Warm UP- page 36
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1. How does our system of sensing smell differ
from our sensory system for vision, touch and
taste?
2. Can you recall a time when, with you
attention focused on some activity, you felt no
pain from a wound or injury?
3. What is the gate control theory? Give an
example of how it would be used?
4. How are your senses of smell and taste
connected?
5. What sense is associated with the Olfactory
Bulbs?
Chapter 6: Perception
Perception
 Selective
Attention: the
focus of
conscious
awareness on a
particular
stimulus.
Selective Attention
 The
most
famous
example to
illustrate
selective
attention is
known as the
“cocktail party
effect.”
Testing Selective Attention
Perception
 Visual
Capture:
refers to the
tendency for
vision to dominate
the other senses.
Perceptual Organization
Gestalt: an organized
whole.
 Gestalt psychologists
emphasize humans’
tendencies to integrate
pieces of information into
meaningful wholes.
 Things are not seen as
sum of parts but
immediately as wholes.

Gestalt
Perceptual Organization
 Figure-Ground
Relationship:
tendency to organize
information into
objects (figure) that
stand out from their
background(ground)
Figure Ground Relationship
Gestalt Psychology
 Grouping:
the perceptual tendency
to organize stimuli into coherent
groups
 Grouping Principles:
 Proximity
 Similarity
 Continuity
 Closure
 Connectedness
Proximity: tendency to group
nearby figures together

Similarity: tendency to group
figures that are similar

Continuity: tendency to
perceive continuous patterns

Closure: tendency to fill in the
gaps in visual information.
Connectedness: spots, lines and
areas are seen as unit when
connected

Illusionary Contours: We
constantly filter information so
it makes sense to us.
Depth Perception
 Depth
Perception:
the ability to see
objects in three
dimensions. Allows
us to gauge
distance.
 Visual Cliff:
illustrated that
crawling infants and
newborns perceive
depth.
Types of Depth Perception
 Binocular
Cues: depth cues that rely on
the use of two eyes.
 Examples of Binocular Cues:
 Retinal Disparity: idea that images of
an object from the two eyes differ. The
closer the object, the larger the
difference (disparity.)
 Convergence: extent to which the
eyes converge inward when looking at
an object that brain keeps track of to
measure distance.
Types of Depth Perception
Monocular Cues: distance cues that are
available to either eye alone. Often used in art.
 Examples of 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
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Types of Depth Perception

Examples of Monocular Cues Continued:
 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
 Light and Shadow: nearby objects reflect
more light to our eyes.
Monocular Cue?
Monocular Cue?
Monocular Cue?

What Cues Do You See?
How many Legs?
Perceptual Constancy

Perceptual Constancy: perceiving objects
as unchanging despite changes in retinal
image
color
shape
size
Interplay Between Perceived
Size and Distance

Using monocular cues for distance can
often cause us to perceive incorrect
information.
Diameter of Circles Are the Same
Muller-Lyer Illusion
Warm Up
On
the overhead
Page 39
Cultural Influences on Depth
Perception
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Impossible Image
Impossible Staircase
Day 2
Sensory Deprivation and
Perception
 Blind Person Example
 Some
aspects of perception might
be innate
 Others involve experiences
 Critical
period for development of
sensation and perception
Sensory Deprivation and
Perception
Kittens raised
without
exposure to
horizontal lines
later had
difficulty
perceiving
horizontal bars.
Perceptual Adaptation
 Perceptual
Adaptation
 (vision) ability to adjust to an
artificially displaced visual field
prism glasses
http://jeffmilner.com/backmasking.htm
Perceptual Interpretation
 Perceptual
Set: a
mental predisposition to
perceive one thing and
not another.
 What you see in the
middle is influenced by if
you looked at bottom or
the top
Lochness Monster or a Tree
Trunk?
Perceptual Set Affects
Other Senses
 Perceptual
Set also affects other senses
like audition.
 Ex:
eel is on the wagon vs. eel is on
the orange.
 CONTEXT MATTERS!
 Rat Man
 Lyrics
Perception and the Human Factor
 Human
Factors Psychologists-
explore how people and machines interact
and how machines and environments can
be adapted to human behaviors
Is there Extrasensory
Perception?

Extrasensory Perception: claim that perception
can occur apart from sensory input.
 Astrological
predictions, psychic healing,
communication with the dead
 Telepathy- mind to mind
 Clairvoyance- perceiving remote events
 Precognition- perceiving future events
 Psychokinesis- mind over matter
Example- light as a feather stiff as a
board
Is there Extrasensory
Perception?
 Parapsychology:
study of paranormal
phenomenon, including ESP and psycho
kinesis.
 Research
 Psychics not accurate
 More predictions- police work
 Vague predictions
 Lottery
 No experiment has EVER produced a
convincible demonstration of ESP
Psi Phenomenon
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Blinking lights give the illusion of motion