1. Perceiving Form II Object Recognition Kimberley Clow Office Hours: Mon 10am-12pm kclow2@uwo.ca http://instruct.uwo.ca/psychology/215a-570

2. Outline  Attention  Attention Based Blindness  Recognition by Components  View-Based Recognition  Neurological Pathways  Learning To See  Face Perception  Prosopagnosia  Greebles

3. What Do You See?

4. Different Objects … SnowflakeLightening bolt Can Look the Same

5. Similar Objects … chairs coffeepots sunglasses Can Look Different

6. Attention is Important

7. Object Based Attention Fixation Cue (Prime) Test Valid Invalid (same object) Invalid (different object) Sequence of events

8. Inattentional Blindness Trials 1-3Inattention TrialRecognition Test Inattention Paradigm

9. A Closer Look Trials 1-3 inattention trial recognition test more trials divided attention trial more trials full attention trial

10. Results Performance Relative to Chance Attentional Condition

11. Beyond Attention 1)How can we recognize objects when we can’t see all the parts? 2)How can we distinguish among objects that share common features? 3)How can we recognize group membership of objects that look very different? 4)How can we recognize the same object in multiple orientations?

12. Recognition by Components

13. Examples += + =

14. What Do You See?

15. Read the Words

16. What Do You See?

17. View-Based Recognition

18. Natural Viewpoints Altered Viewpoints

19. Evidence cumulative response (spikes) post-stimulus time (ms) upright 45 degrees off horizontal 135 degrees off inverted 5000 150 120 90 60 30 0

20. Human Evidence Letters Objects 95% confidence interval around chance level % correct responses Stimulus Orientation

21. Remember the Neurology

22. Learning to See Practice Makes Perfect!

23. What About Faces?

24. Prosopagnosia

25. Greebles