On the Same Wavelength: Michael Yartsev Discovers that Bats’ Brains Sync When They Socialize

The Context: When humans talk to each other, there is a correlation in our brain activity—in some areas, it syncs up. But human studies have been limited by brain imaging techniques that do not measure electrical activity and can only pick up on low-level frequencies.

The Study: When bats engage in social behaviors, their brain activity also syncs up, finds a new study published in Cell from a team led by NYSCF – Robertson Neuroscience Investigator Dr. Michael Yartsev of the University of California, Berkeley. 

The Importance: Many disorders, like autism or schizophrenia, affect social behavior. Having a reliable animal model to help us gain a more in-depth understanding how brain activity underlies socialization will help us uncover what goes wrong in these conditions and identify intervention strategies. 

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When you are talking with someone, regardless of whether or not you are on the same page, you are on the same wavelength.

Previous research has shown that when humans hold conversations, our brain activity syncs up as we provide and react to social cues. And according to a new study in Cell from a team led by NYSCF – Robertson Neuroscience Investigator and Assistant Professor of Bioengineering Michael Yartsev, PhD, of the University of California, Berkeley, the same thing happens for bats.

“This is a very core phenomenon that, for two decades, people have been excited about in humans,” said Dr. Yartsev in an article from Berkeley News. “Now that we’ve observed it in an animal model, it opens the door to very detailed research of it.”

Studies in humans have been limited by the recording techniques researchers can use. For example, fMRI imaging cannot extract electrical activity and electroencephalography (EEG) can only pick up low-level frequencies. To fully understand how brain activity changes during socialization, we need more comprehensive data.

So, the team turned to another creature that inhabits a highly complex social environment: bats. Using wireless neural recordings that pick up on high frequencies and electrical activity, the scientists could more easily examine brain activity when the animals were engaging in social behaviors such as grooming, fighting, or sniffing each other.

Upon examining the data, the researchers found that when the bats socialized, their brains showed very strong correlations in high frequency brain waves. And the result was not because the bats were reacting to the same environment or engaging in the same behavior. Bats that were both grooming themselves in separate, identical rooms did not show synchronized brain activity.

According to Dr. Yartsev, the prompt for synchronization was simply sharing in a social interaction. Even in a three-bat “conversation” where only two bats were actively socializing, all three showed synchronized brain activity.

“It’s kind of like, if you think about a dinner table, some people could be talking back and forth, while another person would be sitting there, still paying attention, while still being part of the social interaction,” remarked Dr. Yartsev. “Under that analogy, then, supposedly all of the brains would be correlated simultaneously.

Having a reliable animal model to study the neural basis of social interaction will help us better understand how it differs in those with conditions that affect social behavior, such as autism or schizophrenia, and develop possible interventions.

Read more in a press release from UC Berkeley.

Journal article:

Correlated Neural Activity across the Brains of Socially Interacting Bats
Zhang W, Yartsev MM. Cell. 2019. doi: 10.1016/j.cell.2019.05.023.

Photo Credit: Kim Taylor/Warren Photographic photo