New research reveals that when you gaze into your dog’s eyes or give them a friendly pet, your brain and your pet’s brain might actually synchronize. This fascinating discovery, outlined in a paper published in Advanced Science, marks the first time such brain wave synchronization has been observed between two different species.
Interbrain Activity in Human-Dog Pairs
This phenomenon, called interbrain activity coupling, has been previously noted in human-to-human interactions as well as within other animal species. However, the study provides groundbreaking evidence that this type of brain synchronization also occurs between humans and their dogs.
“This is the first study to report and characterize interbrain activity coupling during cross-species interactions,” the researchers noted. “Our results indicate that the strength, direction, and brain regions involved in human-dog synchronization are strikingly similar to those seen in human-human interactions.”
A Longstanding Bond
Humans and dogs share a companionship that dates back more than 30,000 years, when wolves began forming relationships with early human hunter-gatherers. Over time, domesticated wolves evolved into dogs, developing traits that allowed them to interact closely with humans—becoming more social, trainable, and docile.
“Dogs have evolved an incredible ability to understand and respond to a wide range of human emotions and communicative cues through behaviors, expressions, and even vocal tones,” the study’s authors explained. This unique bond with humans is rarely matched by other domesticated animals, such as cats.
Neural Synchronization
In previous studies, neural synchronization—particularly in the frontal and parietal brain regions—has been seen in social interactions between humans and in animals like mice, bats, and primates. These brain regions are associated with joint attention and social engagement.
Researchers in the study used wireless electroencephalograms to track brain activity in humans and dogs while they interacted—through mutual gaze and petting. They found that brain waves synchronized in both species during these interactions. This synchronization was especially strong in the frontal and parietal brain regions.
“Mutual gaze and petting induce interbrain synchronization in both humans and dogs,” the study noted.
Growing Familiarity Strengthens the Bond
As human-dog pairs spent more time together, their brain synchronization grew stronger. Over a five-day period, researchers observed an increase in the strength of this synchronization. Interestingly, humans appeared to take the lead in interactions, with dogs responding as followers.
“The information flow suggests that the human is the leader during these interactions, while the dog follows,” the study stated.
However, not all dogs displayed this synchronized behavior. Dogs that had genetic mutations similar to autism spectrum disorders (ASD) in humans did not exhibit the same level of brain synchronization. These dogs, known as Shank3 mutant dogs, also showed reduced attention during interactions.
LSD and Brain Synchronization
In a surprising turn, researchers discovered that administering a small dose of LSD to the genetically mutated dogs seemed to reverse the social impairments, restoring brain synchronization during interactions. This finding suggests that LSD could play a role in improving social behaviors, although further research is needed to explore its effects.
“We showed that a single dose of LSD rescued impaired interbrain coupling and joint attention in Shank3 mutant dogs,” the researchers wrote, hinting that this could have potential implications for treating social deficits in autism.
While this is a significant discovery, the underlying mechanisms remain unclear. Nonetheless, it opens new avenues for studying social behavior and human-animal interactions on a neurological level.
