Chapter 6 (G): Perceptual Organization and Interpretation

1. Chapter 6 (G):Perceptual Organizationand Interpretation

2. Do-Now(In Journal) What is an illusion? How can illusionsinfluence and mislead our perception of a stimulus? Provide an example of a perceptual illusionthat you have experienced.

3. Perceptual Organization What do you perceive when you observe this image? Why do you think you perceive two facial images?

4. Perceptual Organization • Gestalt: • An organized whole • Tendency to integrate pieces of information into meaningful wholes

5. Form Perception • Figure-ground: • The organization of the visual field into objects (the figures) that stand out from their surroundings (the ground)

6. Form Perception Look at the images on Hand-Out 6-13: How does Figure 1 illustrate the concept of gestalt? What do you see when you look at Figure 2? What does this suggest about our perception? How does Figure 3 create a conflict of figure-ground? What ambiguous figures does your mind organize and reorganize in Figure 4?

7. Grouping After distinguishing the figure from the ground, our perception needs to organize the figure into a meaningful form using grouping rules

8. Grouping and Reality Although grouping principles usually help us construct reality, they may occasionally lead us astray.

9. Depth Perception • Depth Perception: • Ability to see objects in three dimensions although the images that strike the retina are two-dimensional • Allows us to perceive distance

10. Depth Perception:Binocular Cues Why is it difficult to bring the tips of two pens together with one eye closed? How does the brain use retinal disparityto perceivedistance? How do 3-D movies apply principles of binocular cues?

11. Depth Perception:Binocular Cues Depth perception enables us to judge distances. Gibson and Walk (1960) suggested that human infants (crawling age) have depth perception. Even newborn animals show depth perception. Visual Cliff

12. Depth Perception:Binocular Cues: Try looking at your two index fingers when pointing them towards each other half an inch apart and about 5 inches directly in front of your eyes. What do you see?

13. Depth Perception Binocular Cues: Monocular Cues: Relative Height Interposition Light/Shadows Texture/Detail Motion Parallax Linear Perspective Relative Motion • Convergence • Retinal Disparity

14. Perceptual Constancy • Perceptual Constancy: • Perceiving objects as unchanging (having consistent shapes, size, lightness, and color) even as illumination and retinal images change • Perceptual Set: • A mental predisposition to perceive one thing and not another

15. Perceptual Constancy:Shape Constancy

16. Perceptual Constancy:Color Constancy

17. Perceptual Constancy:Light Constancy The color and brightness of square A and B are the same.

18. Size-Distance Relationship The distant monster (below, left) and the top red bar (below, right) appear bigger because of distance cues.

19. Size-Distance Relationship:Ames Room Both girls in the room are of similar height. However, we perceive them to be of different heights as they stand in the two corners of the room.

20. Size-Distance Relationship:Ames Room The Ames room is designed to demonstrate the size-distance illusion.

21. 3-D Sidewalk Illusions

22. 3-D Sidewalk Illusions

23. 3-D Sidewalk Illusions

24. 3-D Sidewalk Illusions

25. 3-D Sidewalk Illusions

26. Perceptual Set A mental predisposition to perceive one thing and not another. What you see in the center picture is influenced by mixing both pictures.

27. Perceptual Set Other examples of perceptual set. (a) Loch Ness monster or a tree trunk; (b) Flying saucers or clouds?

28. Influences of Perception

29. Review How do gestaltsinfluence our perception? How do we use retinal disparity to understanddepth? What does perceptual set suggest about our abilities to perceive? How do biological, psychological, and social-cultural influences affect our perception?