They prick up their furry ears and discern sounds just like we do. Yes, we are talking about dogs sharing a sensory human characteristic. Not in the way they move, or the expression in their eyes but in the way they perceive sound. Several willing and highly trained dogs participated in an experiment led by researchers at Eötvös Loránd University who unveiled new and interesting facts about our most loyal pets. The research revealed that dogs have areas in their brains devoted to processing sounds and emotions just like humans do. Let’s find out how the team of experts came to this conclusion.
The brain responses of 22 men and 11 dogs were compared while they were played recordings of an identical set of stimuli, which included three sound types: human vocalisations, dog vocalisations, non-vocal environmental sounds, and a silent baseline. Six golden retrievers and five border collies were specially trained to remain relaxed and motionless in a functional magnetic resonance imaging (fMRI) scanner. This device was able to track any changes in blood flow to the brain that would indicate neural activity. The researchers found that the voice processing areas in both man and dog were stimulated to a higher degree by sounds produced by their own species, and in both cases the activity detected in the brain changed according to the emotion showed in the recordings. These findings provided the first evidence of the existence of voice receptor areas in the brains of dogs, or in any non-primate brain for that matter. And the surprises did not end there: the dogs even showed reactions to non-vocal sounds where the humans did not.
In addition, our four-legged friends were more attuned to the sounds of humans than humans were receptive to canine sounds. This ability of the dogs to react to our vocalisations was explained by the 15 thousand or so years dogs have spent in human company. However the experts also had an advanced hypothesis – the existence of a common ancestor in dogs and humans, which supposedly lived thousands of years ago.
Dogs hear like humans, but what about the other animals?
The analogy detected in sound perception between man and dog came as little surprise to the researchers from the Eötvös Loránd University. A spokesperson said: “We know that dogs are already in tune with the feelings of their owners, and we know that a good owner can detect the emotional changes in his dog, but now we begin to understand why.” However the focus now moves to other mammals: do all species share this hearing perception peculiarity or does the dog remain man’s best friend for exclusively sharing this auditory characteristic with him?