Transcript PSY 368 Human Memory - the Department of Psychology at Illinois

PSY 368 Human
Memory
Memory Processing
Announcements
• Craik and Lockhart (1972) download, read, and
answer focus questions, due Monday Feb 27
• Processing views homework due Web Feb 29
Structural Model
• Memory is
also made
up of
Processes
• Memory composed of storage structures that hold memories
for a period of time
• Sensory memory
• Short-term memory (STM)
• Long-term memory (LTM)
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Structure  Processes
• Structural (Modal) views
• Properties of memorized information (e.g., how long it lasts)
come from where it is stored (Sensor, STM, or LTM)
• E.g., the longer an item is held in STM, the more likely it would get
into LTM (and be stored more ‘durably’)
• We’ve talked about things like rehearsal and elaboration as
being important for moving information between the
different memory systems
• Processing views
• Focus on what gets done to the information
• e.g., rote rehearsal versus elaborative rehearsal
• Need to look at both learning (encoding) and at test (retrieval)
Structure  Processes
• Processing views
• Encoding (focus on ‘getting things into memory’)
• Level of processing
• Interaction of Encoding & Retrieval (focus on ‘getting things in and out
of memory’)
• Transfer-appropriate processing
• Importance of context
• Encoding specificity principle
Demo
For each item below with a ! next to it, indicate if it is alive.
For each item below with a * next to it, indicate if it has an “e.”
! flag
! kite
* house
* jail
! spider
* snake
* picture
! duck
* flame
! bottle
! tree
* happy
* storm
! ball
! class
* horse
! zebra
* test
! window
* hair
* dream
! rock
! table
* fountain
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Rehearsal
Mechanic (1964)
• Task:
• Participants had to repeat nonsense syllables
either once or many times.
• Only half of the participants were warned
of an upcoming recall test.
• Conclusion:
• Rehearsal led to better recall
• Knowing that there is a test coming
prompted additional processing in the
intentional learning group.
• Results:
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Rehearsal
Glenberg, Smith, and Green (1977)
• Task:
• Participants were asked to remember numbers over a delay.
• During the delay, they had to read out words (in time with tones
every 2 sec.)
• Some words were repeated only once during the delay; others
were repeated many times.
• Participants then recalled the numbers followed by a surprise recall
(or recognition) test for the words.
• Results:
• Having nine times as many repetitions only increased recall by 1.5%
(9% for recognition), suggesting that simple maintenance rehearsal
doesn’t help long-term recall much.
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Rehearsal
Mechanic (1964)
• Finding:
• Maintenance did help in one
condition
• Stimuli:
• Unfamiliar stimuli that need to be
learned from scratch
• Rationale:
• Repeating unfamiliar stimuli with no
natural links between them boosts
their representation in phonological
LTM
Glenberg, et al. (1977)
• Finding:
• Maintenance didn’t help
• Stimuli:
• Already known words
• Rationale:
• The recall test relied on meaningful
links between the known words
(already in LTM), which depend
on deeper, semantic features
Demo
For each item below with a ! next to it, indicate if it is alive.
For each item below with a * next to it, indicate if it has an “e.”
! flag
! kite
* house
* jail
! spider
* snake
* picture
! duck
* flame
! bottle
! tree
* happy
* storm
! ball
! class
* horse
! zebra
* test
! window
* hair
* dream
! rock
! table
* fountain
Write down as many of the words as you can remember.
• Count up how many were from the “with an e” and how
many from “is it alive?”
Levels of Processing
• Emphasizes memory processes rather than structures
• Based on the idea that the strength of a memory trace is
determined by how the original info was processed
• Incoming stimuli pass through a series of analyzing mechanisms
• Memory traces are a product of how stimuli are analyzed
• Strength of trace depends on:
• Attention paid to stimulus
• Depth of processing carried out
• Connections with existing knowledge
Level of Processing
Craik & Lockhart (1972)
• Argue against structural/modal models of memory
• Features that distinguish stores are not clear
• Distinguished elaborative and maintenance rehearsal
• Elaborative - rehearse item using its meaning (better memory)
• Maintenance - rehearse items by repeating it over and over
• Keep in STM/WM, but doesn’t get it into LTM
• Importance of Incidental learning
• If participants know that they’ll be tested for memory they may
engage in different techniques/strategies
Level of Processing
Craik & Lockhart (1972)
• Considered level of processing at study to be more important for
memory than intent to learn
• Levels of processing = how “deeply” the item is processed
• The depth of processing helps determine the durability in LTM.
