科学表明口吃是生理原因的证据:为什么唱歌不口吃? 科学, 生理, 证据, 口吃, 唱歌

whoisit

How a magnet turned off my speech
By Roger Highfield, Science Editor
Last Updated: 4:01pm BST 16/05/2008

Words failed me. I stuttered as Prof Vincent Walsh turned off the speech centre of my brain for a few thousandths of a second to demonstrate the power of transcranial magnetic stimulation, a popular way to interfere with the most complex known object in the universe. DIY brain therapy could halt migraines Sitting in the basement of a lab in Queen Square, London, where the nation's greatest concentration of brain surgeons can be found, I am told to recite a nursery rhyme as a way to see if the experiment has worked. [img=200,200]mhtml:file://C:\Documents and Settings\Administrator\桌面\Website\Useful\How a magnet turned off my speech - Telegraph.mht![/img] Watch as Roger Highfield's speech is turned off For this remarkable demonstration of how to boggle a brain, the professor is wielding what looks like a giant black key against my head. I am reciting a nursery rhyme as he moves the coil about and delivers a high powered pulse, signified by snapping noise, a twitch on my scalp and an unpleasant, though pain free, nervy feeling in my mouth. Prof Walsh is shifting the coil around the left side of my head, hunting for the speech area of my brain, named Broca's area after the 19th century doctor. Disconcertingly for me (Prof Walsh seemed unconcerned), he had difficulty finding my Broca's and only succeeded after he called for a bigger coil to be used, as powerful magnetic pulses were delivered through my skull by his colleague, Dr Neil Muggleton. advertisement I was reciting Humpty Dumpty and hoping that all the Queens Square's neurologists and all the Queens neurosurgeons would not have to put my brain back together again. Finally he located my Broca's and the train of pulses stopped me in my tracks. I wanted to recite the rhyme but stumbled and stuttered as my speech area was disabled. Intriguingly, I could still sing Humpty Dumpty as he buffetted my Broca's: it turns out that singing is controlled by the right side of the brain, the opposite hemisphere to the one he stimulated. "That is why you can sing but not talk." This is also why some people with stroke can sing sentences, even though they cannot speak. The first practical demonstration of TMS was made 23 years ago by Prof Anthony Barker at the University of Sheffield. Since then, it has become a relatively simple, non-invasive, and painless way to interfere with the workings of the brain, though there is a risk of epilepsy. Many scientists now use it for basic research. Some have used it to induce electrical changes in the brain's temporal lobes, which have been linked with religious belief, because some sufferers of temporal lobe epilepsy seem to experience hallucinations that bear a striking resemblance to mystical experiences of holy figures. Many doctors believe it has a role in helping a damaged brain to heal. TMS offers a kinder alternative to electroconvulsive therapy, the treatment of last resort for people with severe depression who do not respond to drugs. Others have used it to treat severe epilepsy, and there are efforts to use it to quieten the voices heard by schizophrenics and to track nerve development in infants. A few even believe that it could actually enhance cognitive skills. Prof Allan Snyder, at the University of Sydney believes TMS can act as "a creativity-amplifying machine". But Prof Walsh is highly sceptical. "Brain stimulation does not release hidden talents and when it is used to improve things in patients, it comes at the cost of blocking some nerve pathways to encourage others."

       资料来源:英国每日电讯报(http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2008/05/16/scibrain216.xml
       视频地址:http://link.brightcove.com/services/player/bcpid1460879018?bctid=1556691972

       翻译：
       这篇文章是英国每日电讯报科学分栏的主编,叫Roger Highfield(当然,他是一名说话正常的人,非口吃者,就是照片上那个可爱的光头),为了更好地了解这个实验写下这篇文章,他亲自来到伦敦国家脑部外科研究中心,接受Vincent Walsh教授的TMS(Transcranial Magnetic Stimulation,跨颅磁性刺激)实验.简单介绍下TMS的作用原理是:利用戴在头上的金属线圈，产生短暂并且变化极快的磁场，就像我们在高中物理学过的一样,变化的磁场产生电流,于是人的神经线路上就产生微小的电流。在进行刺激的短时间内，重复的TMS刺激(rTMS)能抑制某项大脑机能.(本次实验抑制的是左脑的语言中枢),你可以从录像中看到,他的语言在TMS的开启下,他的语言中枢是怎样关闭引起口吃的.而在唱歌的情况下,TMS的开启又是怎样一种情况.
       首先,Walsh教授拿了一个看上去像一把大钥匙的线圈紧靠在Roger的光头上,并且叫Roger背诵一首歌谣(Humpty Dumpty and hoping that all the Queens Square's neurologists and all the Queens neurosurgeons ,请注意,先是背诵).在Roger背诵的同时,Vincent教授定位到了Roger的语言中枢-布洛卡区(在左脑),于是Vincent教授将TMS定位在Roger左脑的语言中枢,并开启TMS装置(开启TMS装置时,线圈会有哒哒哒的声音),结果出现了什么???Roger,一个说话正常的人,口吃了!!!因为TMS抑制了左脑语言中枢,所以说话正常的Roger也像口吃者一样口吃了.你可以看到,只要TMS一出现哒哒哒的声音,Roger就口吃.
       接下来,Walsh教授让Roger唱这首歌谣,并且开启TMS,你可以看到,Roger完整地唱出了歌谣,没有口吃.为什么会这样,因为唱歌是由人的右脑控制,而不是由具有语言中枢的左脑控制,而口吃者的左脑异常,右脑却是正常的,所以唱歌时不口吃,Vincent教授解释到.接下来,Vincent教授亲自上阵,助手将TMS装在他的左脑上,当他背诵歌谣时,助手开启TMS装置,同样,他也口吃了.