Transcript Aug7

Cognitive Processes
PSY 334
Chapter 7 – Human Memory:
Retention and Retrieval
August 7, 2003
Inference-Based Intrusions
 Sulin & Dooling – subjects add details
not present during learning:
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Carol Harris vs Helen Keller
“She was deaf, dumb and blind.”
5% Carol Harris but 50% Helen Keller
subjects falsely recognized the sentence.
 Inferences are made at test-time.
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More inferential errors occur with delay.
Plausible Retrieval
 Reder – much of recall is plausible
inference not actual recall.
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Darth Vader inferred to be evil, not
remembered to be evil.
Heir to hamburger chain story – subjects
asked to recall exact details and make
plausible inferences.
 After a delay, plausible inference is
faster and does not decay as much as
exact memory, with no fan effect.
Inference and Elaboration
 Elaboration leads to more inferences.

Information added as a “theme” to a story
results in better recall of studied material
and more inferences.
 Intruded inferences are not necessarily
“errors” but help guide our thinking and
behavior.
 Listerine court case – false inferences,
not just false statements, not permitted.
Memory Errors
 When exact memory is needed,
inferences and reconstructive processes
can be misleading.
 Loftus -- additional details and
suggestion can change what is recalled.
 John Dean’s recall vs what Nixon
recorded – gist was right but not details.
 False memory syndrome – memories
that never happened can be “planted.”
Structure and Retrieval
 Memory is helped by prompts that are
closely associated with what is to be
recalled.

We prompt ourselves when trying to recall.
 Organized material is easier to learn
because it provides a structure for
prompting recall:
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Trees for minerals, animals, clothing,
transportation.
Mnemonics
 Method of Loci – place items in a
location, then take a mental walk.
 Peg-word System – use peg words as a
structure and associate a list of items
with them using visualization.

Create acronyms for lists of items.
 Convert nonsense syllables (DAX, GIB)
into meaningful items by associating
them with real words (e.g., DAD).
Context Effects
 Recall is better if the physical context
during learning is also present during
testing.
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Experimenter clothing, setting.
Under water.
 Eich suggests that context effects
depend on integrating context and the
material to be learned.
Mood Congruence
 Bower et al. – hypnotized subjects and
induced positive or negative mood.
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Recall better if hypnotized into the same
mood during testing as during learning.
Again, the effect may depend upon
integration of mood with material learned.
 Mood congruence – easier to remember
memories congruent with the current
mood.
State-Dependence
 Material is easier to recall if people
return to the same emotional and
physical state as during learning.
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Drinking – some state dependence
together with overall debilitating effect on
memory.
Marijuana and tobacco.
Caffeine.
 Studying when not intoxicated is better.
Encoding Specificity
 The other items presented during
learning provide a context too.

Presentation of cues in as close to the
original learning context aids recall.
 Encoding specificity principle:

The probability of recalling an item
depends on the similarity of its encoding at
test to its original encoding at study.
Test of Encoding Specificity
 Watkins & Tulving:
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Study pairs of words
Generate associates for words & indicate
which were among studied words.
Cued with first word of pair.
61% recall in cued task, <54% in associate
recognition task.
 Recognition generally produces higher
scores so result should have been the
opposite of what occurred.
Amnesia
 Studies of amnesics tell us how memory
is organized in the brain.
 Amnesia occurs with damage to the
hippocampus (and some other areas).
 Kinds of amnesia:
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Korsakoff’s syndrome
Retrograde vs anterograde amnesia
 Patient H.M.
What is Spared in Amnesia?
 Memory for facts, knowledge of
meanings of words, language.
 Memory for how to do things (e.g., play
the piano, tie shoes), skills.
 Priming
 Incidental learning – memory for
experience that was not consciously
attended to.
 Working memory – short term memory.
What is Affected by Amnesia?
 Episodic memory – memory for the
details and experiences of one’s own
life.
 Learning and recall of new material -anterograde amnesia

Because conscious learning starts out as
an episodic experience.
Implicit vs. Explicit Memory
 Explicit memory – knowledge we can
consciously recall.
 Implicit memory – knowledge we cannot
recall but which aids performance on a
task.
 Amnesics can do a word-completion task
but not recall learned words.
 Normal subjects also show an explicitimplicit dissociation.
Procedural Memory
 Procedural memory can be for skills, but
also for doing cognitive tasks.
 Berry & Broadbent – control output of
hypothetical sugar factory by changing
size of workforce (computer simulation):
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Non-obvious formula involved.
After 60 trials subjects were good at task
but could not state the rule involved.
 Amnesics can learn to do this too.