Sensory
memory
Ch 5 p116-123
Memory •
•
•
•
Book: “Life is all memory” Do you agree? What would a life without memory be like? h<p://www.youtube.com/watch?v=pv0B0Z6mZrQ 1
"
Learning Objective Topics
• Atkinson & Shiffrin Model"
• What is Sensory Memory?"
•  Iconic"
•  Span and Duration of Iconic Memory"
•  What Influences Iconic Memory? "
•  Echoic"
•  Span and Duration of Echoic "
•  What Influences Echoic Memory? "
•  Iconic and Echoic Compared
Information-processing approach
•  Atkinson & Shiffrin (1968): Modal model of
memory
•  Sensory memory
•  Short-term memory
•  Long-term memory
2
"
Learning Objective Topics
• Atkinson & Shiffrin Model"
• What is Sensory Memory?"
•  Iconic"
•  Span and Duration of Iconic Memory"
•  Processing of Iconic Memory: Brain or Retina?"
•  What Influences Iconic Memory? "
•  Echoic"
•  Span and Duration of Echoic "
•  What Influences Echoic Memory? "
•  Iconic and Echoic Compared
Sensory Memory"
•  Very short-term
storage of information
•  within the sensory
systems
•  allow us to perceive
the information
Information in
the world
Sensory
Memory
(very short
term; .5-2
sec
maximum)
3
Sensory Memory"
•  Decays (fades away) the
fastest of all memory types
that we will talk about
•  Depends on the sense that
we are talking about
Information in
the world
Sensory
Memory
(very short
term; .5-2
sec
maximum)
It depends on the sense: •  Vision: iconic memory
•  Auditory: echoic memory
4
Sensory memory
•  Purpose?
•  Persistence: beyond physical duration
•  Collect and hold until further processing
•  Integration
•  Provides stability for senses
•  Fill-in the blanks (e.g. blinks)
•  Radio Lab Short: Blinks
http://www.radiolab.org/blogs/radiolab-blog/
2009/oct/05/blink/
"
Learning Objective Topics
• Atkinson & Shiffrin Model"
• What is Sensory Memory?"
•  Iconic"
•  Span and Duration of Iconic Memory"
• What Influences Iconic Memory? "
•  Echoic"
•  Span and Duration of Echoic "
•  What Influences Echoic Memory? "
•  Iconic and Echoic Compared
5
Iconic memory
•  Lightning
•  Movie projectors – Flickers -> Flicks
Photography: shutter speed
1/30
1/500
6
Perceptual Span"
How much can we remember from a single glance?
H P
D
S
K O Q D
J
George Sperling (1960)
M V
P
Guesses?
Sensory Memory"
A display with 16 letters will appear briefly. Write
down as many letters as you can remember.
Look at the screen.
7
8
Sensory Memory"
How many could you remember?"
"
What was your subjective impression?
"
"
"
"
"
9
“Whole report” procedure: Ask
participants to recall as many letters as
they can"
George Sperling (1960)
Sensory Memory"
A display with 16 letters will appear briefly.
Afterward, I will ask you to recall either
The top row,
The middle row,
or
The bottom row
Try to remember as many letters as possible in
the row corresponding to what I say: “Top,
Middle or Bottom”
10
Q
G Z
K
S E
B
R
L
V
F
X
11
Q
G Z
K
S E
B
R
L
V
F
X
12
Q
G Z
K
S E
B
R
L
V
F
X
13
Q
G Z
K
S E
B
R
L
V
F
X
How did you do?
14
Sensory Memory"
Sperling’s “Partial report” procedure: "
•  recall as many letters as they can from a
particular line "
•  high tone = top line; middle tone = middle
line; low tone = bottom line)"
"
**Because participants don’t know in advance
which line will be tested, this suggests that
all letters are briefly held in a sensory store"
Sensory Memory • Delayed parGal report method • What was this? • What did it show? 15
Sensory Memory"
Iconic memory --> very short duration
(~500ms)"
" "
"
--> rapid decay (only enough ""
" "
"
" time to recall 3-4 letters)"
" "
"
--> very large capacity"
"
Learning Objective Topics
• Atkinson & Shiffrin Model"
• What is Sensory Memory?"
•  Iconic"
•  Span and Duration of Iconic Memory"
•  What Influences Iconic Memory? "
•  Echoic"
•  Span and Duration of Echoic "
•  What Influences Echoic Memory? "
•  Iconic and Echoic Compared
16
Sensory Memory"
How do we know whether iconic memory results from
processing in the brain or retina?"
"
"
"
Is it even memory at all?
Sensory Memory"
+
+
17
Sensory Memory"
•  Is Iconic memory just an afterimage?"
•  Is it something that happens in the brain or
just an effect of our photoreceptors in the
retina?"
"
"
Sensory Memory"
How do we know whether iconic memory
results from processing in the brain or
retina?"
"
1) Visual after-effects in the retina have color
reversal; not true of iconic memory"
18
Sensory Memory"
•  Retinal effects are eyespecific"
•  Brain effects are visualfield-specific"
Sensory Memory"
•  What if we use a color mask for one eye?"
