Memory
Mental processes that enable us to
acquire, retain and retrieve
information.
Three Processes of Memory
• Encoding
– Transforming info into a form that can be
entered and retained
• Storage
– Retaining info in memory to be used later
• Retrieval
– Recovering stored info
Stage Model of Memory
• Three stages
– Sensory
– Short-term
– Long-term
• What separates the three are differences of the
following
– Capacity
– Duration
– Function
Sensory Memory Store
Sensory
Input
Sensory
Memory
• Function - holds
information long enough to
be processed for basic
physical characteristics
• Capacity - large
– can hold many items at once
• Duration - very brief
retention of images
– .3 sec for visual info
– 2 sec for auditory info
Sensory Memory Store
• Divided into two
subtypes:
Sensory
Input
Sensory
Memory
– iconic memory - visual
information
– echoic memory auditory information
• Visual or iconic
memory was discovered
by Sperling in 1960
Sperling’s Experiment
• Presented matrix of letters for
1/20 seconds
• Report as many letters as
possible
• Subjects recall only half of the
letters
• Was this because subjects didn’t
have enough time to view entire
matrix?
• No
• How did Sperling know this?
K
Z
R
Q
B
T
S
G
N
Sensory Memory Store
Sensory
Input
Sensory
Memory
• Sensory memory forms
automatically, without
attention or interpretation
• Attention is needed to
transfer information to
working memory
Working Memory Store
Sensory
Input
Sensory
Memory
Attention Working or
Short-term
Memory
Working Memory Store
• Function - conscious processing of information
– where information is actively worked on
• Capacity - limited (holds 7 +/- 2 items)
• Duration - brief storage (about 30 seconds)
• Code- Often based on sound or speech even with
visual inputs.
Sensory
Input
Sensory
Memory
Attention Working or
Short-term
Memory
Working Memory Store
• What happens if you need to keep information in
working memory longer than 30 seconds?
• To demonstrate, memorize the following phone
number (presented one digit at a time):
857916 3
Working Memory Store
857-9163
• What is the number?
The number lasted in your working memory
longer than 30 seconds
So, how were you able to remember the
number?
Maintenance Rehearsal
• Mental or verbal repetition of information allows
information to remain in working memory longer
than the usual 30 seconds
Maintenance Rehearsal
Sensory
Input
Sensory
Memory
Attention
Working or
Short-term
Memory
Chunking
• Grouping small bits of information into
larger units of information
– expands working memory load
• Which is easier to remember?
–4 8 3 7 9 2 5 1 6
– 483 792 516
Serial Position
• Primacy Effect
– Remember what you hear 1st
• Recency Effect
– Remember what you hear last
Long-Term Memory Store
• Once information passes from sensory to
working memory, it can be encoded into
long-term memory
Maintenance Rehearsal
Sensory
Input
Encoding
Sensory
Memory
Attention
Long-term
Working or
memory
Short-term
Memory Retrieval
Long-Term Memory Store
• Function - organizes and stores information
– more passive form of storage than working memory
• Unlimited capacity
• Duration - thought by some to be permanent
Maintenance Rehearsal
Sensory
Input
Encoding
Sensory
Memory
Attention
Long-term
Working or
memory
Short-term
Memory Retrieval
Automatic vs. Effortful Encoding
• Automatic processing
– Unconscious encoding of information
– Examples:
• What did you eat for lunch today?
• Was the last time you studied during the day or night?
• You know the meanings of these very words you are
reading. Are you actively trying to process the definition of
the words?
Automatic vs. Effortful Encoding
• Effortful processing
– Requires attention and conscious effort
– Examples:
• Memorizing your notes for your upcoming
Introduction to Psychology exams
• Repeating a phone number in your head until you
can write it down
– Different levels of effortful processing
Shallow processing
• Processing only superficial characteristics of a
piece of information
• Examples:
– visual encoding: encoding of images
• Does a word contain the letter “e”?
• Does a word contain all capital letters?
• Was the word in italics?
– acoustic encoding: sound-based encoding
• Does a word rhyme with gum?
– Maintenance rehearsal: simple repetition
Deep levels of processing
• Elaboration: focus on meaning of
info to encode info into LTM
– don’t simply repeat items over and over
– tie item to other info in memory
– also called elaborative rehearsal
Ways to use deep processing
•
•
•
•
•
Actively question new info
Think about its implications
Relate info to things you already know
Generate own examples of concepts
Don’t highlight a passage as you read
– focus on the ideas in the text
Which level is more effective?
