1. Myers’ PSYCHOLOGY (6th Ed)
Perception
Perception: A mental process that elaborates and assigns meaning to the incoming sensory patterns.
Perception brings meaning to sensation. It produces an interpretation of the world, but it isn’t a perfect representation.

2. Perception
Selective Attention focus of conscious awareness on a particular stimulus

3. Testing Selective Attention

4. Bottom-Up and Top-Down
Bottom-Up processing: Analysis that emphasizes the characteristics of the stimuli rather than our concepts and expectations.
Top-Down perception: Analysis that emphasizes the perceiver’s expectations, rather than individual characteristics.

5. Describe This Picture

7. Describe This Picture The Forest Has Eyes by Bev Doolittle
Bottom-Up: Lines, angles and colors…a guy riding a horse through the forest
Top-Down: We consider the title and direct our attention to aspects that will give meaning to it.

8. Perceptual Constancy Perceptual Constancy
perceiving objects as unchanging despite changes in retinal image
color
shape
size

9. Perceptual Illusions

10. Perceptual Illusions

11. Perceptual Illusions

12. Perceptual Illusions

13. Perceptual Organization- Gestalt
Visual Capture
tendency for vision to dominate the other senses
Grouping
the perceptual tendency to organize stimuli into coherent groups

14. Perceptual Organization
Figure and Ground organization of the visual field into objects (figures) that stand out from their surroundings (ground)
Works for all senses

15. Perceptual Organization- Gestalt
Gestalt- an organized whole
tendency to integrate pieces of information into meaningful wholes
Grouping Principles
proximity- group nearby figures together
similarity- group figures that are similar
continuity- perceive continuous patterns
closure- fill in gaps
connectedness- spots, lines and areas are seen as unit when connected

16. Perceptual Organization- Grouping Principles

17. What shapes do you see in each image?

18. Law of Perceptual Grouping
Law of Common Fate: The Gestalt principle that we tend to group similar objects together that share a common motion or destination.
Think a school of fish, a flock of seagulls, a murder of crows

19. Laws of Perceptual Grouping
Law of Pragnanz: The Gestalt principle which states that the simplest organization, requiring the least cognitive effort, will emerge as the figure.
What is wrong with this image?

20. Perceptual Organization- Grouping Principles
Gestalt grouping principles are at work here.

21. Perceptual Organization-Depth Perception
ability to see objects in three dimensions
allows us to judge distance
Binocular cues
retinal disparity
images from the two eyes differ
closer the object, the larger the disparity
convergence
neuromuscular cue
two eyes move inward for near objects

22. Perceptual Organization-Depth Perception
Visual Cliff

23. Perceptual Organization-Depth Perception
Monocular Cues
relative size
smaller image is more distant
interposition
closer object blocks distant object
relative clarity
hazy object seen as more distant
texture coarse --> close fine --> distant

24. Perceptual Organization-Depth Perception
Relative Size

25. Perceptual Organization-Depth Perception

26. Perceptual Organization-Depth Perception
Monocular Cues (cont.)
relative height
higher objects seen as more distant
relative motion
closer objects seem to move faster
linear perspective
parallel lines converge with distance
relative brightness
closer objects appear brighter

27. Perceptual Organization-Depth Perception
Perspective Techniques

28. Perceptual Organization

29. Perceptual Organization-Muller-Lyer Illusion

30. Perceptual Organization- Size-Distance Relationship

31. More Illusions at the Perceptual Level

32. Perceptual Organization-Brightness Contrast

33. Perceptual Interpretation
Perceptual Adaptation
(vision) ability to adjust to an artificially displaced visual field
prism glasses
Perceptual Set
a mental predisposition to perceive one thing and not another

34. Perceptual Set- Schemas
What you see in the center is influenced by perceptual set

35. Perceptual Set- Schemas
Flying Saucers or Clouds?

36. Perception without Sensation?
Extrasensory Perception
controversial claim that perception can occur apart from sensory input
telepathy
clairvoyance
precognition
Parapsychology
the study of paranormal phenomena
ESP
psychokinesis

37. The End
If you assume your senses give you an accurate and undistorted picture of the world, you are probably wrong. If you don’t believe me, try this.
Silently read the backwards statement below. Flip if over in your mind. What does it say?
.rat eht saw tac ehT

38. Answer How many people saw this: The cat saw the rat.
Look at it again:
.rat eht saw tac ehT
The cat was the rat.
Answer:
The cat was the tar.