Transcript Long term memory & Memory errors

How does information become
store in LTM ?
• Encoding : the process of acquiring
information and transferring it into memory
– Coding : the form with which information is
represented
• Retrieval : the process of transferring
information from LTM back into working
memory
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Chapter summery 10
• The process of acquiring information and
transferring it into memory is called
encoding.
• Encoding therefore refers to the process
used to get information into LTM.
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Encoding & Rehearsal
Rehearsal :repeating it over and over
1. Maintenance rehearsal :
helps maintain information in memory
2. Elaborative rehearsal :
transferring information into LTM
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Maintenance rehearsal
• When you repeat a phone number you just
looked up in the phone book
– Repeating a number without any
consideration of meaning or making
connections with other information
• Rehearsal can keep information in working
memory
• Then forgetting it right after you place the
call
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Elaborative rehearsal
• think about the meaning of an item
• make connections between the item and
something you know
• An effective way of transferring information
into LTM
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Chapter summery 11
• Some mechanisms of encoding are more
effective than others in transferring
information into LTM.
– Maintenance rehearsal helps maintain
information in STM but is not an effective way of
transferring information into LTM.
– Elaborative rehearsal is a good way to
establish LTM.
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Levels-of-processing theory
Idea of LOP ( levels-of-processing ) : 1972
Fergus Craik and Robert Lockhart
– Depend on how information is encoded
Memory depends on how information is
programmed (encoded) into the mind
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Remembering lists
Part 1 : counting the number of vowels
• Cover up the list below :
chair, mathematics, elephant, lamp,
car, elevator, thoughtful, cactus
• Uncover each word by one
• Count the number of vowels in each word
• Go right on to the next one
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Remembering lists
Part 1 : counting the number of vowels
• Now cover the list
• Count backward by 3’s from 100
(100,97,94,91,88,85,82,79,76)
• When you get to 76
• Write down the words you remember
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Remembering lists
Part 2 : visualizing an item’s function
• Cover the list below
Umbrella, exercise, forgiveness, rock,
hamburger, sunlight, coffee, bottle
• Uncover each word one by one
• Visualize how useful the item might be if
you were stranded on uninhabited island
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Remembering lists
Part 2 : visualizing an item’s function
• Cover the list
• Count backward by 3’s from 99
(99,96,93,90,87,84,81,78,75)
• When you reach 75
• Write down the word you remember
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Remembering lists
Which procedure resulted in better memory?
1. Counting the number of vowels
2. Visualizing an item’s function : better
– a meaningful connection has been made between an
item and something else
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levels-of-processing
Idea of LOP : Fergus Craik and Robert
Lockhart 1972
• Memory depends on the depth of
processing that an item receives
–Shallow processing
–Deep processing
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Shallow processing
• Focused on physical features such as
– the number of vowels in a word
– Whether the word is printed in lowercase or
capital letters
• Repeated to keep it in memory
• But without considering its meaning or its
connection
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Deep processing
• Focusing on an item’s meaning
– Considering how an item might be useful in a
particular situation
– Creating an image of the item in relation to
another item
• Involves close attention to meaning
• Relating it to something else
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Depth of processing
Shallow processing :
involves little attention to meaning
– Occurs during maintenance rehearsal
Deep processing :
involves close attention to meaning
– Occurs during elaborative rehearsal
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Levels-of-Processing theory
Prediction of better memory
• Deep processing better than shallow
processing
• Elaborative rehearsal deeper than
maintenance rehearsal
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Varying depth of processing
Fergus Craik and Endel Tulving 1975
• How depth of processing can be varied by
asking different kinds of questions about a word
» A question is presented
» Followed by a word
» Then the participant’s response (memory test)
– Shallow processing : asking question about the word physical
characteristics
– Deeper processing : asking the word’s sound
– Deepest processing : a task that involves the word’s meaning
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Varying depth of processing
Shallow processing : a question about physical features of the word
• Q : Is the word printed in capital letters ?
• Word : bird
Deeper processing : a question about rhyming
• Q : Does the word rhyme with train ?
