Transcript EXPLORING PSYCHOLOGY (7th Edition in Modules) David Myers

Perceptual Organization
Module 13
Overview
Perceptual Organization
 Form Perception
 Depth Perception
 Perceptual Constancy
Perception
Aoccudrnig to rscheearch at Cmabrigde
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the ltteers in a wrod are, the olny
iprmoetnt tihng is that the frist and lsat
ltteer be at the rghit pclae. The rset can
be a toatl mses and you can still raed it
wouthit porbelm. This is bcuseae the
huamn mnid deos not raed ervey lteter by
istlef, but the wrod as a wlohe.
Perceptual Organization
How do we form meaningful perceptions
from sensory information?
We organize it.
Perceptual Organization: Gestalt
 Gestalt--an organized whole
 tendency to integrate pieces of information
into meaningful wholes
 a school of psychology founded in Germany
in the 1900s that maintained our sensations
are processed according to consistent
perceptual rules that result in meaningful
whole perceptions, or gestalts.
Feature Pop Out
• The slanted line amongst vertical lines
Pops Out, but the cross amongst
horizontal and vertical lines does not pop
out.
(a)
(b)
Figure Ground
Organization of the visual field into objects
(figures) that stand out from their surroundings
(ground).
Time Savings Suggestion, © 2003 Roger Sheperd.
Laws of Perceptual Organization
Figure-Ground
Animated necker cube
http://dogfeathers.com/java/necker.html
Figure 5.7: Reversible Images
From MIND SIGHTS by Shepard © 1990 by Roger N. Shepard. Used with permission by W. H. Freeman and Company.
Return
Faces or Vases?
Grouping
After distinguishing the figure from the ground,
our perception needs to organize the figure into
a meaningful form using grouping rules.
Grouping demo
• http://9gag.com/gag/aOqOYv6?ref=9g.m
Perceptual Organization: Gestalt
 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
Laws of Perceptual Organization
Law of Proximity
Law of Continuity
Laws of Perceptual Organization
Law of
Similarity
Law of
Closure
Law of Proximity
The Law of Similarity
The Law of Continuity
Perceptual Organization:
Closure
 Gestalt
grouping
principles
are at
work
here.
Reversible Dancer?
• Note which direction the dancer is rotating.
Clockwise or counter?
http://www.news.com.au/heraldsun/story/0,21985,22556281-661,00.html
Grouping & Reality
Although grouping principles usually help us construct
reality, they may occasionally lead us astray.
Both photos by Walter Wick. Reprinted from GAMES
Magazine. .© 1983 PCS Games Limited Partnership
Depth Perception
Innervisions
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
Figure 13.7 Relative size
Myers: Exploring Psychology, Seventh Edition In Modules
Copyright © 2008 by Worth Publishers
Binocular Cues
Retinal disparity: Images from the two eyes differ.
Binocular Cues
Convergence: Neuromuscular cues. When two
eyes move inward (towards the nose) to see near
objects and outward (away from the nose) to see
faraway objects.
Monocular Cues
Relative Size: If two objects are similar in size, we
perceive the one that casts a smaller retinal image
to be farther away.
Perceptual Organization: Depth
Perception -- Relative Size
Monocular Cues
Interposition: Objects that occlude (block) other
objects tend to be perceived as closer.
Rene Magritte, The Blank Signature, oil on canvas,
National Gallery of Art, Washington. Collection of
Mr. and Mrs. Paul Mellon. Photo by Richard Carafelli.
Interposition
Monocular Cues
Relative Height: We perceive objects that are higher in our
field of vision to be farther away than those that are lower.
Image courtesy of Shaun P. Vecera, Ph. D.,
adapted from stimuli that appered in Vecrera et al., 2002
Tall Arch
Rick Friedman/ Black Star
Monocular Cues
Relative motion: Objects closer to a fixation point
move faster and in opposing direction to those
objects that are farther away from a fixation point,
moving slower and in the same direction.
Motion Perception
Motion Perception: Objects traveling towards us
grow in size and those moving away shrink in size.
The same is true when the observer moves to or
from an object.
Apparent Motion
Phi Phenomenon: When lights flash at a certain
speed they tend to present illusions of motion.
Neon signs use this principle to create motion
perception.
Two lights
one
after the Illusion
other. of motion.
One light jumping
from flashing
one point
to another:
Monocular Cues
Linear Perspective: Parallel lines, such as railroad
tracks, appear to converge in the distance. The
more the lines converge, the greater their
perceived distance.
© The New Yorker Collection, 2002, Jack Ziegler
from cartoonbank.com. All rights reserved.
Perceptual Organization: Linear
Perspective
Linear Perspective
Monocular Cues
Light and Shadow: Nearby objects reflect more light into
our eyes than more distant objects. Given two identical
objects, the dimmer one appears to be farther away.
From “Perceiving Shape From Shading” by Vilayaur
S. Ramachandran. © 1988 by Scientific American, Inc.
All rights reserved.
In or Out?
Monocular Cues
Texture Gradient: Indistinct (fine) texture signals
an increasing distance.
Perceptual Constancy
Perceiving objects as unchanging even as
illumination and retinal images change.
Figure 13.10 Shape constancy
Myers: Exploring Psychology, Seventh Edition In Modules
Copyright © 2008 by Worth Publishers
Link
Figure 13.9 Perceiving shape
Myers: Exploring Psychology, Seventh Edition In Modules
Copyright © 2008 by Worth Publishers
Color Constancy
Perceiving familiar objects as having consistent
color even when changing illumination filters
the light reflected by the object.
Color Constancy
Link
Moon Illusion
The moon just above the horizon
typically appears to be unusually
large because we perceive it as
unusually far away from
ourselves.
This illustrates the importance of
context effects.
Size-Distance Relationship
The distant monster (below, left) and the top red
bar (below, right) appear bigger because of
distance cues.
Alan Choisnet/ The Image Bank
From Shepard, 1990
Ponzo Illusion
• Converging lines indicate that top line is
farther away than bottom line
Figure 5.2: Misperceiving
Reality: Which Line Is Longer?
From Perplexing Puzzles and Tantalizing Teasers, (p.75), by Martin Gardner, 1988, New York Dover.
Size-Distance Relationship
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.
Both photos from S. Schwartzenberg/ The Exploratorium
Ames Room
The Ames room is designed to demonstrate the sizedistance illusion. Ramachandran explains the Ames
room http://www.youtube.com/watch?v=Ttd0YjXF0no
Lightness Constancy
The color and brightness of square A and B are the same.
Visual Illusions
The Ponzo Illusion
The Müller - Lyer Illusion
EXPLORING
PSYCHOLOGY
(7th Edition in Modules)
David Myers
PowerPoint Slides
Aneeq Ahmad
Henderson State University
Worth Publishers, © 2008