Type of Processing
Deep
Semantic
(type of…)
Shallow - Acoustic
Acoustic
(rhymes with...)
Shallow - Visual
Visual
(written in capitals?)
0
10
20
30
40
50
60
70
80
90
100
Percent of words recalled
Deep processing leads to better recall than shallow processing
Enhancing encoding
• Dual coding theory
• Mnemonics
– Visualization
• Link a word with a mental picture
• Sillier the better
– method of loci
– peg word method
• 1 is bun
• 2 is shoe
– Acronym
• 1st letter of each word SQ3R
– Survey, Question, Read, Recite and Review
Method of Loci
• Imagine moving
through a familiar
series of locations
– the campus, your house,
etc.
• Associate each
place/room with a
visual representation
of the objects to be
remembered
Recall vs. Recognition tests
• Importance of retrieval cues evident in recall vs.
recognition tests
• Recall tests - must retrieve info learned earlier
– Examples: Fill-in-the-blank test; essay exams
• Recognition tests - only need to identify the
correct answer
– Example: Multiple choice tests
What is the capital of Vermont?
• Raise your hand if you know the
answer
What is the capital of Vermont?
•
•
•
•
•
•
•
A. Brattleboro
B. Montpelier
C. Rutland
D. Cabot
Raise your hand if you know the answer
Which was easier-recall or recognition?
For your psychology exam, would you rather
have a fill-in-the-blank or a multiple choice test?
Types of Long-term Memory
Long-term Memory
Explicit Memory
Episodic
Memory
Semantic
Memory
Implicit Memory
Procedural
Memory
Classical
Conditioning
Priming
Explicit memory
• aka Declarative or Conscious memory
• Memory consciously recalled or
declared
• Can use explicit memory to directly
respond to a question
• Two subtypes of explicit memory
Subtypes of Explicit Memory
Explicit Memory
Episodic Memory
Semantic Memory
Episodic memory
• Memory tied to your own personal experiences
• Examples:
– 16th birthday?
– Do you remember your 1st spelling bee?
• Q: Why are these explicit memories?
• A: Because you can actively declare your
answers to these questions
Flashbulb Memories
• What were you doing
when…?
• Usually involves
stressful or
emotionally arousing
personal or historical
events
Flashbulb Memories (cont.)
• Anderson & Conway
(1997) coined the term
“flashbulb memory”
• Permanently seared
into the brain
Semantic memory
• Memory not tied to personal events
• General facts and definitions about the
world
• Examples:
– How many tires on a car?
– What is a cloud?
– What color is a banana?
Semantic memory
• Q: Why are these explicit memories?
• A: Because you can actively declare your
answers
• Important note: Though you may have
personal experience with these items,
your ability to answer Q’s does NOT
depend on tying the item to your past
– i.e. Do not have to recall the time last week when
you ate a banana to say that bananas are yellow
Implicit memory
• aka nondeclarative memory
• Influences your thoughts or behavior,
but does not enter consciousness
• Three subtypes
Subtypes of Implicit Memory
Implicit Memory
Classical
Conditioning
Procedural
Memory
Priming
Procedural memory
• Memory that enable you to perform specific learned
skills or habitual responses
• Examples:
– Riding a bike
– Using the shift stick while driving
– Tying your shoe laces
• Q: Why are these procedural memories implicit?
• A: Don’t have to consciously remember the steps
involved in these actions to perform them
– Try to explain to someone how to tie a shoelace
Review of Long-term Memory
• Retrieval transfers info from LTM to STM
• Forgetting - inability to retrieve previously
available information
• Why do people forget?
Maintenance Rehearsal
Attention
Sensory
Input
Sensory
Memory
Encoding
Working or
Long-term
Short-term
memory
Memory Retrieval
Forgetting theories
• Poor encoding
theories
• Decay theories
• Interference
theories
• Retrieval-cue
theories
When do we forget?
Sensory memory
The senses momentarily register
amazing detail.
Short-term memory
A few items are both noticed
and encoded.
Long-term storage
Some items are altered or lost.
Retrieval from long-term memory
Depending on interference,retrieval
cues, moods, and motives, some
things get retrieved, some don’t.
• Forgetting
can occur at
any
memory
stage
Forgetting as encoding failure
• Info never encoded into LTM
Short-term
memory
X
Encoding
Encoding failure
leads to forgetting
Long-term
memory
Encoding failures
• Even though you’ve seen thousands
of pennies, you’ve probably never
looked at one closely to encode
specific features
Which is the real penny?
