New brain imaging research has revealed that dogs have the ability to recognize words and distinguish between different languages.
Researchers in Hungary found that the brain activity of animals differs when they hear a familiar versus an unfamiliar language.
The authors of the study say this is the first time it has been shown that a non-human brain can distinguish between two languages.
Eighteen dogs were trained to lie still in a brain-scanning machine. They were played excerpts from the novel The Little Prince in both Hungarian and Spanish.
All the dogs in the study had only previously heard one of the two languages from their owners.
The dogs were also played mixed excerpts to see if they could clearly differentiate between real words and nonsensical words.
When researchers compared responses to real versus nonsensical content, they found that different types of brain activity were taking place in the dogs’ brains.
The researchers specifically found that distinct activity occurred in the part of the brain responsible for recognizing sound.
This difference was independent of whether the stimulus came from a familiar or unfamiliar language, and there was no evidence that dogs’ brains preferred real words over nonsensical ones.
The study found that, beyond recognizing speech or spoken words, dogs’ brains can also distinguish between Spanish and Hungarian.
Patterns of language-related activity were also observed in other parts of the brain responsible for recognizing sound. The researchers were surprised to learn that the older the dog, the greater its ability to differentiate between familiar and unfamiliar languages.
One of the study’s authors, Laura Kovács, included her own dog, named Kun Kun, in the research.
She said: “A few years ago, I moved from Mexico to Hungary so I could work in the Neuroethology of Communication Lab at Eötvös Loránd University for my postdoctoral research. My dog, Kun Kun, came with me. Until then, I had only spoken to him in Spanish. I was curious whether Kun Kun could notice the difference between people speaking a different language, Hungarian, in Budapest.”
She added: “We know that humans—even infants who cannot yet speak—can notice the difference between languages. But perhaps dogs do not care. We never specifically draw our dogs’ attention to how a particular language sounds. To investigate this, we designed a brain imaging study.”
Laura Kovács explained: “Kun Kun and 17 other dogs were trained to stay still in a brain scanner, where we played them excerpts from The Little Prince in Spanish and Hungarian. All the dogs had only ever heard one of the two languages from their owners, allowing us to compare a highly familiar language with a completely unfamiliar one.”
“We also played the dogs mixed excerpts that sounded completely unnatural. This was done to see whether they could clearly distinguish between normal spoken sentences and nonsensical sentences.”
Co-author Raúl Hernández-Pérez added: “Dogs’ brains can distinguish between real and nonsensical words like human brains, but the fundamental mechanism for detecting this may differ from humans: human brains are particularly sensitive to understanding spoken words, whereas dogs’ brains simply recognize the natural quality of sound.”
The study found that, besides recognizing spoken words, dogs’ brains can also distinguish between Spanish and Hungarian.
He further explained: “Each language has distinct auditory patterns. Our results suggest that dogs living with humans learn the auditory patterns of the languages they are exposed to.”
According to the study’s senior author, Attila Andics: “This study showed for the first time that a non-human brain can distinguish between two languages. This is fascinating because it shows that the ability to learn to recognize a language is not unique to humans.”
“Still, we don’t know whether this ability is specific to dogs or common among non-human species. It is possible that the brain has evolved over tens of thousands of years—dogs living with humans may have become better listeners—but this is not certain. Future studies will need to explore this.”
Laura Kovács added: “If you wonder how Kun Kun is after moving to Budapest, he is just as happy as he was in Mexico City—he saw snow for the first time and enjoys swimming in the Danube. We hope he and his friends continue to help us explore the evolution of language perception.”
The research was conducted by scientists at the Department of Animal Research at Eötvös Loránd University and published in NeuroImage.