Page 129 - Foundations of Cognitive Psychology : Core Readings

Chapter 7

Perception

Philip G. Zimbardo and Richard J. Gerrig

Who are the people in figure 7.1? If their fame has not been too fleeting, you
should be able to recognize each of these individuals. But is this what they re-
ally look like? Probably not, at least on their good days. Your skill at identify-
ing each of these caricatures suggests that your perception of the world relies on
more than just the information arriving at your sensory receptors. Your ability
to transform and interpret sensory information—your ability to have what you
know interact with what you see—allows you to recognize Madonna, Oprah
Winfrey, and Bill Clinton from these exaggerated portraits.
Your environment is filled with waves of light and sound, but that’s not the
way in which you experience the world. You don’t ‘‘see’’ waves of light; you
see a poster on the wall. You don’t ‘‘hear’’ waves of sound; you hear music
from a nearby radio. Sensation is what gets the show started, but something
more is needed to make a stimulus meaningful and interesting and, most im-
portant, to make it possible for you to respond to it effectively. The processes of
perception provide the extra layers of interpretation that enable you to navigate
successfully through your environment.
We can offer a simple demonstration to help you think about the relationship
between sensation and perception. Hold your hand as far as you can in front
of your face. Now move it toward you. As you move your hand toward your
eyes, it will take up more and more of your visual field. You may no longer be
able to see the poster on the wall in back of your hand. How can your hand
block out the poster? Has your hand gotten bigger? Has the poster gotten
smaller? Your answer must be ‘‘Of course not!’’ This demonstration tells you
something about the difference between sensation and perception. Your hand
can block out the poster because, as it comes closer to your face, the hand
projects an increasingly larger image on your retina. It is your perceptual pro-
cesses that allow you to understand that despite the change in the size of the
projection on your retina, your hand—and the poster behind it—do not change
in actual size.
We might say that the role of perception is to make sense of sensation. Per-
ceptual processes extract meaning from the continuously changing, often cha-
otic, sensory input from external energy sources and organize it into stable,
orderly percepts. A percept is what is perceived—the phenomenological, or
experienced, outcome of the process of perception. It is not a physical object or
its image in a receptor but, rather, the psychological product of perceptual

From chapter 8 in Psychology and Life, 14th ed. (New York: HarperCollins, 1996), 258–302. Reprinted
with permission.