Note to the Instructor:



The following PowerPoint slides include the core
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©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Note to the Instructor (Continued):

Each topic listed on the Lecture Outline slide (#4)
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Enjoy!
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Psychology in
Action (8e)
by
Karen Huffman
PowerPoint  Lecture Notes Presentation
Chapter 4: Sensation and
Perception
Karen Huffman, Palomar College
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Lecture Overview

Introduction to Sensation & Perception

Understanding Sensation

How We See and Hear

Our Other Senses

Understanding Perception
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Introduction to Sensation
and Perception


Sensation (process of receiving,
converting, and transmitting raw sensory
information from the external and
internal environments to the brain)
Perception (process of selecting,
organizing, and interpreting sensory
information)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Sensation Versus Perception
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
When you stare at the
cube on the left,
which area is the top,
bottom, or back?
In the figure on the
right, is this a young
woman looking to the
right, or an older
woman with her chin
buried in her jacket?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Sensation Vs. Perception
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Sensation: Processing

Processing
(sensory organs
contain receptors
that receive sensory
information from the
environment)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Sensation: Processing
1.
2.
3.
Three Types of Processing:
Transduction converts the sensory stimuli
into neural impulses that are sent on to the
brain.
Sensory reduction filters and analyzes
incoming sensations before sending on to the
brain.
Coding converts particular sensory input into
a specific sensation sent to parts of the brain.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Sensation: Processing
(Continued)

Transduction,
sensory
reduction, and
coding all
occur at the
sensory level
and messages
are then sent
on to the brain.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Sensation: Thresholds
Psychophysics: Testing limits and changes

•
Absolute Threshold: smallest amount of a
stimulus we can detect
•
Difference Threshold: minimal difference
needed to detect a a stimulus change; also
called the just noticeable difference (JND)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Sensation:
Thresholds

Sensory Adaptation: decreased
sensory response to continuous
stimulation
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
How We See

VISION- How We See
•
Light is a form of electromagnetic
energy that moves in waves.
•
Many types of electromagnetic
waves form the electromagnetic
spectrum.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
How We See: Electromagnetic
Spectrum
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
How We See: Electromagnetic
Spectrum

©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
The flower on
the left looks
normal to us,
whereas the one
on the right was
photographed
under ultraviolet
light.
How We See: Light Waves

Light waves vary in:
•
length (wavelength), which determines
frequency (hue or color).
•
height (amplitude), which determines
brightness or intensity.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
How We See: Anatomy of the Eye

The function of the
eye is to capture
light waves and
focus them on
receptors at the
back of the eyeball.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
How We See: Structures of the
Retina

Receptors for
vision are the
rods and cones
located in the
retina.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Do You Have a Blind Spot?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
How We See: Are You Nearsighted
or Farsighted?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
How We Hear: Audition

Sound results from movement
of air molecules in a particular
wave pattern.

Sound waves vary in:
• length (wavelength), which determines
pitch (highness or lowness).
• height (amplitude), which determines
loudness (intensity of the sound).
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
How We Hear: Audition

The loudness of a sound
is measured in decibels.
Constant noise above 90
decibels can cause
permanent nerve
damage to the ear.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
How We Hear: Anatomy of the Ear

Receptors
for hearing
are hair cells
located in
the cochlea.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Our Other Senses

Our sense of
smell is called
olfaction.

Receptors for
smell are
embedded in a
nasal membrane,
the olfactory
epithelium.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Our Other Senses:
Gustation (Sense of Taste)

Receptors for
gustation are
taste buds, located
in the papillae on
the surface of the
tongue.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Our Other Senses: Three Body Senses


Skin senses involve
three basic skin
sensations- touch
(or pressure),
temperature, and pain.
Receptors for these
sensations occur in
various concentrations
and depths in the skin.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Our Other Senses:
Three Body Senses

Vestibular sense
(or sense of balance)
involves the vestibular
sacs and semicircular
canals located in the
inner ear.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Three Body Senses (Continued)

