Research is now suggesting something dog-lovers have long suspected - man's best friend can tell the difference between our happy and angry faces.

“狗奴”們一直懷疑對汪星人——人類最好的朋友——能夠分辨我們快樂和生氣的表情，日前一項研究認同了這一點。

 
Scientists at the Messerli Research Institute's Clever Dog Lab in Vienna trained dogs to associate pictures of happy or angry faces with a reward.

維也納梅瑟利研究所“聰明狗狗”實驗室（Messerli Research Institute's Clever Dog Lab）的科學家們，訓練狗狗將笑臉或怒容的圖片與獎勵聯系在一起。

In a subsequent test, the scientists showed the dogs images of human faces they had not seen in their training.

在接下來的測試中，科學家們給狗狗展示了一組它們在訓練中從未見過的人臉圖像。

This suggested that dogs could spot the difference between the expressions.

測試表明狗可以分辨出表情的不同。

"The main focus [of our research] is the big question of communication," lead researcher Prof Ludwig Huber said.

“（我們研究的）重點在于“交流”這個重大問題，”研究小組負責人路德維格·胡貝爾（Ludwig Huber）教授說。

"How is it that dogs are so adapted to humans, and what's happened during the process of domestication?"

“狗是如何適應與人類親密相處的？在馴養過程中發生了什么？”

The scientists repeatedly showed 20 dogs half pictures - either the lower mouth region or the upper eye area - of happy or angry human faces.

科學家反復向20只狗展示半張人類的笑臉或怒容圖片——要么是只有嘴的下半部分，要么是只有眼睛的上半部分。

Half the dogs received a treat when they touched an angry face with their nose. The other half were rewarded for touching happy faces.

其中一半的狗用鼻子觸碰生氣表情的圖片時，就會得到獎勵。另一半則在觸碰笑臉時獲得獎勵。

Just over half the dogs learned the task well enough to be tested, and there were then a number of different tests to find out if they could tell the difference solely on the basis of facial expression.

僅有超過一半的狗較好地理解了這一任務，從而有能力接受測試。隨后研究人員又進行了系列不同的測試，來證明它們是否能夠僅靠面部表情分辨出其中的不同。

"[In one test condition], we showed them new faces - faces they've never seen before," Prof Huber told BBC News.

“（在其中一項測試條件下），我們給狗狗展示新面孔，它們之前從未見過這些人臉，”胡貝爾教授接受英國廣播公司采訪時說。

"In another, we showed them different parts of the faces."

“另一項測試中，我們給它們看面部的不同部分。”

Showing dogs the opposite half of the face to the half they had learned to recognise in their training, showed they could "transfer their knowledge" of human facial expressions.

研究人員給狗狗們展示它們在訓練中所辨認的半張面部圖片的另一半，結果表明它們對人類面部表情的知識可以“活學活用”。

"So, for example, in the training, they see the mouth region of the happy face," said Prof Huber, "and they associate that with what the eyes would look like."

“比如，舉個例子，在訓練中，它們看到了笑臉的嘴部區域，”胡貝爾教授說，“然后它們能將其與看上去對應的眼睛聯系起來。”

This study, published in the journal Current Biology, is part of a larger project studying how humans and their canine companions interact.

這項研究發表在《當代生物》（Current Biology）雜志上，是一項關于人類與狗如何互動的大型研究課題的一部分。

Dr Kun Guo, a psychologist and expert in human-animal interaction from the University of Lincoln, said: "Showing dogs only half of the face and then the other half separately means they can't rely on the shape of the eyes or the mouth - they must have some sort of template in their mind.

林肯大學（University of Lincoln）心理學家及人與動物相互關系專家昆·郭（Kun Guo）博士表示：“先讓狗狗看半張臉部圖片，然后再看另半張，這就意味著它們不能依靠眼睛或嘴巴的形狀來辨別表情——它們的腦海中一定有某種樣板。”

"So it looks like they can really discriminate between happy and angry."

“如此看來，狗確實能區分人是高興還是生氣。”

But, he added, this did not show that dogs understood the meaning of those emotional expressions.

但是，他補充說，這并不能夠說明狗懂得那些情緒表情的含義。

Prof Huber agreed but added that the dogs that had had to touch the angry face to be rewarded, in the training, had taken three times as long to learn the task.

胡貝爾教授贊成這一點但又補充說，那些在訓練中需觸碰生氣表情來獲得獎勵的狗要經過三次嘗試才能成功完成任務。

"It seems as if they don't like to touch an angry face," he said.

“看起來就像是它們不喜歡觸碰帶著怒容的臉一樣，”他說。

"So here we have some suggestive evidence that they interpret those pictures, and maybe they really understand an angry face to be something they don't like."

“所以我們這里有一些提示性的證據顯示它們能解讀這些圖片，或許它們確實懂得一張生氣的臉是它們不喜歡的事物。”

Vocabulary

subsequent：隨后的

domestication：馴養

template：樣板，模板

discriminate：區分

（譯者：貓叔  編輯：侯瑋萍）