•  If it doesn’t interrupt visual memory what
would that mean?"
•  If it does what would that mean?"
19
A
X Q
C
B
M R
F
G
D W
S
20
A
X Q
C
B
M R
F
G
D W
S
Sensory Memory"
"
1)  Brightness masks disrupts iconic
memory only if letters and mask shown
to same eye"
-  suggests iconic memory at the level
of retina"
21
Z
D S
A
B Y
V
M
L
C
X
T
##
##
##
##
##
##
##
##
##
##
##
##
##
##
##
##
##
##
##
##
22
Z
D S
A
B Y
V
M
L
X
T
C
Sensory Memory"
"
1)  Brightness & pattern masks disrupt iconic
memory"
-  brightness masking works only if show
letters & mask to same eye (so suggests
level of retina)"
-  Pattern masking works even if show
letters to one eye & mask to the other
eye (so suggests level of brain)"
23
Sensory Memory"
Does iconic memory result from processing in
the brain or retina?"
"
Some aspects of iconic memory may occur at
level of retina, but that at least some features
of iconic memory are due to processing in
the brain"
"
• How does this relate to change blindness? 24
"
Learning Objective Topics
• Atkinson & Shiffrin Model"
• What is Sensory Memory?"
•  Iconic"
•  Span and Duration of Iconic Memory"
•  What Influences Iconic Memory? "
•  Echoic"
•  Span and Duration of Echoic "
•  What Influences Echoic Memory? "
•  Iconic and Echoic Compared
Echoic memory
•
•
•
•
•
How would you study echoic memory?
Questions
Methods
IVs, DVs
Hypotheses
25
Echoic Memory"
Have you ever asked someone “What?”
and then almost immediately realized that
you did know what they just said?
This ability highlights echoic memory
(sensory memory for auditory information)
An Example"
“You’re not listening.”
“What?”
“You’re not listening, Kate.”
“Yes, I am.”
“What did I just say?”
“You’re not listening, Kate.”
“Before that?”
“Don’t know.”
“This is important.”
“Sorry.”
•  You
don’t have to
be consciously
paying attention to
have sensory
memory!!
•  It just has to enter
your sensory
system!!
From A Ghost In the Machine by Caroline Graham
26
"
Learning Objective Topics
• Atkinson & Shiffrin Model"
• What is Sensory Memory?"
•  Iconic"
•  Span and Duration of Iconic Memory"
•  Processing of Iconic Memory: Brain or Retina?"
•  What Influences Iconic Memory? "
•  Echoic"
•  Span and Duration of Echoic "
•  What Influences Echoic Memory? "
•  Iconic and Echoic Compared
27
Sensory Memory"
"
"
"
How do we know whether echoic memory is
influenced by meaning, or only by the
auditory percepts?"
"
Proportion Correct!
Echoic Memory – Suffix Effect"
Ask participants to
listen to a series of
numbers
100!
90!
80!
70!
60!
50!
40!
30!
20!
10!
0!
buzzer suffix!
speech suffix!
1! 2! 3! 4! 5! 6! 7! 8! 9!
End the list either
with a buzzer
noise or with a
speech sound
Serial Position!
Interference from similar types of
sounds as in the list (speech)
Then ask
participants to
No interference from different types of repeat the
numbers
sounds (buzzer)
28
Echoic Memory"
What does it mean for suffix to be similar or different?
context/meaning-based similarity?
- depends on how people interpret the sound
“baa” as animal noise does not interfere; but “baa”
human sound does;
“waa” trumpet noise does not interfere; but “waa” as
human sound does
- so echoic memory is not only perceptual; it is
influenced by the meaning of the auditory information
Echoic memory
•  Why do we care?
•  Allows more time to analyze stimulus
•  Able to process significantly more
•  Practical implications
•  Use silent rehearsal to slow rate of decay
•  Use to distinguish clinical populations: e.g.
schizophrenia
29
"
Learning Objective Topics
• Atkinson & Shiffrin Model"
• What is Sensory Memory?"
•  Iconic"
•  Span and Duration of Iconic Memory"
•  Processing of Iconic Memory: Brain or Retina?"
•  What Influences Iconic Memory? "
•  Echoic"
•  Span and Duration of Echoic "
•  What Influences Echoic Memory? "
•  Iconic and Echoic Compared
Echoic vs. Iconic Memory"
Echoic memory lasts longer
(~2-5 sec for echoic vs. ~500ms for iconic)
Echoic memory has lower capacity (iconic nearly limitless)
***Both Echoic and Iconic are influenced by stimulus
meaning; not purely retention of meaningless,
perceptual information
30
Sensory v. STM
Sensory memory
Short-term memory
•  Capacity
•  Capacity
•  Duration
•  Duration
•  Unprocessed
•  Accurate
•  Passive
•  Can be manipulated
•  Can be inaccurate
•  Active
•  Iconic: 17+ items
•  Echoic: 5+ items
•  Iconic: 500ms
•  Echoic: 2s
•  1-4 items
•  7 +/- 2 items
•  30s without rehearsal
31