Wolpe and Desensitization Therapy

Desensitization is aimed directly at extinction of a troublesome emotional response. It was the first therapy to be called a behavior therapy. Desensitization was proposed by Joseph Wolpe (pronounced VOLE-py). Because desensitization was the first widely-adopted therapy based on a behavioral principles, Wolpe is often called the "father of behavior therapy."

How did Masserman produce neurotic cats? What did Wolpe do, to reduce anxiety in cats?

Wolpe was following up on experiments by a researcher named Masserman . Masserman made cats "neurotic" by giving them electric shocks in a certain box. Soon the cats acted anxious whenever they were put in the box. Masserman observed that the cats lost their "neurosis" if they were fed in the box. He interpreted this in psychodynamic terms, as "breaking through the motivational conflict." Wolpe saw the same events in terms of conditioning. Wolpe replicated Masserman's work and showed that cats could be induced to show gradually less and less fear, by being fed first at a distance, then closer to the box where previously they were shocked.

Wolpe called this counter-conditioning , literally using one association (between the box and feeding) to run "counter" to another association (between the box and shocks). Wolpe also termed the process reciprocal inhibition because he felt the responses of anxiety and eating "inhibited" or prevented each other. By encouraging animals to have a response incompatible with anxiety, while exposing them to the stimulus that previously caused anxiety, he could weaken and eliminate the anxiety response.

What process seems to underlie desensitization?

Desensitization inspired a great deal of research in the 1960s and 1970s. It seems to be a form of Pavlovian extinction. The greater the duration of exposure to the anxiety-provoking stimulus, while preventing the unwanted response, the greater the reduction of the learned response to that stimulus. This is the pattern commonly observed in extinction of a classically conditioned response.

How was desensitization therapy conducted, in Wolpe's original procedure?

Wolpe devised a procedure that worked well, although it took a lot of time. First, he taught the patient to relax deeply, using a technique called Jacobsonian progressive relaxation which may itself take a few weeks to master. Then he encouraged patients to visualize or imagine the anxiety-arousing stimulus while remaining relaxed. To gradually eliminate the anxiety-arousing characteristics of the feared stimulus, Wolpe had his patients make a fear hierarchy from least-fearsome to most-fearsome imagery. For example, if the patient was snake-phobic (terribly afraid of snakes) he or she might produce this list:

1. A tiny snake 50 feet away (the least fearsome image)

2. A larger snake 30 feet away

3. A large snake 10 feet away

4. A large snake on the ground right in front of me

5. A snake bumping against my foot then slithering away

6. A snake being placed in my hands

7. A snake wrapping itself around my arm

8. A snake slithering up my arm toward my neck

9. A snake taking a big bite out of my cheek

10. Falling into a pit of poisonous snakes (the most fearsome image)

How does desensitization work, from a classical conditioning perspective?

The patient started with the least anxiety-arousing image (#1) and moved on to the next only when able to imagine the first image while staying fully relaxed. Given enough time, and enough practice with relaxation techniques, even a truly snake-phobic individual gradually works through the hierarchy until he or she is able to imagine the worst, most horrible scene while staying fully relaxed. At this point, the conditioned emotional response (CER) is fully "undone" or extinguished. To use the terminology from the Conditioning chapter, the conditional stimulus (sight of the snake) no longer elicits a conditional response of anxiety.

Why does desensitization often require patience? When does it work relatively quickly?

Desensitization works, and it is simple to administer, although often one must be patient to "do it right." Patients with genuine, clinical strength phobias (phobias severe to make them seek therapy) may take a long time to desensitize. As noted in Chapter 8 (p.387) certain types of phobias seem to be "prepared" by evolution and are more difficult to treat. These include snake, spider, and small animal phobias. However, even these "deep-down" fears usually yield to desensitization in the long run. Less biologically-based phobias such as test anxiety and fear of flying often are eliminated quickly.

Wolpe (1958) described a three-part systematic desensitization procedure:

What were elements of Wolpe's classic desensitization procedure?

1. The client is trained in deep relaxation.

2. The client and therapist construct a list of anxiety-eliciting stimuli, the so-called "fear hierarchy," ordered from least to most distressing.

3. Starting with the least anxiety-arousing image, the feared stimuli are paired with relaxation, until eventually the most feared stimulus is tolerated calmly.

What was a drawback to Wolpe's original method? What were some short-cuts different therapists adopted?

The original systematic desensitization procedure was slow, lasting over a year in some cases. It commonly required 40 to 50 sessions of 1 hour each (Kraft & Al-Isson, 1965). In the years after Wolpe publicized his original procedure, researchers tried out dozens of variations, looking for more efficient procedures. For example, researchers found that drugs or carbon dioxide/oxygen mixtures could provide rapid relaxation, making time-consuming relaxation training unnecessary.



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Copyright © 2007 Russ Dewey