1. Phonological Loop, Visuospatial Sketchpad & Articulatory Suppression
Psychology 355: Cognitive Psychology Instructor: John Miyamoto 04/23/2018: Lecture 05-1
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2. Lecture probably ends here
Outline
Working Memory (WM) Model is a multi-component model of STM.
Phonological Loop (PL):
Phonological similarity effect
Word length effect
Articulatory suppression reduces phonological similarity effect and word length effect.
Visuospatial Sketchpad (VSP)
Mental subtraction of images
Brooks’ experiment with pointing and verbal responses
Lecture probably ends here
Psych 355, Miyamoto, Spr '18
Quiz 4 Will Be an Essay Quiz

3. Quiz 4 on April 30 is an Essay Quiz
The question on this quiz will be very similar to one of the sample questions in the handout (also, it will be posted on the Psych 355 website).
Purpose of Quiz 4 is to give students practice at answering an essay question. Midterm 2 will have an essay question on it.
The essay question on Quiz 4 will be graded much more leniently than the essay question on Midterm 2.
The TA's will mark the Quiz 4 essay answers to show what would lose points on the midterm exam, even if these errors do not lose points, or only a small fraction of points, on Quiz 4.
Psych 355, Miyamoto, Spr '18
Reminder: The Modal Model of Memory with Empasis on STM

4. Modal Model of Memory (circa 1970)
Control Processes
Input
Sensory Memory
Short-Term Memory
Long-Term Memory
Output: Speech/Actions
Psych 355, Miyamoto, Spr '18
Diagram for the Baddeley-Hitch Working Memory Model

5. Baddeley-Hitch Working Memory (WM) Model
Think of the diagram to the right as an expansion & revision of the standard STM model.
Phonological Loop (PL)
Storage of sounds
Rehearsal
Manipulation of verbal information
Visuospatial Sketch Pad (VSP)
Storage & manipulation of visual images and spatial information.
3. Central Executive (CE)
Directs activity within the PL or VSP.
Coordinates activity between PL, VSP, and LTM.
Basic Idea: At least two short-term memory stores, audition (language), visual/spatial.
What justifies the hypothesis that there are separate memory stores?
What justifies the assumption of an executive process.
Psych 355, Miyamoto, Spr '18
Same Slide Without the Emphasis Rectangles

6. Baddeley-Hitch Working Memory (WM) Model
Think of the diagram to the right as an expansion & revision of the standard STM model.
Phonological Loop (PL)
Storage of sounds
Rehearsal
Manipulation of verbal information
Visuospatial Sketch Pad (VSP)
Storage & manipulation of visual images and spatial information.
3. Central Executive (CE)
Directs activity within the PL or VSP.
Coordinates activity between PL, VSP, and LTM.
Basic Idea: At least two short-term memory stores, audition (language), visual/spatial.
What justifies the hypothesis that there are separate memory stores?
What justifies the assumption of an executive process?
Psych 355, Miyamoto, Spr '18
What Justifies the Hypothesis: PL is Part of WM?

7. What Justifies the Hypothesis: PL Is Part of WM?
Summary of Evidence for PL (Phonological Loop)
Phonological similarity effect: Memory span is smaller for lists of similar-sounding words than for lists of dissimilar-sounding words.
Example 1: Remember the list, D B C T P G (harder)
Example 2: Remember the list, K F Y L R Q (easier)
Word length effect: Memory span is greater for lists of short words than for lists of long words.
Articulatory suppression experiments
Neuropsychological evidence (later - not in this lecture)
Psych 355, Miyamoto, Spr '18
Demo of the Phonological Similarity Effect

8. Demo of Phonological Similarity Effect: Memory Span for Words
On each trial, you will see a sequence of words presented one after the other.
Your Task: Write down all of the words in the order in which they were presented.
For example, if you see
ORANGE  LOOSE  GRIP  TUESDAY
Write down: ORANGE, LOOSE, GRIP, TUESDAY Note that ORANGE, TUESDAY, GRIP, LOOSE is incorrect.
On each trial, make a mental note of how hard it was to do the task.
Psych 355, Miyamoto, Spr '18
Fixation Point for Demo

