1. Biases: An Example
Non-accidental properties: Properties that appear in an image
that are very unlikely to have been produced by chance, and
therefore are likely to reflect properties of the 3-D world.
view-point invariant properties
straight lines
parallel lines

2. ? mental representation view-point invariant of objects
book
key
mental representation
of objects
view-point invariant
cat
etc..
tree ?
mental representation
of bars of light
view-point dependent

3. mental representation of objects view-point invariant
book
key
mental representation
of objects
view-point invariant
cat
etc..
tree
1) Direct models
mental representation
of bars of light
view-point dependent

4. Lades et al Model Poggio & Edelman Model mental representation
book
key
mental representation
of objects
view-point invariant
cat
etc..
tree
Input layer like representation in V1
(called “Gabor Jets”)
Inputs on that layer are matched to
inputs in a memory layer
The object is identified based on
the match with least distortion
1) Direct models:
Lades et al Model
Poggio & Edelman Model
Input layer like representation in V1
3-layer network is trained to rotate
all views of an image to one view.
The hidden units are seen as a way
of rotating images to match memory
images (“radial basis functions”)
mental representation
of bars of light
view-point dependent

5. Lades et al Model Poggio & Edelman Model mental representation
book
key
mental representation
of objects
view-point invariant
cat
etc..
tree
Input layer like representation in V1
(called “Gabor Jets”)
Inputs on that layer are matched to
inputs in a memory layer
The object is identified based on
the match with least distortion
1) Direct models:
Lades et al Model
Poggio & Edelman Model
Input layer like representation in V1
3-layer network is trained to rotate
all views of an image to one view.
The hidden units are seen as a way
of rotating images to match memory
images (“radial basis functions”)
mental representation
of bars of light
view-point dependent

6. Lowe’s SCERPO Model Ullman’s Model mental representation
book
key
mental representation
of objects
view-point invariant
cat
etc..
tree
2) View-point invariant
mental representation
of non-accidental
properties of an image
view-point invariant
Input layer takes information
represented as it is in V1
view-point invarient information
is extracted
this allows the input image to be
rotated in order to fit an image
stored in memory
Lowe’s SCERPO Model
Ullman’s Model
mental representation
of bars of light
view-point dependent

7. The problem with all of these theories:
The representation of objects in memory is stored as
a two-dimensional image, which visual images are
rotated, distorted, and matched to.
But in actuality, objects are three dimensional things
in the world.
So lets make a model which has the basic units that
make up mental representations of objects being
three-dimensional solids, rather than lines and edges.

8. mental representation of objects view-point invariant
book
key
mental representation
of objects
view-point invariant
cat
etc..
tree
mental representation
of geons
view-point invariant
mental representation
of non-accidental
properties of an image
view-point invariant
mental representation
of bars of light
view-point dependent

9. Geons straight, parallel curved, parallel corner Y intersections

10. mental representation of objects view-point invariant
book
key
mental representation
of objects
view-point invariant
cat
etc..
tree
mental representation
of geons
view-point invariant
mental representation
of non-accidental
properties of an image
view-point invariant
mental representation
of bars of light
view-point dependent

11. what processing where processing rectangle unit above unit
book
key
mental representation
of objects
view-point invariant
cat
etc..
briefcase
mental representation
of geons
view-point invariant
what processing
where processing
rectangle unit
above unit
cylinder unit
below unit
cone unit
left of unit
tube unit
righ of unit
temporal binding

12. Evidence for geons? Experiment 1: Visual Priming
Reaction Time: 900 ms.
(response)
(response)
time

13. Evidence for geons? Experiment 1: Visual Priming
Reaction Time: 700 ms.
(response)
(response)
time

14. Evidence for geons? Experiment 1: Visual Priming
Reaction Time: 800 ms.
(response)
(response)
time

15. Evidence For Geons: Priming Studies
Shared?
First Second
Lines Geons Basic Response Time
Edges Cat.
Yes Yes Yes Yes
No Yes Yes Yes
No No No No
700 ms
700 ms
900 ms

16. Evidence For Geons: Priming Studies
Shared?
First Second
Lines Geons Spec. Basic Resp. Time
Edges Cat. Cat.
Yes Yes Yes Yes Yes
No No Yes Yes Yes
No No No Yes Yes
700 ms
800 ms
800 ms

17. Objects, Faces and Rotation:

18. Face Recognition Recognizing faces is an entirely different problem
(computationally) from recognizing objects?
Objects
“M” shaped function
Faces
Shape of rotation function?

19. Face Recognition Experiment

20. Objects, Faces and Rotation:

21. Face Recognition different processes?
Recognizing faces is an entirely different problem
(computationally) from recognizing objects?
Objects
Faces
“M” shaped function
Less affected by illumination
Recognition by components
(Geon Theory)
Shape of rotation function?
More affected by illumination
Recognition by coordinates
(Templates)
different processes?

22. Double Dissociation
Patient Studies
Prosopagnosia: Objects can be recognized, Faces can not.
Processes responsible for
object recognition:
Processes responsible for
face recognition:

23. Double Dissociation
Patient Studies
Prosopagnosia: Objects can be recognized, Faces can not.
(Patient CK): Faces can be recognized, Objects can not
Processes responsible for
object recognition:
Processes responsible for
face recognition:

24. Double Dissociation
Patient Studies
Prosopagnosia: Objects can be recognized, Faces can not.
(Patient CK): Faces can be recognized, Objects can not
Neuroimaging Studies
Faces activate the FFA
area of the temporal lobe
Objects activate the PPA

25. Double Dissociation IF:
General Form
IF:
The ability to perform some task X is affected by or correlated
with some factor A (damage to an area, activity in a part of the
brain, or performing some other task) but not factor B (damage
to a different area, activity in a different part, or some other task),
AND:
The ability to perform some task Y is affected by or correlated
with some factor B but not factor A,
THEN:
There is a double dissociation between X and Y, and the
mechanisms required to perform them are functionally independent.

26. What and Where Pathways
Dissociation
What and Where Pathways
Some patients
Can
identify objects by shape
Cannot
Say where objects are
Cannot navigate the world
Damage
Parietal lobe
Dorsal visual stream X

27. What and Where Pathways
Dissociation
What and Where Pathways
Some patients
Cannot
identify objects by shape
Can
Say where objects are
Cannot navigate the world
Damage
Temporal lobe
Ventral visual stream X

28. What and Where Pathways
Dissociation
What and Where Pathways
Patient D.F.
Cannot
Explicitly line up a line with a line
Task: Take an envelope and line it up with this
line
Can
Use motor system (part of “where” pathway)
to do same task just failed at
Task: Take this envelope and “mail the letter”
pretending that this line is a mailbox

29. Two face recognition systems
Dissociation
Two face recognition systems
Recognize faces normal way “ Hey I know you”
Recognize by change in skin conductance for familiar faces

30. Two face recognition systems
Dissociation
Two face recognition systems
Person A can recognize normal way but no change in skin conductance
Person B cannot recognize in normal way but does have change in skin conductance