Water Cooler: How human connection influences brain waves

If you’ve ever been in a choir, orchestra, band, dance group or other communal, musical group, then you probably wouldn’t be surprised to know that synchronized group activity often results in respiratory and cardiac patterns to synchronize as well.

It makes sense. Everything involved in participation with those types of activities relies on everyone creating and staying on rhythm. But did you know that it can lead to synchronization of your brain waves as well?

Not only that, but synchronization of brain waves doesn’t just happen during activities involving music or rhythm. This can happen across many different social activities, such as solving a problem with other people or taking a walk with someone.

Brain waves are electrical signals that come in various patterns and wavelengths according to different mental states and stimulation. Any type of activity can create and change them. When you engage in activities that require coordination among multiple people, regions of the brain begin to sync up, and research within the last few decades shows that it can also result in brain waves syncing up between brains.

A 2016 study called “Competition in the Brain,” by Michela Balconi and Maria E. Vanutelli found evidence of this. They studied five groups of four subjects and asked them to participate in a cooperative card game requiring the group to play against each other with two people on each team.

While they played, their brain waves were monitored using EEG-based hyperscanning through electrodes attached to their heads. The study wanted to show that it was possible to monitor multiple people’s brain waves at the same time, but came across another discovery. When comparing the results, they found that the brain waves of those on the same team were in sync, while those on opposing teams were not.

EEG hyperscanning is a very new field so the studies that use it are usually very small. They are meant to introduce new ideas rather than produce conclusive proof. That said, studies using EEG hyperscanning have started to proliferate and explore brain waves during many other types of social interaction.

One type of social interaction that has been studied is the use of shared attention, also called joint attention, in which two individuals share focus on an object or each other and use nonverbal communication such as pointing or eye-gazing to interact.

A 2017 study published in the PNAS scientific journal studied shared attention by monitoring 19 babies while an adult sang to them. The adult would look directly at them or away. The researchers found that when the adult looked directly at the baby, their brain waves were much more in sync than when the adult looked away. If the baby vocalized during their interaction, this helped their brain waves become even more synchronized.

One fascinating 2018 study by Viktor Muller, Johanna Sanger and Ulman Lindenberger evaluated a quartet of guitar players while they were playing together. This type of coordinated activity is classified as a joint activity.

They found that the brain waves synchronize between players, but they also found that the connection strength of brain waves between players became closer when the brain waves of individual guitarists were stronger, such as when one was playing a solo.

This showed that the connection between brain waves is not just created by sharing in an activity, but that it is also influenced by the contribution of each person’s brain activity.

The science seems to indicate that the connection between humans is deeper and more complex than we sometimes think, especially when we work together.