Memory
A portion of this lecture is adapted from MIT
open courseware, Memory, by J. Gabrielli
What is the name of your
grade 4 (
4
teacher?
Try to remember…
How many words?
A. 0-6
B. 7
C. 8
D. 9
E. 10-16
Is memory like video
recorder?
Memory
Library metaphor
Encoding: Acquire book
Storage: Shelves
Retrieval: Find book
But this metaphor has some limitations, as you will see later…
WHY DO WE REMEMBER
WHAT WE EXPERIENCE?
WHY DO WE FORGET
WHAT WE EXPERIENCE?
BOTTOM-UP & TOP-DOWN
INFLUENCES ON MEMORY
• Bottom-Up
perceptual experience
what we see and hear
• Top-Down
prior knowledge, concepts,
expectations, subsequent
experience
The 3-stage Model of
Memory
SENSORY MEMORY
Temporary storage of
sensory info
Sensory
Input
High capacity
< 1 sec. (vision)
A few sec. (hearing)
SHORT-TERM Encoding LONG-TERM
MEMORY
MEMORY
Brief storage of info
Relatively permanent
currently being used
storage of info
Limited capacity
< 20 sec.
Retrieval
Unlimited capacity
Long or permanent
Three memory store that differ in
function, capacity and duration
12
The 3-stage Model of
Memory
SENSORY MEMORY
Temporary storage of
sensory info
Sensory
High capacity
Input
< 1 sec. (vision)
A few sec. (hearing)
SHORT-TERM
LONG-TERM
Encoding
MEMORY
MEMORY
Brief storage of info
Relatively permanent
currently being used
storage of info
Limited capacity
< 20 sec.
ATTENTION
Info that passes
through an attentional
gate is transferred to
STM
Retrieval
Unlimited capacity
Long or permanent
ELABORATIVE
REHEARSAL
Info subjected to
elaborative rehearsal
is transferred to LTM
13
How do psychologists know that
memory has this kind of structure?
Through experiments, of course!
What letters do you see?
H
A
G
B S
K L
N O
What letters do you see?
H
A
G
B S
K L
N O
(whole-report)
H
A
G
B S
K L
N O
middle row??
H
A
G
B S
K L
N O
(partial-report)
You’re better with partial
report.
Why?
Sperling’s Test
K
Z
R
Q
B
T
S
G
N
George Sperling flashed a group
of letters (see left) for 1/20 of a
second. People could recall only
37% of the letters
When he signaled to recall a
particular row immediately after
the letters disappeared with a
specific tone, they could do so
at 76 % correct.
ATTENTION & SENSORY
STORES
• 12 letter display
whole-report condition
37% correct (4 letters)
• 12 letter display tone after display (high, medium, low
partial-report condition
76% correct (3 letters)
• Much is sensed, but attention selects only a
little to be remembered
Test your understanding
What do you think will happen if Sperling
delayed the tone signal by more than 1
second?
The 3-stage Model of
Memory
SENSORY MEMORY
Temporary storage of
sensory info
Sensory
High capacity
Input
< 1 sec. (vision)
A few sec. (hearing)
SHORT-TERM
LONG-TERM
Encoding
MEMORY
MEMORY
Brief storage of info
Relatively permanent
currently being used
storage of info
Limited capacity
< 20 sec.
Retrieval
Unlimited capacity
Long or permanent
26
SHORT-TERM MEMORY
• limited capacity
• 7+/-2 chunks
Test of Digit Span
I will read a list of numbers and
you have to repeat them back.
Span of 4:
6 1 9 4
Span of 5:
3 7 8 5 2
Span of 6:
9 6 5 2 8 3
Span of 7:
4 2 6 9 8 5 1
Span of 8:
8 1 6 3 7 2 4 9
Span of 9:
6 2 5 7 3 4 9 8 1
Span of 10: 9 3 8 2 4 7 1 5 3 6
Span of 11: 5 8 1 4 7 9 3 2 6 1 7
SHORT-TERM MEMORY
• limited capacity
• 7+/-2 chunks
• BUT…prior knowledge defines
chunks, allows for more
information to be retained in
memory, may also miscode
information
What letters do you see?
F
B
I
C
I
A
I
B
M
M
T
V
What letters do you see?
