段落A

According to the latest figures, the majority of the world’s population is now bilingual or multilingual, having grown up speaking two or more languages. In the past, such children were considered to be at a disadvantage compared with their monolingual peers. Over the past few decades, however, technological advances have allowed researchers to look more deeply at how bilingualism interacts with and changes the cognitive and neurological systems, thereby identifying several clear benefits of being bilingual.

段落A：根据最新数据，全球多数人口现在是双语或多语言的，他们在成长过程中就会说两种或更多种语言。过去，这样的孩子被认为与他们的单语同龄人相比处于不利位置。然而，在过去几十年中，技术进步使研究人员能够更深入地研究双语对认知和神经系统的相互作用和变化，从而确定了双语的几个明显好处。

段落B

Research shows that when a bilingual person uses one language, the other is active at the same time. When we hear a word, we don’t hear the entire word all at once: the sounds arrive in sequential order. Long before the word is finished, the brain’s language system begins to guess what that word might be. If you hear ‘can’, you will likely activate words like ‘candy’ and ‘candle’ as well, at least during the earlier stages of word recognition. For bilingual people, this activation is not limited to a single language; auditory input activates corresponding words regardless of the language to which they belong. Some of the most compelling evidence for this phenomenon, called ‘language co-activation’, comes from studying eye movements. A Russian-English bilingual asked to ‘pick up a marker’ from a set of objects would look more at a stamp than someone who doesn’t know Russian, because the Russian word for ‘stamp’, marka, sounds like the English word he or she heard, ‘marker’. In cases like this, language co-activation occurs because what the listener hears could map onto words in either language.

段落B：研究表明，双语者在使用一种语言时，同时也会激活另一种语言。当我们听到一个词时，我们并不是一次性听到整个词：声音是按顺序到达的。在单词完成之前很久，大脑的语言系统就开始猜测那个单词可能是什么。如果你听到“can”，你很可能在单词识别的早期阶段激活诸如“candy”和“candle”之类的单词。对于双语者来说，这种激活不限于一种语言；听到的语言输入会激活其属于的语言的相应单词。关于这种现象（称为“语言共同激活”），一些最具有说服力的证据来自研究眼动。让一个俄语-英语双语者从一组物体中“拿起一个记号笔”，他会更多地看着一个邮票，而不是一个不懂俄语的人，因为俄语中“stamp”的发音marka听起来像他或她听到的英语单词“marker”。在这种情况下，语言共同激活发生是因为听众听到的内容可能对应于两种语言中的单词。

段落C

Having to deal with this persistent linguistic competition can result in difficulties, however. For instance, knowing more than one language can cause speakers to name pictures more slowly, and can increase ‘tip-of-the-tongue states’, when you can almost, but not quite, bring a word to mind. As a result, the constant juggling of two languages creates a need to control how much a person accesses a language at any given time. For this reason, bilingual people often perform better on tasks that require conflict management. In the classic Stroop Task, people see a word and are asked to name the colour of the word’s font. When the colour and the word match (i.e., the word ‘red’ printed in red), people correctly name the colour more quickly than when the colour and the word don’t match (i.e., the word ‘red’ printed in blue). This occurs because the word itself (‘red’) and its font colour (blue) conflict. Bilingual people often excel at tasks such as this, which tap into the ability to ignore competing perceptual information and focus on the relevant aspects of the input. Bilinguals are also better at switching between two tasks; for example, when bilinguals have to switch from categorizing objects by colour (red or green) to categorizing them by shape (circle or triangle), they do so more quickly than monolingual people, reflecting better cognitive control when having to make rapid changes of strategy.

