Although a growing body of research provides critical information about the spatio-temporal dynamic of the brain network mediating the understanding of causality between an action and its outcome at the individual level, little remains known about this cognitive process when the action outcome has a social connotation. To address this question, we recorded electrical brain activity from 16 healthy adults while they performed an intention understanding task including actions with three different types of causality; 1) private intentions by two agents acting independently from one another; 2) communicative intentions by two agents acting in an interactive way with one another; 3) physical causality among objects. Electrophysiological results showed differential electrical activity for private compared to communicative intentions within 400 ms post-stimulus. Brain source localization of the difference waves between communicative and private actions showed a generator located in the vicinity of middle cingulate cortex, which reinforces the role of this brain area in predicting social intentions.

electrical brain imaging, intention understanding, theory of mind, ERP