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Long Term Memory

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Title: Long Term Memory


1
Chapter 5
  • Long Term Memory

2
Transfer of Information to LTM
In the modal model of memory, transfer of
information from short-term to long-term memory
was thought to be a function of rehearsal.
3
Supportive evidence comes from a study by Rundus
(1971).
Participants were given lists to learn where the
words were presented at the rate of one word per
second. Participants were asked to rehearse out
loud. Rundus looked at the relationship between
rehearsal and recall.
4
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5
Maintenance vs. Elaborative Rehearsal
  • Maintenance rehearsal Rehearsal for the purpose
    of maintaining information in short-term memory.
  • Elaborative rehearsal Rehearsal for the purpose
    of coding information in long-term memory.

6
An experiment to illustrate the importance of the
distinction
Participants are presented a series of words at a
rate of one word every two seconds. They are
instructed to remember the last word in the
series that begins with a particular letter
(e.g., the letter c).
7
Example
Remember the last word that begins with the
letter c.
8
Example
tree
9
Example
cake
10
Example
boat
11
Example
candy
12
Example
rock
13
Example
bread
14
Example
book
15
Example
pen
16
Example
cold
17
Example
flag
18
Example
bowl
19
Example
What was the last letter that began with the
letter c?
20
Example
Now recall all of the words just viewed.
21
Since candy was rehearsed for the greatest
amount of time, it should be remembered best.
However, research using this paradigm found no
relationship between the length of time a word
was rehearsed and later recall.
22
This leads to the conclusion that only
maintenance rehearsal was used when remembering
the last c word.
23
This leads to the conclusion that only
maintenance rehearsal was used when remembering
the last c word. Transfer to long-term memory
requires elaborative rehearsal.
24
Elaborative rehearsal allows information to be
coded in long-term memory.
25
Elaborative rehearsal allows information to be
coded in long-term memory. Coding in long-term
memory will be discussed in chapter 6.
26
Forgetting in Long-Term Memory
27
Theories of LTM forgetting
  • Decay Memory traces decay with the passage of
    time
  • Interference Other learning interferes with
    memory
  • Retroactive interference
  • Proactive interference
  • Retrieval failure Access to information in LTM
    is lost
  • Motivated forgetting Person deliberately forgets

28
Dissatisfaction with decay theory
Studies of retention following waking and
sleeping states indicate that it is the activity
that occurs during the retention interval that is
responsible for forgetting, not the retention
interval itself.
29
Dissatisfaction with interference theory
Studies of forgetting illustrate that when
appropriate cues are provided, forgetting can
virtually be eliminated.
30
An illustrative experiment (Tulving and Psotka,
1971)
  • Experiment designed to distinguish between
  • trace dependent forgetting forgetting occurs
    when memory trace is lost from memory store
  • cue dependent forgetting forgetting occurs
    when appropriate cues are absent

31
Tulving and Psotka presented a series of
categorized lists to participants. Retroactive
interference caused forgetting of the first list
learned. Providing recall cues (category labels)
to participants alleviated forgetting.
32
Experiment supports the notion of cue-dependent
forgetting.
33
Permanence of memory
In a survey, 84 of psychologists surveyed
believed that memories were permanent. Are
memories permanent?
34
Evidence in support of the permanence
hypothesis.
  • Brain stimulation studies
  • Hypnosis
  • Spontaneous recovery of memory

35
Doubts about the evidence
  • Memory like responses during brain stimulation
    studies only occurs in approximately 3 of the
    patients studied, and then they cant be
    verified.
  • Hypnosis can lead to the fabrication of memories.
    Cases of hypermnesia can be explained by the
    lowering of a response criterion.
  • Spontaneous recovery of memories does not suggest
    that all memories are potentially recoverable.

36
Evidence of substitution (Loftus)
  • Participants view a series of slides depicting an
    accident.
  • Half of the participants are asked a question
    that implied the existence of a traffic sign
    other than what was presented.
  • A subsequent test revealed that participants
    remembered the sign that had been implied rather
    than the sign actually presented.
  • What was implied substituted for what was
    actually experienced.

