#2 - The vomeronasal organ (VNO) is found inside the noses

[Administrator]

Complete Question Explanation

Weaken-CE. The correct answer choice is (A)

In this stimulus the author discusses the VNO, a small organ found in the noses of some animals. Humans have a microscopic version of the organ, and when researchers are able to stimulate its cells, subjects report subtle smell sensations. Based on this information, the author concludes that the VNO, though microscopic, functions in humans. This is a causal conclusion:

• Cause Effect
  Test subject stimulation subtle smell sensations

The question that follows is a Weaken question, so we should look for the answer choice that hurts the author’s argument that the referenced stimulation of the VNO led to subtle smell sensations. There are several ways to weaken a causal argument. In this case the assertion is that the subtle smell sensations noted can be attributed to a functioning VNO, so if an answer choice provides an alternative cause for this effect, it will be the correct answer choice.

Answer choice (A) is the correct answer choice. What this choice basically says is that researchers may have stimulated other cells, which means it’s possible that other cells (not VNO cells, as asserted by the author) that caused the subtle smell sensations that were reported by test subjects. Since this choice suggests the possibility of an alternative cause, as discussed above, it is the answer which weakens the author’s causal conclusion.

[SMR]

Hello powerscore. I'm having trouble with question #40. I chose the correct answer but the way I approached the problem was not using cause and effect reasoning. I do see the causality now but I do not see it present in the conclusion just the premise that states, "when researchers have been able to stimulate VNO...subtle smell sensations." With that being said, I was under the impression that if a causal relationship occurs in the premise and not the conclusion then there is no error of causality to exploit so you wouldn't use the causality approach to weaken the argument. The powerscore explanations online state that there is a causal conclusion but the diagram shows the causal premise that comes before the conclusion. Can someone please breakdown all the causal relationships present in the stimulus. Thank you so much I appreciate it!!!

[KelseyWoods]

Hi SMR!

This argument is a little bit tricky. Essentially, the premise says that when they stimulate the VNO cells, the subjects experience subtle smell sensations. But the premise doesn't specify that the stimulation of the VNO cells causes the subtle smell sensations. Just that they occur together. (As a side note, that premise statement is technically conditional, as it features the conditional indicator word "when." Remember that conditional and causal reasoning are very different types of reasoning so be careful not to confuse the two!)

The author's conclusion, then, is the causal part. The author concludes that the VNO must be a functioning sensory organ--basically, he's saying that since when you stimulate the VNO, you get subtle smell sensations, then stimulating the VNO must CAUSE the subtle smell sensations. (the VNO causing smell sensations = VNO is a functioning sensory organ). That's the causal relationship we want to attack.

Answer choice (A) weakens that causal argument by providing an alternate cause of the subtle smell sensations. Instead of the VNO stimulation causing the smell sensations, (A) suggests that something else stimulated in the noses might have caused the subtle smell sensations.

Hope this helps!

Best,
Kelsey

[SMR]

Thank you Kelsey your explanation helped a lot! I appreciate it!

[JayI]

Hi,

I dont understand why Answer choice C is incorrect. If "certain chemicals" have an effect on animals and do not have an effect on humans, then that would weaken the argument. Moreover, answer choice A attacks "stimulation" of the subtle smell sensation. This sentence doesnt seem to be the conclusion, so how do we know we need it attack it?

[Adam Tyson]

Focus on the causal reasoning here, Jayl. The author wants us to believe that the stimulated VNO cells are responsible for the test subjects experiencing those subtle smell sensations. That is the stimulated VNO cells were the cause, and the smell sensations were the effect.

When we are asked to weaken a causal claim, one of our favorite ways to do so is to suggest that some other cause was at work - we usually refer to that as an "alternate cause" attack. Answer choice A does exactly that by suggesting that the VNO cells may not have been the cause, but rather that some other cells may have been stimulated, and it may be those cells rather than the VNO cells that caused the smell sensations. It certainly doesn't prove that, but we don't need to prove anything in a weaken answer, but only introduce an element of doubt about the conclusion. Our reaction to answer A should be "Hmmm, maybe some other cells were stimulated and caused those sensations" (thoughtfully stroke your chin and look up towards the ceiling as you say this)

Answer C does nothing to suggest an alternate cause, or any of our other typical causal attacks. So what if certain chemicals are involved in the way VNO cells function in non-human animals? The cause - VNO cell stimulation - could still bring about our effect - the smell sensations. Maybe humans don't need those chemicals for VNO cells to function? Maybe the reason our VNO cells are not all that highly developed is because we don't have those chemicals? Heck, maybe those chemicals would be of no use to us humans because we are so different from those other animals? None of this matters if all we want to do is suggest that the stimulated VNO cells might not have caused the smell sensations. A gives us an alternate cause, while C talks about something else that is not either our cause or our effect. Alternate cause for the win!

I hope that helps. Keep at it!

[glasann]

I had a hard time choosing between A, B and D. I do see how A weakens the conclusion, however I'm having trouble seeing why B and D don't also weaken it for the following reasons:

B - regardless of its relativity to other animals, if humans' VNO is underdeveloped and rudimentary doesn't that cast doubt on it being a "functioning sensory organ in humans", as the conclusion draws?

D - seems like a similar issue as answer choice B.

Can you please clarify what's wrong with these, especially B? Are we just assuming a little too much with those?

Thank you!

[Adam Tyson]

The short answer to both B and D, glasann, is "so what?" We already knew the VNO in humans was a tiny little thing, and we knew that we didn't know much about it. But we also knew that when it was stimulated, the subjects smelled stuff. So what if it is rudimentary and undeveloped and is missing some secondary structures - it still seems to be doing something, functioning in some way related to smell, rather than being completely dormant, right? Neither of those answers raises doubts about whether the VNO is actually doing something, functioning in some was that we may not entirely understand, and that may not be exactly the same as a VNO in another animal. Only answer A does that, by questioning whether the VNO had anything to do with those smells the subjects reported.