PERCEPTUAL ORGANIZATION
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When we are given a cluster of sensations, we
organize them into a “gestalt” or a “whole”
“The whole is greater than the sum of the parts.”
We take in sensory information and infer a
perception that makes sense to us based on our
past experiences.
What is a Figure/Ground Relationship?
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Discriminate the focus of stimulus from the
background.
One stimulus can trigger more than one perception.
How Do We Organize Stimuli Into a
Meaningful Form?
Our mind has “Rules” for Grouping
 1. Proximity
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2. Similarity
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3. Continuity
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4. Connectedness
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5. Closure
Examples of Grouping
Examples of Grouping
DEPTH PERCEPTION
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Seeing things in 3 dimensions—but we only have a
2-dimensional retina
Both an innate (born with it) and a learned skill
Utilizes both “binocular” clues and “monocular clues”
Visual Cliff Experiment
Binocular Clues
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Retinal Disparity
Our eyes are about 2 ½ inches apart
Provides an important clue to the relative distance
between 2 objects
Retinal disparity is greatest directly in front of your
face
Let’s Make Finger Sausages!
3D Movies Increase Retinal Disparity!
It’s More Difficult to Judge Distant
Objects
Much less retinal disparity
 We depend on monocular depth clues
 1. Relative height
 2. Relative size
 3. Linear perspective
 4. Light and shadow
 5. Interposition
 6. Relative Motion
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We Depend on Monocular Clues
1. Relative height: We perceive object higher
in our visual field as being further away.
We Depend on Monocular Clues
But…
We Depend on Monocular Clues
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2. Relative Size: If we assume that 2 objects are
roughly the same size, we perceive the one that
“looks” smaller (casts a smaller retinal image) to be
further away
We Depend on Monocular Clues
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3. Linear Perspective: The more parallel lines
converge (come together), the greater their
perceived distance.
We Depend on Monocular Clues
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4. Light and Shadow: Nearby objects reflect
more light to our eyes. If 2 objects identical in
shape and size, the dimmer one appears further
away. Also, our brain “assumes” that light comes
from above.
We Depend on Monocular Clues
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5. Interposition: If one object blocks the view of
another, we perceiving the “blocking” object as
being closer.
We Depend on Monocular Clues
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6. Relative Motion: If we ourselves move, objects
that are actually stable may appear to move.
Let’s Review Depth Perception
Reviewing Depth
Perception
MOTION PERCEPTION
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Shrinking objects are retreating
Enlarging objects are approaching
Large objects appear to move slower than smaller
objects moving at the same speed
Tennis Shoe and
Batteries
Motion Perception
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Stroboscopic Movement
Motion Perception
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Phi Phenomenon
Phi Phenomenon
PERCEPTUAL CONSTANCY
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How we recognize objects without being deceived
by changes in their:
 Shape
 Size
 Brightness
 Color
Shape Constancy
Shape Constancy
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But we can be fooled
Size Constancy
Size Constancy
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But we can be fooled…
Color & Light Constancy
Light Constancy
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But we can be fooled…
6.5.4 Perceptual Constancy
PERCEPTUAL INTERPRETATION
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Life experience has a huge impact
Perceptual Adaptation
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Can we change how we perceive?
Perceptual Set
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Emotions, expectation, and context ALL influence our
perceptions
The Brain is a Great ‘Face Detector’
It’s All About Context
Even Culture Influences Context