1. Perception

2. Perceptual Organization
Closure: we see the whole picture, even if there are gaps

3. Perceptual organization
Figure-Ground: seeing figures against a background
**What we perceive as the figure vs. background influences our perception

4. Perceptual Organization
Proximity: we group things by closeness
Similarity: We group similar (like) objects together

5. Perceptual Organization
Continuity: We prefer to see smooth continuous patterns
Common Fate:
things move together,
belong together

6. Movement The perception of movement is relative to other objects
Stroboscropic motion: illusion of movement by the quick progression of still images

7. Depth Perception Depth means distance away Monocular cues: (one eye)
create the illusion of
3D on flat surfaces

8. Monocular cues

9. Monocular cues
same size objects look different if placed at different distances
clearer an object, the nearer it seems
Nearer objects block further objects
Shadows and highlights give depth perception

10. Depth Perception Binocular Cues: (2 eyes)
Retinal disparity: image on BOTH eyes seen at dif angles
Convergence: Tension in our eyes as we focus on an object getting closer to us

11. Perceptual Constancies
Size Constancy: Perceive an object as being 1 size no matter how far away
Color Constancy: Color stays the same even in different light
Shape Constancy: Shapes stay the same, even at dif angles
Brightness Constancy: Judge brightness on the color of objects around it

12. Visual Illusions Muller-Lyer: we are reminded of building structure:
We perceive
in-facing arrows
as longer

13. Visual Illusions
Ponzo Illusion: Size constancy makes us think the top line is longer + further away

14. Practice Look at the selected illusions with 3 or 4 other students.
Discuss what perceptual principles are at work with your illusions.

15. Exit Slip 1. Pick one illusion. 2. Describe it or sketch it.
3. Identify all the perceptual principles in the illusion.