DOG BRAINS DIFFER BY BREED PURPOSE
NetPlaces Network Staff
Erin Hecht, assistant
professor of neuroscience in Harvard’s department of Human Evolutionary Biology,
wondered what goes on in a dog’s head so she launched a canine brain study which
revealed that “different breeds have different brain organizations owing to
human cultivation of specific traits.” Obviously the study was limited to
The Harvard canine brain study was based on 63 MRI scans from dogs of 33
Dr. Hecht was able to identify “neuroanatomical features” that related to
different breed behaviors such as hunting, guarding, herding, and companionship.
Sight hunting and retrieving for example, were both tied to brain regions
involved in vision, eye movement, and spatial navigation. She described her
epiphany as “Holy cow! How come no one else has done this?”
When she presented her study of the canine brain in 2012 she was met with yawns.
Dr. Hecht said “It took a long time to convince other scientists and funding
agencies that dogs could really tell us something about brain evolution.”
She persevered. Having done some canine research while studying human brain
evolution at Emory University, Dr. Hecht was motivated by a nature show on
controlled breeding of Russian foxes. (In years past, foxes were bred for those
extraordinary coats favored by “the rich and famous.”) She wondered if any
geneticists had thought about studying their brains.
Dr. Hecht contacted the Russian Academy of Sciences and was able to secure fox
brains for a pilot study. From a veterinary neurologist at Georgia state’s
College of Veterinary Medicine, she obtained scans of purebred dog’s brains. She
also used her own two Australian shepherds to help her prove that breed
differences are discernable in the brain.
The study revealed anatomical differences depending on breed. Dr. Hecht defined
six different networks in the canine brain that processed or directed rewards
behavior, fear or anxiety, eye movement, canine social behavior, vision, and the
dog’s extraordinary scent processes.
She discovered that tracking and hunting by scent was not just a nose-thing but
that it is dependent on “higher order regions” in the brain. Dr. Hecht observed
“It’s not about having a brain that can detect if the scent is there. It’s about
having the neural machinery to decide what to do with that information.”
But here’s the interesting part. Canine skills are inherited according to breed
but also learned by observation and human teachings. Dr. Hecht cites purebred
Border Collies as an example, explaining they are not born knowing how to herd.
She says there’s “something already in a herding breed’s brain but they have to
be shown what to do and how to do it.”
Of course she’s right, she’s the professor but she probably never thought about
why Herding breeds herd you towards the kitchen when they’re hungry…
Your Sporting breed may alert when a covey of quail takes flight but he has to
be taught to mark where your target went down and then be trained to retrieve
it. A purebred guard dog is super alert to strange noises because its in his
genes but to be a man-stopper he must be trained. Your toy breed dog needs no
training to be stuck to your ankle but your Bloodhound has to be trained for the
Obedience ring – taught to disregard all those scents he is genetically
compelled to investigate.
Flock Guardians are equally amazing! Among the best known is the Great Pyrenees.
The Pyr doesn’t herd sheep, that is a totally different inherited talent. Flock
guardians were developed to protect a totally different species and they do that
by “instinct” with a little lesson from the older dogs.
Think about this. The flock guardian spends months alone dependably protecting
sheep, even taking a parental interest in the lambs. Learning plays a crucial
role but there’s clearly something already in the flock guardian dog’s brain
when they are born.
That is analogous to what goes on with language. We don’t pop out of the womb
being able to speak, but clearly all humans are predisposed in a very
significant way to learn language. Dr. Hecht says “If we can figure out how
evolution got similar skills into dog brains, it might help us understand how
humans evolved the skills that separate us from other animals.”
To that end, Hecht is began to follow dogs specifically bred for performance.
With the help of Sophie Barton, a Ph.D. candidate in the Graduate School of Arts
and Sciences, they are studying both champion dogs and their low-skill
littermates. “We’re looking for animals raised in the same environment where,
for whatever reason, one has excelled and one dropped out” she said.
As for the question she gets asked most “What’s the smartest dog?” Dr. Hecht has
the science to back up her diplomatic answer. “This research suggests there’s
not one type of canine intelligence. There are multiple types.” Indeed, there
are differences in the way different breeds think and perform. The Golden
Retriever is among the Rhodes Scholars of dogdom but has diminished guarding
instinct as compared to a Rottweiler.
Physical and psychological differences are noted in other species, including
domestic breeds. A Persian cat is not as predatory as a Siamese. The Clydesdale
is a gentle giant compared to a fractious Thoroughbred racehorse. A goat is not
a sheep and the elephant has a genius IQ.
But no species is as diverse in size, function, and appearance as the dog. And
now we know that among all animals, only the dog’s brain matches his capacity
for devotion to and love of the human species.
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