Unit 4(G):
Perceptual Organization
and Interpretation
Mr. McCormick
A.P. Psychology
Do-Now
(In Journal)
 What is an illusion?
 How can illusions influence and
mislead our perception of a
stimulus?
 Provide an example of a perceptual
illusion that you have experienced.
Perceptual Organization
 What do you perceive when you observe this image?
 Why do you think you perceive two facial images?
Perceptual Organization
 Gestalt:
 An organized whole
 Tendency to integrate pieces of information into
meaningful wholes
Form Perception
 Figure-ground:
 The organization of the visual field into objects (the
figures) that stand out from their surroundings (the
ground)
Form Perception
 Look at the images on Hand-Out 6-13:
 How does Figure 1 illustrate the concept of
gestalt?
 What do you see when you look at Figure 2?
What does this suggest about our perception?
 How does Figure 3 create a conflict of figureground?
 What ambiguous figures does your mind
organize and reorganize in Figure 4?
Grouping
 After distinguishing the figure from the ground, our
perception needs to organize the figure into a meaningful
form using grouping rules
Grouping and Reality
Although grouping principles usually help us construct
reality, they may occasionally lead us astray.
Depth Perception
 Depth Perception:
 Ability to see objects in three dimensions
although the images that strike the retina are
two-dimensional
 Allows us to perceive distance
Depth Perception:
Binocular Cues
 Why is it difficult to bring the tips of
two pens together with one eye
closed?
 How does the brain use retinal
disparity to perceive distance?
 How do 3-D movies apply principles
of binocular cues?
Depth Perception:
Binocular Cues
Depth perception enables us to judge distances.
Gibson and Walk (1960) suggested that human
infants (crawling age) have depth perception. Even
newborn animals show depth perception.
Visual Cliff
Depth Perception:
Binocular Cues:
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. What do you see?
Depth Perception
Binocular Cues:
 Convergence
 Retinal Disparity
Monocular Cues:
 Relative Height
 Interposition
 Light/Shadows
 Texture/Detail
 Motion Parallax
 Linear Perspective
 Relative Motion
Perceptual Constancy
 Perceptual Constancy:
 Perceiving objects as unchanging (having
consistent shapes, size, lightness, and color)
even as illumination and retinal images
change
 Perceptual Set:
 A mental predisposition to perceive one thing
and not another
Perceptual Constancy:
Shape Constancy
Perceptual Constancy:
Color Constancy
Perceptual Constancy:
Light Constancy
The color and brightness of square A and B are the same.
Size-Distance Relationship
The distant monster (below, left) and the top red
bar (below, right) appear bigger because of
distance cues.
Size-Distance Relationship:
Ames Room
Both girls in the room are of similar height.
However, we perceive them to be of different heights
as they stand in the two corners of the room.
Size-Distance Relationship:
Ames Room
The Ames room is designed to
demonstrate the size-distance illusion.
3-D Sidewalk Illusions
3-D Sidewalk Illusions
3-D Sidewalk Illusions
3-D Sidewalk Illusions
3-D Sidewalk Illusions
Perceptual Set
A mental predisposition to perceive one thing
and not another. What you see in the center
picture is influenced by mixing both pictures.
Perceptual Set
Other examples of perceptual set.
(a) Loch Ness monster or a tree trunk;
(b) Flying saucers or clouds?
Influences of Perception
Review
 How do gestalts influence our
perception?
 How do we use retinal disparity to
understand depth?
 What does perceptual set suggest about
our abilities to perceive?
 How do biological, psychological, and
social-cultural influences affect our
perception?
Homework
 Unit 4 Test: “Sensation and Perception”
 Chapter 5 Outline: “States of
Consciousness”