Page 148 - Nutrition Counseling and Education Skills: A Guide for Professionals

behavioral response. For example, food in a dog’s mouth would reliably produce saliva. The triggering event,
food in the mouth, became known as the unconditioned stimulus, whereas the response that was triggered
salivation was called the unconditioned response. This relationship was built into the organism and hence
unconditioned.

Conditioning occurs when a neutral stimulus—one that originally does not trigger a particular response
(e.g., salivation)—eventually comes to produce that response. This occurs by pairing the originally neutral
stimulus with the unconditioned stimulus. When conditioning has occurred, the conditioned stimulus (CS),
which was originally neutral, produces the same response as the unconditioned stimulus, or one that is very
similar. In the example, the CS was the presence of the laboratory assistant. Pavlov showed that bells, tones,
lights, and many other stimuli could serve as the CS and could come to elicit the response of salivation, which
is labeled a conditioned response because it is triggered by or produced by a CS.6

Many types of responses have been found to react to classical conditioning principles. Not only reflexive
responses, such as salivation and eye blink, but also complex emotional responses can be classically
conditioned. The heart pounds and beads of perspiration appear on the forehead as one hears the siren of an
ambulance approaching a neighbor’s home. The same phenomenon may occur when the teacher passes out
examination questions. Try to construct a scenario to account for this response in terms of classical
conditioning principles or think of situations in nutrition and dietetics in which classical conditioning might
play a part in human behavior or emotional responses.

Operant Conditioning

At about the same time that Pavlov was delineating the principles of classical conditioning, a young American
scientist, Edward Thorndike, was pursuing the investigation of learning principles from another perspective.
Thorndike used many types of animals in his research and designed and constructed “puzzle boxes” for cats. A
hungry cat was placed inside the box with food located outside. To have access to the food, the cat had to
solve the puzzle of how to escape from the box. Thorndike observed that the cats made trial-and-error
responses until escape was achieved and the food consumed. Gradually, the time required to complete the
puzzle decreased. Furthermore, the behavior that achieved success in solving the puzzle became dominant,
and unsuccessful behaviors were eliminated.6

Thorndike proposed an explanation for this phenomenon based on a principle he called the Law of Effect.
This law stated that behaviors could be changed by their consequences. Responses that were followed by
satisfying consequences would be strengthened. Behaviors not followed by satisfying consequences, or
behaviors followed by annoying consequences, would be weakened and less likely to occur in the future.
Thorndike’s Law of Effect was applied to principles of learning and formed the foundation for the study of
operant or instrumental conditioning, which is learning based on reinforcement or reward.

The focal point of research on the Law of Effect is the relationship between responses, or behaviors, and
the consequences of those behaviors. Four types of response–consequence outcomes have been characterized.6
First, responses or behaviors may produce positive outcomes, a consequence known as positive reinforcement.
An example of reinforcement would be the praise and attention an overweight person may receive after losing
a noticeable amount of weight. Second, responses may produce negative outcomes; this consequence is known

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