A sign of positive feelings

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Students participating in the classroom EEG study.
Credit: Micah Schaffer

A 2013 study led by Leonhard Schilbach of the University Hospital of Cologne in Germany described the study of real-world interactions between people as the ‘‘dark matter of social neuroscience’’.

While the field is still far from fully understood, some new light has now been shed into that darkness, thanks to work led by Suzanne Dikker, a research scientist at New York University.

In a report published in the journal Current Biology, Dikker and her colleagues establish that brain synchronisation between students is a reliable marker of how well they like each other, and how they feel about the lesson they are undertaking.

“How well our brainwaves sync up with those of another person appears to be a good predictor of how well we get along and how engaged we are,” says Dikker. “Overall, our findings suggest that brain-to-brain synchrony is a possible neural marker for everyday social interactions.”

To test brainwaves in a dynamic, real-world environment, the scientists wired up 12 high school students and their teacher to low-cost electroencephalogram (EEG) machines and monitored their brainwaves. This was done 11 times over the course of a single semester.

The EEG readings were analysed against self-reported responses from the students, addressing matters such as how engaged they felt with the classroom activities, how focused they felt, and how much they liked the other students, both individually and as a group.

The study found that students who felt close to each other were much more like to have synchronised brainwaves, even if they were not interacting during the class. This phenomenon was most pronounced if the students in question had the opportunity to meet and talk immediately prior to the class beginning.

On a group level, the degree to which each student felt positive about the classroom activities turned out to be a predictor of how synchronised his or her brainwaves were with the rest of the class.

Causality is uncertain, so it might be more accurate to suggest that the more synchronised a student’s brainwaves were with other members of the group, the more likely he or she was to approve of the class activities.

Previous investigations into Schilbach’s dark matter have been conducted in tightly controlled laboratory conditions. Dikker and her colleagues are the first to test brainwave synchrony in semi-open semi-structured circumstances.

The results may in time shed light on the mechanics of learning, which are thought to depend equally on classroom engagement and social dynamics.

The factors that create in-group brainwave synchrony remain unknown, but Dikker’s team suggests that shared attention is one important factor.

The research invites further investigation, but in the meantime at least one thing has become clear. When someone explains that her best friend “thinks like I do” it is not just a figure of speech. It is also an accurate expression of neuroscientific reality.

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