9. Word Span Trial with 5 Words: How Hard Is This?*
Note to Self: The following slides advance automatically on a timer, i.e., don't advance the slides manually.
Psych 355, Miyamoto, Spr '18
Next: On Click – Display Stimulus Words on a Timer, 1 Slide per second

10. Digit
EASE
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11. Digit
GONE
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12. Digit
SING
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13. Digit
TOP
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14. Digit
CRISP
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15. What Were the Words? Correct Answer: EASE, GONE, SING, TOP, CRISP
Remember how hard was that task. Next: Repeat task but with different stimulus words.
Fixation Point
Psych 355, Miyamoto, Spr '18

16. Word Span with 5 Words: How Hard is This?*
Note to Self: The following slides advance automatically on a timer, i.e., don't advance the slides manually.
On Click, Display Stimulis on Timer, 1 Slide per Second
Psych 355, Miyamoto, Spr '18

17. Digit
RAKE
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18. Digit
FATE
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19. Digit
TASTE
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20. Digit
BREAK
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21. Digit
BAIT
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22. What Were the Words? Correct Answer: RAKE, FATE, TASTE, BREAK, BAIT
Which word list was harder to remember?
List 1: The words are not similar in sound.
List 2: The words are similar in sound.
List 2 is harder to remember.
This is the phonological similarity effect.
Psych 355, Miyamoto, Spr '18
Theoretical Analysis of the Phonological Similarity Effect

23. Interpretation of Phonological Similarity Effect
Compare:
List 1: EASE GONE SING TOP CRISP MINT DOOR
List 2: RAKE FATE TASTE BREAK BAIT RATE FADE
Interpretation of Phonological Similarity Effect
Phonological similarity effect: Memory span is smaller for similar-sounding words than for dissimilar sounding words.
What does this show about working memory?
Interpretation of Phonological Similarity Effect
Psych 355, Miyamoto, Spr '15

24. Interpretation of Phonological Similarity Effect
Phonological similarity effect: Memory span is smaller for similar-sounding words than for dissimilar sounding words.
What does this show about working memory?
Basic Assumption of PL: One way that people maintain information in STM is by rehearsing the sound of words.
Similar-sounding words are more confusable in a sound-based rehearsal. Memory span for similar-sounding words should be smaller if retention is based on rehearsal in the PL.
The predicted smaller memory span for lists of similar-sounding words is confirmed (even if the stimuli are presented visually!).
Psych 355, Miyamoto, Spr '15
Repeat: Evidence for the Existence of a Phonological Loop

25. Evidence for the Hypothesis: PL Is Part of WM
Phonological similarity effect: Memory span is smaller for lists of similar-sounding words than for lists of dissimilar-sounding words.
Example 1: Remember the list, D B C T P G (harder)
Example 2: Remember the list, K F Y L R Q (easier)
Word length effect: Memory span is greater for lists of short words than for lists of long words.
Articulatory suppression experiments
Neuropsychological evidence (later - not in this lecture)
Phonological similarity effect was explained in lec04-4.p355.spr15.pptm.
Demo of the Word Length Effect
Psych 355, Miyamoto, Spr '15

26. Next: Demo of Word Length Effect
Word length effect: Memory span is smaller for list of long words than for lists of short words.
"Long" means multisyllabic.
We already did some trials with short words.
Next: Memory span trial with long words.
Psych 355, Miyamoto, Spr '18
Fixation Point for Demo

27. Word Span with 5 Words: How Hard is This?*
Note to Self: The following slides advance automatically on a timer, i.e., don't advance the slides manually.
Psych 355, Miyamoto, Spr '18
On Click, Display Stimulus on a Timer, 1 Slide per Second

