PSAT Reading Question 31: Answer and Explanation

Question: 31

Which choice is an underlying assumption Professor Watanabe makes regarding "staying time?"

• A. If mice stay longer with a painting, then it must be due to an association with the reward used.
• B. If mice are given rewards, they will have better vision and therefore be better equipped to differentiate between paintings.
• C. If mice spend more time viewing the paintings they saw when receiving a reward, then they are experiencing the same pleasure derived from the reward.
• D. If mice stay with a painting for as long as pigeons and Java Sparrows, then the mice have the ability to discriminate between paintings.

Correct Answer: A

Explanation:

A

The question asks for an underlying assumption that Professor Watanabe makes regarding "staying time." This is the first question in a paired set, but it is easy to find, so it can be done on its own. Since there is no line reference, use lead words and the order of the questions to find the window for the question. Q20 asks about line 12, so the window for Q21 most likely begins after line 12. Scan the second paragraph, looking for the lead words staying time. The paragraph says that staying time is a measure of how long the mice stayed in the compartments with their respective paintings. The last sentence of the paragraph says, As mice know that morphine causes pleasure, they should stay longer near the painting associated with the morphine injection if able to discriminate between paintings. Therefore, Professor Watanabe assumes that the mice are able to associate paintings with pleasure, or reward, and that this results in them staying longer near a particular painting. Eliminate answers that don't match this prediction. Keep (A) because it matches the prediction. Eliminate (B), because it is a Right Words, Wrong Meaning trap answer: the passage does not suggest that giving the mice rewards will give them better vision. Eliminate (C) for the same reason: the passage does not suggest that mice spend more time viewing the paintings they saw when receiving a reward because they are experiencing the same pleasure derived from the reward. There is no measure of whether the mice are experiencing pleasure again or to what degree they might. Eliminate (D) because the passage does not compare the staying time of mice with those of pigeons and Java Sparrows. The correct answer is (A).