• Word : pain
Deepest processing : a fill-in-blanks question
• Q : Does the word fit into the sentence
“ He saw a ________ on the street ” ?
• Word : car
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Varying depth of processing
Deeper processing is associated with better memory20
Chapter summery 12
Levels of processing theory states that
memory depends on how information is
encoded or programmed into the mind.
• According to this theory, shallow processing is not
as effective as deep processing.
• An experiment by Craik and Tulving
showed that memory was better following
deep processing than following shallow
processing.
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Transfer-appropriate processing
Memory performance is enhanced if
• type of task at encoding matches
the type of task at retrieval
Memory performance is sometimes determined
not by depth of processing
but by the relationship between
how information is encoded
and how it is retrieved later
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Transfer-appropriate processing
Donald Morris and coworkers 1977
• Participants were presented with 32
sentences during the encoding part of
the experiment
•
Tasks during encoding
1. The meaning task
2. The rhyming task
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Transfer-appropriate processing
Meaning-task encoding
– Participants heard fill-in-the-blanks sentences
in which the word blank replaced the target
word
– Participants heard the target word
• Participants had to response “ yes ” if they thought
it fit into the sentence
• Participants had to response “ no ” if they thought it
didn’t fit into the sentence
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Transfer-appropriate processing
Meaning-task encoding
“ The blank rode the bicycle ”
– Target word :
boy
– Answer : would be “ yes ”
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Transfer-appropriate processing
Rhyming-task encoding
– Participants heard a statement involving
rhyming, in which the word blank replaced the
target word
– Participants heard the target word
• Participants had to respond “ yes ” if the statement
was correct
• Participants had to respond “ no ” if the statement
was not correct
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Transfer-appropriate processing
Rhyming-task encoding
“ Blank rhymes with toy ”
– Target word : boy
– Answer : would be “ yes ”
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Transfer-appropriate processing
Donald Morris and coworkers 1977
• Encoding task ( same 32 target words )
1. meaning group : 32 target words
2. rhyming group : 32 target words
•
Retrieval task ( both groups test both )
1. Standard recognition test in retrieval
2. Rhyming recognition test in retrieval
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Transfer-appropriate processing
Standard recognition test in retrieval
– Both groups presented with the 32 same
target word and 32 new words
– Indicate whether a word had been one of the
target words during acquisition ?
– Result : meaning-task encoding group better
» Meaning task would result in deeper processing than
rhyming task
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Transfer-appropriate processing
Rhyming recognition test in retrieval
– Both groups presented with the 32 same target
word and 32 new words
– Indicate whether each word rhymed with one of
the words they had heard during acquisition ?
– Results : rhyming-task encoding group better
» Meaning task would result in deeper processing than rhyming task
» LOP cannot explained this results
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Transfer-appropriate processing
How well the conditions at
encoding and retrieval match
The key to the better performance
of the rhyming group was
transfer-appropriate processing
both encoding and retrieval
were based on sound
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Chapter summery 13
• Transfer appropriate processing refer to
the finding that memory performance is
enhanced when the type of coding that
occurs during acquisition matches the type
of retrieval that occurs during a memory
test.
• The result of an experiment by Morris
support this idea.
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Additional factors that aid encoding
• Forming connections with other information
• Generating information
• Organizing information
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Forming connections with other
•
Task : Remembering the word chicken
Which sentence do you think would
result in the best memory ? ( A = 2 )
1. She cooked the chicken
2. The great bird swooped down and carried off the
struggling chicken
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Forming connections with other
Craik and Tulving 1975
• Memory is much better when the word is
presented within the complex sentence
• Complex sentence creates more
connections between the word to be
remembered and other things
• These other things act as cues that help
us retrieve the word
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Forming connections with other
Gordon Bower and David Winzenz 1970
• Imagery can help create connections
– They presented a list of 15 pairs of nouns,
such as boat and tree, to participants for 5
seconds each
– Repetition group : silently repeat the pairs
– Imagery group : form the mental picture in which the two
items were interacting
– Recall all
– Results : imagery group superior
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Imagery can help create connections
Repetition group : silently
repeat the pairs
Imagery group : form the
mental picture in which the
two items were interacting
Results : imagery group superior
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Forming connections with other
T.B. Rogers and coworkers 1979
• Self-reference effect
Memory is better if you are asked to relate a word to yourself
• Participants were presented with a cue question and then a
word ( shy , outgoing )
– Cue question :
» Is the word long ?