SHALLOW
DEEP
Level of Processing
Example
1) Visual Form
“DOG” includes the letters D, O,
and G
2) Phonology
Rhymes with FOG
3) Semantics
(Meaning)
A four-legged pet that often chases
cats and chews on bones
Levels of Processing
Craik and Tulving (1975)
Task:
• Participants viewed words and were asked to make three
different types of judgments:
• Visual processing (e.g. “Is LOG in upper case?” Y/N)
• Phonological (e.g. “Does DOG rhyme with LOG?” Y/N)
• Semantic (e.g. “Does DOG fit in the sentence: ‘The ___ chased
the cat’?” Y/N)
• Finally, participants were asked to recognize the words they
had seen before in a surprise test including both old and new
words.
Levels of Processing
Craik and Tulving (1975)
Results:
• Words that were more deeply processed were more easily
recognized -- particularly for questions with a “YES” response.
Conclusions:
• Deeper processed items had
stronger memory traces than
shallow processed items.
• “Yes” responses were better
recalled because these items
are better integrated with
the encoding question.
Levels of Processing
Hyde and Jenkins (1973)
• Auditory study of words with incidental and intentional
tasks
• Half knew they be tested later
• Half didn’t know about a later test
• Control group: no instruction, but told about later memory test
• Task: studied 24 common words, auditory presentation,
free recall task SHALLOW (1) Look for “e” and “g” in word
DEEP
(2) Identify part of speech
(3) Rate how common the word is
(4) Rate pleasantness of word
Levels of Processing
Hyde and Jenkins (1973)
Results
• Depth of processing effect
• Incidental: the deeper the
level of processing, the more
words recalled.
• Incidental: recall on the
pleasantness task was as good
as control group recall.
Levels of Processing
Craik and Watkins (1973)
• Tested the idea that rehearsal doesn't really help memory.
• Had people rehearse a word until another word that started
with the same letter occurred in the list.
• Task: report the last word that began with that letter.
• Rehearse words that start with "g”
daughter, oil, rifle, garden, grain, table, anchor, football, giraffe
Operational definition of rehearsal time: the number of intervening words
garden = 0 grain = 3
Rehearsal time ranged from 0 to 12.
Levels of Processing
Craik and Watkins (1973)
• Tested the idea that rehearsal doesn't really help memory.
• Had people rehearse a word until another word that started
with the same letter occurred in the list.
• Task: report the last word that began with that letter.
• 10 minutes after the final trial, subjects got a surprise recall test:
report as many of the words that began with "g”.
daughter, oil, rifle, garden, grain, table, anchor, football, giraffe
Results:
• Recall of an item was not correlated with how long it had been rehearsed.
• garden remembered just as well as grain
Levels of Processing
Criticisms:
• It is difficult to operationally define depth of
processing.
• Can’t use processing speed to define it.
• Different levels of processing can occur simultaneously, rather
than in series, making them hard to separate in a task.
• Deeper processing does not always lead to better performance.
• Ignores effects of retrieval task
Transfer-appropriate processing
Morris, Bransford, and Franks (1977)
• Focus on processing at study (encoding) AND test
(retrieval)
• If processing at study and test match, better memory
• Levels of Processing effect for tasks that use a lot of
semantic processing (like free recall)
Transfer-appropriate processing
Morris, Bransford, and Franks (1977)
• Task:
• Participants made either a phonological or semantic judgment
about each item on a word list.
• Study: eagle (yes/no fits clue)
• Deep - The ____ is the US national bird.
• Shallow - rhymes with legal
• The learning was incidental: participants were not told that they
would have to later recall the words.
