PSAT Reading Practice Question 31
Question: 31
This passage is adapted from "The Ability to Discriminate Paintings Found in Mice," a 2013 press release by Keio University
Keio University Professor Emeritus Shigeru
Watanabe has reported the ability to discriminate
paintings in pigeons and Java Sparrows in the past,
but his latest experiments have identified that this same
05ability exists in mice. He began by examining if the mice
stayed longer in front of paintings by Kandinsky or
Mondrian. He found that most mice did not display any
discrepancy in staying time (painting preference). They
did not show a preference for paintings when shown
10Renoir vs. Picasso, either. However, when mice were
injected with morphine while viewing one painting and
injected with saline solution when viewing the other,
the mice clearly began to stay for longer periods near
the paintings associated with morphine injection. In
15the second experiment, mice were able to discriminate
between pictures after training them to touch one of
the pictures displayed on a touch screen in order to
receive milk. Mice have been generally considered non-
visual animals, but this research indicates that mice are
20capable of higher-order visual perception.
Two types of apparatuses were used for the
experiments. The first was an apparatus with three
compartments. An iPod was installed on either side of
the apparatus, and slide shows of pictures of paintings
25were shown in sequence. Sensors recorded the staying
time of mice in the compartments with their respective
paintings. Next, mice were confined in one of the
compartments with a painting immediately after
receiving an injection of morphine (3mg/kg). During
30this confinement, paintings were displayed on the
iPod. The next day, mice received saline injections and
were confined in another compartment and shown
different paintings. After this procedure repeating
three times, mice were allowed to walk freely around
35the apparatus without any injection. 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
(Experiment 1).
40The second apparatus was a touch screen on which
a pair of paintings was displayed. If the mice touched
one of the paintings—one of Kandinsky's paintings, for
example—the mice would be rewarded with milk. If
they touched the other painting (Mondrian's painting,
45in this case), they would not receive milk. If mice
are capable of discrimination, they should touch the
painting associated with the milk reward (Experiment
2).
The first experiment, in which a slide show program
50on the iPod displayed 10 paintings each of Kandinsky
and Mondrian to the mice, did not indicate a longer
staying time for either artist's paintings. Analysis of
individual mice revealed only one mouse out of the
twenty stayed longer near Kandinsky's paintings. The
55mice did not indicate a preference for Picasso or Renoir
either, although one mouse out of the twelve stayed
longer near Renoir's painting. In the experiment which
used morphine (conditioning in Experiment 1), mice
stayed longer at the painting shown to them after the
60morphine injection for both the Kandinsky/Mondrian
and Picasso/Renoir pairs. In short, they were able to
discriminate between the paintings. When mice were
shown a number of the 10 paintings after the morphine
injection (e.g. five Kandinsky paintings), they recorded
65a longer staying time with the remaining paintings of
the same artist, even when those paintings had not
previously been shown to them (e.g. the five remaining
Kandinsky paintings). This is a phenomenon called
generalization and indicates that the mice were able
70to categorize a certain style of painting into a group. In
the touch screen experiment (Experiment 2), once mice
could correctly discriminate the pairs of Kandinsky and
Mondrian paintings, they were trained with different
pairs. After repeating this four times, mice were able
75to correctly choose the artist's painting in pairs of
paintings never shown to them around 80% of the
time. However, when the paintings were switched to
Picasso-Renoir pairs, the mice were unable to choose
correctly. This means that the mice were discriminating
80or categorizing a painting style as a single group.
Among mammals, humans place importance
on their sense of sight. Birds generally have excellent
vision. Mice have excellent senses of smell and hearing,
but it has been thought that they are non-visual
85animals. This is understandable considering the fact
that mice are nocturnal and burrowing creatures. This
experiment demonstrates that mice have much better
visual perception abilities than previously thought.
Additionally, it means that perception of complex visual
90stimuli like paintings extend to non-human animals.
Which choice is an underlying assumption Professor Watanabe makes regarding "staying time?"
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).