Understanding Psychology (10th Ed)

Vision: Shedding Light on the Eye
Illuminating the Structure of the Eye
Neuroscience in Your Life:
Seeing Vision in the Brain
Color Vision and Color Blindness: 
The 7-Million-Color Spectrum
Hearing and the Other Senses
Sensing Sound
Smell and Taste
The Skin Senses: Touch, Pressure, 
Temperature, and Pain
Becoming an Informed Consumer 
of Psychology:
Managing Pain
How Our Senses Interact
What basic processes underlie the sense of 
vision?
● 
How do we see colors? 
What principles underlie our organization of the 
visual world and allow us to make sense of our 
environment?
● 
How are we able to perceive the 
world in three dimensions when our retinas are 
capable of sensing only two-dimensional images?
● 
What clues do visual illusions give us about our 
understanding of general perceptual mechanisms?
M O D U L E 1 3
Perceptual Organization: 
Constructing Our View of the World
The Gestalt Laws of Organization
Top-Down and Bottom-Up Processing
Depth Perception: Translating 2-D to 3-D
Perceptual Constancy
Motion Perception: As the World Turns
Perceptual Illusions: The Deceptions 
of Perceptions
Exploring Diversity: 
Culture and 
Perception
feL82795_ch04_096-137.indd Page 97 20/07/10 11:29 PM user-f463
feL82795_ch04_096-137.indd Page 97 20/07/10 11:29 PM user-f463
/Volumes/202/MH00543_r1/hin73516_disk1of1/0073373516/Access_Archive/hin73516_...
/Volumes/202/MH00543_r1/hin73516_disk1of1/0073373516/Access_Archive/hin73516_

---

98
Prologue
Never Forgetting a Face
She never forgets a face. Literally. 
For a woman known as C. S., remembering people is not a 
problem. In fact, she—like a very few other individuals—can 
remember faces of people she met years ago, sometimes only in 
passing. These “super-recognizers,” as they are called, excel at 
recalling faces. 
One super-recognizer said she had identifi ed another woman 
on the street who served her as a waitress fi ve years earlier in a 
diff erent city. Critically, she was able to confi rm that the other 
woman had, in fact, been a waitress in the diff erent city. Often, 
super-recognizers are able to recognize another person despite 
signifi cant changes in appearance, such as aging or a diff erent 
hair color. 
But being a super-recognizer is a mixed blessing. As one 
woman with this ability says, “It doesn’t matter how many years 
pass, if I’ve seen your face before I will be able to recall it.” In 
fact, she sometimes pretends she doesn’t remember a person, 
“because it seems like I stalk them, or that they mean more to me 
than they do when I recall that we saw each other once walking 
on campus four years ago in front of the quad!” (Munger, 2009; 
Russell, Duchaine, & Nakayma, 2009)

Looking
Ahead

Most of us are reasonably good at recognizing people’s faces, 
thanks in part to regions of the brain that specialize in detecting 
facial patterns. Super-recognizers represent a small minority of 
people who happen to be exceptionally good at facial recogni-
tion. At the other extreme are people with “faceblindness,” a rare 
disorder that makes it extremely diffi
cult for them to recognize 
faces at all—even those of friends and family. 
Disorders such as super-recognition and faceblindness 
illustrate how much we depend on our senses to function 
normally. Our senses off er a window to the world, not only 
providing us with an awareness, understanding, and apprecia-
tion of the world’s beauty, but alerting us to its dangers. Our 
senses enable us to feel the gentlest of breezes, see fl ickering 
lights miles away, and hear the soft murmuring of distant 
songbirds. 
In the next four modules, we focus on the fi eld of psychology 
that is concerned with the ways our bodies take in information 
through the senses and the ways we interpret that information. 
We explore both sensation and perception.
Sensation
encom-
passes the processes by which our sense organs receive informa-
tion from the environment.
Perception
is the brain’s and the sense 
organs’ sorting out, interpretation, analysis, and integration of 
stimuli. 
Although perception clearly represents a step beyond 
sensation, in practice it is sometimes diffi
cult to fi nd the precise 
boundary between the two. Indeed, psychologists—and 
philosophers as well—have argued for years over the distinction. 
The primary diff erence is that sensation can be thought of as an 
organism’s fi rst encounter with a raw sensory stimulus, whereas 
perception is the process by which it interprets, analyzes, and 
integrates that stimulus with other sensory information. 
For example, if we were considering sensation, we might ask 
about the loudness of a ringing fi re alarm. If we were considering 
perception, we might ask whether someone recognizes the 
ringing sound as an alarm and identifi es its meaning. 
To a psychologist interested in understanding the causes of 
behavior, sensation and perception are fundamental topics, 
because so much of our behavior is a refl ection of how we react 
to and interpret stimuli from the world around us. The areas of 
sensation and perception deal with a wide range of questions— 
among them, how we respond to the characteristics of physical 
stimuli; what processes enable us to see, hear, and experience 
pain; why visual illusions fool us; and how we distinguish one 
person from another. As we explore these issues, we’ll see how 
the senses work together to provide us with an integrated view 
and understanding of the world.
feL82795_ch04_096-137.indd Page 98 20/07/10 11:29 PM user-f463
feL82795_ch04_096-137.indd Page 98 20/07/10 11:29 PM user-f463
/Volumes/202/MH00543_r1/hin73516_disk1of1/0073373516/Access_Archive/hin73516_...
/Volumes/202/MH00543_r1/hin73516_disk1of1/0073373516/Access_Archive/hin73516_

---

99
As Isabel sat down to Thanksgiving dinner, her father carried the turkey in on a tray and 
placed it squarely in the center of the table. The noise level, already high from the talking 
and laughter of family members, grew louder still. As Isabel picked up her fork, the smell 
of the turkey reached her and she felt her stomach growl hungrily. The sight and sound 
of her family around the table, along with the smells and tastes of the holiday meal, 
made Isabel feel more relaxed than she had since starting school in the fall.
Put yourself in this setting and consider how different it might be if any one of your 
senses were not functioning. What if you were blind and unable to see the faces of 
your family members or the welcome shape of the golden-brown turkey? What if 
you had no sense of hearing and could not listen to the conversations of family 
members or were unable to feel your stomach growl, smell the dinner, or taste the 
food? Clearly, you would experience the dinner very differently from someone whose 
sensory apparatus was intact. 
Moreover, the sensations mentioned above barely scratch the surface of sensory 
experience. Although perhaps you were taught, as I was, that there are just fi ve 
senses—sight, sound, taste, smell, and touch—that enumeration is too modest. 
Human sensory capabilities go well beyond the basic fi ve senses. For example, we 
are sensitive not merely to touch but to a considerably wider set of stimuli—pain, 
pressure, temperature, and vibration, to name a few. In addition, vision has two 
subsystems—relating to day and night vision—and the ear is responsive to informa-
tion that allows us not only to hear but also to keep our balance. 
To consider how psychologists understand the senses and, more broadly, sensation 
and perception, we fi rst need a basic working vocabulary. In formal terms,