evidence for a visuospatial sketch pad (vsp) psychology 355: cognitive psychology instructor: john...

Evidence for a Visuospatial Sketch Pad (VSP)

Psychology 355: Cognitive Psychology

Instructor: John Miyamoto

4/28/2015: Lecture 05-2

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Outline

• Brandimonte's Mental Subtraction ExperimentMental Subtraction + Articulatory Suppression

• Brook's Image Scanning ExperimentInterference between VSP & PL

• Similarities and differences between PL and VSP

Psych 355, Miyamoto, Spr '15 2#

3Psych 355, Miyamoto, Spr '15

Baddeley-Hitch Working Memory (WM) Model

1. Phonological Loop (PL)o Short-term storageo Rehearsalo Manipulation of verbal

information

2. Visuospatial Sketch Pad

(VSP)o Short-term storage of visual

& spatial informationo Manipulation of visual

images and spatial information.

3. Central Executiveo Directs activity within the PL

or VSP.o Coordinates activity between

PL or VSP, and between these components and long-term memory (LTM).

Brandimonte Mental Subtraction Task

Next

Next


A

A'

Sample stimuli, A and A' o First, the subject sees A. o 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.

Brandimonte: Mental "Subtraction" Task

Brandimonte, M. A., Hitch, G. J., & Bishop, D. V. M. (1992). Influence of short-term mem ory codes on visual image processing: Evidence from image transformation tasks. Journal of Experimental Psychology: Learning, Memory, and Cognition, 18, 157-165.

Same Slide with “Remainder” Image After Subtraction


A

A'

Sample stimuli, A and A' o First, the subject sees A. o Next A disappears and the subject sees A'.

Mental Subtraction Task: The subject must mentally "subtract" the

second stimulus from the first, and name the object that remains.

Remainder = ice cream cones.

Brandimonte: Mental "Subtraction" Task

Brandimonte, M. A., Hitch, G. J., & Bishop, D. V. M. (1992). Influence of short-term mem ory codes on visual image processing: Evidence from image transformation tasks. Journal of Experimental Psychology: Learning, Memory, and Cognition, 18, 157-165.

Instructions for a Sample Trial in the Mental Subtraction Experiment

Remainder after mental subtraction

Subject is not shown this image.


Subtraction Task: The subject must mentally "subtract" the second

stimulus from the first, and name the object that remains.o Possible answer for A and A' on Left: Ice cream cones. o 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.

Summary: Mental "Subtraction" Task

Combined with Mental Subtraction with Articulatory Suppression

A X

BA' B' Y


Combine Mental Subtraction with Articulatory Suppression

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 1. Why?

Interpretation of Mental Subtraction Experiment

Screen 1 Screen 2 Mental Image(not displayed to subject)


Interpretation of Mental Subtraction Experiment

• The stimuli were designed so that subjects could name the object

before "subtracting" the second image. o E.g., with stimulus 1, a subject might think "candy".

• If a subject silently says "candy" while looking at the first image,

it is harder to see "fish" after subtracting the second image.

• Saying "la, la, la, la, ...." suppressed the tendency to name the left

part of the stimulus, so the subject relies only on the visual image

in VSP. This makes the subtraction task easier.

Summary re Mental Subtraction


Summary re Mental Subtraction

Basic Assumption re VSP: 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 ...

1) ... people are in the habit of naming the image

(recoding initial image into the PL), but .....

2) .... the task is actually performed more easily in VSP.

Result: Articulatory suppression does improve performance

on the mental subtraction task. o This result is hard to explain if STM is a single storage area

without separate PL & VSP.

Brook's Image Scanning Experiment


Next: Brook’s Image Scanning Experiment

Brooks, L. R. (1968). Spatial and verbal components of the act of recall. Canadian Journal of

Psychology, 22, 349-368.

• Purpose #1:

To show that there are 2 different stores: VSP and PL

• Purpose #2: To show that ...o Performing two different tasks in VSP interfere with each other.o Performing two different tasks in PL interfere with each other.o Performing one task in VSP and a different task in PL does not

cause as much interference

Image Scanning Experiment


Image Scanning (Brooks)

• Experiment has 4 conditions.o 2 types of stimulus: Diagrams or Sentenceso 2 types of responses: Pointing or Vocal Response*

• Dependent variable = time to perform a task

• Next: Explain the different stimulus types and response modes

Response Mode

Pointing Vocal

Diagrams 28.2 11.3

Sentences 9.8 13.8

Stimulus Types

* There was actually a third response type, “tapping”, but it will not be discussed here – it turned out not to be very informative.

Point Out that Goldstein Textbook Omits the Sentence Stimuli






Response Mode

Pointing Vocal

Diagrams 28.2 11.3

Sentences 9.8 13.8

Stimulus Types

Explain Diagram Stimulus x Vocal Response

Goldstein's discussion of this study omits the Sentence stimuli.Only the diagram stimuli are discussed in the textbook.






Response Mode

Pointing Vocal

Diagrams 28.2 11.3

Sentences 9.8 13.8

Stimulus Types NextSlide

Explain Diagram Stimulus x Vocal Response


Image Scanning (Brooks, cont.)

Condition: Diagrammatic Stimulus & Vocal Response

• Memorize the figure. Then it is removed.

• Start your scan at the star and (mentally)

move clockwise around the figure.

• Say "OUT" when you reach an outside

corner..

• Say "IN" when you reach an inside corner.

• Correct response:

out, out, in, in, out, out, in, out, out, out

• Dependent variable:

Response time (time to complete the task)Explain Diagram Stimulus with Pointing Response


Image Scanning (cont.)

