The brain-wave rhythms of two people having a conversation begin to align with one another, according to a new study conducted at the Basque Centre on Cognition, Brain, and Language (BCBL) in Spain.
The researchers say that this inter-brain synchrony may be a key factor in understanding language and interpersonal communication.
Previous research has suggested that the brain “synchronizes” according to what is heard and correspondingly adjusts its rhythms to auditory stimuli. In the new study, the researchers went a step further and simultaneously analyzed the complex neuronal activity of two strangers who hold a dialogue for the first time.
They found that something as simple as an everyday conversation causes the brains of the participants to begin to work simultaneously.
By recording cerebral electrical activity, the researchers found that the neuronal activity of two people involved in an act of communication “synchronize” in order to allow for a “connection” between both people.
“It involves interbrain communion that goes beyond language itself and may constitute a key factor in interpersonal relations and the understanding of language,” said researcher Dr. Jon Andoni Duñabeitia.
Overall, the rhythms of the brain waves corresponding to the speaker and the listener adjust according to the sound of the verbal messages expressed in a conversation. This creates a connection between the two brains, which begin to work together towards a common goal: communication.
“The brains of the two people are brought together thanks to language, and communication creates links between people that go far beyond what we can perceive from the outside,” he said. “We can find out if two people are having a conversation solely by analyzing their brain waves.”
During the study, the researchers evaluated 15 pairs of people of the same sex, complete strangers to each other, separated by a folding screen. This ensured that the connection generated was truly thanks to the communication established.
Using a script, the partners held a general conversation and took turns playing the roles of speaker and listener.
Through electroencephalography (EEG) — a non-invasive procedure that analyses electrical activity in the brain — the researchers measured the movement of their brainwaves simultaneously and found that their oscillations took place at the same time.
“To be able to know if two people are talking between themselves, and even what they are talking about, based solely on their brain activity is something truly marvelous. Now we can explore new applications, which are highly useful in special communicative contexts, such as the case of people who have difficulties with communication,” said Duñabeitia.
In the future, the understanding of this interaction between two brains would allow for the analysis of very complex aspects of the fields of psychology, sociology, psychiatry or education.
“Demonstrating the existence of neural synchrony between two people involved in a conversation has only been the first step,” said researcher Dr. Alejandro Pérez. “There are many unanswered questions and challenges left to resolve.”
Pérez adds that the practical potential of the study is enormous. “Problems with communication occur every day. We are planning to get the most out of this discovery of interbrain synchronization with the goal of improving communication,” he concluded.
The findings are published in Scientific Reports.