1. Sensation and Perception Part Two
Perceptual Adaptation
Perceptual sets
Clues of vision
Gestalt principles

2. Perceptual sets: expectations, assumptions and shortcuts based on culture, context and experience

3. Perceptual Constancy
Perceiving familiar objects as having consistent color, size, shape etc.
Color Constancy

4. Clues in vision Feature detectors (specialized neurons) Monocular cues
Interposition (front or back?)
Relative size/height (place in context defines size)
Texture gradient/relative clarity (far away is blurred)
Linear perspective (parallel lines)
Shading (adds contour and depth)
Motion paralax/ relative motion (the moon is following you)
Binocular cues (stereopsis) 3D
- Depth perception
Retinal disparity (mystery pictures; the floating hot dog)

5. Interposition/Occlusion Heuristic

6. Ponzo illusion/relative height

7. Müller-Lyer illusion

8. Linear perspective and texture gradient

9. Shading

10. Relative motion
Optical illusion Ballerina

11. CN Tower visual cliff

12. 3D

13. You will see a “finger sausage” as shown in the inset.
Binocular Cues
Retinal disparity: Images from the two eyes differ. 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.
You will see a “finger sausage” as shown in the inset.

14. Principles of Gestalt Groupings
The whole may be greater than the sum of the parts
Figure and Ground
Closure
Continuity also Common fate (movement)
Similarity
Proximity
Connectedness

15. Is the whole greater than the sum of the parts?

16. Figure and ground

17. Closure
Gestalt grouping principles are at work here.

18. To understand better try drawing these!

19. Good Continuation

20. Common Fate

21. Phi phenomena and stroboscopic movement

22. Human Factors Psychology