Joint Action Produces Super Mirror Neurons

Abstract: Behavioral evidence suggests that joint coordinated movement attunes one's own motor system to the actions of another. This attunement is called a joint body schema (JBS). According to the JBS hypothesis, the attunement arises from heightened mirror neuron sensitivity to the actions of the other person. This study uses EEG mu suppression, an index of mirror neuron system activity, to provide neurophysiological evidence for the JBS hypothesis. After a joint action task in which the experimenter used her left hand, the participant's EEG revealed greater mu suppression (compared to before the task) in her right cerebral hemisphere when watching a left hand movement. This enhanced mu suppression was found regardless of whether the participant was moving or watching the experimenter move. These results are suggestive of super mirror neurons, that is, mirror neurons which are strengthened in sensitivity to another after a joint action task and do not distinguish between whether the individual or the individual's partner is moving.