Lydia Denworth in Scientific American:
What is found in a good conversation? It is certainly correct to say words—the more engagingly put, the better. But conversation also includes “eyes, smiles, the silences between the words,” as the Swedish author Annika Thor wrote. It is when those elements hum along together that we feel most deeply engaged with, and most connected to, our conversational partner, as if we are in sync with them. Like good conversationalists, neuroscientists at Dartmouth College have taken that idea and carried it to new places. As part of a series of studies on how two minds meet in real life, they reported surprising findings on the interplay of eye contact and the synchronization of neural activity between two people during conversation. In a paper published on September 14 in Proceedings of the Natural Academy of Sciences USA, the researchers suggest that being in tune with a conversational partner is good but that going in and out of alignment with them might be better.
Making eye contact has long been conceived as acting like a cohesive glue, connecting an individual to the person with whom they are talking. Its absence can signal social dysfunction. Similarly, the growing study of neural synchrony has focused on the positive aspects of alignment in brain activity between individuals.
In the new study, by using pupil dilation as a measure of synchrony during unstructured conversation, psychologist Thalia Wheatley and graduate student Sophie Wohltjen found that the moment of making eye contact marks a peak in shared attention—and not the beginning of a sustained period of locked gazes. Synchrony, in fact, drops sharply after looking into the eyes of your interlocutor and only begins to recover when you and that person look away from each other. “Eye contact is not eliciting synchrony; it’s disrupting it,” says Wheatley, senior author of the paper.
More here.