• Next: Diagrammatic stimulus combined with pointing response:

Response Mode

Pointing Vocal

Diagrams 28.2 11.3

Sentences 9.8 13.8

StimulusType

NextSlide

PreviousSlide


Condition: Diagrammatic Stimulus &

Pointing Response

• Memorize the figure. Then it is removed.

Same as before

• Start your scan at the * and (mentally) move

clockwise around the figure. Same as before.

• Point to "Out" when you reach an outside

corner.

• Point to "In" when you reach an inside corner..

• Correct response: (See diagram)

out, out, in, in, out, out, in, out, out, out

• Dependent variable:

Response time (time to complete the task)

Image Scanning (Brooks, cont.)

Stimulus

Respond by pointing to letters on this sheet.

Transition to Next Condition: Sentence Stimulus & Vocal Response



• Explain sentence stimulus combined with vocal response:

Response Mode

Pointing Vocal

Diagrams 28.2 11.3

Sentences 9.8 13.8

StimulusType

NextSlide

Condition: Sentence Stimulus & Vocal Response


Image Scanning (Lee Brooks, cont.)

Condition:

Sentence Stimulus & Vocal Response

• Memorize the sentence.

Then it is removed.

• Now work from the beginning to the end of the sentence.

Say "yes" each time you encounter a noun; say "no" when

you encounter a word that is not a noun.

• Correct response:

• Dependent variable: Response time (time to complete the task)

Sentence Stimulus

A bird in hand is worth two in the bush.

no, yes, no, no, no, no, no, no, yes, yes

Transition to Condition with Sentence Stimulus & Pointing Response



Condition:

Sentence Stimulus & Vocal Response

Response Mode

Pointing Vocal

Diagrams 28.2 11.3

Sentences 9.8 13.8

StimulusType

NextSlide


Image Scanning (Lee Brooks, cont.)

Condition: Sentence Stimulus &

Vocal Response

• Memorize the sentence.

Then it is removed.

• Work from the beginning to the end of

the sentence. Point to "yes" each time

you encounter a noun; say "no" when

you encounter a word that is not a

noun..

• Correct response: no, yes, no, yes, no,

no, no, no, no, yesRespond by pointing to

letters on this sheet.

Sentence Stimulus: A bird in hand is worth two in the bush.

Image Scanning Results


Response Mode

Pointing Vocal

Diagrams 28.2 11.3

Sentences 9.8 13.8

Results: Image Scanning (Lee Brooks)

StimulusType

Faster Slower

Slower Faster

Same Slide: Why is Pointing Slower than Vocal For Diagrams & Opposite for Sentences?


Response Mode

Pointing Vocal

Diagrams 28.2 11.3

Sentences 9.8 13.8

• Why is diagram/pointing slower than diagram/vocal?

Why is sentence/vocal slower than sentence/pointing?

Results: Image Scanning (Lee Brooks)

StimulusType

Faster Slower

Slower Faster

Discussion of Results


Response Mode

Pointing Vocal

Diagrams 28.2 11.3

Sentences 9.8 13.8

• Diagram/Pointing: The stimulus and response compete for a common

cognitive resource, representation in VSP. Information processing

bottleneck causes slower response.

• Diagram/Vocal: Stimulus & response use separate cognitive

resources. No bottleneck.

Why is Diagram/Pointing Slower than Diagram/Vocal?

StimulusType

Slower Faster

Why is sentence/vocal slower than sentence/pointing?


Response Mode

Pointing Vocal

Diagrams 28.2 11.3

Sentences 9.8 13.8

• Sentence/Vocal: Again, stimulus and response compete

for a common cognitive resource, representation in PL. Information

processing bottleneck causes slower response.

• Sentence/Pointing: Stimulus & response use separate cognitive

resources. No bottleneck.

Why is Sentence/Vocal Slower than Sentence/Pointing?

StimulusType

xxx

Faster Slower


Brooks' experiment supports the existence of a visuospatial sketch pad (VSP) because ....

• If there were only one STM store (not separate PL & VSP), then the

effect of the pointing response would be the same in the visuospatial

task and the verbal task. Similarly for the effect of the verbal

response.

• WM model assumes multiple memory stores – this lets

WM predict conflicts between similar mental codes.

• The preceding experiment illustrates a basic principle:

A response in one modality (verbal or spatial) will interfere more

with a memory representation in the same modality than with a

memory representation in a different modality.

Summary - END

Summary: Comparison Between PL & VSP

Phonological Loop

CommonCharacteristics

Differences

Visuospatial Sketchpad

Common

Characteristics

Differences

Psych 355, Miyamoto, Win '13 26Comparison of PL & VSP - END

Summary: Comparison Between PL & VSP

Phonological Loop• Limited capacity

• Information is retained by an active process (verbal rehearsal)

• Information is highly accessible

• Multiple verbal inputs interfere with each other.

• PL processes linguistic information;

Visuospatial Sketchpad• Limited capacity

• Information is retained by an active process (manipulation of mental imagery)

• Information is highly accessible

• Multiple visual inputs interfere with each other.

• VSP processes visual imagery and spatial information.

Psych 355, Miyamoto, Spr '15 27

Verbal processing does not interfere as much with visual processing

Different areas of the brain show enhanced activity during verbal and visual/spatial rehearsal.

END

evidence for a visuospatial sketch pad (vsp) psychology 355: cognitive psychology instructor: john...

Documents

remainder image

visual image processing

subject names

image transformation

mental subtractionsubject

memory ltm

shortterm memory stores

separate memory stores