PrepTest 144, Section 2, Question 12
In an experiment, two groups of mice—one whose(70 more words not shown)
Which one of the following,(7 more words not shown)
- AThe doses of(25 more words not shown)
- BNeither the mice(17 more words not shown)
- CSome chemical substances(12 more words not shown)
- DScientists have not(13 more words not shown)
- EThe mice who(17 more words not shown)
Reading the argument
Maybe the mice remembered better because they were calmer. But were they highly stressed to begin with?
The experiment found better next-day recall among mice given ginkgo. The author offers an indirect explanation: ginkgo reduces stress, and reducing very high stress can improve recall. On that account, ginkgo wouldn't need to improve memory directly. It could help by removing a problem that was getting in the way of remembering.
What we’re looking for
That explanation needs the problem to be present. If these mice weren't under unusually high stress, there may have been no high-stress barrier for ginkgo to remove. For the weakener, I'd look for evidence that the mice didn't have the stress level this explanation depends on.
Working the answers
- A
A higher dose is different from the doses used in the stress studies, but different doesn't automatically mean ineffective. Perhaps the higher dose still reduces stress. To use A against the argument, we'd need information showing that the larger dose loses that effect or works in some conflicting way. The dose comparison alone doesn't supply it.
- BCorrect
Neither group showed physiological signs of higher-than-normal stress. That undercuts the proposed explanation that ginkgo improved recall by lowering very high stress. It doesn't prove that ginkgo directly enhances memory, and it doesn't mean the mice had no stress at all. It gives us a reason to doubt that the particular stress problem invoked by the author was present.
- C
Which substances? The answer doesn't establish that ginkgo is among the stress-reducing substances that temporarily impair memory. What some other chemicals do doesn't tell us why the ginkgo group recalled this maze better the next day.
- D
We can have evidence that ginkgo reduces stress without knowing exactly which component produces the effect. Not having identified the responsible substance doesn't show that the effect is absent or that it cannot explain improved recall. The argument relies on the reported effect, not a complete account of its chemistry.
- E
Learning the maze initially and remembering it the next day are different tasks. Both groups could take equally long to learn the route, then differ in how well they retain it. The proposed stress explanation concerns that later recall, so equal learning times don't undermine it.
More Weaken questions
Learn the LSAT our way
Our platform drills Weaken questions at your level and adjusts as you improve.