Russian physiologist Ivan Pavlov was the first to describe
. In classical conditioning, also called
“respondent conditioning” or “Pavlovian conditioning,” a
comes to respond to a neutral stimulus as he
would to another, nonneutral stimulus by
to associate the two stimuli.
’s contribution to learning began with his study of dogs. Not surprisingly, his dogs drooled every time he gave
them food. Then he noticed that if he sounded a tone every time he fed them, the dogs soon started to drool at the
sound of the tone, even if no food followed it. The dogs had come to associate the tone, a neutral stimulus, with
food, a nonneutral stimulus.
Conditioned and Unconditioned Stimuli and Responses
Psychologists use several terms to talk about classical conditioning. In Pavlov’s
, salivation was the
unconditioned response, which is a response that occurs naturally. Food was the unconditioned stimulus, the
stimulus that naturally evoked salivation. The tone was the conditioned stimulus, the stimulus that the dogs learned
to associate with food. The conditioned response to the tone was salivation. The
is usually the
same as, or similar to, the unconditioned response.
Suppose Adam has a psychology class with Professor Smith, who is determined to teach him about classical conditioning. In the first class, Professor Smith whips
out a revolver and shoots it into the air. The revolver is loaded with blanks, but when Adam hears the loud bang, he cringes out of surprise. Professor Smith
repeats this action several times during the class. By the end of the hour, Adam cringes as soon as she whips out the revolver, expecting a bang. He cringes even
if she doesn’t shoot. In this scenario, the unconditioned stimulus is the bang, the
is cringing, the
is the revolver, and
the conditioned response is cringing.
Acquisition of Conditioned Responses
Subjects acquire a conditioned response when a conditioned stimulus is paired with an
Conditioning works best if the conditioned stimulus appears just before the unconditioned stimulus and both stimuli
end at about the same time. In the above example, Professor Smith’s conditioning will work best if she displays the
revolver right before firing and puts it away after shooting.
After Adam has been conditioned to cringe at the sight of the revolver, Professor Smith comes into the next class
and pulls out the revolver again. He cringes, but she doesn’t shoot. If she pulls it out again and again on several