Sensory Memory
Iconic Memory
Echoic Memory
Iconic Memory
What is the evidence?
Subjective experience
Objective measurements
Judge duration of a light
Interference
Sperling’s (1960) work
capacity
decay (forgetting)
Iconic Memory
What is the evidence?
Subjective experience – flash demo
Iconic Memory
What is the evidence?
Objective measurements
Judge duration of a light
Interference
Sperling’s (1960) work
capacity
decay (forgetting)
Objective measurements
judge duration of a light
Simple task:
When light comes on, press button
When the light goes off, press button
time
milliseconds (ms)
Light
ON
0
time
milliseconds (ms)
Light
ON
Button
pressed
0
200
time
milliseconds (ms)
Light
ON
Button
pressed
Light
OFF
0
200
600
time
milliseconds (ms)
Light
ON
Button
pressed
Light
OFF
Button
pressed
0
200
600
1000
time
milliseconds (ms)
Light
ON
Button
pressed
Light
OFF
Button
pressed
0
200
600
1000
Objective measurements
judge duration of a light
participant thinks light is ON
longer than it actually is
and a measurement can be obtained
Iconic Memory
What is the evidence?
Objective measurements
Judge duration of a light
Interference
Sperling’s (1960) work
capacity
decay (forgetting)
demos
Ref to Demos (labs)
N
&
E
C
&
Demo 1
Interference
basic effect is that performance decreases
Proactive interference (&, letter)
interference comes before the stimulus
in this paradigm called a forward mask
Retroactive interference (letter, &)
interference comes after the stimulus
in this paradigm called a backward mask
How does the interference actually work?
Integration &
F
the stimulus and the interference become
enmeshed (integrated)
- could occur w/ proactive or retroactive
interference
How does the interference actually work?
Integration &
F
the stimulus and the interference become
enmeshed (integrated)
- could occur w/ proactive or retroactive
interference
Interruption
processing of stimulus gets stopped when
processing of interfering material begins
- could occur for retroactive interference
(but not proactive interference)
Demo 2 -- Sperling’s (1960) work
Present stimulus array (matrix of letters) briefly
(e.g., 50 ms)
F
D
R
L
S
M
N
V
E
G
K
C
Sperling’s (1960) work
Present stimulus array (matrix of letters) briefly
(e.g., 50 ms)
Task
Report all of the letters—called whole report
participants do okay but not very good
Sperling’s (1960) work
Present stimulus array (matrix of letters) briefly
Task
Report all of the letters—called whole report
participants not very good
Report one row of the letters—called partial report
cued by a tone (high, middle, low)
then estimate number of letters that can
be retrieved
Sperling’s (1960) work
Span of apprehension
Number of items that could be retrieved
Whole report – 4.5 letters
Sperling’s (1960) work
Span of apprehension
Number of items that could be retrieved
Whole report – 4.5 letters
Partial report – 3.03 x 3 rows = 9.1 letters
Sperling’s (1960) work
Span of apprehension
Whole report – 4.5 letters
Partial report – 9.1 letters
Higher estimate for partial report than whole report
Why?
Sperling’s (1960) work
Span of apprehension
Whole report – 4.5 letters
Partial report – 9.1 letters
Higher estimate for partial report than whole report
Why? Fast Forgetting (decay of icon)?
Sperling’s (1960) work
Partial report
delay report of row (w/ delayed cue)
track performance as a function of delay
(retention interval)
F
D
R
L
S
M
N
V
E
G
K
C
F
D
R
L
S
M
N
V
E
G
K
C
Partial report with different delays for the tones
Probability of Report as Function of Time
1.0
P(r)
0.0
0
1
Time (s)
Probability of Report as Function of Time
1.0
9.1 items
P(r)
4.5 items
0.0
0
1
Time (s)
Probability of Report as Function of Time
1.0
9.1 items
P(r)
4.5 items
(same as measure
from whole report)
0.0
0
1
Time (s)
Conclusion: Image or icon decays very quickly
Different partial report procedure
(Averbach & Coriell, 1961)
Use a visual marker as a cue to report a
single letter from a matrix
Different partial report procedure
(Averbach & Coriell, 1961)
Use a visual marker as a cue to report a
single letter from a matrix
X P N V B W D L
F Y C T Q H Z G
X P N V B W D L
F Y C T Q H Z G
X P N V B W D L
F Y C T Q H Z G
Performance with bar cue ( ) much better than that
with the circle cue (
).
Why?
Performance with bar cue ( ) much better than that
with the circle cue (
).
Why? Circle cue acted as a backward mask
—metacontrast mask (which produced a
metacontrast effect).
Evidence for integration vs. interruption ideas?
Iconic Memory
What is the evidence?
Subjective experience
Objective measurements
Judge duration of a light
Interference
Sperling’s (1960) work
measured capacity
decay (forgetting)
Have a good day!