PT50, S4, Q17 - A group of mountain climbers was studied

[stephen.dewart]

"The argument is most vulnerable to criticism on the grounds that it overlooks the possibility that..."

I chose (C) because it seemed to suggest that, hey, if performance levels were different in speech versus the other areas (comprehension and reasoning), then perhaps speech IS controlled by a distinct part of the brain. No...?!

(A) -- the correct answer -- confuses me. That the climbers' performance in all the areas (including speech) was impaired by oxygen deprivation to their entire brain -- how is this any different than what's already said in the passage? ("The combination of worsened performance disproves the theory...") Seems to strengthen or at least agree with it, no?

[giladedelman]

Thanks for the question!

This is an identify the flaw question, which really means we're looking for an assumption. So our first job is to identify the core of the argument, which is something like this:

A group of mountain climbers performed worse in speech, understanding, and judgment due to oxygen deprivation at high altitudes. Therefore, the area of the brain controlling speech is not distinct from that controlling other functions.

Now it's our job to identify the gap in the logic. What is the author assuming? If he's concluding that because speech deteriorated along with two other abilities, they must all be in the same area in the brain, then he must be assuming that only one area of the brain was affected by oxygen deprivation. But what if these functions are all in different areas that all were affected by diminished oxygen? Then the conclusion doesn't hold up!

(A) is correct. It negates the assumption we identified by suggesting that the entire brain was affected by oxygen deprivation -- which means we can't conclude anything about whether speech and the other functions are in the same area!

(B) is out of scope. We don't care about the climbers' overall ability before they started.

(C) is tempting, like you said, but it doesn't address the author's big assumption that only one area of the brain is affected. It's too big a leap for us to say that if the different functions showed different levels of impairment, then they're in different areas.

(D) is out of scope. We really don't care about the 6,100 meter threshold.

(E) is out of scope. We don't care about the climbers' special efficiency rates; we care about what we're told, which is that their brain functions diminished.

Does that make things any clearer for you? Please don't hesitate to ask more questions if you're still unsure about this one.