Sperling (1960) Mixed Arrays

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Sperling (1960)Mixed Arrays

• Dr. Timothy Bender
• Psychology Department
• Missouri State University
• 901 S. National Avenue
• Springfield, MO 65897

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Mixed Arrays
In the sixth experiment in Sperlings (1960)
classic study of the characteristics of the
iconic memory (visual sensory memory), he
explored what effect the type of stimulus had on
performance under the Partial Report Method.
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Mixed Arrays
Usually, in the Partial Report Technique
participants see an array of letters with two or
more rows. They are provided a cue as to which
row of the array to report. Usually, the signal
is a tone that occurs at the offset of the array.
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Mixed Arrays
In his sixth experiment, Sperling used a 2x4
array of 4 letters and 4 single-digit numbers.
There were two letters and two numbers in each
row. Participants were tested for their memory
for the top and bottom rows, as well as their
memory for the four numbers and the four letters.
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Mixed Arrays
The purpose of this research was to see if people
could maintain the visual iconic trace long
enough to make categorical distinctions as well
as they make spatial distinctions. If the
participants could make number versus letter
distinctions as quickly as they could top versus
bottom distinctions, then they should score
equally well on both types of tasks.
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Mixed Arrays

• In the first part of this demonstration, you
  will see 10 different 2x4 arrays of letters and
  numbers. As each array disappears, you will hear
  a tone. A high tone means you should record the
  top row. And a low tone means you should record
  the bottom row. Record both the letters and the
  numbers in their correct locations.

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Mixed Arrays

• You will need to listen to the tones a few times
  in order to recognize which one is high and which
  is low.

Move the cursor over this speaker to hear the
high tone. Move the cursor over this speaker to
hear the low tone.
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Mixed Arrays

• Procedure
• After the next slide, you will see 10 stimuli.
  
• Each stimulus will start with a slide telling
  you to get ready. Click on that slide to see the
  actual stimulus.
• You will then see a sign in the middle of
  the screen. Focus on the sign.
• The sign will remain for about 1 second and
  will be followed by a 2x4 array of letters and
  numbers.
• The array will last for about 70 milliseconds.
  
• The tone will occur as the array disappears.

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Mixed Arrays
Your job is to write down the letters and numbers
in the row that corresponds to the tone. Record
these in their correct positions as quickly as
you can. It is important that you write down a
letter or number in every position, even if it
feels like a guess. However, do NOT just write
down all Xs or something like that. Also, do not
try to predict which row will be cued. That
actually may reduce your overall score.
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Get Ready for Stimulus 1
11

12
Record your response.
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Get Ready for Stimulus 2
14

15
Record your response.
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Get Ready for Stimulus 3
17

18
Record your response.
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Get Ready for Stimulus 4
20

21
Record your response.
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Get Ready for Stimulus 5
23

24
Record your response.
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Get Ready for Stimulus 6
26

27
Record your response.
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Get Ready for Stimulus 7
29

30
Record your response.
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Get Ready for Stimulus 8
32

33
Record your response.
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Get Ready for Stimulus 9
35

36
Record your response.
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Get Ready for Stimulus 10
38

39
Record your response.
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Mixed Arrays

• Scoring
• Give yourself one point for each letter or
  number in the correct location for all 10
  stimuli.
• Multiply that number by 2, because there were
  2 rows possible.
• Divide that number by 10 to get your mean
  score.

1. D58M 6 C8B9
2. S82Z 7 4VY6
3. 1GK3 8 H91W
4. 72PK 9 1G4D
5. L4K8 10 2H9N

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Mixed Arrays

• In the second part of this demonstration, you
  will see 10 different 2x4 arrays of letters and
  numbers. As each array disappears, you will hear
  a tone. A high means you should record all 4
  numbers in their correct positions. A low tone
  means you should record all 4 letters in their
  correct positions.

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Mixed Arrays

• You will need to listen to the tones a few times
  in order to recognize which one is high and which
  is low.

Move the cursor over this speaker to hear the
high tone. Move the cursor over this speaker to
hear the low tone.
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Mixed Arrays

• Procedure
• After the next slide, you will see 10 stimuli.
  
• Each stimulus will start with a slide telling
  you to get ready. Click on that slide to see the
  actual stimulus.
• You will then see a sign in the middle of
  the screen. Focus on the sign.
• The sign will remain for about 1 second and
  will be followed by a 2x4 array of letters and
  numbers.
• The array will last for about 70 milliseconds.
  
• The tone will occur as the array disappears.

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Mixed Arrays
Your job is to write down the 4 letters or the 4
numbers, depending on the signal. Record these in
their correct positions as quickly as you can.
Write down a letter or number in every position
in which you think one occurred, even if this
feels like a guess. However, do NOT just write
down all Xs or something like that. Also, do not
try to predict whether you will report letters or
numbers. That actually may reduce your overall
score.
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Get Ready for Stimulus 1
46

47
Record your response.
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Get Ready for Stimulus 2
49

50
Record your response.
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Get Ready for Stimulus 3
52

53
Record your response.
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Get Ready for Stimulus 4
55

56
Record your response.
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Get Ready for Stimulus 5
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59
Record your response.
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Get Ready for Stimulus 6
61

62
Record your response.
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Get Ready for Stimulus 7
64

65
Record your response.
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Get Ready for Stimulus 8
67

68
Record your response.
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Get Ready for Stimulus 9
70

71
Record your response.
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Get Ready for Stimulus 10
73

74
Record your response.
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Mixed Arrays

• Scoring
• Give yourself one point for each letter or
  number in the correct location for all 10
  stimuli.
• Multiply that number by 2, because there were
  either letters or numbers possible.
• Divide that number by 10 to get your mean
  score.

1 //82 4 6/4/ 7 //25 10 /8/6 /5/9 83//
/9/1 /25/ 2 F//N 5 /HL/ 8 /5/3 /CV/ /R/W
/12/ 3 T//B 6 /WZ/ 9 /J/P /GJ/ /K/N
//MS
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Mixed Arrays

• Compare your class scores for the Rows task and
  the Numbers/Letters task. If you did not perform
  nearly as well on the Letters/Numbers task, you
  are in good company. For Sperlings trained
  participants, the average score on the
  Letters/Numbers task was 4.6. The average score
  on the Rows task was 7.5.

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Mixed Arrays

• Making a categorical distinction in that short of
  a period of time is very difficult. In fact, this
  type of result has led researchers to suggest
  that iconic memory processing is pre-categorical.

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References

• Sperling, G. (1960). The information available in
  brief visual presentations. Psychological
  Monographs General and applied, 74, 1-29.