
dissimilar (beer-dog)
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Levels of Processing
– Recall was best when participants
• listed the differences between the similar pairs
• listed the similarities between the dissimilar pairs
– similarities give you the connections
– dissimilarities give you distinctiveness
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Incidental Learning
• Hasher and Zacks
– what is learned incidentally
• frequency
• spatial location
• temporal factors
– recency
– duration
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Incidental Learning
• Hasher and Zack’s five predictions about the
difference between intentional and incidental learning.
• Incidental learning is
– 1. Automatic and effortless
– 2. NOT influenced by instruction or practice
– 3. NOT influenced by a secondary task
– 4. NOT influenced by emotional state (depression or
anxiety)
– 5. Does NOT change with age (very young or old)
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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Intentional Learning
• Rote (repetition) memory
• Three theories of why repetition works (somewhat)
– association strength
– multiple copies
– encoding cues (add more context cues)
• Massed vs. distributed repetition
– or why you should not cram for the test
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Intentional Learning
• Distributed repetition
(spreading your studying out over several days)
– works much better
– why?
• More than one context
• the boredom of cramming leads to decreased
attention
– low arousal
– low efficiency
– less effort
Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D.
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