Expertise in dance modulates alpha/beta event-related desynchronization during action observation.

We presented professional dancers and non-dancers with videos of two movement styles, dance movements and everyday movements. Participants were asked to indicate by a button press to which category a movement belonged. We computed event-related desynchronization (ERD) in alpha and beta frequency bands between 7.5 and 25 Hz relative to a visual baseline condition. Power in alpha and lower beta frequency bands was significantly reduced if dancers watched dance movements but not if non-dancers watched dance movements, in particular between 1 and 2 s after movement onset. During observation of everyday movements no such group difference was evident. Thus, ERD in alpha and beta frequency bands was modulated by a participant's expertise with a certain movement style. The results are discussed in light of a human observation-execution matching system similar to the macaque mirror neuron system and strengthen the idea of a functional relationship between such a system and rhythmical activity in the alpha and beta frequency bands.