Perception Is…

1. Perception Is… • The process of recognizing, organizing, and interpreting sensory information

2. Two Theories • Bottom-up theories • -Parts are identified, put together, and then recognition occurs • Top-down theories • -People actively construct perceptions using information based on expectations

3. Constancy • Our ability to recognize that size, shape and brightness (color) don’t change even when sensory input of an object changes. • Size constancy • Shape constancy • Brightness constancy

4. Sensory adaptation -Occurs when sensory receptors change their sensitivity to the stimulus -Constant stimulation leads to lower sensitivity -The brain is constantly processing and adjusting it’s perception of sensory input

6. Sensory Adaptation can lead to After Images

7. After Images in Color

8. http://www.youtube.com/watch?v=cGt3LRZxjAw

9. Gestalt Organizational Principles Module 07: Perception

10. Gestalt • The “whole,” or the organizational patterns that we tend to perceive; • the Gestalt psychologists emphasized that the whole is greater than the sum of its parts. • By breaking experiences into their basic parts, something important is lost.

13. Draw what you Just saw • Now compare your drawing with the original. • In what ways is it similar, what details did you miss?

14. Law of Praganz • Reality is organized and reduced to the simplest form possible.

15. Gestalt Organizational Principles: Figure-Ground Relationships Module 07: Perception

16. Figure-Ground • The organization of the visual field into objects (figures) that stand out from their surroundings (ground). • The figure is the object(s) that stands out or draws one’s attention. • The ground is the background.

17. Figure-Ground

18. Gestalt Organizational Principles: Grouping Principles Module 07: Perception

19. Grouping • The perceptual tendency to organize stimuli into understandable units. • Several principles of grouping include: • Similarity • Proximity • Closure • Continuity

20. Grouping - Similarity • The tendency to place items that look similar into a group

21. Grouping - Proximity • The tendency to place objects that are physically close to each other in a group

22. Grouping – Closure • The tendency to look at the whole by filling in gaps in a perceptual field http://www.youtube.com/watch?v=Hodp2esSV9E

23. Grouping – Continuity • The tendency to perceive that movement of an object continues once it appears to move in a particular direction

24. Grouping- Common fate • Objects that move or function in a similar manner will be seen as a unit.

25. What Principles Do we See

26. Depth Cues

27. Depth Cues • Eleanor Gibson and her Visual Cliff Experiment. • If you are old enough to crawl, you are old enough to see depth perception. • We see depth by using two cues that researchers have put in two categories: • Monocular Cues • Binocular Cues

28. Binocular Cues • We need both of our eyes to use these cues. • Retinal Disparity (as an object comes closer to us, the differences in images between our eyes becomes greater. • Convergence (as an object comes closer our eyes have to come together to keep focused on the object).

29. Monocular Cues • You really only need one eye to use these (used in art classes to show depth). • Linear Perspective • Interposition • Relative size • Texture gradient • Shadowing • Relative Height

35. Illusions and Perceptual Set

36. Ponzo Illusion • Tricks our sense of size constancy

37. Mueller Lyon Illusion • Tricks our sense of linear perspective

38. Lets test ourselves • http://bcs.worthpublishers.com/gray/content/psychsim5/Visual%20Illusions/PsychSim_Shell.html

39. What Depth Cues did the vertical/Horizontal lines trick?

40. Illusions of Motion • Autokinetic effects

41. Phi Phenomenon : apparent movement between flashing stationary images • http://www.yorku.ca/eye/balls.htm

42. Stroboscopic: When images are flashed in sequence to create the illusion of continuous movement • “cell animation” • http://www.youtube.com/watch?v=XeWIhWiT6bE

43. Emotions and Motivation • Influence our attention and perception

44. Perceptual Set • Experience builds expectations which direct perceptions

47. 2 minutes study and look for a pattern