Kinesthesia provides the brain with
information about bodily posture and bodily
movement. Kinesthetic receptors are found
throughout the muscles, joints, and tendons
of the body.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception

Illusions:
false or misleading
perceptions help
scientists study the
processes of
perception (e.g., the
horizontal-vertical
illusion)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
The Muller-Lyer Illusion
Which vertical line is longer?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception
Do You
See the
Cow?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception
Now Can
You See
the Cow?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception
(Continued)

Perception’s three basic processes:
Selection
2. Organization
3. Interpretation
1.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception: Selection

Selection (choosing where to direct attention)
involves three factors:
Selective Attention (filtering out and
attending only to important
sensory messages)
Feature Detectors (specialized neurons
respond only to certain sensory
information)
Habituation (brain’s tendency to
ignore environmental factors that
remain constant)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception: Selection

Kittens raised with
only vertical visual
stimuli fail to
develop the ability
to detect horizontal
lines. Can you
explain why?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization

Organization: assembling of information into
patterns that help us understand the world

We organize sensory information in terms of:
 Form
 Constancy
 Depth
 Color
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization

Form Perception
Gestalt psychologists developed laws
explaining how people perceive form
according to:





Figure and ground
Proximity
Continuity
Closure
Similarity
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization
Form PerceptionBasic Gestalt
Principles
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization
Form Perception:
Can You Explain
These Impossible
Figures?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization


Perceptual Constancy: Tendency to
perceive the environment as remaining the
same even with changes in sensory input.
Four best-known constancies:




Size
Shape
Color
Brightness
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization
Can You
Identify the
Size, Shape,
Color, and
Brightness
Constancies?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization-- The Ames Room Illusion
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization

Depth
Perception:
ability to perceive
three dimensional
space and
accurately judge
distance
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization
Depth Perception
(Continued)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization

Depth Perception involves both binocular
(two eyes) and monocular (one eye) cues.

Two Binocular Cues for Depth:
Retinal disparity (separation of the eyes
causes different images to fall on each retina)
Convergence (the closer the object the more
the eyes turn inward)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization
Binocular CuesRetinal
Disparity
(left)
Convergence
(right)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization

Six Monocular Depth Cues: Can You Find Them?
1. linear perspective
2. interposition
3. relative size
4. texture gradient
5. aerial perspective
6. light and shadow
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization

Color Perception
is a combination of
two theories:
1.
Trichromatic:
color perception
results from mixing
three distinct color
systems (red,
green, and blue)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization

Color Perception
is a combination of
two theories:
2. Opponent-process: color perception
results from three systems of color
opposites (blue-yellow, red-green,
and black-white)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization

People who have
red-green color
deficiency have
trouble perceiving
the green colored
number in the
center of this circle.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Organization and Color Perception
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Four Factors in Interpretation

Interpretation
(how we explain
sensations) involves
four major factors:
1.
Perceptual
adaptation
(brain adapts to
changed
environments)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Four Factors in Interpretation
2. Perceptual set:
readiness to perceive
in a particular manner,
based on expectations
Some groups are more
likely than others to be
affected by the center item
in this collection. Can you
explain why?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Four Factors in Interpretation

Another
example of
perceptual set.
Do you notice
anything wrong
with these
photos?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Understanding Perception:
Four Factors in Interpretation
3.
Frame of reference:
based on the context of the situation
4.
Bottom-up or top-down
processing: information either
starts with raw sensory data or with
thoughts, expectations, and
knowledge
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Problems with Believing in
Subliminal Perception and ESP

Subliminal
perception
may occur, but there
is little or no evidence
of subliminal persuasion.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Problems with Believing in
Subliminal Perception and ESP

Extrasensory perception (ESP):
supposed ability to perceive things
that go beyond the five normal
senses
•
ESP research is criticized due to lack of
experimental control and replicability.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Psychology in
Action (8e)
by
Karen Huffman
PowerPoint  Lecture Notes Presentation
End of Chapter 4:
Sensation and Perception
Karen Huffman, Palomar College
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)