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Memory
MAR 3503
January 24, 2012
Basic memory processes
• Encoding
– Codes can be acoustic, visual, or semantic
• Storage
– Can store episodic, procedural, or semantic
memories
• Retrieval
– Can be done via recognition or recall
Sensory memory
• “Holding cells”
– Holds information from the sensory registers until
it can be processed further
• Fleeting
• Brings continuity to the world
• Only some is passed on for further processing
Short-term (working) memory
• Holds limited amounts of information until it
is:
– Used in response
– Stored more permanently
– Lost
• Information can be encoded:
– Acoustically (ECVTGB or HLEITF)
– Visually
– And other ways (e.g., kinesthetically)
STM capacity
• Is determined with a memory span test
• “Magic number” thought to be 7 +/- 2
• Capacity can be increased by “chunking”
• 7 meaningful units, rather than 7 letters or
numbers
STM: The importance of rehearsal
•Ps given a list of nonsense syllables
•Told to count backwards (to prevent rehearsal)
•Stopped after certain number of seconds, tested for memory of syllables
Peterson & Peterson, 1959
Long-term memory
• …Holds information more permanently after it
has been transferred from STM
• Potentially unlimited capacity
• Usually involves semantic coding
– Surface features are less important
A model of memory
Environmental input
Response
Retrieval
Short-term
(working) memory
Sensory memory
Encoding
Long-term
memory
Storage
How LTM and STM interact
How LTM and STM interact
• The serial position curve
• Primacy effect
– Early items in list remembered well because you had
time to transfer them into LTM
• Recency effect
– Later items in list remembered well because they’re
still in STM
• Obvious implications for
– Lists
– Commercials
The seven sins of memory
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The sin of transience
The sin of absent-mindedness
The sin of blocking
The sin of misattribution
The sin of suggestibility
The sin of bias
The sin of persistence
Transience
• Memories are connections between neurons
in the brain
– Without use, these connections weaken or even
disappear
• Forgetting
– Information is likely still there, just not being
retrieved properly
LTM: How do we get info to stay in?
• Rehearsal
– Transmits info to LTM, strengthens connections
between neurons
– Not just any rehearsal though (some work better
than others)
• Best: Elaborative rehearsal/elaborative
encoding
– This helps us create cues for remembering
Elaboration
• Ps saw 40 adjectives
• For each, they were
asked to indicate:
– Whether it was in
uppercase letters
– Whether it rhymed with
XXXX
– Whether it meant the
same as YYYY
– Whether it described
them
• Their memory for the
adjectives was tested
Rogers et al., 1977
How LTM is organized
Associative Network
OREO
cow
milk
farm
cookie
chocolate
wheat
flour
brown
bakery
cake
mud
slice
pie
golf
Principles of an associative networks
• Spreading activation
• Priming
– …Activating a node in memory
– A primed, or activated, node may then activate
other nodes and may trigger associated behaviors
• One implication
– The more associations a node (e.g., a product)
has, the better its chance of getting
activated/retrieved
Retrieval from LTM
• Retrieval cues
– Pull information from long-term memory into
short-term memory
• Which cues will be effective?
– Encoding specificity
• The best cues for retrieval are the ones that were there
at encoding
Retrieval: Context dependence
Cues can be very broad. Memory can be helped by similarities between the encoding and
retrieval environments.
Godden & Baddeley, 1975
Retrieval: Context dependence
• Retrieval is better when the conditions of
retrieval match the conditions of encoding
– Under water
– Classroom
– Mood
– Odors
– Chemicals
Encoding
(Learning)
Retrieval
(Test)
Cues and
context
Absent-mindedness
• Lapses of attention that result in failing to
remember information
– Info that never gets encoded properly
– Info that is available in memory by is overlooked at
the time we need to retrieve it
• Divided attention often at fault
– Prevents us from transferring info to LTM
– Interferes with recollection (specific details of event)
but not familiarity (remembering that an event
happened)
Absent-mindedness
• Failures of retrospective memory
– Not remembering something that happened in the
past
– Divided attention often at fault
• Prevents us from transferring info fully to LTM, or creating
the right cues
• Interferes with recollection (specific details of event) but
not familiarity (remembering that an event happened)
• Failures of prospective memory
– Not remembering something that you’re supposed to
do
• Time-based cues easy to forget
• Event-based cues easier to elaborate on, more likely to
succeed
Blocking
• Two types of interference
– Retroactive interference
• Learning new info interferes with the memory of the
old
Blocking
• Interference, continued
– Proactive interference
• Old knowledge interferes with ability to learn
something new
– Part-list cueing
• Learn a list
• Recall for part of the list is cued
• The partial retrieval can block recall of the rest of the
list
– Ex. “We’re better than Tide and Cheer”
Blocking
• Names are very commonly blocked
– Name retrieval comes after visual and conceptual
memory, which can interfere with the name
• They’re also only tenuously linked to a name
– Also partly due to there being only one name per
person, so you can’t fall back on a synonym
• The tip of the tongue effect
Tip of the tongue
• Most common for infrequent words
– Lack of use weakens connections between lexical
and phonological aspects of words
• They still exist; that’s why you can know what the first
letter is
• “Ugly sisters” play a part
– The related but incorrect words that you come up
with
– Like part-list cueing—blocks the true word from
coming forth
Misattribution
• Another reason why the filing cabinet
metaphor isn’t right
• Deese lists and lures
• Schemas can be activated at encoding and
misapplied
– (Similar to miscategorization)
– Leads to schema-consistent recall
• Can work in a marketer’s favor
• Or against it
Suggestibility
• The power of the
question
– Watch a tape of a car
accident
– How fast were the cars
going when they…?
Contacted?
31.8 mph
Hit?
34.0 mph
Collided?
39.3 mph
Smashed?
40.5 mph
•1 week later: Did you see any broken glass when they:
•Smashed: 32% yes
•Hit: 14% yes
•Control condition (no verb): 12% yes
Loftus & Palmer, 1974
Bias
• Our desires and beliefs guide our memories
– Just as the format of a question can shape the answer, so
can the answer we want to give shape the answer we
actually give
• Stereotypes influence what we recall about others
– People “remember” women were more emotional than
men last month
– People are more likely to “remember” Black-sounding
names correspond to criminals than White-sounding
names
• We’ll talk about biased memories more later in the
semester
Persistence
• Ever get a song stuck in your head?
• The opposite of the other sins—remembering
something you want to forget
• Usually negative memories fade faster than
positive ones (see bias, too)—why don’t
these?
– Continual reminding
– Cues too common or too strong
– Suppression backfires
Why the irony?
• Two processes:
– Automatic target search: automatically “looks for” the
unwanted (to-be-suppressed) thought all during the
suppression period, and if it finds the target it alerts the
controlled distracter search to focus on something else
– Controlled distracter search: operates when the person
implements the plan to think of something else. But when
cognitive resources are scarce or stretched to the limit (for
instance, under cognitive load, as when you are asked to
remember a number for later recall), this distracter search
may fail
Ironic sexism
Summary
• How can memory be improved?
– Rehearsal and chunking keeps info in STM longer
• This may aid transfer to LTM
– Elaborate encoding (including self-relevance) encourages
integration into LTM
– Retrieval and encoding should occur under similar
conditions
– Interference should be minimized
• But, what’s stored might not be the same as what’s
retrieved. Watch out for
– Schemas
– Leading questions
Next time
• What are attitudes?
• How do we form them?