1. “What” and “Where” Pathways in the Brain – A Hypothesis About Localization of Perceptual Functions
Psychology 355: Cognitive Psychology Instructor: John Miyamoto 04/03/2018: Lecture 02-2
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2. Outline Brain anatomy “What” and “Where” Pathways Double dissociations
Close connection between perception and action
Psych 355,, Miyamoto, Spr '18
Diagram of Lobes of the Brain

3. Lobes of the Left Hemisphere
Head is facing LEFT 3
Psych 355, Section, Spr '18
Terminology for Different Orientation in Brain Anatomy

4. Terminology for Different Orientation in Brain Anatomy
Superior
Dorsal
Head is facing LEFT
The orientation nomenclature is important as it provides the anatomical basis for the ‘ventral’ and ‘dorsal’ pathway.
"dorsal" derives from the Latin for back.
"ventral" derives from Latin for belly or stomach.
"rostral" derives from Latin for beak.
"caudal" derives from Latin for tail.
Anterior
Posterior
Rostral
Caudal
Inferior
Ventral
Psych 355, Miyamoto, Spr '18
Summary of Terminology

5. Summary of Terms for Orientations in Brain Anatomy
TOP: "superior" or "dorsal": "dorsal" derives from the Latin for back.
BOTTOM: "inferior" or "ventral" "ventral" derives from Latin for belly or stomach.
FRONT: "anterior" or "rostral" "rostral" derives from Latin for beak.
BACK: "posterior" or "caudal" "caudal" derives from Latin for tail.
Psych 355,, Miyamoto, Spr '18
Diagram Showing the "What" and "Where" Pathways in Brain Anatomy

6. "What" versus "Where" Pathways in Monkey & Human Brains
"Where" Visual Pathway
"Where" pathway is more activated by spatial tasks. A.k.a. the dorsal pathway.
"What" pathway more activated by tasks that require processing of object properties. A.k.a. the ventral pathway.
Human
"What" Visual Pathway
Monkey
Figure 3.33, Goldstein
Psych 355, Miyamoto, Spr '18
"What" Task in Monkey

7. "What" Task with Monkeys (Object Discrimination)
Monkey is shown an exemplar:
Now monkey has to pick the matching object:
If monkey pushes aside the matching object, he finds food hidden under it.
The “what” task requires attention to object properties, color and shape.
Psych 355, Miyamoto, Spr '18
"Where" Task

8. "Where" Task with Monkeys (Landmark Discrimination)
Monkey is taught that the reward will be next to the landmark:
Next the monkey sees two potential hiding places for the reward.
The reward is hidden under the block that is next to the landmark.
Double Dissociation Btwn "What" & "Where" Tasks in Monkeys
Psych 355, Miyamoto, Spr '18

9. Double Dissociation Between "What" & "Where" Pathways
Figure 3.32, Goldstein
Surgical removal of part of temporal lobe makes object discrimination difficult; landmark discrimination not impaired.
Start Discussion of Double Dissociation
Psych 355, Miyamoto, Spr '18

10. Double Dissociation Between "What" & "Where" Pathways
Figure 3.32, Goldstein
Surgical removal of part of temporal lobe makes object discrimination difficult; landmark discrimination not impaired.
Surgical removal of part of parietal lobe makes landmark discrimination difficult; object discrimination is not impaired.
Start Discussion of Double Dissociation
Psych 355, Miyamoto, Spr '18

11. Double Dissociation Between "What" & "Where" Pathways
Figure 3.32, Goldstein
Surgical removal of part of temporal lobe makes object discrimination difficult; landmark discrimination not impaired.
Surgical removal of part of parietal lobe makes landmark discrimination difficult; object discrimination is not impaired.
Double dissociation!
"What" and "Where" Dissociations in Human Studies
Psych 355, Miyamoto, Spr '18

12. "What" & "Where" Pathways: Double Dissociation in Human Patients
"Where" Visual Pathway
Patient with bilateral parietal- occipital damage: Patient could not describe locations of familiar places but could describe the appearance of objects.
Patient with bilateral inferior temporal damage: Patient could not describe appearance of objects, but could describe locations.
"What" Visual Pathway
Appearance question: What does your toothbrush look like?
Location question: Where is your toothbrush?
Psych 355, Miyamoto, Spr '18
Alice vs Bert – Double Dissociation Btwn Naming & Reaching

