Psychology2016

180 CHAPTER 5

Notice that the responses, CR (conditioned response) and UCR (unconditioned

response), are very similar—salivation. However, they differ not only in strength but

also in the stimulus to which they are the response. An unconditioned stimulus (UCS) is

always followed by an unconditioned response (UCR), and a conditioned stimulus (CS) is

always followed by a conditioned response (CR).

Is this rocket science? No, not really. Classical conditioning is actually one of the

simplest forms of learning. It’s so simple that it happens to people all the time without

them even being aware of it. Does your mouth water when you merely see an advertise-

ment for your favorite food on television? Do you feel anxious every time you hear the

high-pitched whine of the dentist’s drill? These are both examples of classical condition-

ing. Over the course of many visits to the dentist, for example, the body comes to asso-

ciate that sound (CS) with the anxiety or fear (UCR) the person has felt while receiving

a painful dental treatment (UCS), and so the sound produces a feeling of anxiety (CR)

whether that person is in the chair or just in the outer waiting area.

Pavlov and his fellow researchers did many experiments with the dogs. In addi-

tion to the metronome, whistles, tuning forks, various visual stimuli, and bells were used

If you find yourself cringing at the mere
sight of a hypodermic needle, your
cringing is a CR to the CS of the needle.
The pain of the shot would be the
original UCS.

Figure 5.1 Classical Conditioning

Before conditioning takes place, the sound of the metronome does not cause salivation and is a neutral

stimulus, or NS. During conditioning, the sound of the metronome occurs just before the presentation of

the food, the UCS. The food causes salivation, the UCR. When conditioning has occurred after several pair-

ings of the metronome with the food, the metronome will begin to elicit a salivation response from the dog

without any food. This is learning, and the sound of the metronome is now a CS and the salivation to the

metronome is the CR.

Before Conditioning

During Conditioning

Neutral Stimulus

(NS) Metronome

Unconditioned Stimulus

(UCS) Food

Conditioned Stimulus

(CS) Metronome

Unconditioned Response

(UCR) Salivation

Conditioned Response

(CR) Salivation

After Conditioning

Neutral Stimulus

(NS) Metronome

No Salivation

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