PrepTest 136, Section 2, Question 4
Traditional "talk" therapy, in which a patient with(57 more words not shown)
Which one of the following(8 more words not shown)
- AAll neurochemical changes(4 more words not shown)
- BImprovements in a(15 more words not shown)
- C"Talk" therapy has(8 more words not shown)
- DIf chemical changes(18 more words not shown)
- EDirect intervention in(19 more words not shown)
Reading the argument
Talking to a therapist changes brain chemistry. It also seems to help behavior. Does that mean the chemical changes explain all the improvement?
Maybe a therapist suggests that a patient talk to a friend, and following that advice improves the patient's behavior. The sessions could produce chemical changes as well. Seeing both results after therapy doesn't yet tell us that the chemistry accounts for everything the conversation accomplished.
Now the author proposes replacing the conversation with drugs that act on brain chemistry. That raises two questions. Can drugs reproduce the relevant chemical effects? And even if they can, would reproducing those effects capture all the benefit of the therapy? If part of the improvement depends on something else about the interaction, changing chemicals alone could leave that benefit behind.
What we’re looking for
The necessary-assumption question asks what this replacement argument relies on. We need the behavioral improvements attributed to therapy to work through the chemical changes. Otherwise the author hasn't explained why an intervention confined to chemistry could be just as effective.
Working the answers
- A
All neurochemical changes? We're concerned with the changes associated with the improvements from this therapy. The author doesn't need every chemical change in the brain to produce a psychological change. A extends the claim far beyond the process on which the proposed replacement depends.
- BCorrect
The word “only” matters. If therapy produces improvements through chemical changes and also through a separate contribution that the proposed drugs don't reproduce, replacing therapy with those drugs could lose that contribution. The argument needs the chemical route to account for the improvements it promises to preserve.
This can initially sound too strong. But the conclusion promises treatment as effective as talk therapy, not merely some benefit from a drug. That is why leaving part of therapy's benefit outside the chemical explanation creates a problem. B doesn't settle the separate question of whether suitable drugs can actually be developed; it states an assumption needed by the offered reasoning.
- C
The author uses the improvements associated with talk therapy as the starting point for the prediction. The reasoning doesn't require therapy to have failed at bringing about psychological change. The question is how its benefits arise and whether a drug can reproduce them.
- D
Even if both fields study aspects of the same improvement, they needn't become indistinguishable. Psychology and neuroscience could remain separate fields while physicians developed an equally effective treatment. Merging fields of study is no part of the proposed substitution.
- E
A drug could be just as effective and cost more. The conclusion compares treatment effectiveness, not prices. We don't need a prediction about cheaper care to make this particular argument.
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