Dogs have a way of looking at people in a peculiar manner, as if they are trying to understand what they are saying. That quizzical look may not be one of confusion, however, but one of understanding. They are actually sensitive to emotions that words carry. New research involving brains scan on dogs and humans has identified similarities in how people and dogs perceive sound. It turns out that dogs do hear human sounds and can pick up on tones to read emotions.
Attila Andics from the MTA-ELTE Comparative Research Group led the study that was published Thursday in Current Biology. He said that it was a successful “vocal communication” between the two species. To test their theory, he and his colleagues trained six golden retrievers and five border collies to lie still in the scanning machine. Only those dogs who felt comfortable and wanted to participate were involved in the brain scans.
The study involved using a functional MRI machine to scan the brains of the 11 dogs while they were exposed to nearly 200 various dog and human produced sounds. Responses were recorded as they listened to barking, whining, crying and laughing. They measured the blood flow and recorded changes as they occurred. Researchers found that the dedicated voice area that discerns emotional cues lit up the same, whether the sound came from dogs or humans. They also noted that the primary auditory cortex was activated more by happy sounds.
Of the sounds the dogs were exposed to, their brains were activated 38 percent when they heard noises from other dogs, 13 percent when listening to humans and 48 percent from non-verbal cues. People were also studied in comparison. Only 10 percent of people had their vocal region of their brain activated by environmental sounds and three percent showed increased activity from non-verbal cues.
Both humans and dogs were more tuned in to their own species, however. Dogs are more likely to pick up on animal noises over human talking. Humans, on the other hand, pay closer attention to human activity and sounds than to animal sounds.
Dogs can tell when people are happy, sad or angry. They have a good understanding of what humans tell them, even if they cannot really decipher the words. Tone is what conveys the emotions. Much like when people laugh, dogs use short bursts of sound to convey happiness and longer, deeper barks to communicate when they are upset about something.
The ability for dogs to understand people’s emotions and make sense out of human sounds may have been enhanced by their close proximity to them, as man’s best friend, but it is likely something that has evolved for over 100 million years. Even wolves and coyotes respond to vocal commands and human emotions.
The study was the first step in seeing how dogs understand human communication and read the emotions behind their words. It has been cited as the first study of its kind, comparing the brain activity of humans and dogs, although it was limited to just one area of the brain. Further studies are expected to explore other areas to determine if there are more similarities.
By Tracy Rose