Most dog owners are convinced 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 dogs really understand human speech or if they rely on other information to get the meaning. For example, does the word “fetch” form a picture of a stick or ball in the dog's mind, or does the dog bring back the object based on the owner's voice or gesture? A new study by scientists at Atlanta's Emory University seems to indicate that “man's best friend” does indeed know what the owner is saying.
The researchers began by asking the owners of twelve dogs of various kinds to train their pets to identify two toys of different materials, such as a toy animal and a ball. Once the dogs had mastered the task, they took turns inside a special scanner. The owners then tested their dog's language skill 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.
The scans suggested that the parts of the dogs' brains responsible for processing of sounds showed different brain patterns when they heard words they were familiar with, compared with the ones they had never heard before. While that was not enough to prove that the dogs were picturing their toys when they heard the word, it did indicate some sort of recognition. The researchers believe this is an important step forward in understanding how dogs process language.
Even more interesting was that the dog's brains showed a higher level of neural(神经)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 say the dogs may become cheerful at the sound of new words to try to understand them in the hope of delighting their masters. “Dogs want to please their owners, and perhaps also receive praise or food,” says Empty neuroscientist Gregory Burns, senior author of the study.
However, though your pet may understand human speech, the scientists recommend using visual signals and smell for training. “When people want to teach their dog a trick, they often use spoken command because that's what humans prefer, ”Prichard says.“ From the dog's view, however, a visual command might be more effective, helping the dog learn the trick faster.”
