Puppet Strings

FAU researchers are claiming they have identified a way to measure human interaction using a single brain rhythm. But this recently-published study didn’t come without its share of finger-wagging.


This hand gesture actually formed part of an experiment conducted by neuroscience Doctors J.A. Scott Kelso, Emmanuelle Tognoli, Julien Lagarde and Gonzalo DeGuzman.

The 20-year study might shed light on correcting preexisting social disorders such as schizophrenia and autism, as well as probing the mechanics of social behavior.

Using dual-electroencephalograms (machines that record electricity in the brain or brainwaves), the researchers inspected two people placed in one room separated by a barrier. The test subjects were asked to randomly twitch their fingers until the barrier was abruptly lifted, revealing both participants and their hand movements.

According to the study, 62 percent of respondents synchronized their movements upon being exposed to one another’s finger-wagging, while 38 percent were unaffected and continued gesturing independently.

“What this research suggests is that a unique pattern can be seen in the brains of two people interacting and that these brain activities distinguish independence from cooperation,” said Kelso, who is a founder of the Center for Complex Systems and Brain Sciences in the Charles E. Schmidt College of Science.

The data collected from the EEG readings steered the four researchers toward a single brain rhythm, which they called the “Phi Complex”, that was present in both subjects.

Since rhythms control bodily movements like a pilot flies an airplane, the “Phi Complex” can peg down when a person is socially interacting and when someone is not, says Kelso.

The “Phi Complex” is very important because it “measures behavior[,] the timing relationship between two people and the informational exchange between their two brains,” says Tognoli, a postdoctoral fellow at the Human Brain and Behavior Laboratory at FAU.

This rhythm allows researchers to pinpoint in real-time behavioral disorders in schizophrenic and autistic people, by scanning how the “Phi Complex” functions during social interaction.

This “reading” would also clue scientists into what triggers leader/follower behaviors and male/female relationships, says the study.

“An ever-increasing number of … neuroscientists are trying to understand how patterns are generated in the human brain,” says Dr. Gary Perry, dean of the College of Science. “This [study] at the cutting edge of science has proven very fruitful, and Dr. Kelso and his team are pioneers in this area.”