37
Long-term memory representations
While it is clear that under certain
circumstances we can store verbatim
representations, it is also clear that we
typically store meaningful interpretations of
events
38
Two experiments will illustrate this principle.
39
Experiment 1 (Warner, 1968)
Participants heard the instructions for the
experiment including the following
sentence When you score your results, do
nothing to correct your answers but mark
carefully those answers which are wrong.
40
They then had to decide which of two sentences
had been presented When you score your results,
do nothing to correct your answers but mark
carefully those answers which are wrong. When
you score your results, do nothing to correct
your answers but carefully mark those answers
which are wrong.
41
These sentences do not differ in terms of
meaning, but they do in terms of style.
Participants were able to pick out the original
sentence only about 50 of the time, about
chance.
42
When asked to pick out the correct sentence among
two that differed in meaning, participants were
almost always correct When you score your
results, do nothing to correct your answers but
mark carefully those answers which are
wrong. When you score your results, do nothing
to your correct answers but mark carefully those
answers which are wrong.
43
This suggests that the meaning of the sentence
was retained, not the specific wording.
44
Experiment 2 (Mandler and Ritchey, 1977)
Participants were asked to study a series of
pictures like this one
45
Participants were then given a recognition test
to determine if they could pick out the correct
picture.
Which of the following pictures is the one you
just saw?
46
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47
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48
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49
Participants tended to notice meaningful changes
in the pictures (e.g., the map/picture in the
front of the room), but tended not to notice
changes in irrelevant detail (e.g., the teachers
clothes)
50
Divisions of long-term memory
Some have theorized that long-term memory
consists of more than one memory system.
51
Long-Term Memory
Declarative Memory
Procedural Memory
Episodic Memory
Semantic Memory
52
More on the distinction between episodic and
semantic memory
53
Supporting evidence
  • Case studies. Brain damage has produced memory
    deficits where the individual retains world
    knowledge, but loses personal memories (e.g., the
    case of K.C.)
  • Neuroimaging. Neuroimaging studies have found
    that different parts of the brain are active
    depending on whether retrieval is from semantic
    memory (left frontal lobe) or episodic memory
    (right frontal lobe).

54
Implicit and Explicit Memory
55
The distinction between implicit and explicit
memory
  • Explicit memory Conscious recollection of past
    events
  • Implicit memory when past experience influences
    behavior with out conscious recollection of that
    past experience

56
Previously Mentioned Examples of Implicit Memory
  • Driving on the right side of the road without
    consciously recalling having learned to do so.
  • Avoiding a particular food without consciously
    recalling the fact that you got sick when you ate
    it last.
  • Disliking someone without consciously recalling
    the horrible things they have done to you.

57
Other examples?
58
Other examples?Perhaps intuition?
59
Examples of Explicit Memory?
60
A Laboratory Paradigm for Studying Implicit Memory
  • Present learning material under some other
    pretext (i.e., so that the participant doesnt
    know that his or her memory for the material will
    be tested.
  • Test memory with something that doesnt appear to
    be an explicit or obvious test of memory.

61
Example
  • Have participants rate words with regard to their
    pleasantness
  • food
  • psychology
  • alcohol
  • Have participants solve the following word
    anagram problems
  • yopolgyshc
  • mpentterda

62
Having been exposed to the word psychology
should make it easier to solve the first anagram
than the second anagram yopolgyshc --
psychology mpentterda -- department
63
Other Implicit Memory Tasks
  • Word fragment completion
  • p _ _ c h _ l _ _ y
  • Word stem completion
  • psyc__________
  • Lexical decision task

64
Lexical Decision Tasks
  • Basic task Present letter string to
    participant. Have him or her decide as quickly
    as possible if string makes a word.
  • Repetition priming present string a second
    time. Response second time will be faster
    relative to control
  • Semantic priming present a string that is
    semantically related to previous string.
    Response will be faster relative to control

65
Dissociations between implicit and explicit memory
66
A dissociation occurs when the results obtained
with implicit memory are qualitatively different
from those obtained with explicit memory
67
An example discussed previously
Patients with hippocampal and temporal lobe
damage display large memory deficits when an
explicit test is used, but no deficit when an
implicit test is used.
68
Dissociations are important since they imply that
the processes underlying these two forms of
memory are different.
69
Examples of other dissociations between implicit
and explicit memory
  • Levels of processing effects are found when an
    explicit test of memory is used, but not when an
    implicit test is used.
  • Explicit memory seems to be unaffected by a shift
    in modality from study to test, while implicit
    memory is significantly affected.

70
Some Theoretical Explanations
  • Memory systems explanation Implicit and
    explicit memory involve different memory systems.
    Example - implicit memory might involve semantic
    memory, whereas explicit memory might involve
    episodic memory.
  • Processing explanation Implicit and explicit
    memory involve different memory processes.
    Example - implicit memory might involve data
    driven processes, whereas explicit memory might
    involve conceptually driven processes.

71
In support of the memory systems explanation
  • Almost by definition explicit memory involves
    episodic memory. Both require conscious
    recollection of past experience.
  • Most of the standard tests used to investigate
    implicit memory involve semantic knowledge
  • Amnesic patients can acquire new vocabulary
    (semantic knowledge) while not having conscious
    awareness of that fact.

