perceptual organization module 13. overview perceptual organization form perception depth...
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Perceptual Organization
Module 13
Overview
Perceptual Organization Form Perception
Depth Perception
Perceptual Constancy
PerceptionAoccudrnig to rscheearch at Cmabrigde Uinervtisy, it deosn’t mttaer in what oredr 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)
Organization of the visual field into objects (figures) that stand out from their
surroundings (ground).
Figure GroundT
ime S
avings Suggestion, ©
2003 Roger S
heperd.
Laws of Perceptual Organization
Figure-Ground
Animated necker cubehttp://dogfeathers.com/java/necker.html
From MIND SIGHTS by Shepard © 1990 by Roger N. Shepard. Used with permission by W. H. Freeman and Company. Return
Figure 5.7: Reversible Images
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 Continuity
Law of Proximity
Laws of Perceptual Organization
Law of Closure
Law of Similarity
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 & RealityAlthough grouping principles usually help us
construct reality, they may occasionally lead us astray.
Both photos by W
alter Wick. R
eprinted from G
AM
ES
Magazine. .©
1983 PCS G
ames L
imited Partnership
Depth Perception
Visual Cliff
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.
Inne
rvis
ions
Figure 13.7 Relative sizeMyers: Exploring Psychology, Seventh Edition In ModulesCopyright © 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.R
ene Magritte, The B
lank Signature, oil on canvas, N
ational Gallery of A
rt, Washington. C
ollection of M
r. and Mrs. Paul M
ellon. Photo by Richard C
arafelli.
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 S
haun P. V
ecera, Ph. D
., adapted from
stimuli that appered in V
ecrera et al., 2002
Tall Arch
Rick F
ried
ma
n/ B
lack S
tar
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 flashing one after the other.One light jumping from one point to another: Illusion of motion.
Monocular CuesLinear Perspective: Parallel lines, such as railroad tracks, appear to converge in the distance. The more the lines converge, the
greater their perceived distance.
© T
he New
Yorker C
ollection, 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 S
hape From
Shading” by V
ilayaur S
. Ram
achandran. © 1988 by S
cientific Am
erican, Inc. A
ll 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 constancyMyers: Exploring Psychology, Seventh Edition In ModulesCopyright © 2008 by Worth Publishers
Figure 13.9 Perceiving shapeMyers: Exploring Psychology, Seventh Edition In ModulesCopyright © 2008 by Worth Publishers
Link
Perceiving familiar objects as having consistent color even when changing illumination filters
the light reflected by the object.
Color Constancy
Color ConstancyLink
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.
From Shepard, 1990
Alan C
hoisnet/ The Im
age Bank
Ponzo Illusion• Converging lines indicate that top line is
farther away than bottom line
From Perplexing Puzzles and Tantalizing Teasers, (p.75), by Martin Gardner, 1988, New York Dover.
Figure 5.2: Misperceiving Reality: Which Line Is Longer?
Size-Distance RelationshipBoth 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 size-distance 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.Cou
rtesy
Edw
ard
Ade
lson
Visual Illusions
The Ponzo Illusion
The Müller - Lyer Illusion
EXPLORING PSYCHOLOGY(7th Edition in Modules)
David MyersPowerPoint Slides
Aneeq AhmadHenderson State
University
Worth Publishers, © 2008