PSYCHOLOGY
are the ones that give us this particular pain sensation.
(a) When heat is being conducted away from the skin we usually experience an
increase in .
(b) What skin sense is induced by tissue damage?
Answers: (a) cold; (b) Pain.
Smell: The Nose Knows
You may think to yourself, "Someone in this room is wearing a perfume that I
can't stand!" How do you know? You can't see the perfume. You can't hear the
perfume. But you, with your sense of smell, know.
The sense of smell allows us to detect the presence of some, but not all, airborne
chemical substances. The sense of smell is also known as olfaction. The
52 PSYCHOLOGY
receptor organ that makes the sense of smell possible is called the olfactory
epithelium, and it is located high in the nose. It is to smell what the retina is to
vision. Several kinds of neurons differentially sensitive to chemicals in gaseous
forms induce the various smell sensations.
The exact number and kind of basic smell sensations, unlike the four basic
taste sensations, are somewhat debatable. Nonetheless, it is possible to identify a
number of elemental sensations. Putrid is one of them; it is the smell of something
rotting or decomposing. Blossoms and blooms have a floral odor. A smell that is
sharp or acrid, such as that produced by burning food, is said to be pungent. Cinnamon
or cloves are said to have a smell that is spicy. The wood and bark of the
camphor tree have a penetrating, fragrant odor. Camphor is also obtained by synthesis
and is used in some medicines. The odor is described simply as camphoric.
(a) The sense of smell is also known as .
(b) The receptor organ that makes smell possible is called the .
Answers: (a) olfaction; (b) olfactory epithelium.
Kinesthesis: Can You Touch the Tip of Your Nose
with Your Eyes Closed?
If you can touch the tip of your nose with your eyes closed, as most people can, you
have an intact sense of kinesthesis. Kinesthesis, also known as proprioception,
is the capacity to know the position in space of various parts of your body. (The
term proprioception is related to the word "property." Your body belongs to you—
it's your property.) Close your eyes and lift or lower a single finger. You know
where it is at all times. When you walk you can sense the position of your legs even
if you're not looking at them. Pianists and dancers rely heavily on kinesthesis.
The receptor neurons for kinesthesis are located in the connective tissue surrounding
the body's joints as well as within the joints themselves.
(a) Kinesthesis is also known as .
(b) Kinesthesis is the capacity to know the position in space of .
Answers: (a) proprioception; (b) various parts of your body.
The Sense of Balance:Walking in an Upright Position
The sense of balance informs you that you are walking in an upright position. What
you are sensing is the relationship of your body, and in particular your head, to the
Earth's gravitational field. The sense of balance is made possible by receptor neurons
Sensation: Studying the Gateways of Experience 53
located in the semicircular canals. Located in the inner ear, the canals are tubular
bones filled with fluid. The movement of this fluid stimulates the firing of receptor
neurons within the canals, and the information is transmitted to the brain.
The sense of balance is also known as the vestibular sense. A vestibule is a
small antechamber or passageway. This is one way to describe the semicircular
canals, important components of the apparatus involved in the sense of balance.
(a) The sense of balance is also known as the .
(b) The sense of balance is made possible by receptor organs located in the .
Answers: (a) vestibular sense; (b) semicircular canals.
SELF-TEST
1. Sensation refers to
a. organized experience
b. thinking and concept formation
c. meaningful knowledge
d. the raw data of experience
2. The waves to which we give the name "light" are a narrow band of
a. the electromagnetic spectrum
b. radio waves
c. ultra-violet waves
d. infra-red waves
3. The trichromatic theory proposes that we have
a. three kinds of optic nerves
b. a triad of lenses
c. three kinds of cones
d. three kinds of rods
4. A sound wave
a. can travel through outer space
b. cannot travel through water
c. has frequency, but not amplitude
d. requires a medium such as air or water
5. What structure in the ear is similar in function to the eye's retina?
a. The basilar membrane
b. The auditory nerve
c. The tympanic membrane
d. The oval window
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6. The four basic taste sensations are
a. sweet, salty, bitter, and hot
b. sweet, bitter, burned, and salty
c. sour, acid, sweet, and mint
d. sweet, salty, bitter, and sour
7. One of the following is not a skin sense.
a. Light touch
b. Incongruent pleasure
c. Deep touch
d. Temperature
8. The receptor organ that makes smell possible is called the
a. vestibular membrane
b. olfactory epithelium
c. odor membrane
d. synaptic epithelium
9. What sense makes it possible for you to touch the tip of your nose with your
eyes closed?
a. The vestibular sense
b. The cardiovascular sense
c. Kinesthesis
d. Synthesis
10. The vestibular sense lets you know when
a. a signal is present
b. a figure is perceived against a ground
c. you are walking upright
d. you have a subliminal perception
ANSWERS TO THE SELF-TEST
1-d 2-a 3-c 4-d 5-a 6-d 7-b 8-b 9-c 10-c
ANSWERS TO THE TRUE-OR-FALSE PREVIEW QUIZ
1. True.
2. True.
3. False. An electromagnetic wave, not a sound wave, has the remarkable property of
being able to travel through a vacuum.
4. True.
Sensation: Studying the Gateways of Experience 55
5. False. Receptor organs in both the connective tissue surrounding the body's joints as
well as within the joints themselves make possible the sense of kinesthesis, the capacity
to know the position in space of various parts of your body.