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
(m)
(n)
(o)
(k)
(l)
Answer
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
(m)
(n)
(o)
(k)
(l)
Other encoding failure demos
• What letters accompany the
number 5 on your telephone?
• Where is the number 0 on your
calculator?
• According to this theory, objects
seen frequently, but info never
encoded into LTM
Forgetting as retrieval failure
• Not all forgetting is due to encoding failures
• Sometimes info IS encoded into LTM, but we
can’t retrieve it
Encoding
Short-term
memory
X
Long-term
memory
Retrieval
Retrieval failure
leads to forgetting
Retrieval failure theories
• Decay theories
• Interference theories
• Retrieval cue theories
Decay theories
• Memories fade away
100
100%
or decay gradually if
Average 90
percentage of 80
unused
information
70
• Time plays critical retained 60
role
50
40
• Ability to retrieve
30
info declines with
20
10
time after original
0
encoding
20
mins
1
hr
8
hrs
24
2
6
31
hrs days days days
Interval between original learning of
nonsense syllables and memory test
Decay theories
• Biology-based theory
• When new memory formed, it creates a
memory trace
– a change in brain structure or chemistry
• If unused, normal brain metabolic processes
erode memory trace
• Theory not widely favored today
– info CAN be remembered decades after original
learning
• even if unused since original learning
Interference theories
• “Memories interfering with memories”
• Caused by one memory competing with
or replacing another memory
Two types of interference
Types of interference
Retroactive
Interference
Proactive
Interference
Retroactive interference
• When a NEW memory interferes with
remembering OLD information
• Example: When new phone number
interferes with ability to remember
old phone number
Retroactive interference
• Example: Learning a new language
interferes with ability to remember old
language
Study French
Study Spanish
papier
livre
papel
plume
école
libro
pluma
escuela
retroactive interference
French 101
Mid-term
exam
Proactive interference
• Opposite of retroactive
interference
• When an OLD memory
interferes with remembering
NEW information
• Example: Memories of
where you parked your car
on campus the past week
interferes with ability find
car today
Proactive interference
• Example: Previously learned language
interferes with ability to remember newly
learned language
Study French
Study Spanish
papier
livre
papel
plume
libro
école
pluma
escuela
proactive interference
French 101
Mid-term
exam
Retrieval cue theories
• Retrieval cue - a clue, prompt or
hint that can help memory
retrieval
• Forgetting the result of using
improper retrieval cues
Which retrieval cues work best?
• Encoding specificity principle cues used during initial learning
more effective during later
retrieval than novel cues
Which retrieval cues work best?
• Context-dependent memory - improved
ability to remember if tested in the same
environment as the initial learning
environment
– Better recall if tested in classroom where you initially
learned info than if moved to a new classroom
– If learning room smells of chocolate or mothballs,
people will recall more info if tested in room with the
same smell
• compared to different smell or no smell at all
Context dependent effects
• Time of day is also important
Learn at 3pm
Perform better at 3pm
12
9
12
3
6
Than 9pm
9
12
3
6
9
3
6
Context-dependent effects
50
• Words heard Percentage
of words
recalled
40
underwater are
best recalled
30
underwater
20
• Words heard on
10
land are best
0
recalled on land
Water/
land
Land/
water
Different contexts
for hearing
and recall
Water/
water
Land/
land
Same contexts
for hearing
and recall
State-dependent effects
• Recall improved if internal physiological
or emotional state is the same during
testing and initial encoding
• Context-dependent - external,
environmental factors
• State-dependent - internal, physiological
factors
State-dependent effects
– Mood or emotions also a factor
– Bipolar depressives
• Info learned in manic state, recall more if
testing done during manic state
• Info learned in depressed state, recall
more if testing done during depressed
state
State dependent effects
Drunk during
learning
Recall better
if drunk
Than if sober
Eyewitness testimony
• Recall not an exact replica of original events
• Recall a construction built and rebuilt from
various sources
– Also known as confabulation or reconstructive
• Often fit memories into existing beliefs or
schemas
• Schema - mental representation of an object,
scene or event
– Example: schema of a countryside may include green grass,
hills, farms, a barn, cows etc.
Loftus experiment
Accident
• Subjects shown video of
an accident between two
cars
• Some subjects asked:
How fast were the cars
going when the smashed
into each other?
• Others asked: How fast
were the cars going
when the hit each other?
Leading question:
“About how fast were the cars going
When they smashed into each other?”
Memory construction
Loftus results
Word Used
in Question
smashed
collided
bumped
hit
contacted
Average
Speed Estimate
41 m.p.h.
39 m.p.h.
