科技 口吃科学 演讲疗法

　　Unravelling the mystery of faltering speech

　　解秘演讲时的口吃

　　DOWN the ages stuttering has been blamed on many things.

　　多年来，口吃可以归咎于许多事。

　　In the second century Galen pinned it on a dryness of the tongue.

　　二世纪时，盖伦（古罗马时期最著名最有影响的医学大师）将口吃归咎于舌头干燥。

　　In the 17th, Francis Bacon reckoned a stiff tongue was responsible.

　　17世纪，弗朗西斯.培根认为僵硬的舌头应对口吃负责。

　　In the 19th, surgeons suggested too large a tongue.

　　19世纪，外科医生指出是长舌头造成了口吃。

　　In the 20th, parental neglect and even an unfulfilled urge for oral sex had their moments of fame ("The King's Speech", a film competing for Oscars this week, stresses psychology).

　　到了20世纪时，父母的忽略，甚至是未实现的口交被认为是造成口吃的原因（"国王的演讲"，本周一部角逐奥斯卡的影片，则强调心理原因）。

　　The suggested remedies were just as diverse.

　　矫正口吃的建议方法也多种多样。

　　Galen thought wrapping the patient's tongue in a cloth soaked in lettuce juice might help.

　　盖伦认为将病人的舌头用浸过莴苣汁的布包起来可能有帮助。

　　Bacon recommended wine. The Victorians wielded scalpels.

　　培根的推荐是酒。维多利亚时代的外科医生们挥舞手术刀。

　　The psychiatrists, the couch.

　　精神科医生的建议是沙发。

　　None of it worked (except in the movies).

　　这些方法都不奏效（电影中除外）。

　　These days, as delegates to the AAAS meeting in Washington, DC, heard, the talk is of brain anatomy and genes.

　　几天来，在华盛顿出席美国科学促进会的代表们都听说了大脑解剖和基因与讲话有关。

　　Luc De Nil, of the University of Toronto, has been poring over stutterers' brains using positron emission tomography and functional magnetic resonance imaging.

　　多伦多大学的卢克.德.尼尔已经用正电子发射断层扫描和功能性磁共振成像仔细研究了口吃者的大脑。

　　He has found that parts of the brain linked to the production of speech are more active in stutterers than non-stutterers, while those involved in perceiving sounds are less so.

　　他发现大脑的一部分与生成话语的区域相连，口吃者的这个区域要比非口吃者活跃，而感知声音的那些区域则是非口吃者更活跃。

　　The two sorts of brain look different, too. Stutterers tend, for instance, to have more densely packed grey matter in the areas associated with processing and producing sounds.

　　两者的大脑看起来也不同。比如，有关处理和产生声音的区域上覆盖的灰质，口吃者要更密集。

　　Such differences in activity and anatomy, though, must have deeper causes.

　　活动性和解剖上的不同一定存在着更深层的原因。

　　And, in time-honoured fashion, there is a debate about whether those causes are genetic or environmental.

　　而这些原因是基因上的还是环境上的，其争论的历史也相当悠久。

　　Dennis Drayna of America's National Institutes of Health argued to the meeting that persistent stuttering is at least partly a matter of genes.

　　美国国家卫生研究院的丹尼斯.德雷纳在会上说道，持续的口吃至少一部分原因是基因问题。

　　It runs in families. Studies of twins suggest a genetic component larger than those known to be involved in high cholesterol and osteoporosis.

　　在家族中遗传。对双胞胎的研究表明这个遗传因素要比胆固醇和骨质疏松症的遗传因素高。

　　At least two studies of adopted children suggest that those whose adoptive parents stutter are no more likely to develop the impediment than those taken on by non-stutterers.

　　至少，有两个关于被收养孩子的研究表明，孩子是否会发展成为口吃者，其可能性，收养者是口吃者并不比非口吃者大。

　　To discover which genes might be responsible, Dr Drayna looked at 44 Pakistani families.