KEY TERMS
56 PSYCHOLOGY
auditory nerve
basilar membrane
brightness
cochlea
cognition
cones
cornea
decibel (dB)
deep touch
electromagnetic spectrum
electromagnetic wave
fovea
hertz (Hz)
hue
incus
infra-red rays
kinesthesis
lens
light touch
loudness
malleus
olfaction
olfactory epithelium
optic nerve
oval window
pain
perception
periphery
photons
photoreceptors
pitch
proprioception
retina
rods
saturation
semicircular canals
sensation
skin senses
stapes
taste buds
temperature
timbre
trichromatic theory
tympanic membrane
ultra-violet rays
vestibular sense
vestibule
5 Perception: Why Do Things
Look the Way They Do?
57
PREVIEW QUIZ
True or False
1. T F In the study of perception, a distinction can be made between the
geographical world and the psychological world.
2. T F Figure-ground perception is always stable and never reversible.
3. T F Research suggests that there are innate, or inborn, organizing tendencies
in perception.
4. T F Learning appears to play no part in perception.
5. T F Clairvoyance is another name for psychokinesis.
(Answers can be found on page 70.)
The link between sensation and perception is clear. Perception is possible
because we have sensations. The raw data of experience—sensations—
become organized wholes at the level of perception. We experience a world
of objects—trees and songs—not flashes of light and random bits of sound.
In this chapter you will learn how this organization arises.
Objectives
After completing this chapter, you will be able to
• state the Gestalt laws of perception;
• describe the role that learning plays in perception;
• explain what illusions teach us about perception;
• explain how both binocular vision and monocular cues play a role in depth perception;
• discuss some of issues associated with the topic of extrasensory perception.
Kurt Koffka (1886–1941), one of the founders of Gestalt psychology, said that
the great question of perception is: "Why do things look the way they do?"
At first the question seems almost silly. We are tempted to answer, "Because
things are they way they are." It would seem that tall things look tall because they
are tall. And distant things look distant because they are distant. On the other
hand, why does the Moon look larger just above the horizon than it does when
it's overhead? It hasn't gotten any bigger, or any closer. And, if a series of disconnected
dots are arranged in the pattern of, say, the letter F, it looks like the letter,
not a bunch of disconnected dots—which, it could be argued, it actually is.
You learned in the last chapter that visual images on your retina are upsidedown.
Nonetheless, you perceive them as right side up. At the level of sensation, it's
an inverted world. At the level of perception, the world doesn't look inverted at all.
Koffka's question does not have to be limited to the sense of vision. The same
question could be adapted to the other senses. The principles set forth in this
chapter, largely in connection with vision, can be readily applied to perception in
general.
Sensation, as indicated in chapter 4, is the raw data of experience. Perception,
on the other hand, is the organization and the meaning we give to primitive
information. It can be said with some degree of confidence that we use
sensory information to create a psychological world.
Returning to Koffka, he said that there is a distinction between the geographical
world and the psychological world. The geographical world is the
actual world "out there," the world as defined and described by physics. The psychological
world is the world "in here," the world as experienced by the subject.
Although common sense usually says it's the so-called "real world" or
physical world that determines our behavior, it can be argued that common sense
isn't sufficiently analytical. Reflection suggests that we behave in terms of what
we perceive to be true, not necessarily in terms of what is actually true.
If ice is thin in the physical world, and it is solid in your psychological world, you
are likely to skate on it. And, of course, you may make a serious mistake as a result.
58 PSYCHOLOGY
In sum, it can be argued that we act to a large extent in terms of our perceptions.
And it is for this reason that the study of perception is a basic one in psychology.
(a) Perception is the and the meaning we give to primitive information.
(b) Koffka made a distinction between the geographical world and the world.
Answers: (a) organization; (b) psychological.
The Gestalt Laws: Is Our Perception of the World
Due to Inborn Organizing Tendencies?
Imagine that you are looking up and you see a single bird flying in the sky. The
bird is a figure, a well-defined perceptual object tending to stand out. The sky is
ground (or background), the perceptual field that surrounds the figure. This is
figure-ground perception. One of the features of this kind of perception is that
the figure is usually smaller than the ground and tends to be seen as coming forward
from the ground. Other examples include seeing a button on a blouse, a
book on a table, or a car on the road.
It can be argued that this kind of perception, the ability to distinguish a figure
from a field, is an inborn organizing tendency. We aren't taught to do it. We probably
start doing it spontaneously early in infancy. An infant reaching for a milk
bottle suggests to us that he or she perceives the bottle as a perceptual object, a figure
in a field. Figure-ground perception is probably the most fundamental organizing
tendency we possess.
Keep in mind once again that perception does not necessarily reflect the structure
of the world itself. For example, a word printed in black ink on a white page
is perceived as slightly in front of the white surface. We are tempted to think that
this is because the word is "on" the page. But imagine that a black piece of paper
is covered with a stencil. The entire page is inked white, with the exception of the
word. Now, from a physical point of view, the white ink is on the black surface.
Nonetheless, unless carefully studied, the word, emerging in black, will be perceived
as slightly forward and on the page.
perception is probably the most fundamental organizing tendency we
possess.