The discovery of mirror neurons in the monkey motor cortex has inspired wide-ranging hypotheses about the potential relationship between action control and social cognition. In this paper, we consider the hypothesis that this relationship supports the early development of a critical aspect of social understanding, the ability to analyse others’ actions in terms of goals. Recent investigations of infant action understanding have revealed rich connections between motor development and the analysis of goals in others’ actions. In particular, infants’ own goal-directed actions influence their analysis of others’ goals. This evidence indicates that the cognitive systems that drive infants’ own actions contribute to their analysis of goals in others’ actions. These effects occur at a relatively abstract level of analysis both in terms of the structure infants perceive in others’ actions and relevant structure in infants’ own actions. Although the neural bases of these effects in infants are not yet well understood, current evidence indicates that connections between action production and action perception in infancy involve the interrelated neural systems at work in generating planned, intelligent action.

The role of motor experience in the processing of perceived actions is hotly debated on both behavioral (e.g., action understanding) and neural (e.g., activation of the motor system) levels of interpretation. Whereas some researchers focus on the role of motor experience in the understanding of and motor activity associated with perceived actions, others emphasize the role of visual experience with the perceived actions. The question of whether prior firsthand motor experience is critical to motor system activation during perception of actions performed by others is best addressed through studies with infants who have a limited repertoire of motor actions. In this way, infants can receive motor or visual training with novel actions that are not mere recombinations of previously acquired actions. In this study, 10-month-old infants received active training with a motorically unfamiliar action that resulted in a distinct sound effect. They received observational experience with a second, similarly unfamiliar action. Following training, we assessed infants' neural motor activity via EEG while they listened to the sounds associated with the actions relative to a novel sound. We found a greater decrease in mu power to sounds associated with the motorically learned action than to those associated with the observed action that the infants had never produced. This effect was directly related to individual differences in the degree of motor learning via motor training. These findings indicate a unique effect of active experience on neural correlates of action perception.