It has long been thought that dogs respond to the way humans say things rather than what they say, but a new study indicates that canines understand both forms of communication — with separate parts of their brain.
Current Biology published a report on Wednesday that concludes dogs process the meaning of words in the left side of the brain, while they process emotional cues from sound in the right side.
Using a test group of 250 dogs, Victoria Ratcliffe, a researcher at the University of Sussex in England, conducted an experiment. Placing a speaker on either side of a dog’s head, Ratcliffe issued the command to “come.” According to NPR, she kept the command neutral at first, then:
In some instances, she removed all the inflections in the speaker’s voice. In other instances, she kept the inflections in the speaker’s voice but removed the words (or replaced the words with gibberish).
For each command, Ratcliffe recorded which way the dogs turned their heads — toward the left speaker or toward the right speaker. Even though both speakers were playing the same sounds, a clear pattern emerged.
When the dogs heard commands that still had meaningful words in them, about 80 percent of the animals turned to the right. When they heard commands, with just emotional cues in them, most dogs turned to the left.
According to Attila Andics, a neurobiologist, the result is surprising because it shows “that dogs are able to differentiate between meaningful and meaningless sound sequences.” It also shows that dogs are processing at least two different aspects of speech with different sides of their brain.
It’s only a beginning to understanding the way dogs perceive our communication, but Andics says there is at least one practical outcome:
Tell all the emotional things to the dog in his left ear. For commands that you want a dog to get clearly and precisely, tell them in [their] right ear.