Communicative hand gestures and object-directed hand movements activated the mirror neuron system

Humans produce hand movements to manipulate objects, but also make hand movements to convey socially relevant information to one another. The mirror neuron system (MNS) is activated during the observation and execution of actions. Previous neuroimaging experiments have identified the inferior parietal lobule (IPL) and frontal operculum as parts of the human MNS. Although experiments have suggested that object-directed hand movements drive the MNS, it is not clear whether communicative hand gestures that do not involve an object are effective stimuli for the MNS. Furthermore, it is unknown whether there is differential activation in the MNS for communicative hand gestures and object-directed hand movements. Here we report the results of a functional magnetic resonance imaging (fMRI) experiment in which participants viewed, imitated and produced communicative hand gestures and object-directed hand movements. The observation and execution of both types of hand movements activated the MNS to a similar degree. These results demonstrate that the MNS is involved in the observation and execution of both communicative hand gestures and object-direct hand movements.