Most dog owners believed that their four-legged friends know exactly what they mean when they use certain words like sit， stay， or treat. However， researchers have always wondered whether canines1 really understand human speech or if they rely on other clues to deduce2 the meaning. For example， does the word “fetch” conjure3 up an image of a stick or ball in the dog’s mind， or does the dog retrieve4 the object based on cues such as the owner’s tone or gesture？ A new study seems to indicate that “man’s best friend” is not faking it——he/she does indeed know what the owner is saying.
　　大多数养狗的人相信，当他们使用某些词语，比如说“坐下”、“待着”、“吃”的时候，他们的四条腿的朋友能准确地知道他们的意思。然而，研究人员一直想知道犬类是否真正理解人类的语言，或者它们是否依赖其他线索来推断其含义。例如，“取过来”这个词是不是会在狗的脑海中唤起棍子或球的形象，还是说狗会根据主人的语气或手势等线索来搜寻物体？一项新的研究似乎表明“人類最好的朋友”并非虚言——它们的确知道主人在说什么。
　　“Many dog owners think that their dogs know what some words mean， but there really isn’t much scientific evidence to support that. We wanted to get data from the dogs themselves—not just owner reports，” said Ashley Prichard， a Ph.D. of psychology.
　　“许多养狗人认为他们的狗知道某些词的意思，但实际上没有多少科学证据支持这种说法。我们想从狗身上获得数据，而不仅仅只是通过狗主人的报告。”心理学博士阿什利·普里查德说。
　　The researchers began by asking the owners of twelve dogs of various breeds5 to train their pets to identify two toys with different textures6， such as a stuffed animal and a ball， by name. Once the dogs had mastered the task， they took turns inside a functional magnetic resonance imaging （fMRI） scanner7. The owners then tested their dogs by first calling out the names of the toys they had been trained to recognize and then saying meaningless words such as “bobbu” and “bodmick” while holding up random objects the dogs hadn’t seen before.
　　研究人员首先要求12只不同品种的狗的主人训练他们的宠物通过名字识别两种不同质地的玩具，比如填充玩具动物和球。一旦这些狗完成了这项任务，它们就轮流进入功能磁共振成像仪。然后，狗的主人测试他们的狗，首先喊出它们被训练来识别的玩具的名字，然后说一些无意义的单词，比如“bobbu”和“bodmick”，同时举起狗以前从未见过的随机摆放的物体。
　　The fMRI scans revealed that the regions of the dogs’ brains responsible for auditory8 processing showed different brain patterns when they heard words they were familiar with， compared with the ones they had never encountered9 before. The researchers believe this is an important step forward in understanding how dogs process language.
　　功能磁共振扫描显示，狗的大脑负责处理听觉的区域在听到它们熟悉的单词时，与听到它们从未遇到过的单词的时候相比，显示出了不同的大脑模式。研究人员认为这是理解狗如何处理语言的重要一步。
　　Even more interesting was that the dog’s brains showed a higher level of neural10 activity at the sound of unknown words. This is the exact opposite of what happens in human brains， which get more active at the sound of familiar words. The researchers hypothesize11 the dogs may be perking12 up at the sound of new words to try to understand them in the hopes of delighting their masters.
　　更令人感兴趣的是，狗的大脑在听到未知单词的声音时表现出更高水平的神经活动。这与人脑中的情况恰恰相反，人脑在听到熟悉的词语时更加活跃。研究人员猜测，这些狗可能会因听到新词的声音而提起精神，试图理解它们，希望取悦它们的主人。
　　However， though your pet may understand human speech， the scientists recommend using visual and scent cues for training. When people want to teach their dog a trick， they often use a verbal command because that’s what we humans prefer. From the dog’s perspective13， however， a visual command might be more effective， helping the dog learn the trick faster.
　　然而，尽管你的宠物可能理解人类的语言，科学家仍建议使用视觉和气味线索进行训练。当人们想教他们的狗一个把戏时，他们经常使用口头命令，因为这是我们人类更喜欢使用的。然而，从狗的角度来看，视觉命令可能更有效，能帮助狗更快地学会这个技巧。