Dogs have been man’s best friend for thousands of years, a source of companionship and loyalty¹ since the Stone Age.

几千年以来，狗狗都是人类最好的朋友，从石器时代开始就是人类忠诚的陪伴。

Now scientists suspect they have discovered the root of the relationship - a dog really does understand his master’s voice.

如今，科学家们猜测他们找到了友谊的根源——狗狗真的能听懂他的主人在说什么。

Researchers have found that pet dogs process language in a similar way to humans.

研究者发现，宠物狗的语言处理和人类有一定相似度。

They learn to recognise the words that are spoken - the groups of consonantsand vowelsthat make up spoken commands.

他们会学着去辨认主人的话——这些由一系列辅音和元音组成的口头命令。

But tests suggest they also notice the more subtle aspects of human communication - the emotional tone, intonation² and volume changes that influence the meaning of language.

不过试验表示，他们也发现了人类交流上一些微妙的方面——情绪基调、声调和音量会对语言的意思产生影响。

Scientists at Sussex University think this is because dogs process language in the same way as we do.

苏塞克斯大学的研究者们认为，狗狗的语言在某种意义上和我们是一样的。

They tested the way different aspects of language seemed to go through different parts of the brain.

他们试验后发现脑中不同的领域似乎掌管不同方面的语言。

Humans have a ‘hemispheric bias³’ when it comes to communication, with different aspects of language favouring the left or right side of the brain.

人类在交流时会有“半脑偏见”，不同方面的语言会有左右脑不同分工处理。

The researchers’ tests suggest that dogs process speech in the same way.

研究者的试验发现狗狗们也是如此。

A group of 25 dogs were placed between two speakers playing recorded commands - such as ‘come on then’.

25只狗被放养在两个发出命令的人身边——比如发出“过来”这样的命令。

When the command was delivered in a flat, emotionless tone, the dogs turned right, suggesting the animals were concentrating on the words, not the intonation.

当命令以一种平的，不带感情的语调说出来时，狗狗马上向右转，这说明动物对词语有反应，而不纠结于声调上。

But when the commands exaggerated intonation or emotion, the animals turned left.

不过当放大了声调和情绪时，狗狗向左转了。

The results suggest that like us, dogs process different aspects of human speech in different parts of the brain, perhaps indicating why they can be trained to follow people.

结果显示，和我们一样，狗狗脑中不同的区域掌管不同的语言，这也许是为何他们能被训练成人类好帮手的原因。

Researcher Dr David Reby, from the University of Sussex, said: ‘This is particularly interesting because our results suggest that the processing of speech components⁴ in the dog’s brain is divided between the two hemispheres in a way that is actually very similar to the way it is separated in the human brain.’

苏塞克斯大学的大卫·雷贝学者说道：“这很有意思，因为我们的研究成果表明了狗狗大脑也有半球分区来掌管语言，这和人类大脑有着一定相似度。”

Victoria Ratcliffe, who co-wrote the paper, added: ‘Although we cannot say how much or in what way dogs understand information in speech from our study, we can say that dogs react to both verbal and speaker-related information and that these components appear to be processed in different areas of the dog’s brain.’

论文的第二作者维多利亚·拉克特里夫补充道：“虽然从研究中，我们不能说明多大程度上狗狗明白语言中的信息，我们可以说狗狗对口头的或者说说出口的信息都会有反应，而且这些似乎是由狗狗大脑中不同的区域在掌管。”

In their paper, published in the journal Current Biology, the scientists wrote: ‘The striking correspondence between dogs’ and humans’ hemispheric biases⁵ reported here may reflect convergent⁶ evolution if dogs have been selected to respond to human vocal⁷ signals during domestication⁸.’

在他们的这篇刊登于《当代生物学期刊》的论文中，学者们写道：“狗狗和人类半脑偏好的惊人一致性也许反映了在驯化中，如果狗狗被选为对人类口头信号作出反应，他们就会拥有聚集性的进化。”