PrepTest 130, Section 3, Question 17
A group of mountain climbers was studied to(60 more words not shown)
The argument is most vulnerable(11 more words not shown)
- Athe climbers' performance(14 more words not shown)
- Bthe climbers' performance(13 more words not shown)
- Cthe climbers showed(12 more words not shown)
- Dsome of the(11 more words not shown)
- Emany of the(22 more words not shown)
Reading the argument
The climbers' speech, comprehension, and judgment all got worse at high altitude. Reduced oxygen could explain that, though fatigue or some other feature of the climb might also contribute. Observing the changes together doesn't by itself isolate their cause.
Then the author makes a much more specific claim about the brain: because the abilities deteriorated together, the area controlling speech cannot be distinct from the areas controlling other functions.
Why should that follow? One ability could deteriorate because of exhaustion and another because of reduced oxygen. That would allow different processes to produce the observed combination. My first objection is that the shared timing doesn't establish a single explanation for every change.
What we’re looking for
For the flaw question, the key is to preserve the possibility of distinct brain areas despite the simultaneous decline. We should look for an explanation of how the observed impairments could occur without disproving that separation.
Working the answers
- ACorrect
This gives us an even simpler possibility: one cause could affect several distinct areas at once. If oxygen deprivation affects the entire brain, the speech area could work less well while separate areas responsible for comprehension and judgment also work less well.
That doesn't require all three abilities to be controlled in the same place. Affecting the whole brain would reach each distinct region, so the combination of symptoms cannot establish that the regions are identical. We don't even need different causes for the different impairments; a widespread effect of the same cause would preserve the theory the author claims to disprove.
- B
The climbers could start above average and still experience the reported declines. Their initial ability level doesn't show whether one brain area or several areas control the affected functions. The argument concerns the location of control, not whether these climbers were unusually capable beforehand.
- C
Unequal impairment across speech, comprehension, and reasoning doesn't by itself establish where those abilities are controlled. One cause could affect several abilities to different degrees, whether their controlling regions are distinct or not. A gives the missing account of how distinct areas could all be affected; C merely varies the amount of decline.
- D
Symptoms beginning just below 6,100 meters wouldn't resolve the brain-area question. The conclusion doesn't depend on that exact altitude marking the first impairment. Moving the point of onset leaves the unsupported inference from several impaired abilities to a shared controlling region.
- E
Prior training might affect how well the climbers tolerate reduced oxygen. But it doesn't tell us whether the impaired functions are controlled by the same brain area. The climbers could have trained and still show the same combination of effects from oxygen deprivation across distinct areas.
More Flaw questions
Learn the LSAT our way
Our platform drills Flaw questions at your level and adjusts as you improve.