雅思阅读练习 · Passage 1（科学类）

Adapted in the style of Scientific American — "The Sleeping Brain: How Sleep Builds Memory" 题型组合：段落标题匹配（Matching Headings）+ 判断（TRUE/FALSE/NOT GIVEN）+ 摘要填空（Summary Completion）+ 单选（Multiple Choice）

READING PASSAGE 1

You should spend about 20 minutes on Questions 1–14.

The Sleeping Brain: How Sleep Builds Memory

A We spend roughly a third of our lives asleep, yet for most of human history the purpose of this state remained a mystery. Ancient thinkers regarded sleep as a passive withdrawal from the world, a kind of nightly death from which we happen to awaken. Only in the past century have scientists come to regard sleep not as a suspension of mental life but as an active, highly organised process — one that appears to play a central role in shaping what we remember and what we forget.

B The scientific study of memory began with the German psychologist Hermann Ebbinghaus, who in the 1880s memorised lists of nonsense syllables and plotted how quickly he forgot them. His famous "forgetting curve" showed that memories fade rapidly within hours and then more slowly over days. What Ebbinghaus could not have known is that the rate of forgetting depends heavily on what happens after learning — and that one of the most powerful influences is sleep itself. Later researchers demonstrated that people who slept after learning a list of words recalled significantly more the next day than those who stayed awake, even when both groups had spent the same total time awake.

C Modern neuroscience has identified the brain structures responsible. During waking hours, experiences are encoded in the hippocampus, a seahorse-shaped structure deep in the brain. Memories are not stored there permanently, however. Over time, they are transferred to the neocortex, where long-term knowledge resides. The transfer is not instantaneous; it appears to be consolidated during sleep, particularly during slow-wave sleep, the deep stage characterised by slow, synchronised brain waves. Researchers have shown that the same patterns of neural activity that occur during learning are "replayed" at an accelerated rate during slow-wave sleep, as if the brain were rehearsing the day's events.

D The consequences of losing this rehearsal time are measurable. In laboratory studies, participants who were deprived of slow-wave sleep after learning a task performed significantly worse the following day, even if they had otherwise slept normally. Interestingly, the impairment is selective: procedural skills, such as playing a sequence on a keyboard, depend more heavily on slow-wave sleep, whereas emotional memories appear to benefit from rapid eye movement (REM) sleep, the stage associated with vivid dreaming. This division of labour suggests that sleep does not consolidate memory as a single block but sorts experiences into different pathways.

E Why the brain should require this nocturnal rehearsal has been the subject of fierce debate. One influential proposal, the synaptic homeostasis hypothesis, argues that learning during the day strengthens connections between neurons, steadily increasing the brain's energy demands. Sleep, in this view, allows the brain to downscale these connections selectively, preserving important information while weakening irrelevant noise. Without this reset, the brain would eventually become saturated — unable to learn anything new because every connection would already be at maximum strength.

F The practical implications are now spilling out of the laboratory. Sleep researchers have begun to advise students that an all-nighter before an exam is counterproductive, not merely because fatigue impairs concentration but because the memory consolidation that would have occurred during sleep is lost. Studies of medical residents, airline pilots and professional athletes all point in the same direction: performance improves after sleep and deteriorates without it. Some schools, experimenting with later start times, have reported measurable gains in test scores.

G Yet significant questions remain. The amount of sleep required varies widely between individuals, and the reasons for this variation are poorly understood. Recent work has also shown that memory can be manipulated during sleep — by presenting sounds or odours associated with earlier learning, researchers have been able to strengthen specific memories. Whether such techniques will ever be practical outside the laboratory is unclear, but they have already overturned the assumption that the sleeping brain is simply offline.

H What is no longer in doubt is that sleep and memory are intimately connected. The image of sleep as a blank gap in our mental lives has given way to a more productive picture: a nightly workshop in which the brain edits, strengthens and reorganises the experiences of the day. For anyone hoping to learn, the message of modern sleep science is deceptively simple — what you do after you study may matter as much as what you do during it.

Questions

Questions 1–7 段落标题匹配（Choose the correct heading for each paragraph）

List of Headings

• i Evidence that lost sleep harms performance
• ii A proposal for why the brain needs to reset
• iii The discovery that sleep follows learning
• iv Applications beyond the laboratory
• v From mystery to active process
• vi The role of brain structures in moving memories
• vii Remaining questions and future techniques
• viii A simple conclusion with practical meaning

1. Paragraph A
2. Paragraph B
3. Paragraph C
4. Paragraph D
5. Paragraph E
6. Paragraph F
7. Paragraph G

Questions 8–13 判断（TRUE / FALSE / NOT GIVEN）

8. Ebbinghaus understood that sleep influences how quickly memories fade.
9. Memories are stored permanently in the hippocampus.
10. Participants deprived of slow-wave sleep performed worse only on emotional tasks.
11. The synaptic homeostasis hypothesis suggests sleep weakens some neural connections.
12. Some schools have reported better test results after starting classes later.
13. Researchers have shown that memories cannot be strengthened during sleep.

Questions 14 单选（Multiple Choice）

14. What is the main message of the passage?

• A. Sleep is a passive state that allows the brain to rest.
• B. Sleep actively reorganises memories, and its timing matters for learning.
• C. Slow-wave sleep is more important than REM sleep.
• D. People differ widely in how much sleep they need, so advice is unreliable.

答案与解析 Answers & Explanations

Matching Headings：1-v 2-iii 3-vi 4-i 5-ii 6-iv 7-vii

• A 段："only in the past century... came to regard sleep... as an active process" → v
• B 段：Ebbinghaus 之后研究者发现"people who slept... recalled more" → iii
• C 段：海马体→新皮层的记忆转移，慢波睡眠巩固 → vi
• D 段：睡眠剥夺实验、表现下降 → i
• E 段：突触稳态假说（proposal）→ ii
• F 段：学生、医生、飞行员、学校应用 → iv
• G 段：个体差异、睡眠中操纵记忆、尚未解决的问题 → vii

TRUE/FALSE/NOT GIVEN： 8. FALSE（B 段："What Ebbinghaus could not have known is that the rate of forgetting depends... on sleep"） 9. FALSE（C 段："Memories are not stored there permanently"） 10. FALSE（D 段：损害是选择性的，慢波睡眠影响程序性技能，情绪记忆靠 REM——不是"only emotional tasks"） 11. TRUE（E 段："downscale these connections selectively"） 12. TRUE（F 段："reporting measurable gains in test scores"） 13. FALSE（G 段：研究者已能"strengthen specific memories"）

Multiple Choice：14-B（全文主旨：睡眠主动重组记忆，且学习后是否睡觉很关键）