YSM Issue 95.1

SPANISH “PERRO” VS.
HUNGARIAN “KUTYA”
CAN DOGS DISTINGUISH HUMAN LANGUAGES?
BY BREANNA BROWNSON
Just about everyone with a pet has experienced the
phenomenon of talking to an animal without any
expectation of an intelligible response. Even though our
pets don’t understand exactly what we’re saying, many pet
owners claim that they have grown closer to their pets by
talking to them. Have you ever wondered just how much your
pet takes away from these interactions? Laura Cuaya and her
fellow researchers at Eötvös Loránd University’s Department
of Ethology have made great strides in understanding how
dogs process what they hear.
Cuaya was motivated to study speech perception in dogs because
of her personal experience moving from Mexico to Hungary with
her dog, Kun-kun. “Before, I had only talked to him in Spanish. So
I was wondering whether Kun-kun noticed that people in Budapest
spoke a different language, Hungarian,” Cuaya said.
Cuaya noted that dogs are a particularly interesting species
because their evolutionary history starts completely separated
from humans but later switches to paralleling them after dog
domestication. “With dogs, we have a wonderful opportunity to
study the evolution of speech perception. Dogs needed to adapt
their social minds to a human environment. Understanding humans
became important for them,” Cuaya said. Although there
are different biological mechanisms and neuronal pathways in
dog and human brains, both species have developed unique
manners of completing the same task—recognizing human
speech patterns—over the course of their evolutionary history.
Cuaya conducted a study on eighteen family dogs, including
her own dog, Kun-kun, to determine how the canine
brain detects speech and represents language. Her research
focused on determining how dogs react to four main types of
sound: natural speech in a familiar language, natural speech
in an unfamiliar language, scrambled speech in a familiar language,
and scrambled speech in an unfamiliar language. To observe
which parts of the dogs’ brains were active in response to
different types of speech, Cuaya used functional magnetic resonance
imaging (fMRI), a scan that measures small changes in
blood flow to map brain activity. Then they used multivoxel pattern
analysis (MVPA), a technique that correlates neural activity
patterns with different areas of the brain where stimuli are
processed, to analyze the fMRI results.
One of the biggest challenges Cuaya faced was making
sure the dogs stayed still in the fMRI machine. For
fMRI scans to be usable, there can only be up to three millimeters
of movement while the dogs are laying in the scanners.
Dog trainers were brought in to teach the dogs to stay
still for the duration of the scan, and dog owners
stayed nearby throughout the entire
Neuroscience
FEATURE
scans to keep the dogs comfortable and relaxed. The dogs were
free to leave at any time.
Cuaya found that the primary auditory cortex responsible
for processing simple sounds in dog brains showed different
responses to scrambled and normal speech. Furthermore, different
neural activity patterns were seen in the secondary auditory
cortex, the part of the brain that processes more complex
noises, when dogs listened to the language they were most
often exposed to compared to a language they hadn’t heard
before. Even though we don’t teach our dogs the language we
speak, they become familiar with it because of the evolutionary
advantage associated with it. When we speak, our dogs
are actually picking up on the rhythms in our voice and the
sounds of our words. Dogs with the ability to recognize subtle
cues in their owners’ language were more easily domesticated,
and with domestication came the benefit of food and shelter.
Cuaya offered an analogy to help us better understand dog
speech perception by comparing it to an experience many of
us can relate to when traveling. “Maybe you have experienced
this feeling as a tourist in a new place. You think to yourself, ‘I
don’t know what language that is, but I know it’s not English,’”
Cuaya said. Dogs experience the same thing when hearing
people speak in a language they aren’t used to.
The next time you go to vent about your day to your pets, maybe
you’ll think twice about just how much of your speech they’re really
picking up on. They might be paying more
attention than you think, and
you have our mutualistic
evolution with dogs to
thank for that. ■
IMAGE COURTESY OF DR. CUAYA
www.yalescientific.org
March 2022 Yale Scientific Magazine 27