13. Another Example of Double Dissociation of "What" & "Where" Pathways:
Appearance question: What does your toothbrush look like?
Location question: Where is your toothbrush?
damage to temporal lobe
damage to parietal lobe
Psych 355, Miyamoto, Spr '18
Orientation Task – Another Double Dissociation Example

14. Orientation Matching Task
Patient D.F. has damage to temporal lobe due to carbon monoxide poisoning.
Patient D.F. must turn the card to match the orientation of the slot.
(The results are recorded so that perfect accuracy is indicated by a vertical line.)
D.F. does very poorly on orientation matching when compared to normal controls.
D.F.'s performance. Pretty bad.
Normal Controls
Psych 355, Miyamoto, Spr '18
Mailing Task

15. Mailing Task (Requires Perception & Action)
Patient D.F. must put the card through the slot.
D.F. does almost as well as normal controls.
Mailing Task: Put the letter through the slot.
D.F.'s performance. Pretty good
Normal Controls
Psych 355, Miyamoto, Spr '18
Comparison Btwn Orientation & Mailing Tasks

16. Orientation Matching Task Mailing Task
Orientation Matching Task – Primarily perception
Mailing Task – Coordinate perception with action
This is a single dissociation. Mechanisms for the task are different but they may not be independent.
Psych 355, Miyamoto, Spr '18
“What” Pathway = Perception Pathway; “Where” Pathway = Action Pathway?

17. Orientation Matching Task Mailing Task
Hypothesis: "What" Pathway = Perception Pathway "Where" Pathway = Action Pathway
Summary - END
Psych 355, Miyamoto, Spr '18

18. Summary
Double dissociations are a useful tool for investigating localization of function.
Hypothesis: "What" Pathway = Perception Pathway "Where" Pathway = Action Pathway (or maybe just more linked to action)
END - Or Continue to Class Experiment
Psych 355, Miyamoto, Spr '18

19. Class Experiment: Demonstration of Top Down Processing
Instructor: Divide the classroom into a “left group” and “right group”.
I will show you an image. Briefly write down a label for what you see. E.g., if you see a chair, write down “chair.”
Left half of the room will close their eyes for the first image. Right half of the room will close their eyes for the second image.
Everyone will open their eyes and complete the experiment.
Condition 1: View Image 1a
Psych 355, Miyamoto, Spr '18

20. Students on Left – Eyes Open Students on Right – Eyes Closed
Label this image “Image 1a”. Write down a name for what you see.
Condition 2: View Image 1b
Psych 355, Miyamoto, Spr '18

21. Students on Left – Eyes Closed Students on Right – Eyes Open
Label this image “Image 1b”. Write down a name for what you see.
View Image 2
Psych 355, Miyamoto, Spr '18

22. Label this image “Image 2”. Write down a name for what you see.
Everybody’s Eyes Open
Label this image “Image 2”. Write down a name for what you see.
Collect Results of Class Demo Experiment
Psych 355, Miyamoto, Spr '18

23. Results of Classroom Experiment
We will only collect data for what you saw in Image 2.
People on the LEFT SIDE:
Raise your right arm if you wrote down “mouse” or “rat” for Image 2?
Raise your left arm if you wrote down “old man” or “man” or “face” for Image 2?
People on the RIGHT SIDE:
Show Images 1a, 1b, 2
Psych 355, Miyamoto, Spr '18

24. LEFT SIDE saw Image 1a RIGHT SIDE saw Image 1b EVERYONE saw Image 2 .
Top Down Processing: What you see in Image 2 is influence by what you expect from Image 1.
EVERYONE saw Image 2 .
Results of Classroom Experiment
Psych 355, Miyamoto, Spr '18

25. Results of the Classroomn Experiment
Left side of the room saw Image 1a only.
Categorization of Image 2 by left side of the room:
29 saw “mouse”
0 saw “old man”
Right side of the room saw Image 1b only.
Categorization of Image 2 by right side of the room:
17 saw “mouse”
13 saw “old man”
Image 1a
Image 2
Image 1b
Results exhibit influence of top- down processing: Prior exposure to mouse-like or man-like image influences interpretation of second image.
Psych 355,, Miyamoto, Spr '18
Tomorrow’s Topics - END

26. Tomorrow’s Class More discussion of top-down and bottom-up processes.
Perceptual features
Gestalt principles of perception
Psych 355,, Miyamoto, Spr '18
END