2. PERCEPTION OF OBJECTS Problems for Perception Gestalt Heuristics Intelligent Perception Figure-Ground Separation

3. Problems for Perception We are remarkably good at correctly perceiving the environment To do this, our brains must overcome problems with the input from sense organs

4. Ambiguous Information Any particular pattern of stimulation on the retinas could be caused by many different patterns in the environment This is called the inverse projection problem

5. Viewpoint Invariance Ability to recognize an object even when seen from different viewpoints

6. Gestalt Heuristics Heuristics are problem-solving strategies that are based on previous knowledge The Gestalt approach emphasizes perceiving whole patterns, not individual parts

7. Law of Pragnanz Perceive the simplest possible object, given the sensory information received

8. Law of Similarity Objects that look similar are grouped into the same pattern

9. Law of Good Continuation Points are grouped together when they form smooth, continuous lines or curves

10. Law of Proximity Objects that are close together tend to be grouped into the same pattern

11. Law of Common Fate Objects that are move together are grouped into the same pattern

12. Law of Familiarity Objects are more likely to be grouped into patterns that are familiar

13. Law of Common Region Objects in the same region of space tend to be grouped together

14. Law of Uniform Connectedness Uniform areas that are connected appear to be part of the same object

15. Law of Synchrony Events that occur at the same time are grouped together

16. Intelligent Perception Top-down processing allows us to correctly interpret sensory information We are typically unaware of the top-down strategies that we use: unconscious inference

17. Figure and Ground Accurate perception requires segregating the object we are perceiving (figure) from its background (ground)

18. FigureGround Seen as in frontSeen as behind Thing-likeUnformed More memorableLess memorable MeaningfulLess meaningful Owns the border Not grouped with border