Dogs and Humans Process Sounds Similarly
But it's still not clear why dogs have evolved this ability.
Posted Aug 30, 2016
My email inbox was "ringing" late yesterday evening and early this morning with news of a soon-to-be published study concerning the ways in which dogs process human vocalizations. It's my pleasure to share these new and very exciting results with you.
Dogs are "in," and people all over the globe want to know more about the cognitive and emotional lives of these amazing beings. Thus, the discovery that "Brain scans confirm that dogs understand what you’re saying, and how you say it" is extremely exciting and important. News of this discovery based on research by Attila Andics of the Department of Ethology at Eötvös Loránd University in Budapest can be seen in many different popular outlets. The research report by A. Antics, A. Gábor, M. Gácsi, T. Faragó, D. Szabó, and Á. Miklósi titled "Neural mechanisms for lexical processing in dogs" will be published in Science on September 2, 2016.
To perform this study, 13 dogs were trained to lie still in an fMRI brain scanner and listen to a series of words including those indicating praise and neutral words that were previously recorded by their trainers. All of the words "were spoken with a high-pitched praising intonation as well as with a flat, neutral intonation." It’s important to keep in mind that the dogs in the experiment were listening to their trainer’s familiar voice.
Dogs, like people, use the left hemisphere to process words
Right hemisphere brain region is used to process intonation
Praising activates dog's reward centre only when both match
The results of this exciting research can be summarized as follows. "To distinguish between a praising and a neutral intonation, the dogs activated a region in their brain’s right hemisphere. That same region, known as the right middle ectosylvian gyrus, was previously found to be a center for processing emotional sounds from other dogs as well as from humans. The dogs’ reward center in the brain was activated only when dogs heard words of praise that were spoken with a praising intonation."
Dr. Andics also notes, “There is a well-known distribution of labor in the human brain ... It is mainly the left hemisphere’s job to process word meaning, and the right hemisphere’s job to process intonation. The human brain not only separately analyzes what we say and how we say it, but also integrates the two types of information, to arrive at a unified meaning. Our findings suggest that dogs can also do all that, and they use very similar brain mechanisms.”
It's interesting to speculate on why dogs have evolved this ability. In an essay titled "Dogs understand both vocabulary and intonation of human speech" we read, "Thus, dogs seem to understand both human words and intonation. The authors note that it is possible that selective forces during domestication could have supported the emergence of the brain structure underlying this capability in dogs, but, such rapid evolution of speech-related hemispheric asymmetries is unlikely." In other words, it's still not clear why dogs have evolved the ability to differentiate praise and neutral words.
Oh, we knew all this already
While this research confirms what many people have already "known," it's good to see the science behind these intuitions. Please stay tuned for more on the cognitive and emotional lives of dogs and other animals with whom we share our homes and our magnificent planet. There still is so much to learn ...
Marc Bekoff's latest books are Jasper's Story: Saving Moon Bears (with Jill Robinson), Ignoring Nature No More: The Case for Compassionate Conservation, Why Dogs Hump and Bees Get Depressed: The Fascinating Science of Animal Intelligence, Emotions, Friendship, and Conservation, Rewilding Our Hearts: Building Pathways of Compassion and Coexistence, and The Jane Effect: Celebrating Jane Goodall (edited with Dale Peterson). The Animals' Agenda: Freedom, Compassion, and Coexistence in the Human Age (with Jessica Pierce) will be published in early 2017.