Fig. 1.

Experimental stimuli. These photographs illustrate the experimental stimuli. The resting state stimulus (top left) consisted solely of observing a black background. The purely kinematic movement (top right) was performed by the opening and closing of the hand fingers to thumb, by the participant (self-movement) and also by the confederate (purely kinematic movement). The goal-relevant movement (bottom left) illustrates the same hand motion but this time grasping a token of the same type that was used in the economic game. The ball stimuli (bottom right) consisted of a video showing two balls that moved in the trajectory and speed at which the participant and confederate moved their hands.