cognitive - memory.ppt © 2001 laura snodgrass, ph.d.1 memory the multistore or stage theory...

Cognitive - memory.ppt © 2001 Laura Snodgrass, Ph.D. 1

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


Memory

• Memory Encoding

• Structure of knowledge– Characteristics of memory– models

• feature set• hierarchical• spreading activation• propositional net


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


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


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


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.


LTM

• Encoding– information represented in many codes

• Retention– three types of LTM

• semantic• episodic• Procedural

• Retrieval– forgetting - storage failure or retrieval failure?


Factors That Influence Retrieval

• Organization– making connections

• Context– state dependent learning

• Interference– retroactive - new interferes with old– proactive - old interferes with new


Factors that Influence Retrieval

• Emotional factors– rehearse strong emotional situations– anxiety causes extraneous thoughts– Freud’s repression

• actively block unpleasant experiences


Mnemonics

Set of Loci Grocery list items ImagesDriveway Grapefruit Grapefruit instead of rocks

along drivewayGarage door Tomatoes Tomatoes splattered on

garage doorFront door of house Lettuce Lettuce leaves for awningCoat closet Oatmeal Oatmeal oozing out of doorChair Sugar Bag of sugar as throw pillowTV Coffee Juan Valdez on TVDining table carrots Legs made of carrots

Method of Loci


Mnemonics

Numbered pegs List of words Image

One is a bun Cup Hamburger bun with smashedcup

Two is a shoe Flag Running shoes with a flagThree is a tree Horse Horse stranded in treeFour is a door Dollar dollar bill tacked to front doorFive is a hive Brush Queen bee brushing her hairSix is sticks Pan Boiling pan full of cinnamon

sticksSeven is heaven Clock St. Peter checking clock at

gates of heavenEight is a gate Pen Pens as the pickets in a fenceNine is a vine Paper Newspapers as the blossoms

on a vineTen is a hen shirt Baked hen wearing a flannel

shirt

Peg-word system


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


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


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)


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


Recall

• Successful retrieval depends upon– efficient memory organization– strategy for search

• Failures are often due to– lack of associations– bad cues (inappropriate associations)


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


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-?


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?


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


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


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


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


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


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


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


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)


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


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


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”)


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


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


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


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


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



• 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



• 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



– 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



– 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)



– 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


Incidental Learning

• Hasher and Zacks– what is learned incidentally

• frequency• spatial location• temporal factors

– recency– duration


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)


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


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.1 memory the multistore or stage theory...

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