Question 72·Hard·Central Ideas and Details
Cognitive psychologist Dr. Mei Chen investigated how brief daytime sleep might influence the accuracy of episodic memory. Participants studied twenty lists of semantically related words, each list strongly implying but never actually containing a critical "lure" word (for example, a list with bed, pillow, and dream implicitly suggested the absent word sleep). After the learning phase, half the participants remained awake in a dim room for 90 minutes, while the other half took a 90-minute nap during which Chen recorded dense bursts of brain activity known as sleep spindles. When tested later, the two groups remembered roughly the same number of originally presented words, but the napping group generated far fewer lure words during free recall. Chen concluded that sleep spindles may bolster a person’s ability to distinguish studied information from closely related but novel material.
According to the passage, which choice best states Chen’s principal finding regarding the effect of the nap on participants’ memory performance?
For questions asking about a study’s main finding, go straight to the sentences that report the results—often near the end of the description—and carefully note any comparisons ("same number," "more," "less") between groups. Separate different aspects of performance (like accurate vs. false recall), then choose the answer that correctly captures all of those reported effects without adding anything new or flipping the direction of the result.
Hints
Find where the memory results are described
Look for the part of the passage that talks about how the two groups performed "when tested later" on the words they had studied.
Separate accurate recall from false recall
In that key sentence, identify what it says about the number of originally presented words remembered, and separately what it says about the number of lure words produced.
Check for change versus no change
Ask yourself: Did the nap change how many real list words people remembered? Did it change how often they mistakenly recalled lure words? Then pick the answer that reflects both of those outcomes.
Step-by-step Explanation
Locate the key result in the passage
Focus on the sentence beginning with "When tested later" and the one that follows it. These sentences directly compare the memory performance of the napping group and the awake group.
Understand what happened to accurate recall
The passage says, "the two groups remembered roughly the same number of originally presented words." This means that taking a nap did not noticeably change how many of the real study-list words participants could correctly remember.
Understand what happened to false recall
In the same sentence, the passage notes that "the napping group generated far fewer lure words during free recall." So, compared with those who stayed awake, people who napped made fewer errors by mistakenly recalling lure words that were never actually shown.
Combine both effects and match to an answer choice
Putting these details together, the nap did not increase recall of the original words, but it did reduce the number of falsely recalled lure words. Among the choices, only "The nap reduced the number of falsely recalled lure words without increasing recall of the originally presented words." matches this description.