脑刺激可改变用手习惯
文章来源:未知 文章作者:meng 发布时间:2010-09-28 03:15 字体: [ ]  进入论坛
(单词翻译:双击或拖选)

Each time we perform a simple task, like pushing an elevator button or reaching for a cup of coffee, the brain races to decide whether the left or right hand will do the job. But the left hand is more likely to win if a certain region of the brain receives magnetic stimulation1(刺激,激励) , according to new research from the University of California, Berkeley. UC Berkeley researchers applied2 transcranial magnetic stimulation (TMS经颅磁刺激) to the posterior(其次的,较后的) parietal(颅顶骨的) cortex region of the brain in 33 right-handed volunteers and found that stimulating3 the left side spurred an increase in their use of the left hand.

The left hemisphere of the brain controls the motor skills of the right side of the body and vice4 versa(反之亦然) . By stimulating the parietal cortex, which plays a key role in processing spatial5 relationships(空间关系) and planning movement, the neurons that govern motor skills were disrupted.

"You're handicapping the right hand in this competition, and giving the left hand a better chance of winning," said Flavio Oliveira, a UC Berkeley postdoctoral researcher in psychology6(心理学) and neuroscience and lead author of the study, published this week in the journal Proceedings7 of the National Academy of Sciences.

The study's findings challenge previous assumptions about how we make decisions, revealing a competitive process, at least in the case of manual tasks. Moreover, it shows that TMS can manipulate the brain to change plans for which hand to use, paving the way for clinical advances in the rehabilitation8(复原) of victims of stroke and other brain injuries.

"By understanding this process, we hope to be able to develop methods to overcome learned limb disuse," said Richard Ivry, UC Berkeley professor of psychology and neuroscience and co-author of the study.

At least 80 percent of the people in the world are right-handed, but most people are ambidextrous9(双手灵巧的) when it comes to performing one-handed tasks that do not require fine motor skills.

"Alien hand syndrome," a neurological disorder10 in which victims report the involuntary use of their hands, inspired researchers to investigate whether the brain initiates11 several action plans, setting in motion a competitive process before arriving at a decision.

While the study does not offer an explanation for why there is a competition involved in this type of decision making, researchers say it makes sense that we adjust which hand we use based on changing situations. "In the middle of the decision process, things can change, so we need to change track," Oliveira said.

In TMS, magnetic pulses alter electrical activity in the brain, disrupting the neurons in the underlying12 brain tissue. While the current findings are limited to hand choice, TMS could, in theory, influence other decisions, such as whether to choose an apple or an orange, or even which movie to see, Ivry said.

With sensors13 on their fingertips, the study's participants were instructed to reach for various targets on a virtual tabletop while a 3-D motion-tracking system followed the movements of their hands. When the left posterior parietal cortex was stimulated14, and the target was located in a spot where they could use either hand, there was a significant increase of the use of the left hand, Oliveira said.



点击收听单词发音收听单词发音  

1 stimulation BuIwL     
n.刺激,激励,鼓舞
参考例句:
  • The playgroup provides plenty of stimulation for the children.幼儿游戏组给孩子很多启发。
  • You don't get any intellectual stimulation in this job.你不能从这份工作中获得任何智力启发。
2 applied Tz2zXA     
adj.应用的;v.应用,适用
参考例句:
  • She plans to take a course in applied linguistics.她打算学习应用语言学课程。
  • This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。
3 stimulating ShBz7A     
adj.有启发性的,能激发人思考的
参考例句:
  • shower gel containing plant extracts that have a stimulating effect on the skin 含有对皮肤有益的植物精华的沐浴凝胶
  • This is a drug for stimulating nerves. 这是一种兴奋剂。
4 vice NU0zQ     
n.坏事;恶习;[pl.]台钳,老虎钳;adj.副的
参考例句:
  • He guarded himself against vice.他避免染上坏习惯。
  • They are sunk in the depth of vice.他们堕入了罪恶的深渊。
5 spatial gvcww     
adj.空间的,占据空间的
参考例句:
  • This part of brain judges the spatial relationship between objects.大脑的这部分判断物体间的空间关系。
  • They said that time is the feeling of spatial displacement.他们说时间是空间位移的感觉。
6 psychology U0Wze     
n.心理,心理学,心理状态
参考例句:
  • She has a background in child psychology.她受过儿童心理学的教育。
  • He studied philosophy and psychology at Cambridge.他在剑桥大学学习哲学和心理学。
7 proceedings Wk2zvX     
n.进程,过程,议程;诉讼(程序);公报
参考例句:
  • He was released on bail pending committal proceedings. 他交保获释正在候审。
  • to initiate legal proceedings against sb 对某人提起诉讼
8 rehabilitation 8Vcxv     
n.康复,悔过自新,修复,复兴,复职,复位
参考例句:
  • He's booked himself into a rehabilitation clinic.他自己联系了一家康复诊所。
  • No one can really make me rehabilitation of injuries.已经没有人可以真正令我的伤康复了。
9 ambidextrous MxdzS     
adj.双手很灵巧的,熟练的,两面派的
参考例句:
  • I'm neither left-handed nor right-handed;I'm ambidextrous.我不是只用左手或右手,我是双手并用。
  • Jack is an ambidextrous hitter;he can bat right-handed or left-handed.杰克是一位双手都很灵巧的打击手,他可以用右手或左手打击。
10 disorder Et1x4     
n.紊乱,混乱;骚动,骚乱;疾病,失调
参考例句:
  • When returning back,he discovered the room to be in disorder.回家后,他发现屋子里乱七八糟。
  • It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。
11 initiates e9c5430fb8a57cddedf60c5a1d5a56a7     
v.开始( initiate的第三人称单数 );传授;发起;接纳新成员
参考例句:
  • The booklet initiates us into the problems of living abroad. 这本小册子使我们对国外的生活情况有了初步了解。 来自《简明英汉词典》
  • Everybody initiates and receives messages in some form or other. 每个人都以各种不同的方式发出并接收信息。 来自辞典例句
12 underlying 5fyz8c     
adj.在下面的,含蓄的,潜在的
参考例句:
  • The underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
  • This word has its underlying meaning.这个单词有它潜在的含义。
13 sensors 029aee483db9ae244d7a5cb353e74602     
n.传感器,灵敏元件( sensor的名词复数 )
参考例句:
  • There were more than 2000 sensors here. 这里装有两千多个灵敏元件。 来自《简明英汉词典》
  • Significant changes have been noted where sensors were exposed to trichloride. 当传感器暴露在三氯化物中时,有很大变化。 来自辞典例句
14 stimulated Rhrz78     
a.刺激的
参考例句:
  • The exhibition has stimulated interest in her work. 展览增进了人们对她作品的兴趣。
  • The award has stimulated her into working still harder. 奖金促使她更加努力地工作。
TAG标签: hand brain magnetic
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