» Does the word describe you ?
•
•
•
•
Apply the cue question to the word
Answer yes or no
Recall for the word that resulted in a yes response
Results : better memory for word that describe themselves
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Self-reference effect
Memory is better if you are asked to relate a word to yourself
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Self-reference effect
Retrieval cues
• The self provides information that become
linked to the word and that make it easier
to remember later
Deeper processing
• Word describes you results in deeper
processing
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Generating information
Generation effect :
•
Generating material yourself, rather than passively
receiving it, enhances learning and retention.
Norman Slameka and Peter Graf 1978
•
Participants study a list of word pair in two different
ways
1. Read group : read these pairs of related words
•
King-crown , horse-saddle , lamp-shade
2. Generate group : fill in the blank with a word that is related
to the first word.
( king-cr___ , horse-sa___ , lamp-sh___ , etc. )
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Generating information
Norman Slameka and Peter Graf 1978
• After study task
• Presented with the first word in each pair
• Indicate the word that went with it
• Results : generate group learned 28%
more word pair than read group
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Organizing information
The memory system uses organization to
access information efficiently.
• Reading a list
– Get paper and pen ready
– Read the following words
» Apple, desk, shoe, sofa, plum, chair, cherry, coat,
lamp, pants, grape, hat, melon, table, gloves
– Then cover them and write them down as
many as possible
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Organizing information
• Look at the list you created
• Notice whether similar items are group
together
» Apple, cherry, plum
» Shoe, coat, pants
– Remembering words in a particular category
may serve as a retrieval cue for other words
in that category
• Create a recall list that is more organized
than the original list that you read
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Organizing information
Gordon Bower and coworkers 1969
• Presenting material to be learned in a
“tree” which organized a number of words
according to categories
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Organizing information
Gordon Bower and coworkers 1969
Organized 4 trees
• Participants studies trees for minerals ,
animals , clothing , transportation for 1
minute each
• Recall from all 4 trees
• Results : recalled an average of 73 words
from all 4 trees ( well organized )
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Organizing information
Gordon Bower and coworkers 1969
Randomized 4 trees
• Participants studies and recall
• Results : remember only 21 words
• Conclusion : organizing material to be
remembered results in substantially better
recall
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Organizing information
Balloon experiment
John Bransford and Marcia Johnson 1972
• Read a following passage :
• If the balloon popped, the sound wouldn’t be able to carry since
everything would be too far away from the correct floor. A closed
window would also prevent the sound from carrying, since most
buildings tend to be well insulated. Since the whole operation
depends on the steady flow of electricity, a break in the middle of a
wire would also cause problems. Of course, the fellow could shout,
but the human voice is not loud enough to carry that far. An
additional problem is that the string could break on the instrument.
Then there would be no accompaniment to the message. It is clear
that the best situation would involves less distance. Then there
would be fewer potential problems. With face to face contact, the
least number of things could go wrong.
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Organizing information
Balloon experiment
John Bransford and Marcia Johnson 1972
• What was that all about ?
• Found it extremely difficult to remember
this passage
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Organizing information
Balloon experiment
John Bransford and Marcia Johnson 1972
– Group : saw the picture before read a passage
– Another group : saw the picture after read a passage
• Compare both : first group remember more
• Key : organization  easier to comprehend
– Picture : provides a framework that helps the reader
link one sentence to the next to create a meaningful
story
– How the ability to remember material depends on how
that material programmed into the mind
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Balloon experiment
If the balloon popped, the sound wouldn’t be
able to carry since everything would be too
far away from the correct floor. A closed
window would also prevent the sound from
carrying, since most buildings tend to be
well insulated. Since the whole operation
depends on the steady flow of electricity, a
break in the middle of a wire would also
cause problems. Of course, the fellow could
shout, but the human voice is not loud
enough to carry that far. An additional
problem is that the string could break on the
instrument. Then there would be no
accompaniment to the message. It is clear
that the best situation would involves less
distance. Then there would be fewer
potential problems. With face to face
contact, the least number of things could go
wrong.