28. Digit
HABITUALLY
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29. Digit
NEUROTOXIN
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30. Digit
ANTICIPATION
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31. Digit
DECIDUOUS
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32. Digit
SAXOPHONE
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33. What Were the Words?
Correct Answer: HABITUALLY, NEUROTOXIN, ANTICIPATION, DECIDUOUS, SAXOPHONE
Which word list was harder to remember?
First list: Short dissimilar sounding words
Third list: Long dissimilar sounding words .
Theoretical Analysis of the Word Length Effect
Psych 355, Miyamoto, Spr '18

34. Interpretation of Word Length Effect
Word length effect: Memory span is smaller for lists of long words than for lists of short words.
What does this show about working memory?
Basic assumption of PL: One way that people maintain information in STM is by rehearsing the sound of words.
Prediction: Since longer words take longer to rehearse, it takes longer to complete the list and return to each word in the list. Therefore we are more likely to forget words from a list of N long words than to forget words from a list of length N short words. Thus, memory span should be smaller for longer words.
Prediction is confirmed.
Psych 355, Miyamoto, Spr '18
Word Length Effect & Digit Span: Chinese, Welsh, & English - END

35. Word Length Effect & Digit Span
England
How long does it take to pronounce the digits, 1, 2, 3, ...., in various languages?
Welsh > English > Chinese
What is digit memory span for speakers of various languages?
Welsh < English < Chinese
Interpretation:
Everybody has the same basic STM capacity.
Chinese speakers can rehearse digits faster than English speakers. Therefore they can retain more digits on the average in a Digit Span task.
English speakers can rehearse digits faster than Welsh speakers. Therefore they can retain more digits on the average in a Digit Span task.
Wales
Finding for Welsh speakers was originally noticed by: Ellis, N. C.; Hennelly, R. A. (February 1980). "A bilingual word-length effect: Implications for intelligence testing and the relative ease of mental calculation in Welsh and English". British Journal of Psychology 71 (1): 43–51.
They noticed that Welsh children did worse than English speaking children on a digit span portion of the Wechsler IQ test. They investigated the reasons for this; they found that the word length effect was the probable cause.
Psych 355, Miyamoto, Spr '18
Return to List of Evidence for PL: Next Is Articulatory Suppression

36. Evidence for the Hypothesis: PL Is Part of WM
Phonological similarity effect: Memory span is smaller for lists of similar-sounding words than for lists of dissimilar-sounding words.
Example 1: Remember the list, D B C T P G (harder)
Example 2: Remember the list, K F Y L R Q (easier)
Word length effect: Memory span is greater for lists of short words than for lists of long words.
Articulatory suppression experiments
Neuropsychological evidence (later - not in this lecture)
Phonological similarity effect was explained in lec04-4.p355.spr15.pptm.
Articulatory Suppression
Psych 355, Miyamoto, Spr '18

37. What Is Articulatory Suppression?
Articulatory Suppression: Have subject speak an irrelevant sound, e.g., "the, the, the, the, ....", while performing a memory task.
Purpose of articulatory suppression: Prevent use of PL while performing the memory task. The conflicting task ("the, the, the, ...") prevents use of PL.
Prediction: Articulatory suppression should reduce or eliminate the phonological similarity effect and the word length effect because ....
articulatory suppression prevents use of PL while performing the memory task, and ...
phonological similarity effect and word length effect result from speech-based representations in PL whose use is blocked by articulatory suppression.
Impact of Articulatory Suppression on Word Length Effect
Psych 355, Miyamoto, Spr '18

