Scientists are providing a fuller understanding of the essential role that sleep plays in brain health, identifying an abrupt transition at about 2.4 years of age when its primary purpose shifts from brain building to maintenance and repair.
Researchers on Sept. 18 said they conducted a statistical analysis on data from more than 60 sleep studies. They looked at sleep time, duration of rapid eye movement (REM) sleep, brain size and body size, and devised a mathematical model for how sleep changes during development.
There are basically two types of sleep, each tied to specific brain waves and neuronal activity. REM, with the eyes moving quickly from side to side behind closed eyelids, is deep sleep with vivid dreams. Non-REM sleep is largely dreamless.
Photo: Reuters 照片：路透
During REM sleep, the brain forms new neural connections by building and strengthening synapses — the junctions between nerve cells, or neurons — that enable them to communicate, reinforcing learning and consolidating memories. During sleep, the brain also repairs the modicum of daily neurological damage it typically experiences to genes and proteins within neurons as well as clearing out byproducts that build up.
At about 2.4 years of age, the findings showed, sleep’s primary function changed from building and cutting connections during REM sleep to neural repair during both REM and non-REM sleep. “It was shocking to us that this transition was like a switch and so sharp,” said Van Savage, a UCLA professor of ecology and evolutionary biology and of computational medicine who is a senior author of the research published in the journal Science Advances.
REM sleep declines with age. Newborns, who can sleep about 16 hours daily, spend about 50 percent of their sleeping time in REM, but there is a pronounced drop-off at around 2.4 years. It drops to about 25 percent by age 10 and to about 10 percent to 15 percent around age 50. “Sleep is required across the animal kingdom and is nearly as ubiquitous as eating and breathing,” Van Savage said. “I’d say it is a pillar of human health.”(Reuters)
科學家近日提出更完整的理論，進一步闡釋睡眠對大腦健康扮演不可或缺的角色。科學家確認，兒童大腦約在二歲五個月時會發生突然的轉變。此時，睡眠的首要目的從大腦發育轉變成維護與修復。
研究人員於九月十八日指出，他們對超過六十個睡眠研究提供的資料進行統計學分析。他們觀察睡眠時間、快速動眼期的持續長度、大腦和身體尺寸，並且設計出一套數學模型，研究睡眠在成長過程中會如何發生變化。
基本上，睡眠分成兩種類型，各自和特定的腦波與神經元活動密切相關。在快速動眼期，眼球會在緊閉的眼皮後方快速左右移動，進入深層睡眠，此時做的夢也特別清晰。非快速動眼期則大多是無夢的。
在快速動眼期睡眠中，大腦藉由建立以及強化「突觸」──也就是神經細胞（或稱神經元）的相接處──形成新的神經連結，讓它們得以互相交流，藉此加深學習並且鞏固記憶。在睡眠期間，大腦也會修復平日受到的少量神經系統損傷──通常發生於基因和神經元裡面的蛋白質──同時清除累積的副產物。
研究顯示，在大約二歲五個月左右，睡眠的首要功能會發生改變，從快速動眼期睡眠中持續建立並且切斷連結，轉變成在快速動眼期以及非快速動眼期這兩個睡眠期間進行神經修復。這份研究近日發表於期刊《科學進展》，其資深作者范‧薩維奇指出：「我們很訝異，這個轉變就像是切換開關一樣，非常突然。」范‧薩維奇是美國加州大學洛杉磯分校生態學和演化生物學教授，同時也是計算醫學教授。
快速動眼期睡眠會隨著年紀增長而減少。新生兒一天可以睡到十六個小時，其中大約一半的睡眠時間都花在快速動眼期。然而，大概到兩歲五個月的時候，快速動眼期就會顯著降低。到了十歲，快速動眼期約佔睡眠時間的百分之二十五；到五十歲時，快速動眼期更衰退到睡眠時間的百分之十到十五左右。「睡眠在整個動物界都是必要的活動，就跟進食和呼吸一樣無所不在。」范‧薩維奇表示：「我會說，睡眠是人類健康的支柱。」（台北時報章厚明譯）
Floods that killed more than 200 people in eastern Spain last week were caused by a storm that dumped a year’s worth of rainfall in less than 24 hours. The tragedy has raised questions about whether earlier warnings could have prevented so many deaths, while the widespread damage shows how many cities are not adapted to withstand rainfall amplified by climate change. An extremely hot Mediterranean and warmer air temperatures exacerbated a type of storm system becoming more common in the Iberian peninsula due to global warming. Experts said that a building boom in the region in recent decades might have put
A: Originally, supergroup Mayday was also going to launch four charity concerts starting today. B: I know, they were trying to boost Hualien’s tourism industry. A: And all 14 artists from B’in Music were going to join the free concerts. B: But they just announced all shows will be postponed due to Typhoon Kong-Rey. A: Well, safety first. A: 原本今天起，天團五月天的公益演唱會也將開跑。 B: 我知道，主要是為了振興花蓮的觀光業。 A: 「相信音樂」旗下14組歌手，聽說這次都會共襄盛舉。 B: 結果主辦單位宣布所有演出因颱風康芮延期。 A: 嗯安全至上吧。 （By Eddy Chang, Taipei Times／台北時報張聖恩）
For people with hearing loss, clear communication can seem like a distant dream. However, advancements in technology are __1__ this barrier. TranscribeGlass, a wearable device, can translate spoken words into text displayed on a transparent screen directly in the user’s field of vision. This innovation enables people with hearing disabilities to fully engage in conversations. Assistive technology like captioning is an important means of communication for people with hearing loss. Captioning software on cellphones can be a helpful option, but it has limitations. Many users often find themselves __2__ to constantly glance down at the phone screen, which disrupts eye contact
Continued from yesterday（延續自昨日） https://www.taipeitimes.com/News/lang __4__ several devices offer real-time captions for the hearing impaired, TranscribeGlass distinguishes itself with its advanced functionality and user-friendliness. Traditional real-time captioning solutions can restrict both users and speakers by requiring speakers to stay close to a microphone. TranscribeGlass, on the other hand, can ensure clear communication even in challenging acoustic settings because it can __5__ audio from a distance, even from across a lecture hall. With TranscribeGlass, clear and effortless communication is finally within reach. 雖然有多款設備為聽障人士提供即時字幕，但TranscribeGlass以其先進的功能和好用性脫穎而出。傳統的即時字幕解決方案會需要說話者靠近麥克風，限制了使用者和說話者。相比之下，即使在具有挑戰性的聲音環境中，TranscribeGlass也可以確保清晰的溝通，因為其可接收到遠處的音訊，甚至可以從演講廳的另一邊接收到音訊。有了TranscribeGlass，清晰且輕鬆的溝通終於觸手可及。 What Did You Learn? 1. (A) invading (B) sustaining (C) eliminating (D) triggering 2. (A)
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