FBI CIA IBM MTV
F
B
I
C
I
A
I
B
M
M
T
V
FBI
CIA
IBM
MTV
What letters do you see?
GDCEIAHBF
What letters do you see?
ABCDEFGHI
What words do you see?
LEAF PAPER SEAT TIRE CAR FISH
ROCK WIRE WHEEL BEACH TREE
BOY RADIO RULE
What words do you see?
WHILE I WAS WALKING THROUGH
THE WOODS A RABBIT RAN
ACROSS MY PATH
LEAF PAPER SEAT TIRE CAR FISH
ROCK WIRE WHEEL BEACH TREE
BOY RADIO RULE (13)
WHILE I WAS WALKING THROUGH
THE WOODS A RABBIT RAN
ACROSS MY PATH (13)
LEAF PAPER SEAT TIRE CAR FISH
ROCK WIRE WHEEL BEACH TREE
BOY RADIO RULE (13)
WHILE I WAS WALKING THROUGH
THE WOODS A RABBIT RAN
ACROSS MY PATH (13)
Bottom-up or top-down?
SHORT-TERM MEMORY
• limited capacity
• 7+/-2 chunks
• BUT…prior knowledge defines
chunks, allows for more information to
be retained in memory, may also
miscode information
WHERE WERE THE
CHESS PIECES?
Chase & Simon 1973
Chess board presented for 5 seconds
the value & price of knowledge
The 3-stage Model of
Memory
SENSORY MEMORY
Temporary storage of
sensory info
Sensory
High capacity
Input
< 1 sec. (vision)
A few sec. (hearing)
SHORT-TERM
LONG-TERM
Encoding
MEMORY
MEMORY
Brief storage of info
Relatively permanent
currently being used
storage of info
Limited capacity
< 20 sec.
Retrieval
Unlimited capacity
Long or permanent
51
Encoding and Retrieval
• Encoding - process that controls movement
from working to long-term memory store
• Retrieval - process that controls flow of
information from long-term to working memory
store
• Repetition & Rehearsal
• Elaboration
LONG-TERM MEMORY
• serial position effect
primacy (LTM)
recency (STM)
• encoding and depth of processing
• organization
• encoding specificity
• passive forgetting vs. interference
• proactive interference
• retroactive interference
• false memories
Primacy Effect = LTM Recency Effect = STM
Courtesy of Elsevier, Inc., http://www.sciencedirect.com. Used with permission. Source: Glanzer, M., and A. R. Cunitz.
"Two Storage Mechanisms in Free Recall." Journal of Verbal Learning and Verbal Behavior 5, no. 4 (1966): 351-60.
LONG-TERM MEMORY
• serial position effect
primacy (LTM)
recency (STM)
• encoding and depth of processing
• organization
• encoding specificity
• passive forgetting vs. interference
• proactive interference
• retroactive interference
• false memories
Which is More Effective?
Elaboration leads to better recall
than shallow processing
Type of
Processing
Deep
Shallow -Acoustic
Shallow - Visual
0Percentage
10 20of Words
30 40
50 0%-100%
60 70
recalled:
80
Percent of words recalled
90 100
Depth of Processing
Depth of Processing
Level of
Processing
Type of
Encoding
Example
Shallow
Structural Encoding:
Emphasizes the
physical structure
Is the word
written in capital
letters?
Intermediate
Phonemic Encoding:
Emphasizes what a
word sounds like
Does this word
rhyme with
weight?
Semantic Encoding:
Emphasizes the
meaning of the input
Would the word
fit into the
sentence:
He met a ____
on the street.
Deep
If word is in CAPITAL LETTERS,
Tap left hand
If word is in lower case letters,
Tap right hand
zebra
CAR
TABLE
mosquito
MONKEY
train
DESK
termite
BUS
wasp
camel
SOFA
WHAT WERE THE WORDS?