38. Word Length Effect & Articulatory Suppression
List 1: (long words) helicopter, transformation, synergy, counterpoint, ....
List 2: (short words) ant, top, ear, dog, red, .....
Condition 1A: Subjects read List 1, then try to remember it.
Condition 2A: Subjects read List 2, then try to remember it.
Condition 1B: Subjects read List 1 while saying "the, the, the, the, ...." Then they try to remember it.
Condition 2B: Subjects read List 2 while saying "the, the, the, the, ...." Then they try to remember it.
Psych 355, Miyamoto, Spr '18
Comment re Articulatory Suppression & Phonological Similarity Effect

39. Articulatory Suppression Reduces the Word Length Effect
Normal Word Length Effect
Articulatory Suppression
Cond 1A vs 2A
Cond 1B vs 2B
book dog neurotoxin mendacious
Results for Conditions 1A and 2A were not shown graphically in the Goldstein textbook. Results for Conditions 1B and 2B are shown in Figure 5.13.
Conditions 1A and 2A: Normal word length effect was found.
Conditions 2A and 2B (with articulatory suppression): Lists of short or long words remember about equally.
Psych 355, Miyamoto, Spr '18
Interpretation of This Result

40. Articulatory Suppression Reduces the Word Length Effect
Normal Word Length Effect
Articulatory Suppression
Cond 1A vs 2A
Cond 1B vs 2B
book dog neurotoxin mendacious
Articulatory suppression prevents rehearsal of word sounds (perhaps the subject rehearses the word images).
So word length no longer has as much effect.
Comment re Articulatory Suppression & Phonological Similarity Effect
Psych 355, Miyamoto, Spr '18

41. Articulatory Suppression & the Phonological Similarity Effect
Articulatory suppression also reduces the phonological similarity effect. (Results shown in a later lecture and in the textbook.)
These results support the existence of PL and the importance of verbal rehearsal in PL.
Summary re PL
Psych 355, Miyamoto, Spr '18

42. Summary re Phonological Loop (PL)
Basic assumption of PL: One way that people maintain information in a short-term memory store is by rehearsing the sound of words.
This assumption predicts that ...
... similar sounding words should be more easily confused in PL (phonological similarity effect)
... longer words should be harder to maintain in PL (word length effect).
... preventing people from verbal rehearsal should eliminate these effects (articulatory suppression).
Psych 355, Miyamoto, Spr '18
Return to Diagram of Baddeley-Hitch WM Model

43. Baddeley-Hitch Working Memory (WM) Model
Next
Phonological Loop (PL)
Short-term storage
Rehearsal
Manipulation of verbal information
Visuospatial Sketch Pad (VSP)
Short-term storage of visual & spatial information
Manipulation of visual images and spatial information.
Next
Basic Idea: At least two short-term memory stores, audition (language), visual/spatial.
What justifies the hypothesis that there are separate memory stores?
What justifies the assumption of an executive process.
3. Central Executive
Directs activity within the PL or VSP.
Coordinates activity between PL or VSP, and between these components and long-term memory (LTM). ##
Psych 355, Miyamoto, Spr '18

44. Next: Brandimonte's Mental Subtraction Task
Results for the mental subtraction task support two hypotheses:
There exists a memory storage system based on storage of visual information. (Will be called the "visuospatial sketchpad" or VSP)
Articulatory suppression prevents rehearsal in PL, thereby forcing the subject to maintain information in VSP.
Psych 355, Miyamoto, Spr '18
Description of the Mental Subtraction Task

45. Brandimonte: Mental Subtraction Task
Brandimonte, M. A., Hitch, G. J., & Bishop, D. V. M. (1992). Influence of short-term mem­ory codes on visual image processing: Evidence from image transformation tasks. Journal of Experimental Psychology: Learning, Memory, and Cognition, 18,
The mental subtraction task is not discussed in the Goldstein textbook.
Sample stimuli, A and A'
First, the subject sees A.
Next A disappears and the subject sees A'.
Mental Subtraction Task: “Mentally subtract" the second stimulus from the first; then name the object that remains.
* Important to note that if the subject names the first image, A or B, then it is harder to access a name for the image that remains after subtraction, X or Y, respectively.
Psych 355, Miyamoto, Spr '18
Same Slide with “Remainder” Image After Subtraction