72
In support of the processes explanation
  • The dissociation involving levels of processing
    is consistent with this explanation
  • The dissociation involving a shift in study-test
    modality also supports this explanation.

73
Implicit memory might be responsible for a number
of memory illusions
  • False fame effect
  • Cryptomnesia
  • Deja vu

74
False Fame Effect Laboratory Paradigm
  • Stage 1 (exposure to names). Participants read a
    list of fictitious names under pretense that it
    is a test of name pronunciation
  • Stage 2 (fame judgements). Names from stage 1
    are combined with an equal number of famous names
    and new fictitious names. Participants asked to
    identify famous names.

75
False Fame Effect Results and explanation
  • Results Old fictitious names (stage 1) are more
    likely to be judged as famous than new fictitious
    names (stage 2)
  • Explanation The initial exposure to the
    fictitious names created a sense of familiarity.
    Because it was not accompanied by conscious
    recollection of its source, it was interpreted as
    evidence of fame.

76
Cryptomnesia
Cryptomnesia refers to unintentional plagiarism.
More specifically, claiming ownership of an idea
or words because you dont recall the original
source.
77
Examples
  • John Lennon
  • John Lennons Free as a Bird
  • Shangri-Las Remember
  • My repetition priming study

78
Cryptomnesia Laboratory Paradigm
  • Participants tested in small goups
  • Stage 1 (generation) Participants given
    categories (e.g. fruit) and asked to generate a
    certain number of examples from the category
    (e.g. apple)
  • Stage 2 (recall own) Each participant asked to
    write down only the examples he or she had
    generated earlier
  • Stage 3 (recall new) Participant generates new
    examples

79
Results
10 of the time participants recalled old
examples (stage 2) or generated new examples
(stage 3) that actually had been generated by
someone else in the experiment. This rate
exceeds that of chance.
80
Explanation
Exposure to items generated by other participants
increased the availability of the items. When an
item came to mind, and the participant couldnt
consciously recall the items source, the
participant claimed the item as their own.
81
Deja Vu
Titchener attributed deja vu experiences to a
quick look that was processed unconsciously.
This created a sense of familiarity (and the deja
vu experience) when the scene was processed more
deliberately.
82
déjà vu Laboratory Paradigm
  • Study Phase Participants study a long list of
    medium frequency words
  • Test Phase
  • Single item, yes/no recognition test given
  • subliminal presentation of context word before
    each item
  • sometimes the context word matches the test word

83
déjà vu Results
When a new word on the recognition test is
preceded by the matching context word, there
was an increase in the likelihood of saying old.
84
déjà vu Explanation
The subliminal presentation of the context word
was processed at an unconscious level. That
resulted in a sense of familiarity when the word
was presented on the recognition test. The
familiarity was falsely attributed to having seen
the item during the study phase.
85
Metacognition
Personal knowledge and awareness of the mental
processes involved in knowing and remembering.
86
Two aspects to metacognition
  • Monitoring relevant mental processes
  • Controlling relevant mental processes

87
Two aspects to metacognition
  • Monitoring relevant mental processes
  • Controlling relevant mental processes

Control requires monitoring
88
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89
Monitoring Types of judgements
  • Judgments of Learning A judgment about how well
    information has been learned. Often assessed by
    having a participant predict success on a test.
  • Feeling of Knowing A judgment about the
    likelihood that one can recognize something that
    they cant recall
  • Confidence Level of certainty that answer is
    correct.

90
Judgments of learning (JOL)
  • Typically participant states probability that
    they will get something right on a test (0 100
    scale)
  • Positively correlated with test performance (r
    .5)
  • Delayed JOLs more accurate than immediate JOLs

91
Feeling of Knowing (FOK)
  • Participant states probability that they will
    correctly recognize an item that they cannot
    recall.
  • Positively correlated with later recognition
    performance (r .67)
  • Important question what is the basis for FOK
    judgments?

92
Confidence judgments
  • Participant states confidence that they have
    responded to a test item correctly.
  • Possitively correlated with test performance (r
    .86)
  • There is a fairly consistent error where people
    overstate their confidence.

93
Calibration Curves
94
Inputs to JOLs and FOKs
  • Direct access
  • Cue familiarity
  • Retrieval fluency

95
Inputs to JOLs and FOKs
  • Direct access
  • Cue familiarity
  • Retrieval fluency

Best supported theory suggests that when making
FOKs, one first determines familiarity of cue and
then how easily they can recall related
information
96
Control of learning
  • There is a negative relationship between JOLs and
    study time.
  • However, people dont always spend more time with
    the items they perceive as most difficult.
    Frequently they will stick with those they are
    confident they can master (region of proximal
    learning).

97
Control of retrieval
  • Decision to attempt retrieval depends on FOKs
  • Output of answer depends on response criterion
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