　　为了发现哪种基因与引发口吃有关，德雷纳博士对44个巴基斯坦家庭进行了调查。

　　Marriage between cousins is common in Pakistan, and such inbreeding leads to a high incidence of genetic disorders.

　　近亲结婚在巴基斯坦很普遍，而这种近亲交配引发遗传性疾病的发病率很高。

　　Dr Drayna's analysis suggests that stuttering is linked to mutation of a gene called GNPTAB—a finding confirmed when the same mutation was subsequently discovered in a number of stutterers from Pakistan and India who were unrelated to the original group of families.

　　德雷纳博士的分析表明口吃与一种叫做GNPTAB的基因突变有关——随后，在巴基斯坦和印度非近亲结婚的家庭中发现了许多口吃者也有类似的突变时，这个发现得到了证实。

　　In January Dr Drayna and his colleagues published a paper in the Journal of Human Genetics tracing the responsible mutation back almost 600 generations, to a common ancestor who would have lived around 14,000 years ago.

　　1月，德雷纳博士和他的同事在《人类遗传学杂志》上发表了一篇论文，追踪了约600代人中发生过此种突变的人，他们的祖先是同一个人，生活在约14,000年前。

　　Further study of South Asians has shown that mutations in two other genes, GNPTG and NAGPA, are found in individuals who stutter, but not in non-stutterers.

　　对南亚人的进一步研究表明，另两大基因也存在突变——GNPTG 和 NAGPA,在口吃者中发现了这两种基因，而非口吃者中没有。

　　All three affected genes encode enzymes that regulate lysosomes, the cell's waste-disposal units.

　　所有这三种受影响的基因通过编码酶调节溶解体，溶解体是细胞废物处理单元。

　　Two of the encode mutations involved are also known to cause a rare disease called mucolipidosis.

　　其中有两种编码突变也会引发粘脂沉积症——一种罕见的疾病。

　　Severe mucolipidosis is fatal within ten years of birth.

　　在出生的十年内，严重的粘脂沉积症是致命的。

　　Even the mild variety has symptoms that include abnormal skeletal development and, sometimes, slight mental retardation.

　　即使是温和一点的，也会引发许多症状，包括骨骼发育异常，有时还会有轻度精神发育迟滞。

　　Fortunately for stutterers, close examination of those with the relevant mutations reveals no symptoms of mucolipidosis.

　　在对相关突变进行仔细检查后，并没有发现任何粘脂沉积症的症状，这对口吃者来说是幸运的。

　　Dr Drayna suspects that both conditions are caused by misfolding of the enzymes in question, but that the details are different.

　　德雷纳博士怀疑这两种病状都是由错误折叠酶引起，但细节有所不同。

　　With stutterers, he thinks, a specific group of brain cells involved in speech production is, for an unknown reason, uniquely sensitive to the enzymatic glitch—perhaps producing the patterns seen by Dr De Nil in his brain scanners.

　　他认为，对口吃者来说，参与话语生成的一组特定的脑细胞，不明原因的对酶毛刺有一种独特的敏感——也许将德.尼尔博士在脑部扫描中看到的结构生成出来能够解释这个现象。

　　To investigate further, Dr Drayna is now attempting to splice human stutter-causing genes into the DNA of mice.

　　为了进一步调查，德雷纳博士正尝试将引发人类口吃的基因拼接到老鼠的DNA中。

　　That, of course, raises the question of what a stuttering mouse sounds like.

　　当然，又有了另一个问题，口吃的老鼠听起来像什么呢。

　　To the human ear, it may not sound like anything.

　　人类的耳朵听来，这个声音可能什么都像。

　　Many murine squeakings are too high-pitched to be perceptible.

　　许多小鼠的尖叫声非常高亢，难以感觉它是否口吃。

　　But ultrasonic detectors should deal with that.

　　也许高声波探测仪可以解决这个问题。

　　With luck, the causes of stuttering should soon be understood better.

　　幸运的话，引发口吃的原因很快就会被更好的理解了。

　　Whether that results in treatments more effective than lettuce juice and wine is another matter.

　　而治疗方法是否比莴苣汁和酒更有效，则要另当别论了。