Understanding Psychology (10th Ed)

 
Module 17 
Classical Conditioning 
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and others who have had traumatic experiences, can also be produced by classical 
conditioning. Even years after their battlefi eld experiences, veterans may feel a rush 
of fear and anxiety at a stimulus such as a loud noise (Kaštelan et al., 2007; Kozaric-
Kovacic, & Borovecki, 2005; Roberts, Moore, & Beckham, 2007). 
However, classical conditioning also accounts for pleasant experiences. For 
instance, you may have a particular fondness for the smell of a certain perfume or 
aftershave lotion because thoughts of an early love come rushing back whenever you 
encounter it. Or hearing a certain song can bring back happy or bittersweet emotions 
due to associations that you have developed in the past. Classical conditioning, then, 
explains many of the reactions we have to stimuli in the world around us.
Extinction
What do you think would happen if a dog that had become classically conditioned 
to salivate at the ringing of a bell never again received food when the bell was rung? 
The answer lies in one of the basic phenomena of learning: extinction.  Extinction 
occurs when a previously conditioned response decreases in frequency and eventu-
ally disappears. 
To produce extinction, one needs to end the association between conditioned 
stimuli and unconditioned stimuli. For instance, if we had trained a dog to salivate 
(the conditioned response) at the ringing of a bell (the conditioned stimulus), we 
could produce extinction by repeatedly ringing the bell but not providing meat. At 
fi rst the dog would continue to salivate when it heard the bell, but after a few such 
instances, the amount of salivation would probably decline, and the dog would even-
tually stop responding to the bell altogether. At that point, we could say that the 
response had been extinguished. In sum, extinction occurs when the conditioned 
stimulus is presented repeatedly without the unconditioned stimulus (see Figure 2). 
We should keep in mind that extinction can be a helpful phenomenon. Consider, 
for instance, what it would be like if the fear you experienced while watching the 
shower murder scene in the classic movie Psycho never was extinguished. You might 
well tremble with fright every time you took a shower. 
Once a conditioned response has been extinguished, has it vanished forever? Not 
necessarily. Pavlov discovered this phenomenon when he returned to his dog a few 
days after the conditioned behavior had seemingly been extinguished. If he rang a 
bell, the dog once again salivated—an effect known as  spontaneous recovery  , or the 
extinction
A basic phenomenon of 
learning that occurs when a previously 
conditioned response decreases in 
frequency and eventually disappears.