46. Brandimonte: Mental Subtraction Task
Remainder after mental subtraction
Subject is not shown this image.
Sample stimuli, A and A'
First, the subject sees A.
Next A disappears and the subject sees A'.
Next A’ disappears and the subject must do the mental subtraction.
Mental Subtraction Task: The subject must mentally "subtract" the second stimulus A’ from the first stimulus A, and name the object that remains: e.g., Remainder = Ice Cream Cones.
* Important to note that if the subject names the first image, A or B, then it is harder to access a name for the image that remains after subtraction, X or Y, respectively.
Psych 355, Miyamoto, Spr '18
Instructions for a Sample Trial in the Mental Subtraction Experiment

47. Sample Experiment: Mental Subtraction
Next you will see an image.
After this image is removed, you will see a second image.
Mentally subtract the second image from the first image, and name the image that remains after the subtraction.
Psych 355, Miyamoto, Spr '18
Image 1 of the Mental Subtraction Example

48. Example: Memorize This Image
Image B
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Image to be Subtracted from this Image

49. Subtract This Image from the Preceding Image
Image B'
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Name the Image that Results from Subtraction

50. Subtract This Image from the Preceding Image
Name the image that results from mentally subtracting Image B’ from Image B.
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Name the Image that Results from Subtraction

51. Name the Image that Results From Subtracting Image B' from Image B?
Result of Subtracting Image B' from Image B (This image would not be shown to a subject)
Possible answer: A fish
Psych 355, Miyamoto, Spr '18
Summary: Mental Subtraction Experiment

52. Summary: Mental "Subtraction" TaskX
Subtraction Task: The subject must mentally "subtract" the second stimulus from the first, and name the object that remains.
Possible answer for A and A' on Left: Ice cream cones.
Possible answer for B and B' on Right: Fish
Important to note that if the subject names the first image, then it is harder to access a name for the image that remains after subtracting the second image.
Also, note that subjects were not instructed to name the first image. (Naming the first image happens automatically; this is a mental habit.)
* Important to note that if the subject names the first image, A or B, then it is harder to access a name for the image that remains after subtraction, X or Y, respectively.
Psych 355, Miyamoto, Spr '18
Combine with Mental Subtraction with Articulatory Suppression

53. Combine Mental Subtraction with Articulatory Suppression1 2
Condition 1: Subject does the mental subtraction task.
Condition 2: Subject says "la, la, la, la, ...." while doing the mental subtraction task.
Finding: Subjects perform BETTER in Condition 2 than in Condition Why?
Psych 355, Miyamoto, Spr '18
Interpretation of Mental Subtraction Experiment

54. Interpretation of Mental Subtraction Experiment
The stimuli were designed so that subjects could name the object before "subtracting" the second image.
E.g., with stimulus 1, a subject might think "headphones".
If a subject silently says "headphones" while looking at the left part of stimulus 1, it is harder to see ice cream cones in the image that results from mental subtraction.
Saying "la, la, la, la, ...." suppressed the tendency to name the initial stimulus, so the subject relies only on the visual image in VSP. This makes the subtraction task easier.
Psych 355, Miyamoto, Spr '18
Summary re Mental Subtraction - END

55. Summary re Mental Subtraction
Assumption: People can maintain a visual/spatial representation of information by actively processing it in VSP.
Hypothesis: Suppression of PL can improve processing on tasks if ...
... people are in the habit of naming the image (recoding initial image into the PL), but .....
.... the task is actually performed more easily in VSP alone.
Result: Articulatory suppression does improve performance on the mental subtraction task.
This result is hard to explain if STM is a single storage area without separate PL & VSP.
The result supports the WM model that assumes there are separate PL & VSP memory storage mechanisms.
END
Psych 355, Miyamoto, Spr '18