Coordinated eye movements during dialog.

A commentary on an interesting article by Richardson et al. which illustrates yet again the social synchrony of our brains. See also this PsyBlog link on our nonverbal symphony and synchrony of interactions, as well as this previous post on an EEG signal that reflects social coordination. Or, this link on social context reflected at the level of single cell recordings in the monkey parietal cortex.

A dialogue, though generally understood to be a conversation between two people, allows for much more than the mere exchange of verbal information. Linguistic (for example, syntax) and nonlinguistic (for example, body postures) tell-tales develop and become synchronized as people talk and listen. Visual attention is another dimension in which behavior can become coordinated as when a listener's gaze is directed toward an object of mutual interest by pointing.

Richardson et al. show that the eyes of conversants--who are looking at the same scene but are not within sight of each other--tracked the same objects within the scene for several seconds, starting from the time at which the speaker began to fixate on the object before talking about it and including the time taken by the listener to saccade to the object after hearing what the speaker had begun to say. Another important contribution to the coordination of visual attention comes from having a common ground of understanding. Conversants looking at a Salvador Dalí painting were more likely to exhibit synchronized eye movements if they had previously heard the same introduction, either to the painting itself or to Dalí's life, as compared to pairs of conversants in which one had heard about the painting and the other about his life.