Читать книгу Introduction to Abnormal Child and Adolescent Psychology - Robert Weis - Страница 93

In classical conditioning, learning occurs when the child associates two stimuli paired together in time. One stimulus is initially called the neutral stimulus (NS) because it does not elicit a response. The other stimulus is initially called an unconditioned stimulus (UCS) because it elicits an unlearned or unconditioned response (UCR). The child may come to associate the NS with the UCS if the two stimuli are presented together in time.

Pavlov demonstrated that dogs would associate the sound of a metronome (NS) with the presentation of meat powder (UCS) if the two stimuli were presented contiguously. After repeated presentations, the metronome alone elicited salivation. After conditioning, the previously neutral stimulus (e.g., metronome) is referred to as the conditioned stimulus (CS), whereas the resulting response (e.g., salivation) is referred to as the conditioned response (CR).

Classical conditioning can be used to explain the emergence of certain childhood disorders. For example, a boy who is bitten by a dog might associate the sight of a dog (NS) with the experience of being bitten (UCS). The dog bite, in turn, naturally causes a fear response (UCR). Later, the presence of any dog (CS) may elicit a similar fear response (CR). The boy might develop a phobia for dogs.

Consider another example. A girl is taking notes in her high school math class when she suddenly experiences a panic attack. The attack is so severe that she immediately leaves class and runs to the bathroom for privacy and safety. The girl associates her classroom (NS) with the panic attack (UCS), which naturally causes intense negative emotions (UCR). Later, any thought of reentering her classroom (CS) might elicit feelings of apprehension or anxiety (CR). She might develop a fear of going to school.

One way of decreasing behaviors acquired through classical conditioning is to repeatedly expose the CS until the severity of the CR decreases. When the CS no longer elicits the CR, we say that extinction has occurred.

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Exposure therapy is a primary treatment for most anxiety disorders. In a process called graded exposure, extinction occurs gradually. For example, a therapist might recommend that a boy with a fear of dogs gradually spend more time with dogs, in order to extinguish this fear. Initially, the boy might simply look at pictures of dogs, then remain in a room with a dog on a leash, and finally pet a dog. After the boy is repeatedly exposed to the dog, the dog’s presence no longer elicits an intense fear response (Image 2.7).

In a process called flooding, extinction occurs rapidly—usually within one session. For example, a girl with a fear of school might enter her math classroom with her therapist and remain there until her panic subsides. Although flooding is a more rapid treatment than graded exposure, it is less frequently used with children because it causes greater distress.