Vittorio Gallese (VG). To answer this question, we should first clarify how motor acts and actions are mapped within the cortical motor system and what the notion ofaction understandingmeans. One might think that motor neurons would discharge in association with the activation of specific muscle groups or during the execution of elementary movements. In fact, however, a crucial functional property of macaque premotor area F5 (and of the posterior parietal regions reciprocally connected to it) is that most of its neurons are active only during motor acts, which are movements executed to accomplish a specific motor goal such as grasping, tearing, holding, or manipulating an object. The most interesting F5 neurons are those discharging any time the monkey grasps an object, regardless of the effector used, be it the right hand, the left hand, the mouth, or both hand and mouth (see Rizzolatti, Fogassi, & Gallese, 2000). What are those F5 neurons doing? The data strongly suggest that they map between the observer’s goals and the acting animal’s goals. Umiltaet al.(2008) demonstrated the independence between how the effector moves and the motor end-state it attains. All tested neurons in area F5 and half of the neurons recorded from the primary motor cortex discharged in relation to the accomplishment of the goal of grasping, regardless of the movements made to accomplish it. This property also fully applies to mirror neurons (MNs, Rochat et al., 2010). The sensory-to-motor direct mapping enabled by MNs goes beyond the mere kinematic features of movement. That is, the mapping is between the goal of an animal’s executed actions and the goal of another animal’s actions, even if the other’s movement are only partially seen (Umiltaet al., 2001) or, indeed, even if the other’s movement is not seen but the consequences are heard (Kohler et al., 2002). Also, fMRI evidence shows that posterior parietal and ventral premotor areas are activated in humans by the observation of goal-related motor acts or by listening to action-related sounds (see Rizzolatti & Sinigaglia, 2010). A similar functional property was revealed in congenitally blind patients (Ricciardi et al., 2009). Goal-dependency has also been demonstrated with humans using transcranial magnetic stimulation (TMS; Cattaneo, Caruana, Jezzini, & Rizzolatti, 2009). TMS was used to measure the amplitude of motor-evoked potentials (MEPs) recorded from participants’ hand muscles during the observation of action. It is important to note that the MEPs measured when grasping were similar both when using regular pliers so that the hand closed to effect the grasp and when using reverse pliers so that the hand opened to effect the grasp. MNs provide the first neural mechanism allowing a direct mapping between the visual description of a motor act and its execution. This mechanism provides a parsimonious solution to the problem of translating the visual analysis of an observed movement—in principle, devoid of meaning for the observer—into something that the observer understands because it is directly mapped onto the observer’s motor representations. Some critics of the hypothesis that MNs contribute to action goal recognition suggest that MNs function much like neurons in extrastriate visual areas (eg, the superior temporal sulcus, or STS), which are sensitive to biological motion (Hickok, 2009). However, the extrastriate neurons do not show goal relatedness (Cattaneo, Sandrini, & Schwarzbach, 2010). Let us now turn to mindreading. For decades, the prevalent opinion has been that in humans, action understanding predominantly—or even exclusively—relies upon reading the