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)
Eating glutinous rice balls during the Lantern Festival Lunar New Year celebrations traditionally conclude with the Lantern Festival, which is on the 15th day of the first lunar month. With every household decorated with lanterns and streamers, the Lantern Festival can be seen as an extended New Year celebration. Lighting lanterns during the Lantern Festival can be traced to the Western Han Dynasty in China. The 15th day of the first lunar month is the first full moon of the year, and has the significance of a new start. People light lanterns to pray for a bumper harvest in the coming
A festive time of light 元宵佳節知多少 Occurring on the 15th day of the initial month of the Lunar New Year, when the first full moon appears, the Lantern Festival is a festive time that continues the good cheer and celebration sparked by Chinese New Year. It also simultaneously marks the end of that annual event. It’s a time when lanterns and other colorful lights and decorations adorn stores, businesses, and streets in Chinese communities around the globe. Aside from honoring ancestors, the festival is also meant to foster peace, forgiveness, and harmony. Lantern displays are the center of attention during the Lantern Festival in Taiwan. Parks across
你叫什麼名字？ What’s your name? 對話 Dialogue 馬可：你好！你叫什麼名字？ Make: Nǐ hǎo! Nǐ jiào shénme míngzi? 小實：我叫小實，你呢？ Xiaoshi: Wǒ jiào Xiǎoshí, nǐ ne? 馬可：我叫馬可。 Make: Wǒ jiào Mǎkě. 小實：馬可，你是美國人嗎？ Xiaoshi: Mǎkě, nǐ shì Měiguó rén ma? 馬可：我是美國人，你也是美國人嗎？ Make: Wǒ shì Měiguó rén, nǐ yěshì Měiguó rén ma? 小實：不是，我是臺灣人。很高興認識你。 Xiaoshi: Búshì, wǒ shì Táiwān rén. Hěn gāoxìng rènshì nǐ. 馬可：我也很高興認識你。 Make: Wǒ yě hěn gāoxìng rènshì nǐ. 翻譯 Translation Mark: Hello! What’s your name? Xiaoshi: My name is Xiaoshi, and you? Mark: My name is Mark. Xiaoshi: Mark, are you American? Mark: Yes, I am. Are you American too? Xiaoshi: No, I’m Taiwanese. Nice to meet you. Mark: Nice to meet you too. 單字片語 Vocabulary 1. 叫(jiào) to be called 2. 什麼 (shénme) what 3. 呢 (ne) a (question)
The US state of Colorado is renowned as a destination for outdoor activities. The impressive Rocky Mountains, which cut through the state, are the focus of these pastimes, which include hiking and climbing. In Ouray, a town in southwestern Colorado, “ice climbing” is at the center of winter festivities. Every January since 1996, the town has held the Ouray Ice Festival. Its goal is to expose more people to the thrill of ice climbing. The site of this exciting event is the Ouray Ice Park. The park, which fills a river gorge, features over a hundred different routes where expert ice