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Chapter summery 14
• Additional factors that aid encoding are
• Finding connections with other information ( the
“chicken” sentence experiment; creating images;
the self-reference effect )
• Generating information ( the generation effect )
• Organizing information ( spontaneous organization
during recall; Bower’s “tree” experiment; the
“Balloon experiment” illustrating what happens
when organization is difficult ).
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Factor that aid encoding
• Maintenance rehearsal : shallow processing
• Elaborative rehearsal : deep processing
• Transfer-appropriate processing
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How are memories stored in the brain ?
Canadian psychologist Donald Hebb 1948
• Learning and memory are represented in
the brain by physiological changes that
take place at the synapse.
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Information storage at the synapse
• Synapses : the small spaces between the end
of one neuron and the cell body or dendrite of
another neuron
• Synaptic transmission : When signals reach
the end of a neuron, they cause
neurotransmitters to be released onto the next
neuron
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Information storage at the synapse
Memory
is represented by changes at the synapse
Experience activate the changes of synapse
• Causing structural changes
• Greater transmitter release
• Increased firing
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Information storage at the synapse
Long – term potentiation ( LTP )
• Enhanced firing of neurons after repeated
stimulation
• Repeated stimulation causes not only
structural changes but also enhanced
responding
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Information storage at the synapse
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Chapter summery 15
• Research on the physiological basis of
memory indicates that the formation of
memories is associated with structural
changes at the synapse.
• These structural changes are then
translated into enhanced nerve firing, as
indicated by long – term potentiation.
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Forming memories in the brain :
Fragility of new memories
• Graded amnesia : amnesia is more severe
for events or learning that was closer in
time to the injury
• Retrograde amnesia : amnesia before
injury , the loss of memory for what has
happened prior to the trauma
• Anterograde amnesia : amnesia after
injury
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Retrograde amnesia
• As a football player runs downfield on a
kickoff
• He is hit hard enough to suffer a
concussion
• Sitting on the sidelines after the play
• He remembers lining up for the kickoff
• But doesn’t remember running down the
field or getting hit
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Electroconvulsive therapy
• People receive shock treatment to help
relieve severe depression
• A brief electrical current is passed through
the brain, causing loss of consciousness
for a few minutes
• They can’t remember things that
happened just before the shock
• Amnesia caused by ECT is generally
temporary, so most of the lost memories
are eventually regained
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H.M.
Anterograde amnesia
• Removal of H.M.’s hippocampus made it
impossible for him to form new memories
Retregrade amnesia (partially)
• Amnesia extended back for about 10-15
years prior to his operation
• He could remember events that occurred
before then
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Graded amnesia
• H.M. could remember events from his
childhood, but apparently not with as much
clarity and detail as a person without brain
damage
Graded amnesia = amnesia is most severe
for events that occurred just prior to the
injury and becomes less severe for earlier,
more remote events
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Forming memories in the brain :
Fragility of new memories
Retrograde amnesia
• Head trauma from football playing
• Electroconvulsive therapy ( ECT )
Anterograde amnesia
• Brain surgery : removed hippocampus
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Forming memories in the brain :
Fragility of new memories
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Forming memories in the brain :
Fragility of new memories
Graded amnesia (retrograde amnesia)
• Memory for recent events is more fragile
than memory for remote events
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Forming memories in the brain :
Fragility of new memories
Consolidation
– Transforms new memories from a fragile
state, in which they can be disrupted, to a
more permanent state, in which they are
resistant to disruption
• A consolidation process must occur before
memories become resistant to being
disrupted
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Chapter summery 16
• Concussions and electroconvulsive
therapy can cause retrograde amnesia.
• This retrograde amnesia is graded, so that
memory loss is greatest for events that
happened closest in time to the trauma.
• This indicates that newly formed memories
are fragile.
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