• This constrains (limits) the learning strategies used.
Transfer-appropriate processing
Morris, Bransford, and Franks (1977)
• Task:
• The final test was either:
• A standard recognition test for the learned words.
• A rhyming recognition test for learned words
• e.g., Was a word presented that rhymed with “regal”?
Transfer-appropriate processing
Morris, Bransford, and Franks (1977)
Encoding:
Recognition Rhyming test:
test:
Does ____ rhyme 63%
with legal?
(eagle)
49%
Does ____ have
84%
feathers? (eagle)
33%
• Results:
• Standard recognition test: Deeper processing led to better performance.
• Rhyming recognition test: The shallower rhyme-based encoding task led
to better performance because it matched the demands of the testing
situation.
Transfer-appropriate processing
Morris, Bransford, and Franks (1977)
Encoding:
Recognition Rhyming test:
test:
Does ____ rhyme 63%
with legal?
(eagle)
49%
Does ____ have
84%
feathers? (eagle)
33%
• Conclusion:
• The take-home message is that when the processing at encoding
matches the processing at retrieval, performance will be better.
• It only makes sense to talk about a learning method’s efficiency in
the context of the type of final test.
Context Effects
Abernathy (1940)
• Found that students tested in the same classroom in
which they learned did better on tests than students
tested in a different classroom.
• Context matters
• Interaction of encoding and retrieval
• Context at study (e.g., cues, environment, processing, etc.)
and context at retrieval
• Better memory if the contexts match
Context Effects
Godden and Baddeley (1975)
•
Used subjects from a SCUBA diving club in gear
Study Condition
Test
Condition
On Land
Underwater
On Land
Match
Mismatch
Mismatch
Match
Underwater
Context Effects
Godden and Baddeley (1975)
•
Used subjects from a SCUBA diving club in gear
Results:
• Recall was better when study
environment and test environment
matched, regardless of whether it
was on land or under water.
Context Effects
• Also called state-dependent memory
• Match between study and test state/context predicts memory
performance
• Goodwin et al. (1969) alcohol study:
• Some subjects received 10 oz of 80-proof vodka at study, at test,
or both
(errors)
Study Condition
Results
• For items learned during
intoxication, there is a large
difference in performance at recall
• For items learned during sober, the
difference is smaller
Test
Condition
sober
drunk
sober
1.25
4.58
drunk
2.25
2.50
Context Effects
• For emotional state: mood-dependent memory
• Bartlett & Santrock (1979) mood study:
• happy or neutral mood at study
• happy or neutral mood at test
• Recall was better when moods matched
• This effect is not always replicated -- one important factor is
to produce a strong, sincere, mood.
Encoding Specificity Principle
Tulving (1972, 1983)
• The recollection of an event or a certain aspect of it
depends on the interaction between the properties of the
encoded event and the properties of the retrieval information.
• What is stored determines what retrieval cues are effective
in providing access to what is stored.
• Match between cues at study and test results in better
memory
• The most effective retrieval cues will be the ones you used
during the original learning.
Encoding Specificity Principle
Thompson and Tulving (1970)
• Examined effectiveness of cue
• Had people learn lists of strong or weak associates.
• Strong vs. weak cues (“flower”)
• Strong: bloom
• Weak: fruit
• Study: no cue vs. weak cue
• Test: no cue, weak cue, or strong cue
Encoding Specificity Principle
Thompson and Tulving (1970)
• The best retrieval cue for a word like “flower” would be a
strong associate like “bloom.” “fruit” is weakly associated to
“flower,” and would be unlikely to pull it out.
0.9
0.8
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0.6
Memory 0.5
Accuracy 0.4
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0.1
0
No cue
Weak cue
No cue
Weak cue
Test Cue
Strong cue
• Thompson and
Tulving showed that
this can be reversed if
you change the study
context.
Brief Summary
• Where something is stored isn’t everything. How
you encode and retrieve the information is critical.
• Encoding:
• Levels of processing
• Encoding + Retrieval
• Context effects (environment, mood)
• Transfer-appropriate processing
• Encoding specificity principle (cues)