Using mu rhythm perturbations to measure mirror neuron activity in infants

The Mirror Neuron System hypothesis stating that observed actions are projected onto the observer’s own action system assigns an important role to development, because only actions mastered by the observer can be mirrored. The purpose of the present study was to investigate whether there is evidence of a functioning mirror neuron system (MNS) in early infancy. High-density EEG was used to assess the mu rhythm perturbations in an action observation task where the infants viewed a live model. To reduce noise ICA decompositions were used. The results show a higher desynchronization of the mu rhythm when 8-month-old infants observe a goal-directed action than when they observe a spatially similar non-goal-directed movement. This provides evidence that the MNS is functioning at this age level. Importantly, the results show that mu rhythm perturbations can be used as a tool for studying MNS activity in infants.