If you’ve ever looked at a dog’s big, watery eyes and suddenly felt a connection, you might have been experiencing a moment of brain synchronization.
Chinese researchers have for the first time discovered synchronized neural activity between two different species, humans and dogs, suggesting that humans bond with their pets on a deeper neural level.
Previous studies have shown that when people talk or work together, activity in key parts of the brain can synchronize, but this is the first set of experiments to report a similar phenomenon between humans and another species.
The researchers measured brain activity in both humans and dogs using electrodes attached to their skulls. In their experiment, 10 young beagles were paired with strangers and allowed to get to know each other over a period of five days.
In the experiment, the human-dog pairs communicated non-verbally, such as by gazing at each other or petting each other, while in a control experiment the human and dog remained in the same room but did not interact.
“We observed a dramatic increase in brain correlations between the frontal and parietal lobes during mutual gaze,” wrote the study authors, led by biologist Wei Ren of the Chinese Academy of Sciences.
When human subjects simply stroked a dog, the team observed a similar pattern of synchronization, but in this case synchronization was stronger in parietal brain regions.
In humans, activity in both frontal and parietal brain regions is associated with joint attention. Previous studies have shown that when humans pet dogs, activity in the frontal lobes spikes, suggesting that humans are paying close attention to their pets and are emotionally engaged with them. However, it was not clear until now whether this activity was reflected in dogs’ brains.
In the new study, when humans were instructed to look into the eyes of a dog while petting it, the connection between their brain activity was even stronger than when they were simply petting or gazing at the dog.
To work out whether the human or dog brain is driving this rhythmic neural dance, the researchers employed a special mathematical algorithm.
“After feeding in data from each human and dog interaction, the team found that it was the human brain that initiated the coordinated neural activity. Over the course of the study, brain synchronization between the human-dog pair increased, suggesting that the two were bonding.”

Some scientists hypothesize that the social cognition deficits seen in autism spectrum disorder (ASD) result from reduced brain synchronization with others.
To further explore this hypothesis, the researchers performed the same experiment again, but this time with nine dogs that exhibited characteristics similar to ASD in humans. In this case, human-dog pairs showed less synchronization between their brains and impaired joint attention.
Previous studies have shown that LSD enhances social behavior in mice, so the researchers gave dogs with ASD traits a single dose of the hallucinogen, which ultimately improved the dogs’ synchronization with the humans they were paired with.
Although the study is small and further research is needed, the researchers say these dogs could be a useful model for studying the neural mechanisms underlying the social deficits associated with autism spectrum disorder (ASD).
“Our findings suggest the possibility of brain activity biomarkers for the diagnosis of ASD and the development of non-hallucinogenic analogs of LSD to correct social deficits,” the authors conclude.
The research was published in Advanced Science.