1. Experience Dependent Object Perception
Richard Zemel
Computer Science Department
University of Toronto

2. Two Sets of Experiments
1. To what degree is object perception invariant?
Familiarity
Naming
Reference-Frames
.2. What is the role of experience in completion?
Novel occluded shapes
Occlusion without occluders

3. Collaborators Mary Peterson Larry James Dave Towers Marlene Behrmann
Mike Mozer
Daphne Bevalier

4. Sample Stimuli

5. Familiarity: Methods Training Phase: 16 stimuli, fixed locations
passive viewing (6 blocks)
active: old/new discrimination (2 blocks)
[repeat]
Testing Phase (2 blocks)
new trials distractors
old trials -- half of learned objects:
stay in learned location
shift to diagonally-opposite location

6. Familiarity: Accuracy

7. Familiarity: RT

8. Naming: Methods Training Phase [8 rounds]: 8 named objects
passive [2 blocks]: (160 ms) GIX (500 ms)
active [1 block]: (160 ms) keyboard (feedback)
Testing Phase [6 rounds]: half shift sides, half stay
passive [2 blocks]
active [1 block]: (no feedback)

9. Naming: Accuracy

10. Reference-Frames: Variations

11. Reference-Frames: Methods
Training Phase [2 rounds]: 16 objects
passive [6 blocks]:
active [2 blocks]: old/new (f-back)
Testing Phase: same/different retinal & screen locs
active [2 blocks]: old-new

12. Reference-Frames: Conditions

13. Reference-Frames: Results

14. Experience Dependence When Objects Irrelevant?
Many properties of objects not invariant, but rather depend on experience
Evidence from experiments in which object memory directly relevant to task
Is experience important when the object is unnecessary to accomplish task?

15. Object attention & occlusion

16. Object attention sensitive to layout

17. Object attention & experience

18. Experience affects object attention

19. Completion without occluder?
Subjects complete fragments given experience with potential linking shape: Is evidence of occlusion required?

20. Completion w/o occluder: Methods
Phase 1: Ends displays
Phase 2: V displays
Phase 3: Ends and Vs

21. Missing Occluder: Results

22. Conclusions
Memories of novel objects are specific to learned locations
Both retinal & screen coordinates involved, so not just episodic memory
Object attention applies to recently viewed novel shapes
Experience-dependent object effects can apply to fragments without occluder

23. Current Directions Duration of effects Generalization
Amount of experience required