Brains Couple When People Talk

Uri Hasson, a Princeton psychologist who's also done some interesting work on brain activity while watching movies, has discovered that, when two people converse, their brains become coupled. Writing in a blog at Scientific America Douglas Fields reports:

There have been many functional brain-imaging studies involving language, but never before have researchers examined both the speaker's and the listener's brains while they communicate to see what is happening inside each brain. The researchers found that when the two people communicate, neural activity over wide regions of their brains becomes almost synchronous, with the listener's brain activity patterns mirroring those sweeping through the speaker's brain, albeit with a short lag of about one second. If the listener, however, fails to comprehend what the speaker is trying to communicate, their brain patterns decouple.

. . . .

In order to find out what happens in the brain when the speaker and listener communicate or fail to connect, Hasson, an assistant professor in Princeton's Department of Psychology, and his team had to first overcome both technical problems using new analytical methods as well as special nonmagnetic noise-canceling microphones. He asked his student to tell an unrehearsed simple story while imaging her brain. Then they played back that story to several listeners and found that the listener's brain patterns closely matched what was happening inside the speaker's head as she told the story.

These results are exciting but not surprising. Back in the late 60s and early 1970s William Condon did high-speed video taping of people interacting with one another. He found, for example, that the listener's head and body movements tracked the intonation patters of the speaker's language. Interestingly enough, this was true even for neonates, their body motions tracked speech patterns of nearby speakers.

I made such interactional synchrony the conceptual centerpiece of my 2001 book on music, Beethoven's Anvil. I also reprise and extend some of those ideas in my essay-review of Steven Mithen's The Singing Neanderthals. See also my post, The Sound of Many Hands Clapping: Group Intentionality.