Within- and between-nervous-system inhibition of return: Observation is as good as performance

Inhibition of return (IOR) has been shown to occur when an individual returns to a target location (within-person IOR) and when an individual moves to a location just engaged by another individual (between-person IOR). Although within- and between-person IOR likely result from the same inhibitory mechanisms, different processes must activate these mechanisms following the performance and observation of action. Consistent with the suggestion that the mirror neuron system may be responsible for activating the inhibitory mechanisms behind IOR on observation trials, between-person IOR was only detected under restricted viewing conditions known to activate mirror neurons. These results indicate that mirror neuron system may be involved in both higher-order and automatic cognitive behavior.