Unit III, Sensation & Perception: Perception

1. Unit III, Sensation & Perception: Perception

2. Bell Ringer For 11/14/2011

3. Perception • Understanding & interpreting info. from a stimulus • Ex. The Stroop Effect

4. What Do You See?

5. Gestalt Psychology • Tendency to integrate pieces of info into wholes • See patterns & groupings, not small, individual pieces • “The whole is greater than the sum of the parts”

6. Gestalt Psychology • Answers the questions: • What is it? (Figure-ground relationship) • How far away is it? (Depth Perception) • Where is it going? (Perceptual Constancies) • Trying reading the next slide.

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8. Gestalt Psychology • Figure-Ground Perception • Perception of figures against a background • Organize your visual field into objects (figures) that stand out from their surroundings (ground) • Once you determine the figure from the ground you organize the figure into a meaningful form.

9. Gestalt Psychology • Laws Of Grouping: • Similarity – Group objects together that are similar. • Proximity – Group nearby objects together. • Continuity – Perceive straight or curvy lines as continuous,flowing patterns. • Closure – Perceive a complete or whole figure even when there are gaps. • CommonFate – Objects moving in the same direction belong together.

13. Movement & Motion • Perception Of Motion – To sense movement, humans need to see an object change its position relative to other objects • Ex. Cars at a traffic light • Stroboscopic Motion – Illusion of movement is produced by showing the rapid progression of images or objects that are not moving • Flip books & movies

16. Perceptual Set • Perceive something based on prior perceptual experiences • Ex. Interpretation of ambiguous stimulus • Face on Mars • UFOs • Loch Ness Monsters • Bigfoot

22. Bell Ringer For 11/15/2011 • According To Gestalt Psychology humans have a tendency to ______ ______ _______ _______ into _________.

23. Bell Ringer For 11/15/2011 • Tendency to integrate pieces of information into a whole.

24. Perceptual Constancies • 4 Types: • Size Constancy – An object is the same size no matter how far away it is or if its angle changes • Color Constancy – Objects keep their color though the light may change the appearance • Brightness Constancy – Object is equally bright though light changes • Shape Constancy – An object has only one shape no matter what angle you view it from

25. Perceptual Constancies

26. Optical Illusions • The brain’s use of perceptual constancies tricks our eyes through visual (optical) illusions

27. Optical Illusions • Do you see the gray dots?

28. Optical Illusions • Impossible Figures

29. Optical Illusions • Muller-Lyer Illusion

30. Optical Illusions • Ponzo Illusion • Misapplying size constancy • Which box has the smaller man?

31. Optical Illusions • Are the lines below straight or are they curved?

32. Depth Perception • Ability to see objects in 3 dimensions • Images that strike the retina are two dimensional • Use perceptual cues to determine distance & depth

33. Perceptual Cues • Interposition – If something is blocking our view, we perceive it as closer

34. Perceptual Cues

35. Perceptual Cues • Relative Size – If we know that two objects are similar in size, the one that looks smaller is farther away (size constancy)

36. Perceptual Constancies • Relative Height – Things higherin our field of vision look farther away

37. Perceptual Cues • Linear Perspective – Parallel lines seem to converge with distance • http://channel.nationalgeographic.com/channel/brain-games/

38. Relative Height & Size

39. Perceptual Cues • Relative Brightness – Bright objects appear closer than dimmer objects

40. Perceptual Cues • Aerial Perspective – Clearer objects seem closer • Atmospheric conditions (haze & dust) affect vision