Author ' s personal copy Social grasping : From mirroring to mentalizing

In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: a b s t r a c t a r t i c l e i n f o Because the way we grasp an object varies depending on the intention with which the object is grasped, monitoring the properties of prehensile movements may provide access to a person's intention. Here we investigate the role of visual kinematics in the implicit coding of intention, by using functional brain imaging while participants observed grasping movements performed with social versus individual intents. The results show that activation within the mirror system is stronger during the observation of socially intended movements relative to individual movements. Moreover, areas that form the mentalizing system are more active during social grasping movements. These findings demonstrate that, in the absence of context information, social information conveyed by action kinematics modulates intention processing, leading to a transition from mirroring to mentalizing. Introduction When we perform actions in daily life, these actions are usually driven by a prior intention. For instance, the action of grasping a cup might be performed with the intention to drink or to pass the cup to another person. Because different intentional actions are characterized by different movement profiles (Becchio et al., 2010), monitoring the properties of observed movements may convey information about the actor's intention. Does she intend to drink or to pass the cup to another person? By simply observing the initial phase of the action, observers can discriminate between movements performed with different intents. For example, by watching everyday actions such as lifting a box, they can easily tell whether the actor is trying to deceive them about the real weight of the box (Grezes et al., 2004; Runeson and Frykholm, 1983). Depending on their level of motor skill, they are able to determine whether a basketball player is about to throw a ball or mimic a throw (Sebanz and Shiffrar, 2009). Moreover, by observing an actor reaching towards an object and grasping it, they are able to discriminate correctly between prehensile movements directed at another agent and prehen-sile movements performed in isolation (Manera et al., 2011; Sartori et al., 2011). This suggests that, in the absence of contextual information, observers can …