段落C：然而，处理这种持久的语言竞争可能会导致一些困难。例如，了解超过一种语言可能会导致说话者在命名图片时更慢，并且可能会增加“将单词几乎，但并未完全想起来”（tip-of-the-tongue states）的情况。因此，持续操纵两种语言会导致一个人需要控制在任何给定时间内访问语言的程度。因此，双语者通常在需要冲突管理的任务上表现更好。在经典的斯特鲁普任务中，人们看到一个单词，并被要求命名该单词的字体颜色。当颜色和单词匹配时（即以红色打印的单词“red”），人们会更快地正确命名颜色，而当颜色和单词不匹配时（即以蓝色打印的单词“red”），人们不太正确地命名颜色，这是因为单词本身（“red”）和其字体颜色（蓝色）相冲突。双语者通常擅长这类任务，这类任务需要忽略竞争的感知信息，专注于输入的相关方面。双语者在两个任务之间切换时也更擅长；例如，当双语者需要从按颜色（红色或绿色）分类物体转为按形状（圆形或三角形）分类物体时，他们比单语者更快地做到这一点，反映出在需要快速改变策略的情况下，双语者具有更好的认知控制能力。

段落D

It also seems that the neurological roots of the bilingual advantage extend to brain areas more traditionally associated with sensory processing. When monolingual and bilingual adolescents listen to simple speech sounds without any intervening background noise, they show highly similar brain stem responses. When researchers play the same sound to both groups in the presence of background noise, however, the bilingual listeners’ neural response is considerably larger, reflecting better encoding of the sound’s fundamental frequency, a feature of sound closely related to pitch perception.

段落D：而且，与双语经验相关的好处似乎延伸到更传统与感知处理相关的大脑区域。当单语和双语青少年在没有任何干扰背景噪音的情况下听简单的语音声音时，他们的脑干反应非常相似。然而，当研究人员在同时给这两组人播放相同的声音时有背景噪音时，双语听众的神经反应要大得多，反映出对声音的基频更好的编码，而基频是与音高感知密切相关的声音特征。

段落E

Such improvements in cognitive and sensory processing may help a bilingual person to process information in the environment, and help explain why bilingual adults acquire a third language better than monolingual adults master a second language. This advantage may be rooted in the skill of focusing on information about the new language while reducing interference from the languages they already know.

段落E：这种对认知和感知处理的改进可能有助于双语者更好地处理环境中的信息，并有助于解释为什么双语成年人习得第三种语言的能力比单语成年人掌握第二种语言的能力更强。这种优势可能源于在获取新语言的信息时专注于新语言信息而同时减少来自已知语言的干扰的技能。

段落F

Research also indicates that bilingual experience may help to keep the cognitive mechanisms sharp by recruiting alternate brain networks to compensate for those that become damaged during aging. Older bilinguals enjoy improved memory relative to monolingual people, which can lead to real-world health benefits. In a study of over 200 patients with Alzheimer’s disease, a degenerative brain disease, bilingual patients reported showing initial symptoms of the disease an average of five years later than monolingual patients. In a follow-up study, researchers compared the brains of bilingual and monolingual patients matched on the severity of Alzheimer’s symptoms. Surprisingly, the bilinguals’ brains had more physical signs of disease than their monolingual counterparts, even though their outward behaviour and abilities were the same. If the brain is an engine, bilingualism may help it to go farther on the same amount of fuel.

段落F：研究还表明，双语经验可能通过利用替代的大脑网络来补偿在衰老过程中受损的认知机制，以保持认知机制的敏锐度。老年双语者相对于单语者在记忆方面表现更好，这可能带来了实际的健康益处。在一项涉及200多名阿尔茨海默病（一种退行性脑疾病）患者的研究中，双语患者报告初期病症的出现平均比单语患者晚了五年。在一项后续研究中，研究人员比较了在阿尔茨海默病症状严重程度匹配的双语和单语患者的大脑。惊人的是，尽管他们的外在行为和能力相同，但双语者的大脑在疾病体征方面显示出更多的实际病理迹象。如果大脑是一个引擎，双语能力可以帮助它在相同燃料消耗下走得更远。

段落G

Furthermore, the benefits associated with bilingual experience seem to start very early. In one study, researchers taught seven-month-old babies growing up in monolingual or bilingual homes that when they heard a tinkling sound, a puppet appeared on one side of a screen. Halfway through the study, the puppet began appearing on the opposite side of the screen. In order to get a reward, the infants had to adjust the rule they’d learned; only the bilingual babies were able to successfully learn the new rule. This suggests that for very young children, as well as for older people, navigating a multilingual environment imparts advantages that transfer far beyond language.