New Delhi: Scientists at Harvard University found that dog brains have evolved to better understand human behaviour and communication compared with pre-modern dogs. The study, published in JNeurosci on 10 August, hoped to understand whether dog behaviour toward humans is influenced more by broader evolutionary changes or by personalised training.
According to the paper, which examined MRIs from more than 100 dogs of different breeds, it is a mix of both.
“Over tens of thousands of years of coevolution with humans, dogs have developed exceptional communicative abilities. Through both inherited adaptations and individual learning,” the study found.
Scientists discovered that evolution set up the basic communication architecture in dogs, as they were bred for close contact with humans. Through herding, hunting, guarding sheep and other livestock, or simply companionship, domestication has led to significant changes in the organisation of brain networks within dogs.
“Selective breeding for human-oriented roles is associated with broad changes in hemispheric asymmetry and communication-related connectivity,” the study read.
Hemispheric asymmetry occurs when two different halves of a brain become specialised for different purposes, something that humans, chimpanzees and other primates also possess. The study found that dogs’ brain networks show specialisation in the parts that deal with hearing, processing sounds/words, and associating them with meanings.
However, that does not mean that evolution has bred dogs to understand what humans mean when they speak to them.
Instead, this is where personalised training of dogs comes in. The study said that service dogs, which are trained for specific purposes, had particularly fine-tuned circuits in their brains. They had differences in specific neural pathways involved in hearing a human cue, interpreting it, and then producing the appropriate physical response.
How training and evolution matter
The study used the MRI tractography method to study dog brains, which is a 3-D imaging, non-invasive technique that shows the flow of water molecules within the brain. The scientists used a sample of domesticated dogs, trained service dogs, and dogs of similar breeding background to be able to compare their brain scans and 3-D imagery.
They found that while evolution has made broader changes in all dogs’ brains compared to their ancestral lineages, specialised training leads to finer neural pathways for certain kinds of communication. Researchers further found that certain dogs had better scores in their behavioural measures of trainability, meaning they were easier to train because of certain strong neural connections in their brains—this explains why some dogs might be easier to train than others.
“I think this type of research can help us better understand not only dogs, but also the human–dog relationship,” said Mélina Cordeau, lead author of the study, in a press release.
“We may eventually be able to improve the way we interact with dogs, refine training approaches, and make assistance-dog training more effective,” Cordeau added.
The study also found that interaction with humans shows how dogs weren’t necessarily born with the ability to understand humans, but through both social and natural means, the pathways of communication have been established.
(Edited by Insha Jalil Waziri)