38 m.p.h.
34 m.p.h.
32 m.p.h.
Evidence for separate
implicit/explicit systems?
• Neurophysiological evidence
• Patient H.M.
– Life-threatening seizures originating in
temporal lobe
– surgically removed portions of temporal
lobe
Temporal lobe
• Includes:
– hippocampus
– amygdala
Temporal
lobe
Hippocampus
Hippocampal damage
• Deficits in
forming new
explicit
memories
Patient H.M.
• surgery was effective in reducing seizures
• BUT, had other side effects as well
• Can remember explicit memories acquired
before the surgery
– e.g. old addresses, normal vocabulary
• Had difficulty forming NEW explicit memories
– e.g. remembering the name of someone he met 30 minutes
prior
– cannot name new world leaders or performers
Patient H.M. Summary
• Temporal lobe damage led to deficits in
explicit, but not implicit memory
– H.M. had both episodic and semantic memory deficits
• Damage to the hippocampus alone produces
episodic, but not semantic memory deficits
• Why did H.M. show both types of explicit
memory deficits?
– He had damage not only to hippocampus, but to other
structures as well
Priming
• Pass out demonstration sheets
Priming demonstration
• Unscramble the following word:
•L T E P A
• Answer:
•P E T A L
•P L A T E
Priming
• Why did half the class say plate
and the other half say petal?
• They were primed to do so
• There were two different sheets of
unscrambled words
Priming sheet 1
• Unscramble the
following word:
•
•
•
•
•
•
FINEK
OPONS
KROF
PUC
ECUSAR
LTEPA
• Answer:
•
•
•
•
•
•
KNIFE
SPOON
FORK
CUP
SAUCER
P LAT E
Priming sheet 2
• Unscramble the
following word:
•
•
•
•
•
•
NYPAS
FELA
KTALS
DUB
LOBSOMS
LTEPA
• Answer:
•
•
•
•
•
•
PAN S Y
LEAF
S TALK
BUD
BLOSSOM
PE TAL
Priming
Seeing
the word rabbit
Activates concept
Primes spelling
the spoken
word hair/hare
as h-a-r-e
Priming
• Activation of one or more existing
memories by a stimulus
• Activation not a conscious decision
• BUT, can effect subsequent thoughts
and actions
• Two types of priming
Two types of priming
Priming
Conceptual
Perceptual
Conceptual priming
• When priming stimulus influences your flow
of thoughts
• Thought to involve activation of concepts
stored in semantic memory
• Example: Previous priming demonstration
• Example: If you hear a story about a pitbull,
when someone later asks you to name a dog,
you’re more likely to say “pitbull”
Perceptual priming
• Can you identify the fragmented
stimulus below?
Perceptual priming
• What if you
were shown the
following slide
earlier in the
lecture?
Perceptual priming
• Can you identify
the fragmented
stimulus to the
right?
Perceptual priming
• What if you were
shown the
following slide
earlier in the
lecture?
Perceptual priming
• When a priming stimulus enhances
ability to identify a test stimulus based on
its physical features
• Priming is implicit because you don’t
need to consciously recall seeing the
priming stimulus in order for priming to
occur
Types of Long-Term Memory
•
•
•
•
Semantic memory
Episodic memory
Declarative memory
Procedural memory
Semantic Memory
• Knowledge of
language, including its
rules, words, and
meanings
• Retaining facts
• Semantic memory is
not imprinted on our
brains
Episodic Memory
• Memories of one’s
own life (also includes
the time experiences
occurred)
• Like a personal diary
Declarative Memory
• Holds knowledge that can be called forth
consciously as needed
• “What” and “that”
Procedural Memory
• Memory of learned
skills that do not
require conscious
recollection
• We gradually lose the
ability to describe
what we are doing
when we perform
these skills
Retrospective vs.
Prospective Memory
• Retrospective memory: past experience or
events and previously acquired information
• Prospective memory: things you need to do
in the future
Muscle Memory
• Relying on muscles to
perform complex
motor skills such as
riding a bike, dancing,
typing, hitting a
baseball
Eyewitness Testimony
• Memory does not
always work like a
camera that records
and retrieves
snapshots of events
• Eyewitness testimony
can be flawed
• Misinformation effect
Classical conditioning
• Pavlov
Natural reflex
• Previously
neutral stimulus Neutral stimulus + UCS (food in mouth)
now comes to (ringing bell)
elicit a response
after pairing
with an
Conditioned reflex
unconditioned
CS (ringing bell)
stimulus
UCR
(salivation)
CR
(salivation)