Some Applications of Classical Conditioning

176
Chapter 5
Learning
THE POWER OF SECOND-ORDER
CONDITIONING Cancer patients
may feel queasy when they enter a
chemotherapy room because they
have associated the room with nauseaproducing treatment. Through secondorder conditioning, almost anything
associated with the room can also become a conditioned stimulus for nausea.
One cancer patient, flying out of town on
a business trip, became nauseated just
by seeing her hospital from the air
© Herb Lingl/aerialarchives.com
snakes than of electrical outlets, knives, or other, more dangerous objects (Öhman &
Mineka, 2001, 2003). And experiments with animals suggest that they tend to learn the
type of associations that are most relevant to survival in their environment (Staddon
& Ettinger, 1989). Birds of prey, which strongly depend on vision to find food, may
develop taste aversions on the basis of appearance. Coyotes and rats depend more on
their sense of smell, so they tend to develop aversions related to odor.
Second-Order Conditioning Once we learn that a conditioned stimulus (CS) signals the arrival of an unconditioned stimulus (UCS), the CS may operate as if it actually were that UCS. For instance, suppose that a child endures a painful medical procedure (UCS) at the doctor’s office, and the pain becomes associated with the doctor’s
white coat. The white coat might then become a conditioned stimulus (CS) that can
trigger a conditioned fear response. Once the white coat is able to set off a conditioned
fear response, the coat may take on some properties of an unconditioned stimulus. So
if the child later sees a white-coated pharmacist at the drugstore, that once-neutral store
can become a conditioned stimulus for fear because it signals the appearance of a white
coat, which in turn signals pain. When a conditioned stimulus (the white coat) acts like
an unconditioned stimulus, creating conditioned stimuli (the drugstore) out of events
associated with it, the process is called second-order conditioning.
This process serves as an adaptive “early warning system.” It prepares us for threatening events (UCS) that are signaled not only by a CS but also by associated events
that precede, and thus predict, that CS. But second-order conditioning can also cause
problems. For example, the high blood pressure seen in medical patients known as
white-coat hypertensives (Myers et al., 1996; Ugajin et al., 2005) does not reflect a physical disorder. It occurs simply because the sight of a doctor or nurse has become a conditioned stimulus for fear. Medical staff must be alert to such cases in order not to give
blood pressure medication to patients who don’t need it.
Some Applications of Classical Conditioning
second-order conditioning A process
through which a conditioned stimulus
comes to signal another conditioned
stimulus that is already associated with
an unconditioned stimulus.
The principles of classical conditioning are summarized in “In Review: Basic Processes
of Classical Conditioning.” These principles have proven useful in many areas, including in recent efforts to use insects to help detect explosive material. For example, after
the taste of sugar water has been associated with the smell of a chemical used in certain
explosives, wasps quickly develop a conditioned response to the smell alone. When several of these trained insects are placed in a plastic tube and brought near the target
chemical, they display an immediate attraction to it (Rains, Utley, & Lewis, 2006).
Researchers hope that it may someday be possible to use these so-called Wasp Hounds
177
in review
Classical Conditioning: Learning Signals and Associations
BASIC PROCESSES OF CLASSIC AL CONDITIONING
Process
Description
Example
Acquisition
A neutral stimulus and an unconditioned
stimulus (UCS) are paired. The neutral
stimulus becomes a conditioned stimulus
(CS), eliciting a conditioned response (CR).
A child learns to fear (conditioned response)
the doctor’s office (conditioned stimulus) by
associating it with the reflexive emotional
reaction (unconditioned response) to a
painful injection (unconditioned stimulus).
Stimulus
generalization
A conditioned response is elicited not only
by the conditioned stimulus but also by
stimuli similar to the conditioned stimulus.
A child fears most doctors’ offices and places
that smell like them.
Stimulus
discrimination
Generalization is limited so that some stimuli
similar to the conditioned stimulus do not
elicit the conditioned response.
A child learns that his mother’s doctor’s
office is not associated with the
unconditioned stimulus.
Extinction
The conditioned stimulus is presented alone,
without the unconditioned stimulus.
Eventually the conditioned stimulus no
longer elicits the conditioned response.
A child visits the doctor’s office several times
for a checkup, but does not receive a shot.
Fear may eventually cease.
?
1. If your conditioned fear of spiders is triggered by the sight of other creatures that look like spiders, you are demonstrating
stimulus
.
2. Because of
, we are more likely to learn a fear of snakes than a fear of cars.
3. Feeling sad upon hearing a song associated with a long-lost relationship illustrates
.
and other similar devices to detect explosives or drugs concealed in airline passengers’
luggage. Classical conditioning principles have also been applied in overcoming fears
and understanding certain aspects of drug addiction.
Phobias Phobias are intense, irrational fears of objects or situations—such as pub-
lic speaking—that are not dangerous or that are less dangerous than the fear response
would suggest. Classical conditioning often plays a role in the development of phobias
(Bouton, Mineka, & Barlow, 2001). As mentioned earlier, a person frightened by a dog
may learn a fear that is so intense and generalized that it leads the person to avoid all
dogs and all situations in which dogs might be encountered. Classically conditioned
psychology
applying
PREDATOR
CONTROL THROUGH
CONDITIONING In
the western United States, some ranchers
lace a sheep carcass with enough lithium
chloride to make wolves and coyotes nauseous (Pfister et al., 2003). The predators
associate nausea with the smell and taste
of sheep and afterward stay away from
the ranchers’ flocks. A similar program in
India has greatly reduced the human death
toll from tiger attacks. Stuffed dummies are
connected to a shock generator and placed
in areas where tigers have killed people.
When the animals approach the dummies,
they receive a shock (UCS). After learning
to associate shock with the human form
(CS), the tigers tend to avoid people (CR).