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| 〖删除〗〖版主编辑〗〖转移帖子〗〖顶〗〖精〗[回复][短消息][编辑] | | ［翻译］冥思促进大脑 | 研究人员发现，冥思比仅仅是感觉好或平静下来更有好处，它使你表现得更好－并且会改变你大脑的结构。
冥思的人说，冥思使他们恢复精力，并且有些人宣称他们因此需要的睡眠随之减少。很多研究已经报道大脑在沉思时以一种不同的方式工作－脑波模式有所改变并且神经爆破模式同时发生。但是，冥思是否真的对睡眠更具恢复力还远远没有被考证。
因此美国列克星敦美卡基大学的Bruce O’Hara 和同事决定研究。他们使用被证实的“神经运动警戒任务”，这种方法已经用于量化睡眠对神经敏锐性效果很长时间。测试包括注视LCD屏并在图像出现时以最快的速度按钮。一般，人们要用200至300毫秒反应,但是被剥夺睡眠的人会用更长的时间,并且有时完全错过。
十个志愿者在之前经受过测试，然后经过四十分钟或是睡觉，或是冥思，或是阅读或是目光交流，在各种条件下测试各种项目。40分钟的小睡经提高表现（一个小时之后或从恍惚中清醒）。但是令研究人员吃惊的是冥思是唯一可以作用马上引起良好表现的，尽管没有志愿者在冥思上有丰富的经验。
“每个单独测试项目显示出促进作用，”O’Hara说.在一夜不睡后,这种促进作用显得更加明显.但是，他承认：“我们还并不知道为什么它会起到促进作用。”研究小组现在正在研究经验丰富的冥思者，他们一天冥思要花上几个小时。
大脑建造者
冥思对脑的结构起到什么样的作用还处在争论中。现在，美国波士顿麻萨德塞州高级医院的Sara Lazar和同事们已经用和磁共振的方法比较了拥有1～30年冥思经历的15个冥思者和15个非冥思者 。
他们发现冥思实际上增加一些区域大脑皮层的厚度，这些区域包括注意力和高级处理过程，例如，额前页皮层和右前岛。
“当你冥思时你在锻炼它，使它变得更大，”她说。这个发现和研究显示相符合，熟练的音乐家，运动员和语言学家在相关的皮层都有加厚。这是更进一步的证据，Lazar说，冥思者“并不是坐在那里什么都不做。”
皮层的成长不是因为新神经元的生长，她指出，而是静脉血管变粗，更多的支持性结构如胶质和星细胞和增加的分支和连接造成的结果。
新研究成果在华盛顿举行的神经科学协会年会上公布
Meditating does more than just feel good and calm you down, it makes you perform better – and alters the structure of your brain, researchers have found.
People who meditate say the practice restores their energy, and some claim they need less sleep as a result. Many studies have reported that the brain works differently during meditation – brainwave patterns change and neuronal firing patterns synchronise. But whether meditation actually brings any of the restorative benefits of sleep has remained largely unexplored.
So Bruce O’Hara and colleagues at the University of Kentucky in Lexington, US, decided to investigate. They used a well-established “psychomotor vigilance task”, which has long been used to quantify the effects of sleepiness on mental acuity. The test involves staring at an LCD screen and pressing a button as soon as an image pops up. Typically, people take 200 to 300 milliseconds to respond, but sleep-deprived people take much longer, and sometimes miss the stimulus altogether.
Why don’t you reflect on meditation, in our new interactive forum
Discuss this story >> Ten volunteers were tested before and after 40 minutes of either sleep, meditation, reading or light conversation, with all subjects trying all conditions. The 40-minute nap was known to improve performance (after an hour or so to recover from grogginess). But what astonished the researchers was that meditation was the only intervention that immediately led to superior performance, despite none of the volunteers being experienced at meditation.
“Every single subject showed improvement,” says O’Hara. The improvement was even more dramatic after a night without sleep. But, he admits: “Why it improves performance, we do not know.” The team is now studying experienced meditators, who spend several hours each day in practice.
Brain builder
What effect meditating has on the structure of the brain has also been a matter of some debate. Now Sara Lazar at the Massachusetts General Hospital in Boston, US, and colleagues have used MRI to compare 15 meditators, with experience ranging from 1 to 30 years, and 15 non-meditators.
They found that meditating actually increases the thickness of the cortex in areas involved in attention and sensory processing, such as the prefrontal cortex and the right anterior insula.
“You are exercising it while you meditate, and it gets bigger,” she says. The finding is in line with studies showing that accomplished musicians, athletes and linguists all have thickening in relevant areas of the cortex. It is further evidence, says Lazar, that yogis “aren’t just sitting there doing nothing".
The growth of the cortex is not due to the growth of new neurons, she points out, but results from wider blood vessels, more supporting structures such as glia and astrocytes, and increased branching and connections.
The new studies were presented at the Society for Neuroscience annual meeting, in Washington DC, US.
| 最初发表时间：2005-12-29 |  | | 未填 |
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