If word names a LIVING thing,
Tap left hand
If word names a non-living thing,
Tap right hand
SPIDER
chair
FOX
TRUCK
lamp
BEE
tiger
boat
RABBIT
tractor
bed
BUTTERFLY
WHAT WERE THE WORDS?
zebra
CAR
TABLE
mosquito
MONKEY
train
DESK
termite
BUS
wasp
camel
SOFA
Appearance
Shallow Encoding
Poor Memory
SPIDER
chair
FOX
TRUCK
lamp
BEE
tiger
boat
RABBIT
tractor
bed
BUTTERFLY
Meaning
Deep Encoding
Good Memory
Courtesy of Elsevier, Inc., http://www.sciencedirect.com.
Used with permission. Source: Craik, F. I. M., and R. S.
Lockhart. "Levels of Processing: A Framework for
Memory Research." Journal of Verbal Learning and
Verbal Behavior 11, no. 6 (1972): 671-84.
LONG-TERM MEMORY
• serial position effect
primacy (LTM)
recency (STM)
• encoding and depth of processing
• organization
• encoding specificity
• passive forgetting vs. interference
• proactive interference
• retroactive interference
• false memories
SERVE
EDUCATE
LAWYER
CAREER
VACUUM
ELECTRICIAN
TEACHER
COOK
DUST
DESIGNED SCRUB
HOUSEWORK
CARPENTER
ENTERTAIN
PLUMBER
ARTIST
RESPONSIBILITES CHILD CARE
PURCHASE CREATIVE
BATHE
FOOD
PHYSICIAN HOME
SKILLED
WRITER
PROFESSIONAL
What did you see?
RESPONSIBILITIES
CAREER
HOME
PROFESSIONAL SKILLED
CREATIVE
HOUSEWORK
CHILD CARE
FOOD
LAWYER
PLUMBER
WRITER
VACUUM
BATHE
PURCHASE
PHYSICIAN
ELECTRICIAN
ARTIST
DUST
EDUCATE
COOK
TEACHER
CARPENTER
DESIGNER
SCRUB
ENTERTAIN
SERVE
Memory better after semantically organized display than after random display
LONG-TERM MEMORY
• serial position effect
primacy (LTM)
recency (STM)
• encoding and depth of processing
• organization
• encoding specificity
• passive forgetting vs. interference
• proactive interference
• retroactive interference
• false memories
© John Wiley And Sons Inc. All rights reserved. This content is excluded from our
Creative Commons license. For more information, see http://ocw.mit.edu/fairuse.
The effect of context on recall of word lists. Words
learned underwater are best recalled underwater, and
vice versa. (From Godden and Baddeley, 1975)
Ebbinghaus’ Curve of Forgetting
Percentage of words remembered
100
90
Immediate recall
80
70
60
20 minutes
50
1 hour
40
9 hours
30
20
10
0
1 2
6
31
Days since learning
Image by MIT OpenCourseWare.
LONG-TERM MEMORY
• serial position effect
primacy (LTM)
recency (STM)
• encoding and depth of processing
• organization
• encoding specificity
• passive forgetting vs. interference
• proactive interference
• retroactive interference
• false memories
WHY DO WE FORGET?
passive forgetting?
or
interference?
Proactive and Retroactive
Interference
Proactive Interference
InInfoforrmmaattioonnbbeeinngg
leleaarrnneeddccuurrrreennttllyy
Interferes
InInfoforrmmaattioonnleeaarrnneedd
pprreevviioouussllyy
Retroactive Interference
InInfoforrmmaattioonnbbeeinngg
leleaarrnneeddccuurrrreennttllyy
Interferes
InInfoforrmmaattioonnleeaarrnneedd
pprreevviioouussllyy
Image by MIT OpenCourseWare.
Retroactive
Interference
© University of Illinois Press. All rights reserved.
This content is excluded from our Creative
Commons license. For more information, see
http://ocw.mit.edu/fairuse.
Long-Term Memory (LTM)
aka What We Usually Mean by “Memory”
Long-Term Memory
Implicit
Explicit/Declarative
(knowing you know)
Episodic
Experienced
events
Semantic
Facts,
knowledge
Procedural
Motor skills
Dispositions
Conditioning
BOTTOM-UP & TOP-DOWN
INFLUENCES ON MEMORY
• Bottom-Up
perceptual experience
what we see and hear
• Top-Down
prior knowledge, concepts,
expectations, subsequent
experience
Is memory like video recorder?
Evidence?
Take 1 min to write down an
empirical evidence